Teleoperating bipedal humanoid robots presents unique challenges, including decreased stability and reduced operator presence. This paper addresses these challenges by proposing a method that leverages the operator's inherent sense of stability by feedback from a sole haptics display to operate a bipedal humanoid robot. We developed a bilateral control system that integrates a device replicating sole haptics feedback and provides the operator with feedback on changes in the robot's center of gravity. We conducted operating experiments in the forward-backward direction to evaluate its effectiveness and investigate the effectiveness of sole haptics on robot operation. The results demonstrate that operating with both vision and sole haptics feedback significantly reduces the robot's fall rate by over 56% when disturbances are applied, compared to using only vision feedback. Moreover, operators reported a 21% higher sense of presence with both vision and sole haptics feedback compared to using only vision feedback.

Compared to traditional agricultural environments, the high density and diversity of vegetation layouts in Synecoculture farms present significant challenges in locating and harvesting occluded fruits and pedicels (cutting points). To address this challenge, this study proposes a Mask R-CNN-based method for locating fruits (tomatoes, yellow bell peppers, etc.) and estimating the pedicels from RGBD images acquired by a camera moved along fixed paths. After obtaining masks of all fruits and pedicels, this method judges the matching relationship between the located fruit and pedicel according to the 3D distance between the fruit and pedicel. Subsequently, this research determines the least occluded best viewpoint for harvesting based on the visible real areas of located fruits in images acquired under the fixed paths, and harvesting is then completed from this best viewpoint following a straight path. Experimental results show this method effectively identifies occluded targets and their cutting positions in both Gazebo simulation environments and real-world farms. This method can select the least occluded viewpoint for a high harvesting success rate.

Humans can perform stable motion with a sense of stability that involves identifying their center of gravity point with plantar sensory system. By contrast, the stability of a humanoid robot is inferior to that of a human. If the sense of stability of a humanoid robot is presented to a human who operates the robot in real time, the operator can control the robot more stably. However, studies wherein humans recognize the projected center of gravity point with a plantar haptic display are lacking. In this study, we investigated the possibility of estimating the projected center of gravity point of a small humanoid robot from only the foot force information. We propose a plantar haptic display to reproduce the foot reaction force on four points of a single sole as large as the force during human running. We conducted an experiment to verify the estimated center of gravity point using the foot reaction forces of a small robot with and without scaling by a weight ratio between an operator and the robot. The results indicated that it is difficult to estimate the projected center of gravity point without scaling; however, it is possible to estimate the movement of the projected center of gravity point with a maximum error of 10mm with scaling.

With the development of wireless communication systems, a variety of different systems have been studied for controlling mobile robots remotely from a cloud service, often called cloud robotics. In cloud robotics, the quality of wireless links in the wireless communication systems is important to control the mobile robots. Since the quality of wireless links changes for a variety of different reasons, such as moving and blockage, such changes may affect robot control. To operate the mobile robots safely with changing wireless link quality, we proposed a safe operation architecture. Our initial proposal realizes the monitoring of the wireless link status using the heartbeat. When the heartbeat detects the disconnection of the wireless link, the mobile robot automatically stops. However, for safer control of mobile robots, an adaptive control method for the safe operation architecture is required to follow the any change in the wireless link quality because the change is not only a disconnection level but also a gradual status. In this paper, we propose a method of discriminating the wireless link status for adaptive control of mobile robots with changes in the wireless link quality. Our method analyzed the trends in the RSSI to determine the wireless link quality, and the wireless link quality is classified into four statuses to judge the safe operation level of the mobile robot. The evaluation of the proposed method based on the experiments with 60 GHz mobile communication system is presented, and the result shows the usefulness of the method.

Improving the energy efficiency of robots is an important issue for the widespread use of robots in society. However, previous methods plan motions to perform tasks in the shortest possible time in consideration of work efficiency. Other methods change the trajectory for same path to decrease unnecessary acceleration/deceleration. On the other hand, it would be efficient to plan a path and trajectory that proceeds to a goal position after waiting in an energy-efficient posture with low joint torque load. The energy-efficient posture is depending on a robot’s structure such as length or mass of each link, joint specifications and a spring of a joint to support weight of a robot. Furthermore, there is a possibility to improve the calculation speed by using quantum computing technology, which can solve combinatorial optimization problems at high speed. In this study, we propose a method for generating low energy-consumption motions for robots using quantum computing technology. The problem is formulated by discretizing the transitions of end-effector positions that represent the robot’s motion in terms of workspace and work time, and by using the total torque required for the motion as an objective function and constraints representing the robot’s performance and the range and time of the target work. Simulation results show that the proposed method reduces the total torque consumption by 10% compared to a simple linear motion, and the computation time could be reduced by 77%. Moreover, a torque consumption reduction of 2% was confirmed compared to the optimized motion without springs.

This paper presents WAS-X (Waseda Anthropomorphic Saxophonist robot X), a saxophonist robot designed following an 'Instrument-centered' approach. WAS-X can play on a regular alto saxophone two octaves of music with a direct MIDI input control, but it is much smaller and simpler to control than its WAS predecessors and can be used in the future for more complex interaction studies. In developing this robot, we used a Design Thinking method with the goal of solving the 'wicked problem' of finding a balanced solution between performance quality and dynamic movement freedom for interaction purposes. From a Design Thinking perspective, we replaced 'User-centered design' with an innovative 'Instrument-centered design' and explored different development alternatives, ultimately focusing on the human holding posture of the saxophone by observing saxophonists and following how beginners learn to play the saxophone.

Currently, an agricultural method called SynecocultureTM has been receiving attention as a means for multiple crop production and recovering from environmental degradation; it helps in regreening the environment and establishing an augmented ecosystem with high biodiversity. In this method, several types of plants are grown densely, and their management relies mainly on manual labor, since conventional agricultural machines and robots cannot be applied in complex vegetation. To improve work efficiency and boost regreening by scaling-up Synecoculture, we developed a robot that can sow, prune, and harvest in dense and diverse vegetation that grows under solar panels, towards the achievement of compatibility between food and energy production on a large scale. We adopted a four-wheel mechanism with sufficient ability to move on uneven terrain, and a two orthogonal axes mechanism with adjusted tool positioning while performing management tasks. In the field experiment, the robot could move straight on shelving slopes and overcome obstacles, such as small steps and weeds, and succeeded in harvesting and weeding with human operation, using the tool maneuver mechanism based on the recognition of the field situation through camera image.

農地内で様々な植物種を混生密生状態で生育させる協生農法環境下では植物同士の区別が難しく，管理のための自動化が課題となっている．本プロジェクトでは，協生農法の鍵である植生の多様性を維持するために，特定の植物が他の植物種に対して過度に繁茂している状態を優勢状態と呼び，優勢状態の植物は剪定する．本論文では，農園の俯瞰カメラから取得した RGB 画像を用いて特定の植物種を対象に，優勢状態の推定を行うことを目的とする．本研究の提案手法としてはまず，RGB 原画像を分割小領域に分割し，各分割小領域内の植物種数を，VGG16 を用いて推定する．植物種数が“2 種類以下”と推測された分割小領域の数の合計が閾値を超えた場合，原画像は優勢状態の候補と判断する．優勢状態の候補とされた場合，“2 種類以下”と推測された分割小領域間でAKAZE 特徴量を用いて類似度を求め，それらが類似している場合は，同じ植物が繁茂しているとみなして優勢状態と判定する．本手法によって優勢状態の推定では高精度の結果を得ることができ，有効性を確認した．

Improving energy efficiency of robots is an important issue for diffusion of robots in society. For reducing the energy consumption of robots, we focused on the gear weight and friction during drive, and investigated Ultra High Molecular Weight Polyethylene (UHMW-PE) for the robot joints as a lightweight, low friction, and high impact strength material. A simple UHMW-PE gear has already been proposed, and the friction and wear reduction effects of the gear alone have been verified. However, the energy efficiency improvement has not been investigated. We designed UHMW-PE gears for comparing to the conventional metal (CAC502) gear. Each gear was incorporated into a humanoid robot finger joint, and the energy consumption when the finger bended was compared. The UHMW-PE gear with excellent self-lubrication reduced energy consumption in the robot finger by around 3%.

A large joint output is required for the robot to perform dynamic motions. Most previous robots output power only with actuators, with a lot of energy. On the other hand, humans perform with high efficiency by storing and releasing energy by tendons. When trying to simulate it with robots, the actuator and elastic element are arranged in series. This mechanism becomes complicated, large and heavy. Therefore, we propose a novel joint mechanism reducing the size and weight by designing using a 5-bar linkage. To make it easy to use for the joint mechanism, we propose to combine the 5-bar linkage and the 4-bar linkage. We developed an ankle joint of the robot with this mechanism. While demonstrating the same performance as the previous mechanism, we succeeded in reducing the size by 20% and the weight by 0.7 kg.

The long-term goal of this study is a training system that can simulate medical cases and advise physicians based on quantitative evaluation of neonatal resuscitation. In this paper, we designed and manufactured a neonatal airway management simulator for quantitative evaluation of tracheal intubation. This robotic simulator is equipped with 25 sensors of 6 types, which detect motions that lead to complications, inside the manikin replicated a neonate. A performance experiment of the developed sensor and an evaluation experiment with physicians were conducted. We observed that an erroneous operation in the laryngoscopy can be detected by the sensors in our simulator.

Knee extensors play a key role in maintaining balance and stabilizing gait. Insufficient training of knee extensors leads to muscle atrophy and progressive overall body instability. However, training knee extensors requires specific exercises which are not easily integrated in activities of daily life. For example, even if walking is one of the most popular daily exercise, its training effects are limited to lower leg muscles. To better integrate knee extensor training in daily life we are developing a training device which can apply additional mechanical load on the knee joint during daily normal walking, to extend the training effects of simple walking to knee extensors. We projected a longterm study to develop an integrated system which combines a training function with an assisting function. Integrated sensors measure the biological data of muscular activity to automatically select the proper mode in real-time. In 2019, we designed a prototype of the training device and evaluated its effects on the knee extensor muscle with preliminary experiments. The results validated the feasibility of the training system and showed that the training load need to be adapted to the gait phase during walking. In this study, we improved the training device with active resistance component to adjust the training load in real-time.

This paper proposes a system for stable ladder climbing of the human-sized four-limbed robot "WAREC-1", including the following 3 components: (a) Whole-body motion planning; (b) Rung recognition system and (c) Reaction force adjustment. These 3 components guarantee appropriate ladder climbing motion, successful rung grub and proper reaction force distribution at contact points throughout the climbing motion, respectively. With this system, (1) Stable ladder climbing in 2-point contact gait by a human-sized robot and (2) Successful and stable climbing of an irregular ladder (with a higher or inclined rung) in both 3-point and 2-point contact gait with the capability of recognizing the target rung and the corresponding motion planning are realized, which have rarely been realized by former studies. Finally, experiment results and data of the robot ladder climbing are also presented to evaluate the proposed system.

<title>Abstract</title>
Operation of tools has long been studied in robotics. Although appropriate hold of the tool by robots is the base of successful tool operation, it is not with ease especially for tools with complicated shape. In this paper, an assist system for a four-limbed robot is proposed for remote operation of reaching and grasping electric drills using deep reinforcement learning. Through comparative evaluation experiments, the increase of success rate for reaching and grasping is verified and the decrease in both physical and mental workload of the operator is also validated by the index of NASA-TLX.

Rodents are often used in medicine, brain science, pharmacology, and psychology, as experimental animals. We have been proposing a novel method that involves usages of mobile robots as agents to interact with animals to understand animal behavior. A robot which is able to locomote not only on floors but also walls are strongly expected to increase the variety of behavioral experiments. The purpose of this study is to develop a new mobile robot which is able to locomote both on floor and on walls interacting with rats. For this purpose, we invented a novel mechanism which made a mobile robot locomote by wheels on iron walls. The mechanism consists of an active bending joint in the body, a passive tilting magnet, and a passive tilting tail. We implemented this mechanism into a new small mobile robot, named WR-7 (Waseda Rat No. 7). In this paper, proposed mechanism and its implementation are described.

We developed a small robot with Inline Archimedean Screw Mechanism in response to the demands of surveying Invasive Alien Species (IAS). There are some harmful IAS in wetlands such as snapping turtles. The current method for the survey is net-trap (“Mondori-wana”) and fumbling search by humans. Both methods are inefficient and unsafe for humans. To improve the efficiency and safety of surveying IAS in wetlands, the mobile robot system is demanded. The target environment is configured with soft ground, covered with water, dense water plants and side hole. There is no mobile robot that can move in such an environment. We proposed Inline Archimedean Screw Mechanism to realize locomotion performance at the target environment. The robot can move on a soft land as if cutting a screw. Furthermore, pushing aside water plants, the robot can prevent itself from getting stuck by dense water plants. Using Inline Archimedean Screw Mechanism, we developed the robot, named WANGOT (WAseda Native species Guardian robOT). WANGOT has the size of W85 × H85 × L460 [mm], the weight of 1.4 [kg] and two actuators and four Archimedean screws. It was possible to move forward at a speed of 27 [mm/s] on artificial turf, and the movement performance on the environment of simulated dense water plant area was confirmed.

多種多様な植物を同じ農地内で混生密生させ、生態系の持つ自己組織化能力を多面的・統合的に活用することで、有用植物を生産する農法として協生農法 ™ がある．現在、協生農法を支援する技術の一環として、主要な管理作業を自動化するロボットの開発が行われているが、単一植物に対する画一的な作業で実現できる慣行農法に比べ、認識・作業の複雑さが課題となっている．協生農法では生育している植物の多様度の高さを重視するが、一部の植物が他の植物に対して優勢することで生態系の種構成や占有率が変化し、多様性を下げてしまう場合があ り、その植物を剪定することで植生のバランスを調整することが求められる．今回の研究では植物群の多様性を下げてしまう恐れのある状態の植物（優勢植物）を検出することを目的とする提案手法では、分割されたRGB 画像に対して CNN での学習を行う CPM(Chopped Picture Method) という手法を用いて優勢植物の検出を行う．今回はミント Mentha suaveolens を優勢植物の検出対象として扱い，「ミント」，「ミント以外の植物」，「その他」の 3 種類のラベルで学習を行った．実験の結果，優勢植物の検出については高い精度が得られ，特に植物群と非植物群の判別は特に高精度であった．

多種多様な植物を同じ農地内で混生密生させ，生態系の持つ自己組織化能力を多面的・統合的に活用することで，有用植物を生産する農法として協生農法™がある．現在，協生農法を支援する技術の一環として，主要な管理作業を自動化するロボットの開発が行われているが，単一植物に対する画一的な作業で実現できる慣行農法に比べ，認識・作業の複雑さが課題となっている．協生農法では，表土を植生で覆うことが重要であり，表土が露出している場合は植生を導入して植生で被覆することが求められる．そこで，今回の研究では表土が露出している箇所を詳細に認識することを目的とする．提案手法では，RGB画像に対しセマンティックセグメンテーションを行うことで圃場を画素単位で植物か否かのラベル情報を推定する．セマンティックセグメンテーションのパラメータを変化させて推定精度を比較評価することにより、Focal Loss損失関数を利用することで，少ない学習用の画像枚数でも高精度での認識を実現できる見通しを得た．

Herein, we have developed a humanoid robot that achieves dynamic motion. Focusing on the running motion that is the basis of the motion, the robot has been developed focusing on the pelvic rotation on the frontal plane and the elasticity in leg joints (that changes according to running speed), which are the characteristics of humans during running. However, the variable joint stiffness mechanism that we have developed was large and heavy. Therefore, to make the mechanism smaller and lighter, we shorten the length of the leaf spring. We succeeded in downsizing the mechanism by changing its rectangular shape to trapezoidal, while maintaining strength and elasticity. The variable joint stiffness mechanism thus developed was more flexible, and its weight was reduced from 1.9 kg to 0.7 kg. The mechanism was mounted on the ankle joint, and it was confirmed that the required specifications were satisfied.

We are developing the biped humanoid robot WATHLETE-1 (Waseda ATHLETE humanoid No.1) that has the same mass arrangement, link ratio, and output characteristics as humans. It is not possible to mount high-power electromagnetic motors and mechanical transmissions that satisfy the hip joint output at running because its weight makes it impossible to realize human body characteristics. To realize the characteristics of the human body, we adopted a hydraulic drive system that has a more advanced design than a mechanical transmission mechanism, that concentrates on the joints, and that can distribute output by splitting and merging oil. We propose a hydraulic circuit that improves the output of the actuator by connecting two hydraulic direct drive systems (HDDs) in parallel, independently mounted on the ankle and the hip joints using proportional valves. As a result, it has been confirmed that hip joint speed was improved by 200% compared to a single HDDs and with the potential of simulating the hip joint output required for a human running at 2.0 m/s.

<p>人間の安定性感覚は人間の姿勢維持に関わる重要な感覚であり，安定性感覚を提示することができればVR体験のリアリティ向上などに繋がると考えられる．本研究では，安定性の指標の一つである重心投影点を再現するため，他者の足裏反力を再現する装置と重心投影点回答システムを用いて，他者の足裏反力を提示された際に，再現した足裏反力から推定した重心投影点を確認する実験を行い，実際の足裏反力を提示した場合は2 cmの精度で重心投影点推定が可能であり，0.1倍した足裏反力を提示した場合には推定が困難であることを確認した．</p>

This article presents the experience of a longlasting collaboration in robotics between the countries of Japan and Italy. The diversity of the approaches to robotics research and technology in the two countries and, at the same time, the similarity of some social drives for robotics progress have created a stimulus for generating new thinking about robotics. Not only has this occurred at the main participant institutions of Waseda University in Tokyo and Scuola Superiore Sant?Anna in Pisa, Italy, but it has also happened worldwide. The authors present a summary of the Italy-Japan workshops, exploring topics on 1) humanoid robotics, 2) the application of robotics for exploration and rescue, 3) biorobotics, 4) the use of robots in education, 5) the ethics of robotics, 6) robotics for sports, and 7) robotics for the arts. The experience of the workshops represents an example of an open-minded approach to robotics that is grounded on social challenges, explored through multidisciplinary discussion. Such interdisciplinary research efforts deserve to be shared with the international robotics community. Indeed, this approach could be used as a base model to foster further international collaborations among countries as well.

Towards the actualization of autonomous switch operation method for the disaster response robot, it is necessary to estimate the position and orientation of the switch in the site. This paper proposes a method for estimating switch orientation information based on the RGB-D sensor information attached to the disaster response robot. The flow of the proposed method in this paper consists of the following three stages. (1) Acquisition of RGB-D information of the switch area using the detection result of YOLOv3. (2) Position estimation of switch operation part by CNN from RGB-D information of switch area. (3) Estimation of switch orientation information using switch operation part position information and information on wall plane on which the switch exists. In the experiment, the proposed method was applied to three types of switch boxes, and the calculation results of the orientation information were evaluated. It was found from the experimental results that the calculation with sufficient accuracy is possible.2020. Int. J. Mech. Eng. Rob. Res

In order to realize a disaster response robot that can reach and climb straight stairs within a certain range, this paper proposes a method for estimating the position and orientation of the stairs using 2D image and 3D point cloud. In this method, first, an object detection method is applied to an RGB image, and a 3D point cloud including stairs is extracted by combining the detection result and the 3D point cloud. Next, a 3D point cloud of a step candidate is extracted by applying plane estimation and region segmentation to the extracted 3D point cloud. The 3D point cloud of the step candidate is projected on a 2D plane, and the orientation of the stairs is estimated by detecting their contour and lines. In addition, the position of the stairs is estimated by searching for a combination of 3D point clouds of the step candidates located at equal intervals using the structural characteristics of the stairs. As a result of simulation using a disaster response robot WAREC-1, it was confirmed that the orientation of the stairs can be accurately estimated by the proposed method. It was also confirmed that the position could be accurately estimated under specific conditions.

Soft robotics has recently become a popular topic owing to its advantages over conventional rigid robotics. In this article, we introduce a soft robot that can grow with its own structure; its main components include an inflatable tube for its body and a tip with an expansion mechanism. The tube is made of conventional laminated film. It leads the robot to improved applicability. The robot can grow along the horizontal and vertical directions, and it can bend around yaw and pitch axis. To achieve this, a mechanism feeds air into the inflatable tube for growing the structure, and another heat welding mechanism allows producing bending points where necessary. The experimental results confirm that the proposed robot can grow in mid-air and bend around the yaw axis with varying bending radii. Further, the robot can climb a wall and displace an upper surface by pitch-axis bending. The designed bending structures are very stable because of heat welding; the growing and climbing capabilities depend on the inner pressure of the tube, and these capabilities allow the robot to select various shapes and move seamlessly in various environments.

A multi-degree-of-freedom (multi-DOF) waist mechanism is required for robotic rats to perform species-typical behaviors, but the existing waist mechanisms are heavy and cumbersome. To solve this problem, we propose a linkage-based slider-coupled symmetric swing (S3) mechanism, which features a single-input multiple-output structure, allowing it to couple multiple DOFs. The linkage mechanism has a variety of forms and linkage curves, making the S3 mechanism suitable for multiple-constraint optimization. Based on kinematic and dynamic analyses, we constrain the S3 mechanism in terms of bending angle, transmission angle, symmetry, and its existence, and then we optimize its dimensions using an interior-point method to make it compact. Compared with an existing waist mechanism, the proposed waist mechanism has only 47.8% of the weight and smaller dimensions, making it more lightweight and compact. Experiments on a robotic rat show that the proposed waist mechanism enables a robotic rat to perform rat-like upright rearing in 0.5s and tail grooming behavior in 0.4s, indicating its good biomimetic and dynamic performances. Comparisons between two generation robotic rats also reveal that the robot with new waist mechanism has similar (sometimes superior) pitching and bending abilities with the former one.

The capability of performing animal-like turning action is very important for a biomimetic robot to be used in realistic world. Although the existed biomimetic robots can imitate turning actions of their counterparts, it is still lacking an effective approach to generate bioinspired turning action of small quadruped animals. To solve this problem, we proposed an effective phase-shift-based motion planning method after systematically analyzing and mathematically modeling the turning action of laboratory rats. Moreover, we introduced an N-step turning strategy to allow the biomimetic robot effectively perform animallike turning action regardless of joint limits. We characterized the action similarity between rats and a rat-inspired robot in terms of joint trajectory and their envelope. The robot is able to closely follow the turning action of rats since the difference of turning angle is less than 7.95. Additionally, the width distribution of trajectory envelope between the robot and rat is quite similar. The proposed turning model can be easily extended to biomimetic robots inspired by other small quadruped mammals, which share similar turning patterns to rats.

To achieve one of the tasks required for disaster response robots, this paper proposes a method for locating 3D structured switches' points to be pressed by the robot in disaster sites using RGBD images acquired by Kinect sensor attached to our disaster response robot. Our method consists of the following five steps: 1)Obtain RGB and depth images using an RGB-D sensor. 2) Detect the bounding box of switch area from the RGB image using YOLOv3. 3)Generate 3D point cloud data of the target switch by combining the bounding box and the depth image.4)Detect the center position of the switch button from the RGB image in the bounding box using Convolutional Neural Network (CNN). 5)Estimate the center of the button's face in real space from the detection result in step 4) and the 3D point cloud data generated in step3) In the experiment, the proposed method is applied to two types of 3D structured switch boxes to evaluate the effectiveness. The results show that our proposed method can locate the switch button accurately enough for the robot operation.

Tactile feedback sensation is an important factor in the surgical and medical application. A simple gripper is developed to perform precision grasping using teleoperation technology. The system provides the user with the tactile feedback sensation through a haptic device that applies forces on the user’s fingertip based on the measured force at the gripper’s fingertip.

We present a music-robotic system capable of performing an accompaniment for a musician and reacting to human performance with gestural and facial expression in real time. This work can be seen as a marriage between social robotics and computer accompaniment systems in order to create more musical, interactive, and engaging performances between humans and machines. We also conduct subjective evaluations on audiences to validate the joint effects of robot expression and automatic accompaniment. Our results show that robot embodiment and expression improve the subjective ratings on automatic accompaniment significantly. Counterintuitively, such improvement does not exist when the machine is performing a fixed sequence and the human musician simply follows the machine. As far as we know, this is the first interactive music performance between a human musician and a humanoid music robot with systematic subjective evaluation.

This paper describes the dynamic analysis of the vertical jumping motion of a one-legged jumping robot that consists of a hip, a thigh, a shin, and a foot. The jumping robot has two kinds of pneumatic artificial muscles, the mono-articular muscle and the bi-articular muscle. The jumping robot is difficult to obtain the output force of each artificial muscle because each joint force is produced by the plural pneumatic artificial muscles. When the robot jumps, the forces can be projected to the waist. Thus, we developed a method that can calculate the magnitude and direction of the resultant of the forces, and convert the resultant force to the output force of the pneumatic muscles. Vertical jumping simulations are conducted, and the effectiveness of the mathematical modeling is verified.

This paper describes a human-friendly robot capable of securing human safety in human-robot collisions. The upper body of the robot has 11 DOFs, including 3 DOFs in the waist, 2 DOFs in each shoulder, 1 DOF in each elbow and 1 DOF in each hand. The upper body is mounted on the base with four omnidirectional wheels. A new light-weight collision force suppression mechanism that is able to operate with very little backlash was developed and was installed at the elbow of the human-friendly robot. The suppression mechanism consists a drum, a clutch gear, two release air bag, two stopper linings, and four compression springs. Also, a base control method to secure human safety is discussed. Through collision experiments, the effectiveness of the collision force suppression mechanism and control method is verified.

Preserving mobility, the ability to keep a correct posture and dynamic balance in order to walk properly, is fundamental to maintain autonomy in daily life. Based on the correlation between muscle groups and autonomy, previous research has suggested that maintaining muscular tone in knee extensors is critical. Continuous training of knee extensors during aging is therefore essential to maintain independence. In this work, it is hypothesized that it is possible to estimate knee extensor activity only from IMU data based on a simple lower limbs model. The accuracy of the knee extensor activity estimation algorithm has been tested using sEMG measurements as control data on three different walking patterns: normal walk, fast walk and stair climbing. Estimated knee torque area and measured muscular activity for each step were compared confirming a high estimation accuracy with a correlation efficient R=0.80. Moreover, muscular activity can be divided based on intensity in three groups of statistically significant difference confirmed by the Steel-Dwass method. Future works should test the usability of the algorithm for different walking patterns, and use the collected data and the refined algorithm to implement a smart resistive device to increase knee extensor exertion during each walking pattern to the level necessary for sufficient extensor training.

We are developing an autonomous monitoring system using mobile robot in response to the demands of autonomous monitoring in forest area. The effective path planning is required for autonomous operation. The robot needs to locomote in the grassy area so as to move in a natural forest area, therefore the path route on grassy area have to be considered. The objective of this study was to develop a path planning method for small mobile robot to move in the forest. We focused on the cost used to generate the path and try to add grass vegetation into the cost map. The grass vegetation degree is effective to generate the optimal path, and the robot could move in forest by following the generated path.

We have developed mobile robots to meet the demand for ecological observation of animals. The purpose of this research is to develop an observation robot specialized for small animals. Robots must have high mobility in forest environments. This robot moves over rough terrain using two active wheels driven by motors and can jump over obstacles by using a two-spring jumping mechanism. The jumping mechanism has a structure that can achieve jumping power even in a forest environment. By this mechanism, it has become possible to jump higher than existing robots in a forest. A spiral cam is used for the jumping mechanism. This cam is effective to achieve a long kicking distance and save space. In this paper, to improve the performance of the robot jumping mechanism, the optimal shape of the cam is examined.

Rapid localization of injured survivors by rescue teams to prevent death is a major issue. In this paper, a sensor system for human rescue including three different types of sensors, a CO2 sensor, a thermal camera, and a microphone, is proposed. The performance of this system in detecting living victims under the rubble has been tested in a high-fidelity simulated disaster area. Results show that the CO2 sensor is useful to effectively reduce the possible concerned area, while the thermal camera can confirm the correct position of the victim. Moreover, it is believed that the use of microphones in connection with other sensors would be of great benefit for the detection of casualties. In this work, an algorithm to recognize voices or suspected human noise under rubble has also been developed and tested.

Many extant studies proposed various stabilizing control methods for humanoids during the stance phase while hopping and running. Although these methods contribute to stability during hopping and running, humanoid robots do not swing their legs rapidly during the flight phase to prevent rotation in the yaw direction. Humans utilize their torsos and arms when running to compensate for the angular momentum in the yaw direction generated by leg movement during the flight phase. In this study, we developed an angular momentum control method based on human motion for a humanoid upper body. The method involves calculation of the angular momentum generated by the movement of the humanoid legs and calculation of the torso and arm motions required to compensate for the angular momentum of the legs in the yaw direction. We also developed a humanoid upper-body mechanism having human link length and mass properties, using carbon-fiber-reinforced plastic and a symmetric structure for generating large angular momentum. The humanoid robot developed in this study could generate almost the same angular momentum as that of a human. Furthermore, when suspended in midair, the humanoid robot achieved angular momentum compensation in the yaw direction.

The interaction test between a robotic rat and living rat is considered as a possible way to quantitatively characterize the rat sociality. In such robot-rat interactions, the robot should be designed to fully replicate a real rat in terms of morphological and behavioral characteristics. To address this problem, a multi-jointed robot prototype has been modified based on our previous work. We optimally update the forelimb of the robot and redesign the control board to make it more dexterous and increase its behavioral capability. Then, we systematically and kinematically analyze the rotational range of joint variables and the workspace of the robot by using traversal method. To evaluate the motion capability of the modified robot, we propose two quantitative parameters: maximum reachable height (MRH) and minimum bendable distance (MBD). Additionally, we achieve to quantitatively evaluate the behavioral similarity between the robot and rat with the calculated accumulative distance (AD) by using dynamic time warping (DTW). These evaluated methods show high promise to improve the robot-rat interaction to be more similar to rat-rat interaction.

The use of Inertial Measurement Unit (IMU) for gait analysis is gaining popularity because of its advantages of low cost and non-limited workspace. In this context, researchers are focusing on methods for automated data analysis. For example, many algorithms for stride length estimation have been developed. These algorithms rely on event detection to compute gait parameters during walking and on orientation estimation for a more precise double integration of acceleration. However, at the present, there is not comparison between existing algorithms, and the applicability of each algorithm for different walking patterns is not clear. In this paper, we studied the effect on the stride length estimation using three different techniques of event detection and two techniques of orientation estimation, by using an IMU on the lateral side of shank above the ankle. In total 6 patterns of stride estimation algorithms were compared on different walking patterns of normal and brisk walking. We evaluated the techniques in terms of precision, accuracy, and shape of the histogram of the stride estimation error.

Tooth brushing plays an important role in one's health, and particularly, in the prevention of oral diseases. It is a fundamental oral care technique in daily life
however, many elderly or handicapped people cannot brush their teeth without assistance from helpers. The purpose of this study is to develop an automatic teeth cleaning mouthpiece robot. One of the most common methods of brushing teeth is to move the toothbrush along the row of teeth. Hence, a mechanism to wipe teeth using sponges is designed and it consists of an eccentric cam, a wiper with sponges, and a rounded guide rail. This mechanism generates rounded wiper motions along the row of teeth. Furthermore, a safety system is designed to prevent aspiration. Brushing stops automatically when the user lifts his/her jaw up from the jaw supporter.

We developed a small mobile robot in response to the demands in the disaster area. A hybrid locomotion mechanism of wheels and multi-rotors are proposed to realize both high locomotion performance and long-term operation. The wheels allow to highly maneuverable move in a narrow space, and the multi-rotors allow to move to a higher position. The objective of this study is to design the locomotion mechanism and develop a platform for confirming the basic locomotion performance. We attached a wheel mechanism into the assembled hobby drone and embedded an electrical system to operate the robot. The wheels also contribute to protect the multi-rotors from obstacles such as rubble. A stabilizer was proposed to stabilize the robot during running with wheels and designed to allow recover from flipping state. The significant of this work is not only improving the locomotion performance of the drone, but also increase the operating time, this leads various uses at disaster sites. In this paper, the details of the locomotion mechanism and some experimental results using the developed platform are shown.

Humans utilize their torsos and arms while running to compensate for the angular momentum generated by the lower-body movement during the flight phase. To enable this capability in a humanoid robot, the robot should have human-like mass, a center of mass position, and inertial moment of each link. To mimic this characteristic, we developed an angular momentum control method using a humanoid upper body based on human motion. In this method, the angular momentum generated by the movement of the humanoid lower body is calculated, and the torso and arm motions are calculated to compensate for the angular momentum of the lower body. We additionally developed the humanoid upper-body mechanism that mimics the human link length and mass property by using carbon fiber reinforced plastic and a symmetric structure. As a result, the developed humanoid robot could generate almost the same angular momentum as that of human through human-like running motion. Furthermore, when suspended in midair, the humanoid robot produced the angular momentum compensation in the yaw direction.

The receptionist job, consisting in providing useful indications to visitors in a public office, is one possible employment of social robots. The design and the behaviour of robots expected to be integrated in human societies are crucial issues, and they are dependent on the culture and society in which the robot should be deployed. We study the factors that could be used in the design of a receptionist robot in Brazil, a country with a mix of races and considerable gaps in economic and educational level. This inequality results in the presence of functional illiterate people, unable to use reading, writing and numeracy skills. We invited Brazilian people, including a group of functionally illiterate subjects, to interact with two types of receptionists differing in physical appearance (agent v mechanical robot) and in the sound of the voice (human like v mechanical). Results gathered during the interactions point out a preference for the agent, for the human-like voice and a more intense reaction to stimuli by illiterates. These results provide useful indications that should be considered when designing a receptionist robot, as well as insights on the effect of illiteracy in the interaction.

Neuroscientific studies show that humans tend to stabilize their head orientation, while accomplishing a locomotor task. This is beneficial to image stabilization and in general to keep a reference frame for the body. In robotics, too, head stabilization during robot walking provides advantages in robot vision and gaze-guided locomotion. In order to obtain the head movement behaviors found in human walk, it is necessary and sufficient to be able to control the orientation (roll, pitch and yaw) of the head in space. Based on these principles, three controllers have been designed. We developed two classic robotic controllers, an inverse kinematics based controller, an inverse kinematics differential controller and a bio-inspired adaptive controller based on feedback error learning. The controllers use the inertial feedback from a IMU sensor and control neck joints in order to align the head orientation with the global orientation reference. We present the results for the head stabilization controllers, on two sets of experiments, validating the robustness of the proposed control methods. In particular, we focus our analysis on the effectiveness of the bio-inspired adaptive controller against the classic robotic controllers. The first set of experiments, tested on a simulated robot, focused on the controllers response to a set of disturbance frequencies and a step function. The other set of experiments were carried out on the SABIAN robot, where these controllers were implemented in conjunction with a model of the vestibulo-ocular reflex (VOR) and opto-kinetic reflex (OKR). Such a setup permits to compare the performances of the considered head stabilization controllers in conditions which mimic the human stabilization mechanisms composed of the joint effect of VOR, OKR and stabilization of the head. The results show that the bio-inspired adaptive controller is more beneficial for the stabilization of the head in tasks involving a sinusoidal torso disturbance, and it shows comparable performances to the inverse kinematics controller in case of the step response and the locomotion experiments conducted on the real robot.

We present a robot designed for children with developmental disorders. These disorders are categorized into autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), and learning disability (LD). While growing, children generally learn through play activities. However, those with developmental disorders require external supports during play because they have difficulties in some aspects. For instance, children with ASD tend not to communicate, those with ADHD find it difficult to concentrate, and those with LD have difficulties in talking, reading, writing, and performing calculations. Thus, some researchers propose robots as solutions to enhance the effects of children's play. In this paper, we present a new type of spherical robot that can jump and roll on the floor. The purpose of this research was to develop a spherical robot that engages with children using its motion capabilities. Specifically, here we present the mechanical design and performance of the robot. The robot has two types of outer spheres with a diameter of 170 mm and made from varied materials. One is a soft sphere made of paper, and the other is a plastic hard sphere. As a result, the jumping height of the internal mechanism reaches 110 mm, that of the soft sphere reaches 65 mm, and that of the hard sphere goes up to 10 mm The robot speed using the hard sphere is 0.65 m/s. In contrast, the robot with the soft sphere exhibits an unstable rolling motion, a seemingly dancing pace, which is difficult to control. Overall, we consider that the proposed jumping and rolling spherical robot can be a suitable tool to aid children with developmental disorders.

<p>This paper proposes a novel motor cooling method using direct-liquid cooling by immersing a heat source directly into coolant. Direct-liquid cooling is more effective than air cooling and indirect-liquid cooling because a heat source and coolant are in direct contact with each other. Further, if the shape of the shaft is designed to be able to perform heat transfer by forcibly circulating the coolant by the rotation of the motor itself, it will be possible to prevent the actuator unit from being enlarged.</p>

<p>We are developing a robot for gas pipe inspection, which obtain trust forces by pneumatic actuators. The air pressure to drive them is provided by a compressor, which is set out of the pipe, via tubes. Fictions between these tubes and pipe walls sometimes constrain motions of the robot hardly. Therefore, we developed a tube-sending mechanism, which stays between the compressor and the robot, to support motions of the robot.</p>

<p>A one-legged jumping robot that can mimic the muscular and skeletal system of a human leg is described in this paper. Its height is 1200 [mm], and its total weight is about 9.0 [kg]. The robot is composed of a waist, a thigh, a shin, a foot, and a toe. It has 6 DOFs in total, including 2 DOFs in the hip, 1 DOF in the knee, 2 DOFs in the ankle, and 1 DOF in the toe. Also, a jumping pattern generation algorithm based on the dynamic model of the jumping robot is proposed. The jumping pattern is created generated considering the output ratio of pneumatic actuators and the characteristics of air supply and exhaust. The effectiveness of air supply-exhaust pattern generation algorithm is verified through a jumping experiment.</p>

<p>A human-friendly robot that consists of two arms, a body and a mobile base has been developed. The robot has a collision force suppression mechanism that passively operates without power supply and a control system. The mobile base has four omnidirectional wheels, and is covered by an air cushion bag to absorb collision forces. In this paper, a new passive collision force suppression mechanism capable of being operated by wires is proposed. When a collision between an object and the arm or the body occurs, the collision/contact force is suppressed by the collision force suppression mechanisms. Through collision experiments, the effectiveness of the suppression mechanisms is confirmed.</p>

<p>The KBHR (Kanagawa Biped Humanoid Robot) that is composed of 42 DOFs have been developed. This paper describes a trajectory generation method for 7-DOF manipulators of the KBHR and a robot vision-based object recognition method. The trajectory generation method is based on numerical analysis using Jacobian pseudo-inverse and transpose matrix. In order to recognize objects, an OpenCV image processing library is used. Through an experiment recognizing an object and handing over it to a person, the effectiveness of the trajectory generation algorithm and the object recognition methods is confirmed.</p>

With the developments of robotics, it has become a fashion trend that ankle rehabilitation robots assist traditional training in rehabilitation field. In this thesis, a novel ankle robot combing with 3 degrees of freedom, combining passive-active training, subjective awareness and objective training was proposed. Prior to robot developments, the requirement of ankle robot was analyzed based on the ankle structure and rehabilitation. In order to acquire the range of ankle motion, an experiment was established to detect the physiological data. Based on traditional rehabilitation therapy, a novel robot-assist rehabilitation therapy combing subjective awareness and objective training was proposed. Based on the requirements analysis, a novel mechanism structure of cross-circle was proposed to robot movement around ankle center. The mechanical structure includes four parts, adduction/abduction parts, dorsiflexion/plantar flexion parts, inversion/eversion parts and sensing unit. Each part of ankle rehabilitation robot was introduced in detail. By means of stress analysis and strength check, the feasibility of the structure was verified. After the mechanism design, the hardware configuration of control system was built up. Finally, the core control strategy, position control and force control were proposed.

The inertial measurement unit is popularly used as a wearable and flexible tool for human motion tracking. Sensor-to-body alignment, or anatomical calibration (AC), is fundamental to improve accuracy and reliability. Current AC methods either require extra movements or are limited to specific joints. In this research, the authors propose a novel method to achieve AC from standard motion tests (such as walking, or sit-to-stand), and compare the results with the AC obtained from specially designed movements. The proposed method uses the limited acceleration range on medial-lateral direction, and applies principal component analysis to estimate the sagittal plane, while the vertical direction is estimated from acceleration during quiet stance. The results show a good correlation between the two sets of IMUs placed on frontal/back and lateral sides of head, trunk and lower limbs. Moreover, repeatability and convergence were verified. The AC obtained from sit-to-stand and walking achieved similar results as the movements specifically designed for upper and lower body AC, respectively, except for the feet. Therefore, the experiments without AC performed can be recovered through post-processing on the walking and sit-to-stand data. Moreover, extra movements for AC can be avoided during the experiment and instead achieved through the proposed method.

The authors are developing anthropomorphic musical performance robots as an approach to understand the human motor control and to enhance the human-robot interaction from an engineering point of view. For this purpose; since 1990, we have developed an anthropomorphic flutist robot. As one of our long-term approaches, we aim to develop an anthropomorphic musical performance robot capable of playing different kinds of woodwind instruments, e.g. flute and saxophone. In this paper, the improvements of the mechanical design and sensing system of the Waseda Flutist Robot No. 4 Refined V (WF-4RV) are detailed. As for the sensing system, an array of sensors has been designed to detect the lip's pressure distribution. On the other hand, the lips and lung have been re-designed to enable the flutist robot to play the saxophone. (C) 2016 Elsevier B.V. All rights reserved.

This paper describes the mechanism of a one-legged jumping robot that can mimic the muscular and skeletal system of a human leg. The jumping robot has a waist, a thigh, a shin, a foot, and a toe. The McKibben-type pneumatic muscle actuators that are able to generate the maximum output force of 1200 [N] are employed. Two kinds of pneumatic artificial muscles, mono-articular and bi-articular muscles, were installed in the rear and in the front of the thigh and shin. A jumping pattern is also developed in consideration of the performance of the pneumatic actuators. Several jumping experiments were conducted, and the effectiveness of the mechanism and jumping pattern was verified.

A biped humanoid robot is prone to fall when walking or operating in a complex environment, and forward fall is one of the most common falling cases. This study focuses on the forward fall issue and presents an"Arm Flexible Landing Strategy" for safe falling. First, the forward falling motion is analyzed from an energy variation perspective of the robot system, and a method to choose best-fit landing attitude of the arm is presented. Then, a exible landing controller is implemented in the arm to reduce the impact force to the robot, thereby further increasing protection. The presented algorithm is very easy to implement and does not require any additional physical elements to the robot. Finally, a series of simulations are made on a humanoid robot to validate the effectiveness of the presented methods on a safe landing.

The ability of climbing steps and slopes are required for on-land tiny mobile robot to move on rough terrain in the riverside area. We have already proposed a new wheel shape
notched wheel that can satisfy the maximum potential of the abilities and easily calculate the abilities. However, the model has not mentioned the phase difference between the left and right wheels. We found that the method of phase difference is so effective to improve the climbing ability of slopes. The climbing step ability become high when the right side of the notched wheels is π/2 different from left side wheels. In this paper, we describe the details of the methods and show some experimental results.

Many conventional robots consisting of rigid frames and active joints have been controlled based on the information regarding collision avoidance in human environments. When these robots collide with a human, he/she can be seriously injured if their sensor systems have a defect or the power supplies are shut down. So, we have developed a human friendly robot that consists of two arms, a body, and a mobile base. It is covered by an air cushion bag which simulates the skin of a human. In this paper, its waist is described, which consists of pitch, roll, and yaw axes. Also, a passive collision force suppression mechanism that is installed in each joints of the human friendly robot is proposed. The passive collision force suppression mechanism consists of two fixed and linear guides, two compression springs, a release system, and a disk damper. When a collision between the robot and the environment occurs, collision/constant forces are first suppressed by the air cushion bag. If a larger collision force is exerted on the robot, the suppression mechanisms will become passively activated and the joints of the waist will disconnect. The robot, moreover, is capable of returning to a desired task by using the suppression mechanisms if the environment is cleared. Through collision experiments, the effectiveness of the waist mechanism and the suppression mechanism is verified.

<p>[Purpose]Ultrasonography is one of widely used noninvasive and convenient methods. However, relatively large measurement variability is a problem to be solved. We developed a robot system for carotid arterial measurement by ultrasonography. In this study, we evaluated variability of the measurements of intima media thickness and carotid arterial diameter. [Methods] The robot consisted of one arm with 6-axis, which is operated by remote control with a probe shaped controller. Data acquisition was executed according to the sign which indicated the distinct intima separated from adventitia by echo-transparent media layer. The variability was measured by two observers with or without the robot system. [Results] There was no difference in acquisition time between the measurements with or without robot. However, variabilities of the measurements with the robot were lower than that without the robot (p<0.05). [Conclusion] The robot system has a potential to reduce variability of ultrasonographic measurements</p>

The study of human nonverbal social behaviors has taken a more quantitative and computational approach in recent years due to the development of smart interfaces and virtual agents or robots able to interact socially. One of the most interesting nonverbal social behaviors, producing a characteristic vocal signal, is laughing. Laughter is produced in several different situations: in response to external physical, cognitive, or emotional stimuli
to negotiate social interactions
and also, pathologically, as a consequence of neural damage. For this reason, laughter has attracted researchers from many disciplines. A consequence of this multidisciplinarity is the absence of a holistic vision of this complex behavior: the methods of analysis and classification of laughter, as well as the terminology used, are heterogeneous
the findings sometimes contradictory and poorly documented. This survey aims at collecting and presenting objective measurement methods and results from a variety of different studies in different fields, to contribute to build a unified model and taxonomy of laughter. This could be successfully used for advances in several fields, from artificial intelligence and human-robot interaction to medicine and psychiatry.

The implementation of strategies for intuitive and natural communication between robots and humans, depending on the specific situation, is becoming more and more important. Intuitive and human-like communication patterns for human-robot cooperation will ease communication cognitive load and allow the user to better focus on the task at hand. This work presents a basic facial expression system for a humanoid robot saxophonist, allowing the robot to change its expression during a musical performance to both send specific cues for synchronization to a partner human player, and also add emotional emphasis to the performance, as human players naturally do.

Humanoid robots are expected to be able to communicate with humans using physical interaction, including hug, which is a common gesture of affection. In order to achieve that, their physical embodiment has to be carefully planned, as a user-friendly design will facilitate interaction and minimise repulsion. In this paper, we investigate the effect of manipulating the visual/tactile appearance of a robot, covering wires and metallic parts with clothes, and the auditory effect by enabling or disabling the connector of the hand. The experiment consists in a hugging interaction between the participants and the humanoid robot ARMAR-IIIb. Results after participation of 24 subjects confirm the positive effect from using clothes to modify the appearance and the negative effect of noise and vibration.

this paper describes a kinematic model of Support robot for elder people. This support robot can help elders who do not have enough physical strength on the lower limbs during sit to stand due to aging. It also follows the natural pattern of human motion during sit to stand. Several experiments were carried out using optotrack to measure the human motion posture while sit to stand motion in addition to estimate the required trajectory for support robot during assisting. Computer program was developed to evaluate the variables of the support robot with the sit to stand trajectory.

One Leg Stance (OLS), a test assessing postural stability, is popularly conducted both in clinic and community settings because it is inexpensive and time-efficient. However, the evaluation based on visual observation and manual time measurement with a stop-watch cannot provide quantitative and detailed parameters for longitudinal or cross-sectional studies. In recent years, to overcome these limitations, the use of Inertial Measurement Unit (IMU) as objective measurement analysis tools is becoming more and more popular. However, the greatest issue is that IMU data segmentation is still time-consuming and prone to errors, as the OLS segmentation is being done manually, off-line, on recorded data. In this paper we proposed a novel algorithm for the automatic segmentation of IMU data of the OLS test. The result showed that the correct rate of detection was over 90% which was close to the correct rate in manual segmentation. Compared to manual segmentation with video, besides being less time-consuming, the proposed algorithm closes the loop making the data acquisition and analysis completely automatic, thus can be integrated in self-assessment smart phone applications, allowing the continuous tracking of postural stability also outside clinics and health-care facilities.

Nowadays, with the development of the proportion of the elderly population in the world, several problems caused by the population aging gradually into people's horizons. One of the biggest problems plagued the vast majority of the elderly is hemiplegia, which leads to the vigorous development of the physical therapists. However, these traditional methods of physical therapy mainly rely on the skill of the physical therapists. In order to make up the defects of traditional methods, many research groups have developed different kinds of robots for lower limb rehabilitation training but most of them can only realize passive training which cannot adopt rehabilitation training based on the patients' individual condition effectively and they do not have a rehabilitation evaluation system to assess the real time training condition of the hemiplegic patients effectively. In order to solve the problems above, this paper proposed a lower limb rehabilitation evaluation system which is based on the virtual reality technology. This system has an easy observation of the human-computer interaction interface and the doctor is able to adjust the rehabilitation training direct at different patients in different rehabilitation stage based on this lower limb rehabilitation evaluation system. Compared with current techniques, this novel lower limb rehabilitation evaluation system is expected to have significant impacts in medical rehabilitation robot field.

The objective of this study was to design a new model of wheel shape for increasing climbing ability of slopes and steps. We made a new model using a statics for calculating the ability easily and found that the arc-shaped notch type seems to be the best and implemented to our robot. In this paper, we introduce the detail of the proposed model and simulation results.

This paper describes the mechanism of a one-legged jumping robot that can mimic the muscular and skeletal system of a human leg. The jumping robot has a waist, a thigh, a shin, a foot, and a toe. The McKibben-type pneumatic muscle actuators that are able to generate the maximum output force of 1200 [N] are employed. Two kinds of pneumatic artificial muscles, mono-articular and bi-articular muscles, were installed in the rear and in the front of the thigh and shin. A jumping pattern is also developed in consideration of the performance of the pneumatic actuators. Several jumping experiments were conducted, and the effectiveness of the mechanism and jumping pattern was verified.

This paper describes the mechanism of a human-friendly robot. The robot consists of two arms, a body and a mobile base. An air cushion bag is developed to cover the entire exterior of the robot. It can reduce the generated impact forces in a collision between any part of the robot and a human. A passive collision suppression mechanism is also developed to deal with greater impact forces. The suppression mechanism is installed in the pitch axis of the elbow and the yaw axis of the waist. The base consists of four omnidirectional wheels, enabling movement in any direction. Moreover, the control method for the base is discussed in this study. Using the robot, collision experiments are conducted and the effectiveness of the robot mechanism and the control method is verified.

Automatic and objective detection algorithms for gait events from MEMS Inertial Measurement Units data have been developed to overcome subjective inaccuracy in traditional visual observation. Their accuracy and sensitivity have been verified with healthy older adults, Parkinson's disease and spinal injured patients, using single-task gait exercises, where events are precise as the subject is focusing only on walking. Multi-task walking instead simulates a more realisitc and challenging scenario where subjects perform secondary cognitive task while walking, so it is a better benchmark. In this paper, we test two algorithms based on shank and foot angular velocity data in single-task, dual-task and multi-task walking. Results show that both algorithms fail when the subject slows extremely down or pauses due to high cognitive and attentional load, and, in particular, the first stride detection error rate of the foot-based algorithm increases. Stride time is accurate with both algorithms regardless of walking types, but the shank-based algorithm leads to an overestimation on the proportion of swing phase in one gait cycle. Increasing the number of cognitive tasks also causes this error with both algorithms.

This paper introduces a motion planning method to generate ladder climbing motion for a four-limbed robot. This method contains the following points: (1) independent planning of path and time in 3 dimensional space for trajectory planning; (2) path length minimization according to given midpoints. In trajectory planning, arc-length parameterization is used to separate path planning and time planning so that they can be done independently. After path is planned, time planning along the planned path can be given freely to meet our requirement, such as speed and acceleration adjustment for the protection of motors, optimization for dynamics analysis, dynamic obstacle avoidance and so on. Results from simulations and experiments authenticate the validity of our motion generation method.

In this paper we tackle the problem of visually predicting surface friction for environments with diverse surfaces, and integrating this knowledge into biped robot locomotion planning. The problem is essential for autonomous robot locomotion since diverse surfaces with varying friction abound in the real world, from wood to ceramic tiles, grass or ice, which may cause difficulties or huge energy costs for robot locomotion if not considered. We propose to estimate friction and its uncertainty from visual estimation of material classes using convolutional neural networks, together with probability distribution functions of friction associated with each material. We then robustly integrate the friction predictions into a hierarchical (footstep and full-body) planning method using chance constraints, and optimize the same trajectory costs at both levels of the planning method for consistency. Our solution achieves fully autonomous perception and locomotion on slippery terrain, which considers not only friction and its uncertainty, but also collision, stability and trajectory cost. We show promising friction prediction results in real pictures of outdoor scenarios, and planning experiments on a real robot facing surfaces with different friction.

Friction estimation from vision is an important problem for robot locomotion through contact. The problem is challenging due to its dependence on many factors such as material, surface conditions and contact area.
In this paper we 1) conduct an analysis of image features that correlate with humans' friction judgements; and 2) compare algorithmic to human performance at the task of predicting the coefficient of friction between different surfaces and a robot's foot. The analysis is based on two new datasets which we make publicly available. One is annotated with human judgements of friction, illumination, material and texture; the other is annotated with static coefficient of friction (COF) of a robot's foot and human judgements of friction. We propose and evaluate visual friction prediction methods based on image features, material class and text mining. And finally, we make conclusions regarding the robustness to COF uncertainty which is necessary by control and planning algorithms; the low performance of humans at the task when compared to simple predictors based on material label; and the promising use of text mining to estimate friction from vision.

Crawling motion by a robot is effective for reducing shock in the case of a fall. It thus decreases the possibility of a locomotion malfunction on uneven terrain. In this paper, the control of crawling motion on uneven terrain is described. Firstly, crawling motion and detailed motion are explained. Then, a method for controlling crawling motion is outlined for its realization. To verify the effectiveness of the proposed method for locomotion on uneven terrain, rough rubble ground was generated in a dynamics simulator and the crawling method was applied to our developed four-limbed robot. Additionally, a crawler robot was generated. A comparison was conducted to verify the difference in locomotion capabilities between the proposed method and other locomotion styles. The simulation results confirmed that the proposed method enabled successful locomotion of our four-limbed robot on uneven terrain.

In this paper, we describe an intraoral pressure control system for the humanoid saxophone-playing robot WAS-4. We studied the model for air flow control in a wind instrument, and via a series of assessment tests to analyze the robot performance, we discovered that the control of the intraoral pressure of the robot is critical for continuous sound production. We then developed a control system to maintain the intraoral pressure stable during note sustaining and changing, preserving reed vibration and sound production. We assessed the effectiveness of the system via a final evaluation experiment.

The demand for monitoring from high points is increasing to support remote control and accurate monitoring. Unmanned ground vehicles with long arms are used to achieve long-term and accurate monitoring. The use of convex steel tapes is effective for achieving both high strength and lightness of the arm, which prevents the robot from collapsing or the arm from falling off. However, the previously proposed methods could not be used under tough environmental conditions such as strong winds as well as when the posture of the robot is changed. The objective of the present study is to design a novel extendable arm structure using convex tapes for outdoor usage. We designed an arm with a novel combination of convex tapes that can endure outdoor interferences. We manufactured the arm using a new method such that there is no need to separate the convex tapes. Our results indicated that the robot could extend its arm up to 4 m at a wind speed of 10 m/s and its posture can be changed to 15 degrees in all directions without the use of additional supports such as an outrigger. This novel arm is useful for supporting remote-controlled aerial work platform outdoors such as in a disaster struck area where only tiny mobile robots can enter. This novel combination method is significant not only because it fills the gap in previous sutures but also because it does not require complex mechanisms such as the outrigger method.

Neurological examination takes an important role in the clinical examination, and requires both deep medical knowledge and high clinical skills. Until now, several education methods for neurological examination have been proposed, such as lectures using videos, and skill trainings with manikins or simulated patients (SPs). However, complex physical skills, such as examination of the upper limbs, are difficult to obtain for inexperienced physicians both in lectures and in skill trainings. In this paper, we propose an arm robot named WKE-3(Waseda Kyotokagaku Elbow Robot No.3) for skill trainings of neurological examination, as a part of the whole body patient robot named WKP (Waseda Kyotokagaku Patient). A novel mechanism, which can simulate both active and passive movement, is implemented in the elbow joint to simulate various symptoms.

Bipedal Walking Robot uses harmonic gears in its leg joints in order to provide high torque. However, those mechanisms increase the leg's weight that automatically increases the required energy. Replacing the drivable gear system with an adjustable stiffness mechanism might help to increase the energy efficiency. In this research we purpose a novel adjustable stiffness mechanism that can be attached to the ankle joint. The developed mechanism can provide passive and active controlled motion, which might help the robot to walk with less energy.

The running trajectory for bipedal robot is generated using numerically calculation method. Such method might limit the robot performance to accurately control its forward velocity. A new method is developed to determine the running trajectory based on linear equation that is developed based on walking trajectory and vertical hopping motion trajectory equations.

Current training for laparoscopy focuses only on the enhancement of manual skill and does not give advice on improving trainees' posture. However, a poor posture can result in increased static muscle loading, faster fatigue, and impaired psychomotor task performance. In this paper, the authors propose a method, named subliminal persuasion, which gives the trainee real-time advice for correcting the upper limb posture during laparoscopic training like the expert but leads to a lower increment in the workload.
A 9-axis inertial measurement unit was used to compute the upper limb posture, and a Detection Reaction Time device was developed and used to measure the workload. A monitor displayed not only images from laparoscope, but also a visual stimulus, a transparent red cross superimposed to the laparoscopic images, when the trainee had incorrect upper limb posture. One group was exposed, when their posture was not correct during training, to a short (about 33 ms) subliminal visual stimulus. The control group instead was exposed to longer (about 660 ms) supraliminal visual stimuli.
We found that subliminal visual stimulation is a valid method to improve trainees' upper limb posture during laparoscopic training. Moreover, the additional workload required for subconscious processing of subliminal visual stimuli is less than the one required for supraliminal visual stimuli, which is processed instead at the conscious level.
We propose subliminal persuasion as a method to give subconscious real-time stimuli to improve upper limb posture during laparoscopic training. Its effectiveness and efficiency were confirmed against supraliminal stimuli transmitted at the conscious level: Subliminal persuasion improved upper limb posture of trainees, with a smaller increase on the overall workload.

© 2015 IEEE. In the near future, robots are expected to perform assistive tasks and do different kind of jobs. In particular, humanoid robots are possible candidates for being used as helpers in activities of daily living. One possible employment is working as a receptionist, providing useful indications to visitors in a public office. The design of how robots could look like is a matter of growing importance, as it is important to create a look that poses no uncanny valley effects on the human user and that is appropriate to potentially serve in different job areas in human society. In this paper we want to describe the study on anthropomorphism of a receptionist robot. We invited Brazilian people with different education levels to interact with two variations of a receptionist robot, different in physical appearance as well as in the sound of the voice. In one case, the appearance was a conversational agent made with computer graphics, in the other, a real humanoid robot. Results gathered from surveys and comments of the participants provide useful directions to design a receptionist robot and insights on the effect of digital divide on anthropomorphism.

© 2015 IOP Publishing Ltd. In this paper, we study the behavioral response of rats to a robotic rat during multi-rat interaction. Experiments are conducted in an open-field where a robotic rat called WR-5 is put together with three laboratory rats. WR-5 is following one rat (target), while avoiding the other two rats (outside observers) during interaction. The behavioral characteristics of each target rat is evaluated by scoring its locomotor activity and frequencies of performing rearing, body grooming and mounting actions. Additionally, the frequency of being mounted by other rats is also measured. Experimental results show that the target becomes more active after interaction. The rat species, with more active behavioral characteristics, is more susceptible to being adjusted by the robot. The increased time spent by the outside observers in the vicinity of the robot indicates that a biomimetic robot has the promise for modulating rat behavior even without direct interaction. Thus, this study provide a novel approach to shaping the sociality of animals living in groups.

In this paper we use an extended footstep planning algorithm to plan optimal humanoid locomotion trajectories subject to constraints on the maximum predicted Zero Moment Point (ZMP) tracking error. The approach can guarantee walking stability bounds with little extra computational burden, thus increasing safety of robots walking in challenging environments. This is done by estimating energy and stability models in simulation through Bayesian optimization, and smartly integrating the models into search-based planning.

In recent years, demands for outdoor mobile robots, such as those for agriculture or environmental monitoring, are increasing. Power supply is one of the most important considerations for these robots, and autonomous battery charging system can be one solution. The objective of this study is to develop a prototype battery charging system for outdoor mobile robots, using wireless power transmission technology. We developed a battery charging station and a power receiver for a mobile robot. The receiver coil was implemented in WAMOT-2, which had been developed for the monitoring. Operation of the system was verified through an experiment.

Locomotive performance is one of the most important issues for land-based mobile robots, which is designed to be used in natural environment, such as grass fields or forests. We propose a novel method to change outer shape of the robot to increase locomotive performance in natural environment. The robots, which are designed using this method, does not require additional actuators, while conventional mobile robots obtain higher locomotive performance in natural environment using multiple actuators. The objective of this study is to propose a novel design method of outer shape of mobile robots, which is inspired from "icebreakers". Through experiments, we confirmed that locomotive performance is greatly affected by outer shape of mobile robots.

This paper explains a motion planning strategy that is not based on time but on "event", which can be explained as the path that the end-effector of robot tracks in our study. Arc-length parameterization is used in this paper to convert a time-based planning into an event-based planning. With our planning, it is possible to choose various time planning on the same given path so that tasks such as dynamic obstacle avoidance and performance test of motors become available. Simulation results about time planning implemented to a given path verifies the effectiveness of our event-based planning.

This paper describes the development of a four-limbed robot capable of climbing vertical ladders. We focused on vertical ladders which are often set in plant facilities. The design concepts and required specifications are explained. We conducted experiments of climbing vertical ladders and the robot succeeded in climbing vertical ladders in JIS.

Robots, especially humanoids, are expected to perform human-like actions and adapt to our ways of communication in order to facilitate their acceptance in human society. Among humans, rules of communication change depending on background culture: greetings are a part of communication in which cultural differences are strong. Robots should adapt to these specific differences in order to communicate effectively, being able to select the appropriate manner of greeting for different cultures depending on the social context. In this paper, we present the modelling of social factors that influence greeting choice, and the resulting novel culture-dependent greeting gesture and words selection system. An experiment with German participants was run using the humanoid robot ARMAR-IIIb. Thanks to this system, the robot, after interacting with Germans, can perform greeting gestures appropriate to German culture in addition to a repertoire of greetings appropriate to Japanese culture.

Drawbacks of conventional colonoscopy include the risk of accidental injury and a dependence on the operator's skill. This study presents a novel minimally invasive self-propelled colonoscope robot. We developed an active-bending module, made with pneumatic parallel links with three degrees of freedom, and assembled in a robot (WQE-5) propelled by a "party horn" mechanism with a thrust generator. We confirm the increase in the passing speed in the curved section of a colon model, achieved by the winding of WQE-5.

An online walking pattern generation is important for a biped humanoid robot to move in dynamic environments. This chapter describes a novel online walking pattern generation using Fast Fourier Transform (FFT). Most previous studies about online walking pattern generation use an inverted pendulum model, which requires other methods to compensate for errors between the model and a real robot. Because our method uses a multi-body robot model, a biped robot can dynamically change its motions online by utilizing only the proposed method. If a robot has external sensors such as a stereo vision system to recognize dynamic environments, the robot can follow a moving target. Verification of the proposed method is conducted through experiments with the human-sized humanoid robots WABIAN-2R and KOBIAN.

Laughter is a very interesting non-verbal human vocalization. It is classified as a semi voluntary behavior despite being a direct form of social interaction, and can be elicited by a variety of very different stimuli, both cognitive and physical. Automatic laughter detection, analysis and classification will boost progress in affective computing, leading to the development of more natural human-machine communication interfaces. Surface Electromyography (sEMG) on abdominal muscles or invasive EMG on the larynx show potential in this direction, but these kinds of EMG-based sensing systems cannot be used in ecological settings due to their size, lack of reusability and uncomfortable setup. For this reason, they cannot be easily used for natural detection and measurement of a volatile social behavior like laughter in a variety of different situations. We propose the use of miniaturized, wireless, dry-electrode sEMG sensors on the neck for the detection and analysis of laughter. Even if with this solution the activation of specific larynx muscles cannot be precisely measured, it is possible to detect different EMG patterns related to larynx function. In addition, integrating sEMG analysis on a multisensory compact system positioned on the neck would improve the overall robustness of the whole sensing system, enabling the synchronized measure of different characteristics of laughter, like vocal production, head movement or facial expression; being at the same time less intrusive, as the neck is normally more accessible than abdominal muscles. In this paper, we report laughter discrimination rate obtained with our system depending on different conditions.

Ankle rehabilitation training takes an important role in the hemiplegic rehabilitation training. Traditional training requires the physical therapist treating the patient as one to one. The training process is repeating and needs a long period. The performances of training rely heavily on the skill of therapists. The training effectiveness depends on the skills of the therapist. To improve the training effectiveness, there are many ankle rehabilitation robots are proposed. However all of them are only focusing on providing a passive training to the patient. In this paper, an ankle rehabilitation robot with three degrees is proposed. This robot can not only realizes the passive training but also has much more sensors to detect the movements of the ankle, especially realizes the patient active training. In this paper, the detail design of the mechanism is introduced. The mechanical structure includes pedal parts, thigh fixing parts, cross slider parts, driving unit and sensing unit. Comparing with current ankle rehabilitation researches, this robot uses linear motion in horizontal and vertical plane instead of rotary motion to realize dorsiflexion/plantar flexion and abduction/adduction. Finally, we present ankle motion space analysis and ankle robot workspace analysis of ankle robot to verify the feasibility of the robot.

Oral presentation is considered as one of the most sought after skills by companies and professional organizations and program accreditation agencies. However, both learning process and evaluation of this skill are time demanding and complex tasks that need dedication and experience. Furthermore, the role of the instructor is fundamental during the presentation assessment. The instructor needs to consider several verbal and nonverbal communications cues sent in parallel and this kind of evaluation is often subjective. Even if there are oral presentation rubrics that try to standardize the evaluation, they are not an optimal solution because they do not provide the presenter a real-time feedback. In this paper, we describe a system for behavioral monitoring during presentations. We propose an ecological measurement system based on Inertial Measurement Units to evaluate objectively the presenter's posture through objective parameters. The system can be used to provide a real-time feedback to the presenters unobtrusively.

Up to now, the number of hemiplegia rehabilitation devices is increasing quickly. But most of ankle rehabilitation training just limit to the training of patients' affected side. They ignore the importance of patients' subjective participation in the recovery of central nervous system. In our new research, we proposed a new method that making use of the movements of the sound side to realize the passive training of the affected side. Therefore, an ankle motion detecting mechanism is proposed to detect the ankle motion of patients' sound side. In this paper, we will introduce the detail design of the mechanism. It includes three detecting units for recording the rotations of ankle. Comparing with other Body-movement information detection method, such as optical measurement method and biological signals measuring method, it can gather the real-time information of three rotations of ankle with a simple structure. This ankle motion detecting mechanism can not only detects the ankle motion but also helps patients do affected ankle strength training. Finally, the workspace analysis of this detecting mechanism is carried out to verify the ability of the designed mechanism.

Robots are possible candidates for performing tasks as helpers in activities of daily living in the future: working as a receptionist is one possible employment. However, the way the receptionist robot should appear, sound and behave needs to be investigated carefully, in order to design a robot which is accepted and perceived in a positive way by common users. This paper describes a study on anthropomorphism of a receptionist robot made for Brazilian people depending on the appearance and on the voice of the receptionist. This experiment was preceded by a preliminary survey about expectation of people regarding receptionists. The main experiment consisted in having Brazilian people interacting with a conversational agent and with a humanoid robot through a video conference. The two receptionists are not only different in physical appearance, but in the sound of the voice, too, which can be either human-like or robotic sound. The two receptionists gave indications to the participants to reach rooms where they could evaluate the receptionists through questionnaires concerning anthropomorphism and uncanniness among other concepts. The results gathered from both experiments provide useful hints to design a receptionist robot.

Environment recognition is an effective way for a mobile robot to move across rough terrain. In particular, this makes it possible to prevent a tiny mobile robot from getting stuck or turning over. Several studies have been conducted on environment recognition using a laser range finder or camera. However, almost all of these studies focused on obstacle detection or shape recognition, which cannot be used to recognize the surface condition such as slipperiness. The purpose of this work is to design a model for estimating the surface condition using a tiny mobile robot. We set slipperiness as one of the parameters for recognizing the surface condition, which is already used by terramechanics, along with two additional parameters, the hardness and unevenness. We find that a robot can roughly estimate the ground hardness by measuring the current peak of a motor and the unevenness from measuring the robot posture. By recognizing the surface condition, the robot can change the parameters of the controlling motor based on the ground characteristics. This new method for recognizing the surface condition is significant, not only because it fills gaps in the previous research, but also because it does not require any special sensors such as a laser range finder and does not consume a large quantity of energy. Therefore, it achieves a core objective of our environmental monitoring system using multiple mobile robot.

The Uncanny valley hypothesis, which tells us that almost-human characteristics in a robot or a device could cause uneasiness in human observers, is an important research theme in the Human Robot Interaction (HRI) field. Yet, that phenomenon is still not well-understood. Many have investigated the external design of humanoid robot faces and bodies but only a few studies have focused on the influence of robot movements on our perception and feelings of the Uncanny valley. Moreover, no research has investigated the possible relation between our uneasiness feeling and whether or not we would accept robots having a job in an office, a hospital or elsewhere. To better understand the Uncanny valley, we explore several factors which might have an influence on our perception of robots, be it related to the subjects, such as culture or attitude toward robots, or related to the robot such as emotions and emotional intensity displayed in its motion. We asked 69 subjects (N = 69) to rate the motions of a humanoid robot (Perceived Humanity, Eeriness, and Attractiveness) and state where they would rather see the robot performing a task. Our results suggest that, among the factors we chose to test, the attitude toward robots is the main influence on the perception of the robot related to the Uncanny valley. Robot occupation acceptability was affected only by Attractiveness, mitigating any Uncanny valley effect. We discuss the implications of these findings for the Uncanny valley and the acceptability of a robotic worker in our society.

Waseda University has researched on biped robots since 1967. This paper describes our latest biped robots: (i) WABIAN-2, (ii) a biped running robot, and (iii) WL-16. WABIAN-2 is a biped humanoid robot and has realized a human-like walk with the knees stretched by utilizing a 2-DOF waist mimicking a human's pelvis motion. We are developing a new biped humanoid robot which can jump by utilizing a pelvic movement and leg elasticity. WL-16 is a human-carrying biped vehicle.

Energy consumption and stability are two important problems for humanoid robots deployed in remote outdoor locations. In this paper we propose an extended footstep planning method to optimize energy consumption while considering motion feasibility and ground friction constraints. To do this we estimate models of energy, feasibility and slippage in physics simulation, and integrate them into a hybrid A* search and optimization-based planner. The graph search is done in footstep position space, while timing (leg swing and double support times) and COM motion (parameterized height trajectory) are obtained by solving an optimization problem at each node. We conducted experiments to validate the obtained energy model on the real robot, as well as planning experiments showing 9 to 19% energy savings. In example scenarios, the robot can correctly plan to optimally traverse slippery patches or avoid them depending on their size and friction; and uses stairs with the most beneficial dimensions in terms of energy consumption.

Analysis of human running has revealed that the motion of the human leg can be modeled by a compression spring because the leg's joints behave like a torsion spring in the stance phase. Moreover, the knee bends rapidly to avoid contact of the foot with the ground in the swing phase. In this paper, we describe the development of a knee joint mechanism that mimics the elastic characteristics of the stance leg and rapid bending knee of the idling leg of a running human. The knee was equipped with a mechanism comprising two leaf springs and a worm gear for adjusting the joint stiffness and high-speed bending knee. Using this mechanism, we were able to achieve joint stiffness within the range of human knee joints that could be adjusted by varying the effective length of one of the leaf springs. In addition, the mechanism was able to bend rapidly by changing the angle between the two leaf springs. The equation proposed for calculating the joint stiffness considers the difference between the position of the fixed point of the leaf spring and the position of the rotational center of the joint. We evaluated the performance of the adjustable joint stiffness and the effectiveness of the proposed equation for joint stiffness and high-speed knee bending. We were able to make a bipedal robot hop using pelvic oscillation for storing energy produced by the resonance to leg elasticity and confirmed the mechanism could produce large torque 210 Nm.

Human running motion can be modeled using a spring-loaded inverted pendulum (SLIP), where the linear-spring-like motion of the standing leg is produced by the joint stiffness of the knee and ankle. To use running speed control in the SLIP model, we should only decide the landing placement of the leg. However, for using running speed control with a multi-joint leg, we should also decide the joint angle and joint stiffness of the standing leg because these affect the direction of the ground reaction force. In this study, we develop a running control method for a human-like multi-joint leg. To achieve a running motion, we developed a running control method including pelvis oscillation control for attaining jumping power with the joint stiffness of the leg and running speed control by changing the landing placement of the leg. For using running speed control, we estimated the ground reaction force using the equation of motion and detected the joint angles of the leg for directing the ground reaction force toward the center of mass. To evaluate the proposed control methods, we compared the estimated ground reaction force with the force measured by the real robot. Moreover, we performed a running experiment with the developed running robot. By using ground reaction force estimation, this robot could accomplish the running motion with pelvic oscillation for attaining jumping power and running speed control.

Facial expressions are important for conveying emotions and communication intentions among humans. For this reason, humanoid robots should be able to perform facial expressions which represent their inner state in a way that is easy to understand for humans. Several humanoid robots can already perform a certain set of expressions, but their capabilities are usually limited to only the most basic emotions. It is necessary to consider a wider range of expressions and take advantage of the use of asymmetry. This chapter describes these aspects as well as insights about artificial emotions models, the mapping of human face into robotic face and finally the generation of facial expressions.

We propose an object detection method based on a saliency map using a reference image containing complex background for service robots. In previous detection methods, images that the user prepares in advance contain mostly simple background. However, in order to make robots perform daily tasks, the robots should be able to detect an object using snapshots that contain a complex background. In order to decrease the effect of features in the background, our proposed method classifies local features based on saliency from images. This paper shows the efficacy of the proposed method
furthermore, we demonstrate that our service robot detects certain objects according to the proposed method.

(Early Access Articles)

We propose a new heel-contact toe-off walking model based on the Linear Inverted Pendulum (LIP) model, which due to the linearity and the ease of manipulation of the equations, could be considered to be advantageous for a future online implementation for the generation of walking patterns. This new model is based on the so called functional rockers of the foot (heel, ankle and forefoot rockers), each of which are modeled as an inverted pendulum, changing the ground contact point position of the inverted pendulums for each rocker. We focus on the motion of the Center of Mass (CoM) in the sagittal plane, as it is the plane on which the rockers take place, but also generate the motions on the frontal plane. The model proved to work for constant velocity, accelerating and decelerating gaits, and the effects of the change of pivot point during heel-contact toe-off could be corroborated in the Zero Moment Point (ZMP) graphs. The implementation of this model could improve the human likeness of the motions, as well as the stability of the locomotion.

This study aims to develop a state transition model and speech recognition module for application to a whole-body patient simulator for scenario based training (SBT) of neurological examination procedures. These procedures are very important for the early identification of neurological system disorders. In neurological examinations, the doctor selects procedures by situation of patients, interacts with the patient and performs a series of medical procedures to judge the site of nerve disorders and lesions. SBT is one type of training that doctor performs to be based on scenario. Scenario is patient situation and examination procedure. SBT is used for the training of such examinations. SBT is often performed using simulated patients (SPs); however, the number of SPs is not sufficient and SPs cannot adequately reproduce diseases. Therefore, we integrated a state transition model with a commercial speech recognition software and developed a dialogue system for SBT. First, we customized the grammatical rules and the different words that the software can recognize. By doing so, the recognition rate improved to about 90%. Second, we developed a probability model for the state transition model. In neurological examinations, patient pause is limited and an order of procedures is generally decided. We developed a state transition model including probability model with the customized speech recognition module.

Neurologic examination takes an important role in the physical examination. By now, several methods have been carried out for medical training which bring the benefits for trainee to master the skills and accumulate experiences. However, because of the limits of these methods, the training effectiveness is limited. With the developments of technology, more and more simulators have been launched to improve medical training effectiveness. However, most of these simulators only focus on mimicking the symptoms, not simulating the pathology of diseases. In this paper, we propose an improved motor nerve model which is used in the elbow robot named WKE-2(Waseda Kyotokagaku Elbow Robot No.2). This robot is designed to simulate the disorders of motor nerves to give the trainee a full training on the elbow examination. The motor nerve model mimics the real motor nerve structure. And the functions of each part are designed from analysis of the real functions of each organ. In this robot, the effects of motor nerve system, and various symptoms related to the examination of elbow force, biceps tendon reflex, involuntary action are simulated. Making use of this robot, a systematic training on the skills as well as the understanding of knowledge is provided. Finally, several experiments are performed to verify our proposed system. The experimental results lead to the consideration that the approach is worth following in further research.

Decreasing balance ability in older adults increases the risk of falls. According to the literature, two balance strategies are revealed, ankle strategy and hip strategy. The aim of this paper is to study the postural stability of the one leg stance on the frontal plane and verify the strategy used in older adults. A hypothesis about two different patterns in hip strategy is made and experiments were conducted with 80 healthy elderly subjects. The posture is captured by Waseda Bioinstrumentation -4 Rev Inertial Measurement Unit (WB-4R IMU). The preliminary analysis shows the dominant pattern is moving the upper body in a lateral direction when losing balance on frontal plane.

In human-robot interaction, it is important for the robots to adapt to our ways of communication. As humans, rules of non-verbal communication, including greetings, change depending on our culture. Social robots should adapt to these specific differences in order to communicate effectively, as a correct way of approaching often results into better acceptance of the robot. In this study, a novel greeting gesture selection system is presented and an experiment is run using the robot ARMAR-IIIb. The robot performs greeting gestures appropriate to Japanese culture; after interacting with German participants, the selection should become appropriate to German culture. Results show that the mapping of gesture selection evolves successfully.

This paper describes a robotic hand that attaches to the wrist of a biped humanoid robot capable of mimicking a human motion. The robotic hand has five tendon-driven fingers that consist of a thumb, and an index, a middle, a ring, and a little finger. The fingers are composed of a V-grooved pulley, an E-type retaining ring, a hinge pin, and a torsional spring. The thumb has two motors for rolling and yawing motions and the other fingers have one motor for rolling motions. The effectiveness of the robot hands is confirmed through many grasping experiments.

Cranial nerve examination takes an important role in the physical examination. All the medical staffs need to be trained to master the skills for examination. By now, several training methods have been carried out for medical training including training with the simulated patient (SP). However, considering the characters of eyeball, the involuntary actions cannot be simulated by Sp. With the developments of technology, more and more robot heads have been launched. However, these simulators only focus on mimicking the healthy human abilities, not simulating disorders for medical training. In this paper, we propose a novel eyeball motion nerve model which is used in the head robot named WKH-2(Waseda Kyotokagaku Head Robot No. 2). This robot is designed to simulate the disorders of eyeball movements to give the trainee a full training on cranial examination. The motor nerve model is carried out from mimicking the real eyeball nerve structure. And the functions of each part are designed from analysis of the real functions of each organ. In this robot, the effects of eyeball motion nerve system, and various symptoms are simulated. Making use of this robot, a systematic training on the skills as well as the understanding of medical knowledge is provided. Finally, several experiments are carried out to verify our proposed system. The experimental results show that the approach is worth following in further research.

The falling of a biped humanoid robot is treated as an extremely unstable state. When an unexpected fall happens, it may cause serious damage to both the robot itself. This study focuses on the falling issue and investigates the effect of the "torso protective strategy" for safe landing of a biped humanoid robot. First, the effectiveness of the torso strategies to the safe landing is analyzed from an energy variation perspective of the robot system. The torso strategies are used to do negative work that reduced the energy of the robot system, thereby reducing the impact velocity of the robot. Then, a comparative simulation is made on a model of humanoid robot to validate the influence of the torso strategies on safe landing.

We propose a new heel-contact toe-off walking model based on the Linear Inverted Pendulum (LIP) model, which due to the linearity and the ease of manipulation of the equations, could be considered to be advantageous for a future online implementation for the generation of walking patterns. This new model is based on the so called functional rockers of the foot (heel, ankle and forefoot rockers), each of which are modeled as an inverted pendulum, changing the ground contact point position of the inverted pendulums for each rocker. We focus on the motion of the Center of Mass (CoM) in the sagittal plane, as it is the plane on which the rockers take place, but also generate the motions on the frontal plane. The model proved to work for constant velocity, accelerating and decelerating gaits, and the effects of the change of pivot point during heel-contact toe-off could be corroborated in the Zero Moment Point (ZMP) graphs. The implementation of this model could improve the human likeness of the motions, as well as the stability of the locomotion.

While robots are often used in autism therapy, the Uncanny valley effect was never studied in subjects with Autistic Spectrum Disorder (ASD). Since persons with ASD have trouble understanding body language, they react differently to the Uncanny valley. In this paper, we propose to investigate the possible difference in the Uncanny valley's perception of an emotional humanoid robot in subjects with ASD and subjects without ASD. Thirty four adult participants (N = 34, control: 19, ASD: 15; age: 28.5) were asked to watch videos of an emotional humanoid robot and rate its emotions and its gait (Perceived Humanness, Eeriness and Attractiveness). We have found differences between the two groups in their perception of the robot's Perceived Humanness (p &lt; .05). Also, while the ASD group performed as well as the control group for emotion recognition task, we found that the ASD group is more sensible to the Uncanny valley effects than the control group. Finally we conclude on what our findings bring to the Human Robot Interaction field.

This paper describes a walking stabilization control for a biped humanoid robot with narrow feet. Most humanoid robots have larger feet than human beings to maintain their stability during walking. If robot's feet are as narrow as humans, it is difficult to realize a stable walk by using conventional stabilization controls. The proposed control modifies a foot placement according to the robot's attitude angle. If a robot tends to fall down, a foot angle is modified about the roll axis so that a swing foot contacts the ground horizontally. And a foot-landing point is also changed laterally to inhibit the robot from falling to the outside. To reduce a foot-landing impact, a virtual compliance control is applied to the vertical axis and the roll and pitch axes of the foot. Verification of the proposed method is conducted through experiments with a biped humanoid robot WABIAN-2R. WABIAN-2R realized a knee-bended walking with 30 mm breadth feet. Moreover, WABIAN-2R mounted on a human-like foot mechanism mimicking a human's foot arch structure realized a stable walking with the knee-stretched, heel-contact, and toe-off motion.

This paper describes the bipedal humanoid robot that makes human laugh with its whole body expression and affect human's psychological state. In order to realize "Social interaction" between human and robot, the robot has to affect human's psychological state actively. We focused on "laugh" because it can be thought as a typical example for researching "Social interaction". Looking through a Japanese comedy style called "manzai" or the art of conversation, we picked out several methods for making human laugh. Then we made several skits with the advice of comedians, and made the whole body humanoid robot perform them. Results of experimental evaluation with these skits shows that the robot's behavior made subjects laugh and change their psychological state seen as a decrease of "Depression" and "Anger".

The design of what a robot could look like is a matter of growing importance. Variations of style, size, shape and colour open endless design possibilities. It is important to create a look that poses no visual uncanny valley effects on the human user and that is appropriate to potentially serve in different job areas in human society. In this paper we want to share the methods applied in the design of a new head for the humanoid robot KOBIAN-R. Our creation process is similar to that of the product design process taking into account the psychology of shape, colour and functionality to name a few. Following the creative process we conducted some surveys to assess our new design. Feedback data from participants from a diverse age range and cultural backgrounds are a precious input towards the future development of this robotic head.

Human running motion can be modeled by a spring loaded inverted pendulum (SLIP). However, this model, despite being widely used in robotics, does not include human-like pelvic motion. In this study, we show that the pelvis actually contributes to the increase in jumping force and absorption of landing impact, both of which findings can be used to improve running robots. On the basis of the analysis of human running motion, we propose a new model named SLIP 2 (spring loaded inverted pendulum using pelvis). This model is composed of a body mass, a pelvis, and leg springs; the model can control its springs during running by use of pelvic movement in the frontal plane. To achieve hopping and running motions, we developed pelvis oscillation control, running velocity control, and stabilization control using an upper body, as control methods. We also developed a new hopping robot using the SLIP 2 model. To evaluate the proposed model and control methods, we performed hopping and running simulations. The simulation results showed that the SLIP 2 model successfully achieves hopping and running motions. The hopping robot was also able to accomplish hopping motion. The simulation results also showed that the difference between the pelvic rotational phase and the phase of oscillation of the mass vertical displacement affects the jumping force. In particular, the results revealed that the human-like pelvic rotation contributes to the absorption of landing impact and to the increase in takeoff forces, which validates our observations in human motion analysis.

In this study we describe a terrain-adaptive biped walking control using a new biped foot mechanism with the capability of detecting ground surface. The foot system consists of three spikes each of which has an optical sensor to detect ground height. A robot modifies a foot-landing motion along the vertical axis and about pitch and roll axes according to sensor values, and this enables the robot to walk on unknown uneven terrain. Verification of the proposed control was conducted through experiments with a human-sized humanoid robot WABIAN-2R.

This paper proposes a stiffness analysis of biped walking vehicle that is based on a parallel kinematics architecture. Namely, WL-16RV (Waseda Leg No.16 Refined V) is a biped walking vehicle that can carry on board a human while overcoming typical human environment barriers. Experimental tests have been carried out on a built prototype of WL-16RV by using a specific set up for validation purposes.

Nowadays, the technologies for detecting, processing and interpreting bioelectrical signals have improved tremendously. In particular, surface electromyography (sEMG) has gained momentum in a wide range of applications in various fields. However, sEMG sensing has several shortcomings, the most important being: measurements are heavily sensible to individual differences, sensors are difficult to position and very expensive. In this paper, the authors will present an innovative muscle contraction sensing device (MC sensor), aiming to replace sEMG sensing in the field of muscle movement analysis. Compared with sEMG, this sensor is easier to position, setup and use, less dependent from individual differences, and less expensive. Preliminary experiments, described in this paper, confirm that MC sensing is suitable for muscle contraction analysis, and compare the results of sEMG and MC sensor for the measurement of forearm muscle contraction.

Different types of sensors are being used to study deglutition and mastication. These often suffer from problems related to portability, cost, reliability, comfort etc. that make it difficult to use for long term studies. An inertial measurement based sensor seems a good fit in this application; however its use has not been explored much for the specific application of deglutition research. In this paper, we present a system comprised of an IMU and EMG sensor that are integrated together as a single system. With a preliminary experiment, we determine that the system can be used for measuring the head-neck posture during swallowing in addition to other parameters during the swallowing phase. The EMG sensor may not always be a reliable source of physiological data especially for small clustered muscles like the ones responsible for swallowing. In this case, we explore the possibility of using gyroscopic data for the recognition of deglutition events.

In the past we achieved to use a rat-like robot and a single rat to develop Animal Models of Mental Disorder (AMMDs) through stress exposure. However, to simulate the real social environment, we use a rat-like robot composed of multiple links to chase a specific rat (target) in a group of rats (outside observers). In this paper, we aim to develop a real-time control system for a multi-link robot surrounded by multiple rats. A virtual impedance model was adopted to generate posture and trajectory for a multi-link robot named WR-5. With the analysis of virtual forces/moments acting on WR-5 based on the model, corresponding dynamic equations can be obtained to control the motion of WR-5. Simulation results show that the head of WR-5 can accurately direct a target object in the following test. After conducting experiments with three rat subjects (a target rat, two outside observers), the output results suggest that the head and body gesture of WR-5 achieves to follow the target in real-time. Meanwhile, the control system allows real-time avoidance of the moving outside observers during interaction.

Humanoid robots have this formidable advantage to possess a body quite similar in shape to humans. This body grants them, obviously, locomotion but also a medium to express emotions without even needing a face. In this paper we propose to study the effects of emotional gaits from our biped humanoid robot on the subjects' perception of the robot (recognition rate of the emotions, reaction time, anthropomorphism, safety, likeness, etc.). We made the robot walk towards the subjects with different emotional gait patterns. We assessed positive (Happy) and negative (Sad) emotional gait patterns on 26 subjects divided in two groups (whether they were familiar with robots or not). We found that even though the recognition of the different types of patterns does not differ between groups, the reaction time does. We found that emotional gait patterns affect the perception of the robot. The implications of the current results for Human Robot Interaction (HRI) are discussed.

We present a grid-based 3D reconstruction method which integrates all costs given by stereo vision into what we call a Cost-Curve Occupancy Grid (CCOG). Occupancy probabilities of grid cells are estimated in a Bayesian formulation, from the likelihood of stereo cost measurements taken at all distance hypotheses. This is accomplished with only a small set of probabilistic assumptions which we discuss in the paper. We quantitatively characterize the method's performance under different conditions of both image noise and number of used stereo pairs, compared also to traditional algorithms. We complement the study by giving insights on design choices of CCOGs such as likelihood model, window size of the cost function and use of a hole filling method. Experiments were made on a real-world outdoors dataset with ground-truth data.

This paper describes the development of a robotic head that has cartoon facial expression ability with comic marks. For communicating with humans, robots should have expressive facial expression ability for indicating their inner state. Our previous research suggests that robots can express its emotion clearly if it performs facial expressions that are adapted to the cultural background of the communication partner. As a first step, we focus on making expressions for Japanese people. Comic mark is a unique and famous way of emotion expression in Japanese culture. First, we defined facial expressions by combining cartoon-like shape of the facial parts with high emotion recognition rates. Then we asked cartoonists to draw comic marks which they think are effective for emotion expression and find the effective comic marks as "Cross popping veins" for "Anger", "Tear mark" for "Sadness" and "Vertical lines" for "Fear". Finally we obtained a model expression which has sufficiently high emotion recognition rate from the combination of the facial expression and the comic marks. In order to achieve these expressions, we developed flexible full color LED display matrix module and mechanism that push and pull the sheet for expressing black lines. Results of experimental evaluation shows that the new robotic head has over 90% average emotion recognition rates for each of the six basic emotions. The results with non-Japanese subjects suggests that impression of emotion expression on robotic head changes depending on the cultural background. These findings encourage us in pursuing this concept of designing robots that display emotions that are adapted to cultural background of communication partner.

This paper present a method for measuring the posture of a human body during different phases of sit to stand motion using inertial sensors. The proposed method fuses data from inertial sensors placed in trunk and thigh using Adaptive Neuro-Fuzzy Inference System (ANFIS) followed by a Kalman Filter (KF). The ANFIS attempts to estimate the position of shoulder of the human, at each sampling instant when measurement update step is carried out. The Kalman filter supervises the performance of the ANFIS with the aim of reducing the mismatch between the estimated and actual. The performance of the method is verified by measurements from VICON (motion analysis system). The obtained results show the effectiveness of the proposed algorithm in prediction the human shoulder position with root mean square error 0.018 m and 0.016 m in the x and y direction, respectively.

We propose a new biped locomotion planning method that optimizes locomotion speed subject to friction constraints. For this purpose we use approximate models of required coefficient of friction (RCOF) as a function of gait. The methodology is inspired by findings in human gait analysis, where subjects have been shown to adapt spatial and temporal variables of gait in order to reduce RCOF in slippery environments. Here we solve the friction problem similarly, by planning on gait parameter space: namely foot step placement, step swing time, double support time and height of the center of mass (COM). We first used simulations of a 48 degrees-of-freedom robot to estimate a model of how RCOF varies with these gait parameters. Then we developed a locomotion planning algorithm that minimizes the time the robot takes to reach a goal while keeping acceptable RCOF levels.
Our physics simulation results show that RCOF-aware planning can drastically reduce slippage amount while still maximizing efficiency in terms of locomotion speed. Also, according to our experiments human-like stretched-knees walking can reduce slippage amount more than bent-knees (i.e. crouch) walking for the same speed.

In this paper, we describe the development of a leg with a rotational joint that mimics the elastic characteristics of the leg of a running human. The purpose of this development was to realize the dynamics of human running, the analysis of which has revealed that the motion of the leg can be modeled by a compression spring and that of the leg joint by a torsion spring. We, therefore, assumed that these elastic characteristics could be used to develop robots capable of human-like running, which requires higher output power than that of existing humanoid robots. Hence, we developed a model of a leg with a rotational joint and fabricated the leg by incorporating a mechanism comprising of two leaf springs for adjusting the joint stiffness. By this means, we were able to achieve human-like joint stiffness, which could be adjusted by varying the effective length of one of the leaf springs. We evaluated the performance of the adjustable stiffness of the joints, and were also able to achieve hopping by resonance of the rotational leg joint.

Although consistent stability is desirable, a biped humanoid robot encounters a high risk of falling. Such falls may cause serious damage to both the robot and the environment. This study focuses on this issue and investigates four strategies based on human protective falling motion. These strategies are: "knee flexion", "torso flexion forward", "torso translation backward" and "knee stretched". First, the effectiveness of the strategies for the safe landing is analyzed from an energy variation perspective of the robot system. The four strategies are used to do negative work that reduced the energy of the robot system, thereby reducing the impact velocity of the robot. Then, a simulation study on a human-sized humanoid robot is conducted to assess the influence of the strategies on safe landing. Finally, based on the simulation results for each strategy, a safe falling motion control method is proposed and validated through simulation.

Human running motion can be modeled by a spring loaded inverted pendulum (SLIP). However, this model, despite being widely used in robotics, does not include human-like pelvic motion. In this study, we show that the pelvis actually contributes to the increase in jumping force and absorption of landing impact, both of which findings can be used to improve running robots. On the basis of the analysis of human running motion, we propose a new model named SLIP 2 (spring loaded inverted pendulum using pelvis). This model is composed of a body mass, a pelvis, and leg springs; the model can control its springs during running by use of pelvic movement in the frontal plane. To achieve hopping and running motions, we developed pelvis oscillation control, running velocity control, and stabilization control using an upper body, as control methods. We also developed a new hopping robot using the SLIP 2 model. To evaluate the proposed model and control methods, we performed hopping and running simulations. The simulation results showed that the SLIP 2 model successfully achieves hopping and running motions. The hopping robot was also able to accomplish hopping motion. The simulation results also showed that the difference between the pelvic rotational phase and the phase of oscillation of the mass vertical displacement affects the jumping force. In particular, the results revealed that the human-like pelvic rotation contributes to the absorption of landing impact and to the increase in takeoff forces, which validates our observations in human motion analysis.

We develsoped a novel small rat-like robot called Waseda Rat No. 4 (WR-4) to interact with real rats. WR-4 can perform both rearing (rising up on its hind limbs) and rotating (body bending during movement) actions faster than live mature rats. After robot-rat interaction involving rearing and body grooming (body cuddling and head curling) actions of WR-4, real rats showed more activity and greater interest in the robot. Similar results evident from rat-rat interaction suggest that a rat-like robot is able to interact with rats in the same way as real rats. Furthermore, lower variances between the rat subjects in robot-rat interaction reveals that a rat-like robot can more effectively impact rat's behavior in a controllable, predictable way. Copyright © Cambridge University Press 2013.

Emotion display through facial expressions is an important channel of communication. However, between humans there are differences in the way a meaning to facial cues is assigned, depending on the background culture. This leads to a gap in recognition rates of expressions: this problem is present when displaying a robotic face too, as a robot's facial expression recognition is often hampered by a cultural divide, and poor scores of recognition rate may lead to poor acceptance and interaction. It would be desirable if robots could switch their output facial configuration flexibly, adapting to different cultural backgrounds. To achieve this, we made a generation system that produces facial expressions and applied it to the 24 degrees of freedom head of the humanoid social robot KOBIAN-R, and thanks to the work of illustrators and cartoonists, the system can generate two versions of the same expression, in order to be easily recognisable by both Japanese and Western subjects. As a tool for making recognition easier, the display of Japanese comic symbols on the robotic face has also been introduced and evaluated. In this work, we conducted a cross-cultural study aimed at assessing this gap in recognition and finding solutions for it. The investigation was extended to Egyptian subjects too, as a sample of another different culture. Results confirmed the differences in recognition rates, the effectiveness of customising expressions, and the usefulness of symbols display, thereby suggesting that this approach might be valuable for robots that in the future will interact in a multi-cultural environment. © 2013 Springer Science+Business Media Dordrecht.

The purpose of this study was to determine safe techniques of performing blood collection using an evacuated tube system, particularly with regard to manipulation of the equipment and at the puncture site. Careful observation of the procedure was used to collect data for evaluating the various venepuncture techniques. Nurses were digitally videotaped performing simulated venepuncture. A self-administered questionnaire and unstructured observation of a videotaped recording were evaluated, and valid responses were analyzed from participants who performed venepuncture using various techniques. The participants who changed hands during the procedure were older than those who did not change hands. Needle movements during puncture and insertion, including rotation and insertion in a wave-like trajectory, were observed. Appropriate training, including recommendations for maintaining the stability of the needle tip, is important to ensure safety when performing venepuncture. Movement of the needle should not place too much pressure on the puncture site. © 2013 Wiley Publishing Asia Pty Ltd.

This study describes a biped walking stabilization based on gait analysis for a humanoid robot. So far, we have developed a humanoid robot as a human motion simulator which can quantitatively evaluate welfare and rehabilitation instruments instead of human subjects. However, the walking motion of the robot looked like humans in our past researches, but a walking stabilization control was not based on gait analysis. To use a humanoid robot as a human motion simulator, not only mechanisms but also a stabilizer should be designed based on human beings. Of course, there are many studies on gait analysis in the field of neuroscience, but most of them are not modeled enough to be implemented on humanoid robots. Therefore, first, we conducted gait analysis in this study, and we obtained following two findings: (i) a foot-landing point exists on the line joining the stance leg and the projected point of center of mass on the ground, and (ii) the distance between steps is modified to keep mechanical energy at the landing within a certain value. A walking stabilization control is designed based on the gait analysis. Verification of the proposed control is conducted through experiments with a human-sized humanoid robot WABIAN-2R. © 2013 Taylor &amp
Francis and The Robotics Society of Japan.

Communication between humans and robots is a very important aspect in the field of Humanoid Robotics. For a natural interaction, robots capable of nonverbal communication must be developed. However, despite the most recent efforts, robots still can show only limited expression capabilities. The purpose of this work is to create a facial expression generator that can be applied to the 24 DoF head of the humanoid robot KOBIAN-R. In this manuscript, we present a system that based on relevant studies of human communication and facial anatomy can produce thousands of combinations of facial and neck movements. The wide range of expressions covers not only primary emotions, but also complex or blended ones, as well as communication acts that are not strictly categorized as emotions. Results showed that the recognition rate of expressions produced by this system is comparable to the rate of recognition of the most common facial expressions. Context-based recognition, which is especially important in case of more complex communication acts, was also evaluated. Results proved that produced robotic expressions can alter the meaning of a sentence in the same way as human expressions do. We conclude that our system can successfully improve the communication abilities of KOBIAN-R, making it capable of complex interaction in the future. © 2013 World Scientific Publishing Company.

Walking is one of the most common activities that we perform every day. If the main goal of walking is to go from a point A to a point B, walking can also convey emotional clues in social context. Those clues can be used to improve interactions or any messages we want to express. We observed a professional actress perform emotive walking and analyzed the recorded data. For each emotion, we found characteristic features which can be used to model gait patterns for humanoid robots. The findings were assessed by subjects who were asked to recognize the emotions displayed in the acts of walking. © 2013 IEEE.

The research on the development of the anthropomorphic flutist robot at Waseda University has been focused in emulating the anatomy and physiology of the organs involved during the flute playing from an engineering point of view, facilitating the symbiosis between the human and the robot (i.e. active interaction between musician and musical robot) and proposing novel applications for humanoid robots (i.e. music education). As a result of this research, the Waseda Flutist Robot No. 4 Refined IV has been developed and a musical-based interaction system implemented so the robot is capable of interacting with musicians by processing both aural and visual cues. However; there is a trade-off relationship between the duration of the flute sound produced by the robot and the sound pressure (volume). In fact, the robot is only capable of playing sounds low-pitched sounds for long periods. In addition, a husky sound is detected while playing high-pitch sounds. From our discussions with professional players, this effect is caused due to the inner shape of the oral cavity. From this, the conversion efficiency ratio between from the exhaled air from the artificial lungs to the produced sound is too low. For this purpose, we have obtained MR images of the head from professional players in order to re-design the oral cavity of the flutist robot. A total of 5 prototypes were tested and the best one has been selected and integrated into the Waseda Flutist Robot No. 4 Refined VI (WF-4RVI). A set of experiments were proposed in order to verify the improvements of the conversion efficiency ratio as well as the sound evaluation function score. From the experimental results, we could verify the improvements compared with the previous version of the flutist robot.

Physicians use ultrasound scans to obtain real-time images of internal organs, because such scans are safe and inexpensive. However, people in remote areas face difficulties to be scanned due to aging society and physician's shortage. Hence, it is important to develop an autonomous robotic system to perform remote ultrasound scans. Previously, we developed a robotic system for automatic ultrasound scan focusing on human's liver. In order to make it a completely autonomous system, we present in this paper a way to autonomously localize the epigastric region as the starting position for the automatic ultrasound scan. An image processing algorithm marks the umbilicus and mammary papillae on a digital photograph of the patient's abdomen. Then, we made estimation for the location of the epigastric region using the distances between these landmarks. A supporting algorithm distinguishes rib position from epigastrium using the relationship between force and displacement. We implemented these algorithms with the automatic scanning system into an apparatus: a Mitsubishi Electric's MELFA RV-1 six axis manipulator. Tests on 14 healthy male subjects showed the apparatus located the epigastric region with a success rate of 94%. The results suggest that image recognition was effective in localizing a human body part.

In this paper a novel approach to kinematics learning and task space control, under switching contexts, is presented. Such non-stationary contexts may appear in many robotic tasks: in particular, the changing of the context due to the use of tools with different lengths and shapes is herein studied. We model the robot forward kinematics as a multi-valued function, in which different outputs for the same input query are related to actual different hidden contexts. To do that, we employ IMLE, a recent online learning algorithm that fits an infinite mixture of linear experts to the online stream of training data. This algorithm can directly provide multi-valued regression in a online fashion, while having, for classic single-valued regression, a performance comparable to state-of-the-art online learning algorithms. The context varying forward kinematics is learned online through exploration, not relying on any kind of prior knowledge. Using the proposed approach, the robot can dynamically learn how to use different tools, without forgetting the kinematic mappings concerning previously manipulated tools. No information is given about such tool changes to the learning algorithm, nor any assumption is made about the tool kinematics. To our knowledge this is the most general and efficient approach to learning and control under discrete varying contexts. Some experimental results obtained on a high-dimensional simulated humanoid robot provide a strong support to our approach.

This paper describes the mechanism and vertical jumping pattern of a one-legged jumping robot that can mimic the muscular and skeletal system of a human leg. The jumping robot has a waist, a thigh, a shin, a foot, and a toe. Its weight is 12.34 kg, and its height is 1010 mm. It has a total of 13 actuators: 10 mono-articular types and 3 bi-articular types. Two kinds of pneumatic artificial muscles such as mono-articular and bi-articular muscles are installed in the rear and the front of the thigh and shin to antagonize each other. For a vertical jump, a joint angle pattern is developed based on the linear and angular momentum. The effectiveness of the mechanism and the jumping pattern of the robot are verified through simulations and experiments.

Walking is one of the most common activities that we perform every day. If the main goal of walking is to go from a point A to a point B, walking can also convey emotional clues in social context. Those clues can be used to improve interactions or any messages we want to express. We observed a professional actress perform emotive walking and analyzed the recorded data. For each emotion, we found characteristic features which can be used to model gait patterns for humanoid robots. The findings were assessed by subjects who were asked to recognize the emotions displayed in the acts of walking.

Neurologic examination procedures require not only abundant knowledge but also prominent skills. During medical education and training, several methods will be put to use such as watching video, reading books, making use of the simulated patient (SP), and so on. These can help medical staffs, especially novices, to master the skills and accumulate experiences. To make up for the drawbacks of the above methods, such as lack of active interactions, limitation of multi-symptom reproductions, etc, the medical training simulators have been developed to improve training effectiveness. However, most of these simulators only mimic the symptoms. They have no the abilities to show the pathology of diseases. This limits the training effectiveness. In this paper, we propose an elbow robot named WKE-1(Waseda Kyotokagaku Elbow Robot No. 1) for neurologic examination training as one part of the whole body patient robot named WKP (Waseda Kyotokagaku Patient). In this robot, we simulate various symptoms occurring during the examination of elbow force, biceps tendon reflex, involuntary action, and also make a physiological neurological model to simulate the pathology of the nervous system. Taking advantage of this robot, the trainee can get a systematic training on both the skills and knowledge. Finally, we take a set of experiments to verify our proposed mechanism and system. The experimental results lead to the consideration that the approach is worth following in further research.

The authors propose a comparison between two force-position controllers with gravity compensation simulated on the DEXTER bioinspired robotic arm. The two controllers are both constituted by an internal proportional-derivative (PD) closed-loop for the position control. The force control of the two systems is composed of an external proportional (P) closed-loop for one system (P system) and an external proportional-integrative (PI) closed-loop for the other system (PI system). The simulation tests performed with the two systems on a planar representation of the DEXTER, an eight-DOF bioinspired arm, showed that by varying the stiffness of the environment, with a correct setting of parameters, both systems ensure the achievement of the desired force regime and with great precision the desired position. The two controllers do not have large differences in performance when interacting with a lower stiffness environment. In case of an environment with greater rigidity, the PI system is more stable. The subsequent implementation of these control systems on the DEXTER robotic bioinspired arm gives guidance on the design and control optimisation of the arms of the humanoid robot named SABIAN. © 2013 Giovanni Gerardo Muscolo et al.

EMG sensors for biomechanics research and portable applications need to be small, wireless and power efficient. This imposes several constraints on the design methodology of such sensors. There are many commercially available devices which are expensive and have proprietary communication protocols. It is difficult to synchronize them with other devices. Furthermore, using gel-based electrodes for signal acquisition increases setup time and running costs.
Hence we present the design of a miniaturized, wireless, low-cost and non-invasive dry-electrode EMG sensor that was prototyped in our lab and dubbed the 'WB-EMG' Sensor. We demonstrate its working being fitted with a gold plated copper core electrode. By mounting the sensor on the extensor carpi ulnaris and recording data during some simple exercises, we were able to show that its envelope in the frequency domain was similar to the expected EMG Pattern.

Physical therapy helps patients to restore the use of the musculoskeletal and the nervous systems through the use of specifics techniques and exercises. The introduction of measurement systems for patient assessment may allow detection of initial stage of diseases, an objective severity assessment, and efficient delivery of drugs and therapies. In rehabilitation centers, sometimes there are specific devices and methodologies available for the locomotion assessment. However, the measurements are usually carried out in a short time slot and this could lead to an overestimation of the walking abilities. © 2013 IEEE.

The increasing age of the world population is posing new challenges to our society, such as how to keep this aging population healthy and active despite of the age. In recent years, there has been a lot of interest for gait analysis for rehabilitation purposes as well as for performance assessment of this aging population. While current systems work well, they still have several limitations. Cost, need for specialized personnel, need to be used in a research center, and sporadic measurement prevent these systems from being widely used.
The authors propose the use of extremely miniaturized, portable measurement systems, which can be worn by the users during their everyday life, and can monitor their gait over a long timespan. This paper presents the preliminary experiments with such a system.

Endotracheal Intubation (ETI) is a common airway procedure used to connect the larynx and the lungs through a windpipe in patients under emergency situations. The process is carried out by a laryngoscope inserted into the mouth, used to help doctors in visualizing the glottis and inserting the tube. Currently, very few studies on objective evaluation of the biomechanics of the doctors during the procedure have been done. Additionally, these studies have been concentrated only on the overall performance analysis, without any segmentation, with a consequent loss of important information. In this paper, the authors present a preliminary study on a methodology to objectively evaluate and segment the biomechanical performance of doctors during the ETI, using surface electromyography and inertial measurement units. In particular, the validation has been performed by comparing three kinds of laryngoscopes involving an expert doctor. Finally, results are presented and commented.

Performing laparoscopic surgery requires several skills, which have never been required for conventional open surgery. Surgeons experience difficulties in learning and mastering these techniques. Various training methods and metrics have been developed to assess and improve surgeon's operative abilities. While these training metrics are currently widely being used, skill evaluation methods are still far from being objective in the regular laparoscopic skill education. This study proposes a methodology of defining a processing model that objectively evaluates surgical movement performance in the routine laparoscopic training course. Our approach is based on the analysis of kinematic data describing the movements of surgeon's upper limbs. An ultraminiaturized wearable motion capture system (Waseda Bioinstrumentation system WB-3), therefore, has been developed to measure and analyze these movements. The data processing model was trained by using the subjects' motion features acquired from the WB-3 system and further validated to classify the expertise levels of the subjects with different laparoscopic experience. Experimental results show that the proposed methodology can be efficiently used both for quantitative assessment of surgical movement performance, and for the discrimination between expert surgeons and novices. © 1964-2012 IEEE.

This paper describes the implementation in a walking humanoid robot of a mental model, allowing the dynamical change of the emotional state of the robot based on external stimuli; the emotional state affects the robot decisions and behavior, and it is expressed with both facial and whole-body patterns. The mental model is applied to KOBIAN-R, a 65-DoFs whole body humanoid robot designed for human-robot interaction and emotion expression. To evaluate the importance of the proposed system in the framework of human-robot interaction and communication, we conducted a survey by showing videos of the robot behaviors to a group of 30 subjects. The results show that the integration of dynamical emotion expression and locomotion makes the humanoid robot more appealing to humans, as it is perceived as more "favorable" and "useful", and less "robot-like."

Walking is one of the most common activities that we perform every day. Even if the main goal of walking is to move from one place to another place, walking can also convey emotional clues in social context. Those clues can be used to improve interactions or any messages we want to express. However, there are not many studies on the effects of the intensity of the emotions on the walking. In this paper, the authors propose to assess the differences between the expression of emotion regarding the expressed intensity (low, middle, high and exaggerated). We observed two professional actors perform emotive walking, with different intensities and we analyzed the recorded data. For each emotion, we analyzed characteristic features which can be used in the future to model gait patterns and to recognize emotions from the gait parameters. Additionally, we found characteristics which can be used to create new emotion expression for our biped robot Kobian, improving the human-robot interaction.

The understanding of emotions in humans is really important in the Human-Robot Interaction field. The affective state of a person can be expressed in several ways, one of them being through the way we walk and our gait can convey emotional clues in social context. Those clues can be used to improve the personal interactions with our peers or add meaning to any message we want to express. However, only a few studies in humanoid robotics were done on the effects of the emotions on the walking. In this paper, we propose to assess the emotional walking patterns created from motion capture data with a survey. Those patterns represent different emotions (sadness, happiness) with different intensities (middle, high and exaggerated). Those emotional walking patterns achieved a high recognition rate of the emotions and the subjects (N=13) could recognize whole body emotions without facial expression on our humanoid robot. Additionally, we found out that at first people might perform poorly at recognizing emotions and their intensities but can get better, even without correction or feedback on their performances. © 2013 IEEE.

A complex relationship exists between national cultural background and interaction with robots, and many earlier studies have investigated how people from different cultures perceive the inclusion of robots into society. Conversely, very few studies have investigated how robots, speaking and using gestures that belong to a certain national culture, are perceived by humans of different cultural background. The purpose of this work is to prove that humans may better accept a robot that can adapt to their specific national culture. This experiment of Human-Robot Interaction was performed in Egypt. Participants (native Egyptians versus Japanese living in Egypt) were shown two robots greeting them and speaking respectively in Arabic and Japanese, through a simulated video conference. Spontaneous reactions of the human subjects were measured in different ways, and participants completed a questionnaire assessing their preferences and their emotional state. Results suggested that Egyptians prefer the Arabic version of the robot, while they report discomfort when interacting with the Japanese version. These findings confirm the importance of a culture-specific customisation of robots in the context of Human-Robot Interaction. © 2013 IEEE.

We propose a two-stage gait pattern generation scheme for the full-scale humanoid robots, that considers the dynamics of the system throughout the process. The fist, stage is responsible for generating the preliminary motion reference, such as step position, timing and trajectory of Center of Mass (CoM), while the second stage serves as dynamics filter which employs a multi-body model and based on Zero Moment Point (ZMP) reference trajectory generates CoM reference trajectory which defines a locomotion stable when executed on the full-scale multi-degree-of-freedom humanoid robot. The approach thanks to introducing a dynamic model at, the stage of feet placement planning provides the ZMP reference, which is ensured to be feasible for the robot. Thanks to the fact it enables instantaneous regeneration of motion. The paper contains description of two approaches used in the first and second stage, as well as experimental results proving the effectiveness of the method. The fast calculation time and the use of the system's dynamic state as initial conditions for pattern generation makes it a good candidate for the real-time gait pattern generator.

We propose a two-stage gait pattern generation scheme for the full-scale humanoid robots, that considers the dynamics of the system throughout the process. The fist stage is responsible for generating semi-dynamically consistent step position and step time information, while the second stage incorporated with multi-body dynamics system is responsible for generation of gait pattern that is feasible and stable on the full-scale multi-degree-of-freedom humanoid robot. The approach allows for very rapid gait pattern regeneration during the swing phase of motion and includes information about present dynamic state when regenerating the new pattern. The paper contains description of a developed method, as well as experimental results proving its effectiveness.

Neurological examinations are among the most important clinical skills to identify disorders in the neurological system at early stages. Training on neurological examination for inexperienced doctors plays an important role in improving accuracy of diagnosis. Such training programs have been conducted until now using physical simulators or simulated patients (SPs). However, conventional simulators can simulate only facial features of patients and not their responses or motions. SP cannot simulate them either. We have therefore been developing a whole-body patient robot named WKP(Waseda Kyotokagaku Patient robot) for training on neurological examination. The main advantage of WKP over conventional simulators and SPs is its ability to simulate motions and responses of patients having disorders in their neurological systems. We then developed a head humanoid with facial expression for training on neurological disorders as a part of WKP. This humanoid is equipped with 21 degrees of freedom
it has 2 liquid crystal panels with lenses, and simulates facial movements with imitating the wrinkles and eyeball movements of patients with disorders in their cranial nerves. We then performed a set of experiments to validate the head humanoid. The main focus of this paper is on mechanical design and performance verification of the head humanoid. © 2013 IEEE.

Physicians use ultrasound scans to do diagnosis by making real-time images of internal organs, because such scans are safe, inexpensive, and non-invasive. However, aging society and limited numbers of physician make it difficult for patients in remote areas to be diagnosed. Besides, physician's technical skills affect the interpretation of the scans and thus the results of the examination. Thus, development of a robotic system for remote diagnosis is required to solve the problems. For this purpose, we proposed the development of a robotic system for automatic ultrasound imaging focusing on human liver. In this paper, we present several elements developed for the robotic system. First element is an algorithm for estimating the position of liver to guide the probe to scan initial position which is the epigastric region. Second element is ultrasound probe scanning protocol design to obtain whole image of the liver. Third element is force control algorithm to maintain the contact between the probe and human body even though the patient is breathing. Fourth element is an algorithm for detecting and correcting the probe's position when improper ultrasound images occurred. These algorithms with an implementation program control the apparatus: a Mitsubishi Electric's MELFA RV-1 six axis manipulator and tested on human subjects. The results confirmed the effectiveness of the approach. © 2013 IEEE.

this paper describes a novel mobility assistive device under development in the Egypt-Japan University of Science and Technology (E-JUST). The proposed system can help patients who do not have enough physical strength on the lower limbs during sit to stand due to aging, diseases such as polymyositis and myopathy, and joint replacement surgery complications. It can follow the natural pattern of human motion during sit to stand providing assistance force under the shoulder. The overall device is compact and employees a parallel mechanism which provide more stiffness. Several experiments were carried out in a VICON room to calculate the human motion posture while sit to stand motion in addition estimate the trajectory of the end effector during assisting. Computer simulation was built to verify the performance of the proposed system with the reference trajectory.

Endotracheal Intubation (ETI) is a common airway procedure used to connect the larynx and the lungs through the windpipe of patients under emergency situations. The process is carried out by a laryngoscope inserted into the mouth, and helps doctors in viewing the glottis and inserting the tube. In 2012, we developed a humanoid robot for ETI training, called WKA-5R, which was able to simulate various patients and scenarios and to evaluate the doctor's medical skills according to applied force, position of laryngoscopes and tubes, and procedure time. In 2013, we have focused our study on the development of a system for the biomechanical evaluation during simulated ETI. We conducted an experiment with 5 expert and 6 novice anesthesiologists and measured 3 biomechanical parameters: angular velocity of wrist joint and elbow joint, surface electromyography (sEMG) of the upper limb, and some angles on the upper part of the body, in order to evaluate joint stiffness in the arm and posture during ETI. In this paper, the authors show the experimental results on comparison between experts and novices, followed by discussion. © 2013 IEEE.

A common problem among elderly people is the loss of motor ability. Rehabilitation exercises can help these people recover strength and maintain a good level of mobility. However, high costs and the need for special equipment make professional rehabilitation impractical for regular use in daily life, precluding elderly the possibility to perform focalized training at home. The idea of telerehabilitation is becoming more and more concrete with the rapid development of internet technology. Telerehabilitation would allow the user to perform exercises at home with online professional direction from the doctor. However, at the present state, the doctor cannot obtain real-time and quantitative data from the user, and this limits the training effectiveness. To overcome this problem, an extremely miniaturized, portable motion capture system, named WB-4R, has been developed. Calibration and real-time link orientation reconstruction are very important to improve the accuracy in real-time measurement. In this paper, using the positive results of preliminary experiments on lower limbs, the authors will show the feasibility of the method and confirm the effectiveness of the developed system.

In this paper, we describe a human gesture recognition system developed to make a humanoid robot understand non-verbal human social behaviors, and we present the results of preliminary experiments to demonstrate the feasibility of the proposed method. In particular, we have focused on the detection and recognition of laughter, a very peculiar human social signal. In fact, although it is a direct form of social interaction, laughter is classified as semi voluntary action, can be elicited by several different stimuli, and it is strongly associated with positive emotion and physical well-being. The possibility of recognize, and further elicit laughter, will help the humanoid robot to interact in a more natural way with humans, to build positive relationships and thus be more socially integrated in the human society.

We present a novel control architecture for the integration of visually guided walking and whole-body reaching in a humanoid robot.We propose to use robot gaze as a common reference frame for both locomotion and reaching, as suggested by behavioral neuroscience studies in humans. A gaze controller allows the robot to track and fixate a target object, and motor information related to gaze control is then used to i) estimate the reachability of the target, ii) steer locomotion, iii) control whole-body reaching. The reachability is a measure of how well the object can be reached for, depending on the position and posture of the robot with respect to the target, and it is obtained from the gaze motor information using a mapping that has been learned autonomously by the robot through motor experience: we call this mapping Reachable Space Map. In our approach, both locomotion and whole-body movements are seen as ways to maximize the reachability of a visually detected object, thus i) expanding the robot workspace to the entire visible space and ii) exploiting the robot redundancy to optimize reaching. We implement our method on a full 48-DOF humanoid robot and provide experimental results in the real world.

Designing humanoid robots able to interact socially with humans is a challenging task. If we want the robots to be actively integrated in our society, several issues have to be taken in account: the look of the robot, the naturalness of its movements, the stability of its walk, the reactivity it might have with its human partners. We propose to improve the reactivity of the robot by using a emotional mental model in order to generate emotional gait patterns. Those patterns will help the understanding of any emotional message conveyed between a human and a robot. We propose a novel emotional gait generation method based on the Emotion mental model. We did preliminary experiments with the Happiness and Sadness emotions and with different intensities.

Extensive literature has been written on occupancy grid mapping for different sensors. When stereo vision is applied to the occupancy grid framework it is common, however, to use sensor models that were originally conceived for other sensors such as sonar. Although sonar provides a distance to the nearest obstacle for several directions, stereo has confidence measures available for each distance along each direction. The common approach is to take the highest-confidence distance as the correct one, but such an approach disregards mismatch errors inherent to stereo.
In this work, stereo confidence measures of the whole sensed space are explicitly integrated into 3D grids using a new occupancy grid formulation. Confidence measures themselves are used to model uncertainty and their parameters are computed automatically in a maximum likelihood approach. The proposed methodology was evaluated in both simulation and a real-world outdoor dataset which is publicly available. Mapping performance of our approach was compared with a traditional approach and shown to achieve less errors in the reconstruction.

Humanoid robots progress everyday closer and closer to a more stable walking suitable for a human environment as the researchers in the Humanoid robotics field focus their effort on the understanding of the human locomotion. Nonetheless for Social Robotics researchers, humanoid robots might have another use, such as being our companions from birth to nursing home. Designing social humanoid robots is one critical step if we want the robots to be active in our society. However, to our knowledge, only a few studies in the area of humanoid robotics have addressed emotion expression with robot gaits. In this paper we propose to assess different emotional gait patterns and the perception of the emotion intensity in those patterns. Actors' emotional movement were captured and then normalized for our robot platform. Several robot simulations were shown to human observers who completed a survey questionnaire in which they indicated their assessment of the portrayed emotion by the robot simulation. The surveyed emotions consist of Sadness, Happiness, Anger, Fear with different intensities (Intermediate, High and Exaggerated). We achieved a high recognition rate of emotions (72.32%). Even if the intensities were less well recognized (33.63%), our study indicates that the intensity might help the recognition of emotional walking.

Cranial nerve system is the core part of human Nervous system. Different diseases on the pathway of the system correspond to different symptoms. According to the diagnosis of these symptoms the doctor can early diagnose out the related diseases on the nervous pathway. In order to master the adept skills, the neurologic medical staffs need to be trained on the diagnostic methods as well as learn abundant knowledge. As a traditional way of education, books and videos are used to help the students to comprehend the knowledge. However, compared with performing the examination on the real patient, this common way lacks vividness. Especially there are no active interactions. Recently more and more medical simulators are developed based on robotic technologies. These simulators bring innovative methods for medical education. Nevertheless, they just focus on the symptoms' reproduction, and do not have the abilities to show the relationships between sicknesses and symptoms. In this paper, we will propose a face robot (Fig. 1) for cranial nerves examination training to improve the training effectiveness. In this robot, we not only simulated various symptoms of optic tracking, eyeball movements, facial paralysis, but also made a cranial neurological model to simulate the different influences of the disorders on the nervous pathway. Finally, we performed a set of experiments to assess our proposed mechanism and control system. Three neurologists with over 30 years' experience were invited to show their opinions on the robot, and to discuss the results. All the results lead to the improvements for further researches. © 2012 IEEE.

Humanoid robots are complex sensorimotor systems where the existence of internal models are of utmost importance both for control purposes and for predicting the changes in the world arising from the system's own actions. This so-called expected perception relies on the existence of accurate internal models of the robot's sensorimotor chains. © 2012 IEEE.

Laparoscopy is a very popular surgical technique for abdominal operations. Due to the difficulties in using the laparoscopes, the surgeons need an extensive training to acquire the right locomotive skill and perform operations. Usually, the training is performed with dry boxes with simple and repetitive exercises, like the peg-board, in which a trainee uses the instruments to move sequentially a set of rubber O rings positioned inside pegs. However, even if the dry box is a good method to train the dexterity of a trainee, it does not include the mental stress, that could be significant during the operation in the actual Operating Room (OR). In this paper we present the comparison results during a peg-board training without and with induced mental stress. In particular, the stress has been introduced by a proposed protocol adaptively setting a countdown with noisy alarm for the last 60s of the exercise. We compared the results by a biomechanical analysis using surface Electromyography, showing that the induced stress situation revealed a significant larger activation of the arms and shoulders muscles. © 2012 IEEE.

In this paper we describe how a humanoid robot can learn a representation of its own reachable space from motor experience: a Reachable Space Map. The map provides information about the reachability of a visually detected object (i.e. a 3D point in space). We propose a bio-inspired solution in which the map is built in a gaze-centered reference frame: the position of a point in space is encoded with the motor configuration of the robot head and eyes which allows the fixation of that point. We provide experimental results in which a simulated humanoid robot learns this map autonomously and we discuss how the map can be used for planning whole-body and bimanual reaching. © 2012 IEEE.

This paper describes a walking stabilization control on a soft ground based on gait analysis for a biped humanoid robot. There are many studies on gait analysis on a hard ground, but few physiologists analyze the walking ability of human beings on a soft ground. Therefore, we conducted anthropometric measurement using VICON motion capture system on a soft ground. By analyzing experimental results, we obtained three findings. The first finding is that step height tends to increase to avoid tripping on a soft ground but there are no significant differences in step length and step width. The second finding is that although the CoM amplitude increases in the vertical direction on a soft ground, there are no significant differences in the CoM trajectories in the lateral direction. The last finding is that the head is stabilized during walking not only on a hard ground but also on a soft ground. Based on these findings, we developed a novel walking stabilization control to stabilize the CoM motion in the lateral direction on a soft ground. Verification of the proposed control is conducted through experiments with a human-sized humanoid robot WABIAN-2R. The experimental videos are supplemented. © 2012 IEEE.

The number of patients with mental disorders is increasing in advanced countries, hence more effective psychotropic drugs are recently desired. In process of development of psychotropic drugs, animal experiments have been playing a very important role. Mental disorder model animals which exhibit behavior disorder like patients with mental disorders are used in these experiments. These animals are normally developed by genetic manipulation, surgical operation in their brain or drug administration. A candidate for a new drug is administrated in these animals to evaluate its effect. However, we have some doubts about conventional mental disorder model animals because they are induced these disorders by using methods which are quite different from causes of mental disorder of human beings. Therefore, the purpose of this study is to develop an novel methodology to create mental disorder model animals. We then developed a small mobile robot and a control system for it. Using them, we have performed some experiments to create a mental disorder model rat. We had then succeeded in developing a mental disorder model rat by exposing stress using the robot during immature period. This rat exhibits low activity in some behavior tests during mature period. For better understanding of how stress exposure induces mental disorder in a rat, we conducted another experiment based on stress vulnerability hypothesis. In this experiment, stress was exposed during both immature and mature period while that had been exposed only during immature period. We prepared several conditions of stress exposure by changing robot behavior pattern to find the one to induce much stress in a rat. From a result of experiment, we found that a rat which received gentle chase by the robot during immature period was induced much stress when it received robot attack during mature period. Thus, we consider that this rat is more appropriate to the mental disorder model than that was developed in our past experiment. © 2012 IEEE.

The number of patients with mental disorders is increasing in advanced countries, hence more effective psychotropic drugs are recently desired. In process of development of psychotropic drugs, animal experiments have been playing a very important role. Mental disorder model animals which exhibit behavior disorder like patients with mental disorders are used in these experiments. These animals are normally developed by genetic manipulation, surgical operation in their brain or drug administration. A candidate for a new drug is administrated in these animals to evaluate its effect. However, we have some doubts about conventional mental disorder model animals because they are induced these disorders by using methods which are quite different from causes of mental disorder of human beings. Therefore, the purpose of this study is to develop an novel methodology to create mental disorder model animals. We then developed a small mobile robot and a control system for it. Using them, we have performed some experiments to create a mental disorder model rat. We had then succeeded in developing a mental disorder model rat by exposing stress using the robot during immature period. This rat exhibits low activity in some behavior tests during mature period. For better understanding of how stress exposure induces mental disorder in a rat, we conducted another experiment based on stress vulnerability hypothesis. In this experiment, stress was exposed during both immature and mature period while that had been exposed only during immature period. We prepared several conditions of stress exposure by changing robot behavior pattern to find the one to induce much stress in a rat. From a result of experiment, we found that a rat which received gentle chase by the robot during immature period was induced much stress when it received robot attack during mature period. Thus, we consider that this rat is more appropriate to the mental disorder model than that was developed in our past experiment.

We developed a three-dimensional mechanical vocal cord model for Waseda Talker No. 7 (WT-7), an anthropomorphic talking robot, for generating speech sounds with various voice qualities. The vocal cord model is a cover model that has two thin folds made of thermoplastic material. The model self-oscillates by airflow exhausted from the lung model and generates the glottal sound source, which is fed into the vocal tract for generating the speech sound. Using the vocal cord model, breathy and creaky voices, as well as the modal (normal) voice, were produced in a manner similar to the human laryngeal control. The breathy voice is characterized by a noisy component mixed with the periodic glottal sound source and the creaky voice is characterized by an extremely low-pitch vibration. The breathy voice was produced by adjusting the glottal opening and generating the turbulence noise by the airflow just above the glottis. The creaky voice was produced by adjusting the vocal cord tension, the sub-glottal pressure and the vibration mass so as to generate a double-pitch vibration with a long pitch interval. The vocal cord model used to produce these voice qualities was evaluated in terms of the vibration pattern as measured by a high-speed camera, the glottal airflow and the acoustic characteristics of the glottal sound source, as compared to the data for a human. (C) Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2012

In animal behavior research, rat models of mental disorders (RMMDs) are developed to screen psychotropic drugs and to clarify the mechanism of mental disorders. Meanwhile, interaction between real rats is used to evaluate the RMMD. However, since rat-rat interaction is hard to control and quantify, we have adopted a bio-inspired robot to interact with real rats owing to its programmability and reconfigurability in testing different models. We have developed several rat-like robots before, however, these robots still can not fully satisfy the requirement of animal experiment. As an improvement, the newest generation rat-like robot called WR-5 is developed. WR-5 can perform mounting and grooming actions naturally as live mature rat owing to adopted differential gear in its waist. Preliminary SIT between WR-5 and mature rats have been conducted strictly following psychological rules. Experimental results show that rats are more active and have fewer frequencies of grooming and rearing actions when WR-5 performs mounting action periodically. The rat-like robot is therefore able to make the anxiety level of rats high by means of performing mounting action.

In this paper, we proposed an automated video processing system to replace the traditional manual annotation, and to improve the adaptivity of the rat-like robot to autonomously interact with rats. The feature parameters of rats, such as body length, body area, circularity, body bend angle, locomotion speed, etc., are extracted based on image processing. These parameters are integrated as the input feature vector of Artificial Neural Network (ANN) and Support Vector Machine (SVM) classification methods respectively. Preliminary experiments reveal that the rearing, grooming and rotating actions could be recognized with extremely high rate (more than 90% by SVM and more than 80% by ANN). Furthermore, SVM needs less training computational cost than ANN. Therefore, SVM is superior to ANN for the behavior recognition of rats. By using the SVM-based recognition system, the behavior of the robot is generated adaptive to the rat behavior for different interactions.

The cranial nerves examination is one part of neurological examination. Neurologic medical staffs, especially the novices, need to be trained and grasp this skill. There are various methodologies to help the trainee to accumulate experiences. However, the best way is to practice on the real patient. The methods have their own drawbacks such as lack of active interactions, limitation of multi-symptoms' reproducing, etc. In order to improve the training effectiveness, a face robot (Fig. 1) is proposed in this paper for cranial nerves examination training as one part of the whole body patient robot named WKP (Waseda Kotokagaku Patient). In this robot, various symptoms of optical tracking, eyeball movements, facial paralysis are simulated and shown to the trainee. Finally, a set of experiments was performed to evaluate our proposed mechanism and control system. Three neurologists with over 30 years' experience were invited to show their opinions on the reproductions of the symptoms, and to discuss the results. All the results lead to the improvements for further research.

During several years of development, the hardware of the anthropomorphic flutist robot Waseda Flutist WF-4RIV has been continuously improved. The robot is currently able to play the flute at the level of an intermediate human player. Lately we have been focusing our research on the interactivity of the performance of the robot. Initially the robot has only been able to play a static performance that was not actively controllable by a partner musician of the robot. In a realistic performance set-up, in a band or an orchestra, musicians need to interact in order to create a performance that gives a natural and dynamic impression to the audience. In this publication we present the latest developments on the integration a Musical-based Interaction System (MbIS) with WF-4RIV. Such a human robot interaction system is to allow human musicians to do natural musical communication with the flutist robot through audio-visual cues. Here we would like to summarize our previous results, present the latest extensions to the system and especially concentrate on experimenting with applications of the system. We evaluate our interactive performance system using three different methods: A comparison of a passive (non-interactive) and an interactive performance, evaluation of the technical functionality of the interaction system as a whole and by examining the MbIS from a user perspective with a user survey including amateur and professional musicians. We present experiment results that show that our Musical-based Interaction System extends the anthropomorphic design of the flutist robot, to allow increasingly interactive, natural musical performances with human musicians.

Neurologic examination takes an important role in diagnosis of the nerve system diseases. Neurologic medical staffs, especially the novices, need to be trained on this skill. There are many methodologies which can help to accumulate experiences, such as watching video, reading books, making use of the simulated patient (SP), and so on. However, the best way is to practice on the real patient. All the above methods have their own drawbacks such as lack of active interactions, limitation of multi-symptoms' reproducing, etc. To improve the training effectiveness, an arm robot is proposed in this paper for neurologic examination training as one part of the whole body patient robot named Waseda Kyotokagaku Patient (WKP). In this robot, various symptoms of the elbow force, biceps tendon reflex, involuntary action, and so on, are simulated and shown to the trainee. Finally, a set of experiments was carried out to verify our proposed mechanism and control system. Three neurologists with over 30 years' experience were invited to show their opinions on the reproductions of patients' symptoms, and to discuss the results. The effectiveness of this system was confirmed. The experimental results lead to the consideration that the approach is worth following in further research.

The purpose of this study is to develop novel training system for medical skills using robot technology. We have developed Waseda Kyotokagaku Airway No.4 (WKA-4) as a novel training simulator for airway management. This robot reproduces several different patients with actuators. For instance, this robot has a unique mechanism in its temporomandibular joint that consists of a set of warm gears and force sensors, hence reproduces a patient with TMJ disorder. This robot also has the tongue that is able to change its shape using air pressure, hence reproduces the difficulty of airway management. We then asked the medical doctors to evaluate the robot using a questionnaire and confirmed that WKA-4 had enough property to use in the training of anesthesiologists.

The emerging field of medical robotics is aimed at introducing intelligent tools. More recently, thanks to the innovations in robot technology (RT), advanced medical training systems have been introduced to improve the skills of trainees. The principal challenges of developing efficient medical training systems is that they must simulate real-world conditions of the task, provide objective assessments of training progress, and provide useful feedback to trainees. So far, many medical training systems have been developed
however, those training system do not fulfill the three conditions of the Active Training system. For the proof of concept of an effective Active Training system, we proposed WKA-4 (Waseda Kyotokagaku Airway No.4) which satisfies all of the requirements of the Active Training system. In this paper, we present the hardware configuration of the WKA-4 briefly, which has 11 embedded actuators and 44 embedded sensors, and simulates real-world condition of the task. In addition, in order to verify the usefulness of feedback of the WKA-4 for medical training, a set of the experiments were carried out to a doctor group and two novice groups. One novice group is provided by the feedback of the embedded sensors of the WKA-4 while the other novice group is not. From the comparisons of the results of the experiments, we verify the effectiveness of our proposed Active Training system. © 2012 IEEE.

Laparoscopy is a very popular surgical technique for abdominal operations. Due to the difficulties in using the laparoscopes, the surgeons need an extensive training to acquire the right locomotive skill and perform operations. Usually, the training is performed with dry boxes with simple and repetitive exercises, like the peg-board, in which a trainee uses the instruments to move sequentially a set of rubber O rings positioned inside pegs. However, even if the dry box is a good method to train the dexterity of a trainee, it does not include the mental stress, that could be significant during the operation in the actual Operating Room (OR). In this paper we present the comparison results during a peg-board training without and with induced mental stress. In particular, the stress has been introduced by a proposed protocol adaptively setting a countdown with noisy alarm for the last 60s of the exercise. We compared the results by a biomechanical analysis using surface Electromyography, showing that the induced stress situation revealed a significant larger activation of the arms and shoulders muscles.

In this paper we describe how a humanoid robot can learn a representation of its own reachable space from motor experience: a Reachable Space Map. The map provides information about the reachability of a visually detected object (i.e. a 3D point in space). We propose a bio-inspired solution in which the map is built in a gaze-centered reference frame: the position of a point in space is encoded with the motor configuration of the robot head and eyes which allows the fixation of that point. We provide experimental results in which a simulated humanoid robot learns this map autonomously and we discuss how the map can be used for planning whole-body and bimanual reaching.

This paper describes a walking stabilization control based on gait analysis for a biped humanoid robot. We have developed a human-like foot mechanism mimicking the medial longitudinal arch to clarify the function of the foot arch structure. To evaluate the arch function through walking experiments using a robot, a walking stabilization control should also be designed based on gait analysis. Physiologists suggest the ankle, hip and stepping strategies, but these strategies are proposed by measuring human beings who are not "walking" but "standing" against force disturbances. Therefore, first we conducted gait analysis in this study, and we modeled human walking strategy enough to be implemented on humanoid robots. We obtained following two findings from gait analysis: i) a foot-landing point exists on the line joining the stance leg and the projected point of CoM on the ground, and ii) the distance between steps is modified to keep mechanical energy at the landing within a certain value. A walking stabilization control is designed based on the gait analysis. Verification of the proposed control is conducted through experiments with a human-sized humanoid robot WABIAN-2R. The experimental videos are supplemented.

This paper describes a walking stabilization control on a soft ground based on gait analysis for a biped humanoid robot. There are many studies on gait analysis on a hard ground, but few physiologists analyze the walking ability of human beings on a soft ground. Therefore, we conducted anthropometric measurement using VICON motion capture system on a soft ground. By analyzing experimental results, we obtained three findings. The first finding is that step height tends to increase to avoid tripping on a soft ground but there are no significant differences in step length and step width. The second finding is that although the CoM amplitude increases in the vertical direction on a soft ground, there are no significant differences in the CoM trajectories in the lateral direction. The last finding is that the head is stabilized during walking not only on a hard ground but also on a soft ground. Based on these findings, we developed a novel walking stabilization control to stabilize the CoM motion in the lateral direction on a soft ground. Verification of the proposed control is conducted through experiments with a human-sized humanoid robot WABIAN-2R. The experimental videos are supplemented.

The neuroscientific research shows that humans tend to stabilize their head orientation, while accomplishing a locomotor task. In order to replicate head movement behaviors found in human walk it is necessary and sufficient to be able to control the orientation (roll, pitch and yaw) of the head in space. The described behaviors can be replicated by giving suitable references to the head orientation. Based on these principles, a model based on an inverse kinematics controller has been designed. In this paper we introduce implementation of the model on a humanoid platform. Along we present results of two sets of experiments performed to verify two aspects of the proposed model. The results prove that the model can be used to efficiently stabilize the head's orientation.

In this work we propose an adaptive model for the head stabilization based on a feedback error learning (FEL). This model is capable to overcome the delays caused by the head motor system and adapts itself to the dynamics of the head motion. It has been designed to track an arbitrary reference orientation for the head in space and reject the disturbance caused by trunk motion. For efficient error learning we use the recursive least square algorithm (RLS), a Newton-like method which guarantees very fast convergence. Moreover, we implement a neural network to compute the rotational part of the head inverse kinematics. Verification of the proposed control is conducted through experiments with Matlab SIMULINK and a humanoid robot SABIAN. © 2012 IEEE.

The surface electromyography (sEMG) signal is affected by different sources of noises: current technology is considerably robust to the interferences of the power line or cable motion artefacts, but still there are many limitations in denoising the baseline. In this paper, we introduce a new technique, named baseline adaptive denoising algorithm (BADA), for denoising the sEMG signal by wavelet thresholding procedure. In particular, the thresholds are estimated using the same baseline signal with fixed and adaptive techniques. Eventually, we verify that the proposed adaptive method performs better than the standard Donoho technique and different variations, in term of noise cancellation and distortion of the signal, quantified by a new suggested indicator of the denoising quality. Copyright © 2012 Inderscience Enterprises Ltd.

In the last years there has been increasing interest on Inertial Measurement Units (IMUs) in several fields, because they can provide a measurement of the orientation, velocity, and acceleration at low cost with high performance. The main reason of the low cost is the possibility to find inertial sensors, as accelerometers, gyroscopes and magnetometers, based on Micro-Electro-Mechanical Systems (MEMS) made by silicon, with further advantages of small dimensions and mass production from the main semiconductor suppliers. In this paper, we present the development of the ultra miniaturized wireless IMU, WB-4 (Waseda Bioinstrumentation number 4), with a 3-axis accelerometer, 3-axis gyroscope and 3-axis magnetometer. Additionally, we illustrate, together with results, the algorithms used for the data filtering and calibration, with particular emphasis on a new methodology for the online calibration of the digital magnetometer.

This paper presents the performance evaluation of our wireless miniature Inertial Measurement Unit (IMU) WB-4 by compared with the Vicon motion capture system. In particular, a magnetic field calibration method is introduced to improve the sensor orientation estimate accuracy.
The WB-4 IMU primarily contains a motherboard for motion sensing, a Bluetooth module for wireless data transmission with PC, and a Li-Polymer battery for power supply. The motherboard is provided with a 32-bit microcontroller and 3-axis miniaturized MEMS accelerometer, 3-axis gyroscope and 3-axis magnetometer to estimate the sensor orientation based on an extended Kalman filter algorithm. In our previous research of WB-4 IMU performance evaluation, the factory calibration parameters of the magnetometer were used for the sensor fusion, which resulted in a higher error on the yaw angle in respect to roll and pitch. This study presents a magnetic calibration method for overcoming that limitation. The experimental results showed that the wireless WB-4 IMU could achieve better orientation performance in all the directions after the implementation of the magnetic calibration method. The yaw angle accuracy was significantly improved from previous error 5.46 degree to 1.77 degree.

In this paper, we describe a human gesture recognition system developed to enable a robot instrument player to recognize the variations in tempo and in articulation dictated by a conductor's movements and accordingly adapt its performance. The enhanced interaction ability would allow the partner musicians, as well as the conductor, to better appreciate a joint musical performance, because of the complete naturalness of the interaction. In addition, the possibility for the robot to change its performance parameters according to the conductor directions, thus being synchronized with all the other human musicians, would lead to an improvement in the overall musical performance.

A device for the gait analysis during a long-distance walking is important for the correct assessment of patients during the rehabilitation. This device should be able to measure all gait parameters in a single unit. In addition, it is required that the measurement system is not spatially constrained. In our group, we have been developing a new wireless system, namely WB-4R, composed of Inertial Measurement Units, to be used in rehabilitation centers for gait analysis that is cheap, small, and relatively maintenance-free. This paper presents the results of a pilot study conducted with healthy subjects. The system was able to detect the gait phase and provide frequency analysis of the angular velocity and acceleration of the lower limbs.

In this paper, we describe the mechanical design system implemented to enable a robot flute player to enhance the expressiveness of its performance, reproducing the different musical articulations with the available features of the instrument. In addition, the robot has been equipped with a Human Gesture Recognition system to recognize the real-time variations in tempo, dynamics, and articulation dictated by the conductor's movements. The possibility for the robot to change its performance parameters according to the conductor directions, thus adding expression to its performance while being synchronized with all the other human musicians, would lead to an improvement in the overall joint musical performance.

This paper describes a walking stabilization control on a soft ground based on gait analysis for a humanoid robot. There are many researches on gait analysis on a hard ground, but few scientists analyze the walking ability of human beings on a soft ground. Therefore, we conducted anthropometric measurement using a motion capture system on a soft ground. By analyzing experimental data, we obtained two findings. The first finding is that although there are no significant differences in step width and step length, step height tends to increase to avoid the collision between the feet and a soft ground. The second finding is that there are no significant differences in the lateral CoM trajectories but the vertical CoM amplitude increases when walking on a soft ground. Based on these findings, we developed a walking stabilization control to stabilize the CoM motion in the lateral direction on a soft ground. Verification of the proposed control is conducted through experiments with a human-sized humanoid robot WABIAN-2R. The experimental videos are supplemented.

The results of the neuroscientific research show that humans tend to stabilize the head orientation during locomotion. In this paper we describe the implementation of inverse kinematics based head stabilization controller on the humanoid platform. The controller uses the IMU feedback and controls neck joints in order to align the head orientation with the global orientation reference. Thanks to the method, we can decouple the orientational motion of the head from the rest of the body. This way stabilized head becomes better platform for proprioceptive sensory apparatus, such as cameras or IMU. In the paper we present three experiments which prove that the method has good performance in damping both, high and low frequency motion of the head. We also prove that the proposed controller improves the stability of the tracked goal point on the image of in-built camera.

This paper describes the development of a new expressive robotic head for the bipedal humanoid robot. Facial expressions of our old robotic head have low facial expression recognition rate and in order to improve it we asked amateur cartoonists to create computer graphics (CG) images. To realize such expressions found in the CGs, the new head was provided with 24-DoFs and facial color. We designed compact mechanisms that fit into the head, which dimensions are based on average adult Japanese female size. We conducted a survey with pictures and videos to evaluate the expression ability. Results showed that facial expression recognition rates for the 6 basic emotions are increased compared to the old KOBIAN's head. © 2012 IEEE.

We describe an interactive learning strategy that enables a humanoid robot to build a representation of its workspace: we call it a Reachable Space Map. The robot learns this map autonomously and online during the execution of goal-directed reaching movements; reaching control is based on kinematic models that are learned online as well. The map can be used to estimate the reachability of a fixated object and to plan preparatory movements (e.g. bending or rotating the waist) that improve the effectiveness of the subsequent reaching action. Three main concepts make our solution innovative with respect to previous works: the use of a gaze-centered motor representation to describe the robot workspace, the primary role of action in building and representing knowledge (i.e. interactive learning), the realization of autonomous online learning. We evaluate our strategy by learning the workspace of a simulated humanoid robot and we show how this knowledge can be exploited to plan and execute complex actions, like whole-body bimanual reaching.

Communication between humans and robots is a very critical step for the integration of social robots into society. Emotion expression through a robotic face is one of the key points of communication. Despite the most recent efforts, no matter how much expression capabilities improve, facial expression recognition is often hampered by a cultural divide between subjects that participate in surveys. The purpose of this work is to take advantage of the 24 degrees of freedom head of the humanoid social robot KOBIAN-R for making it capable of displaying different versions of the same expressions, using face and neck, in a way that they are easy to understand for Japanese and for Western subjects. We present a system based on relevant studies of human communication and facial anatomy, as well as on the work of illustrators and cartoonists. The expression generator we developed can be adapted to specific cultures. Results confirmed the in-group advantage, showing that the recognition rate of this system is higher when the nationality of the subjects and the cultural characterisation of the shown expressions are coincident. We conclude that this system could be used, in future, on robots that have to interact in a social environment, with people with different cultural background. © 2012 Springer-Verlag.

Human-robot communication is a very important aspect in the field of Humanoid Robotics. Non-verbal communication is one of the components that make interaction natural. However, despite the most recent efforts, robots still can show only limited expression capabilities. The purpose of this work is to create a facial expression generator that can be applied to the new 24 DoF head of the humanoid robot KOBIAN-R. In this paper, we present a system based on relevant studies of human communication and facial anatomy, adapted to the specific robotic face. It makes use of polynomial classifiers and is able to produce over 600 thousands of facial cues combinations, together with appropriate neck movement. Results showed that the recognition rate of expressions produced by this system is comparable to the rate of recognition of the most common facial expressions. We conclude that our system can successfully improve the communication capabilities of the robot KOBIAN-R, and that there is potential for using it to implement more complex interaction. © 2012 IEEE.

Human-Robot Interaction is one of the biggest challenges in Humanoid Robotics. Interaction can be carried out through different channels, as humans can communicate through complex languages, including the use of non-verbal communication. Specifically, facial expressions are important for conveying emotions and communication intentions. Several humanoid robots can already perform a certain set of expressions, but their capabilities are somewhat limited and as a result, interaction is not natural. One aspect that could help robots being perceived as real is asymmetry. That is why in this paper we perform an evaluation study of symmetrical and asymmetrical facial expressions of the humanoid robot KOBIAN-R These expressions are made by a generator based on relevant studies of facial anatomy and non-verbal communication and on the work of illustrators and cartoonists. Survey results confirmed the effectiveness of the generator and the importance of asymmetry. We conclude that using this system, robot communication capabilities improve, making possible the development of more advanced interaction in the future. © 2012 IEEE.

The ultrasound diagnosis of the carotid artery is one of the most common non-invasive methods to detect early stage heart and cerebrovascular diseases. However, the precision and repetitiveness of the probe positioning depend exclusively on the operator's skills and dexterity. For this purpose, we propose the development of a robot assisted system to enhance the accuracy and repetitiveness of the probe positioning to measure the wave intensity (WI) index. In this paper, the Waseda-Tokyo Women's Medical-Aloka Blood Flow Measurement Robot System No. 2 Refined (WTA-2R) is presented. The WTA-2R consists of a conventional ultrasound diagnosis system, a 6-DOFs parallel link slave manipulator, a 6-DOFs serial link passive arm, and a master device. Experiments were carried out to verify its effectiveness in terms of accuracy and required time to perform the task. From the experimental results, the positioning accuracy and reduction of required time were confirmed. (C) 2011 Elsevier Ltd. All rights reserved.

In recent years advanced robotic technology has seen increasing use in the medical field to assist in the development of efficient training systems. Such training systems must fulfill the following criteria: they must provide quantitative information, simulate the real-world conditions of the task, and assure training effectiveness. For these reasons, we have developed the Waseda Kyotokagaku Airway series to fulfill all those requirements using actuators and sensors as the main elements. Our WKA series could not completely simulate real-world conditions of the patients such as the motions of head, mandible, and tongue, which is important for the task of human airway management. In order to simulate the motions of those parts as in a real human being, we propose Waseda Kyotokagaku Airway No. 4, which meets all requirements of effective training systems. Particularly, for realistic simulation of the motions of those parts, the WKA-4 has improved mechanisms with high-fidelity simulated human anatomy, and Virtual Compliance Control is implemented to reproduce the stiffness of the human's muscles. In this paper, we present the hardware configuration and discuss the realistic simulation of the motions of those parts using a motion control system and control system for the WKA-4. Finally, we present a set of experiments carried out using doctors to verify our proposed mechanism and control system. © 2011 IEEE.

Our research is related to the development of an anthropomorphic saxophonist robot which reproduced the human organs involved during the saxophone playing. This research approach aims in understanding the human motor control from an engineering point of view and enabling the communication between humans and robots in musical terms. In a previous research, we have presented the Waseda Saxophonist Robot No. 2 (WAS-2) which improved the design of the lip and finger mechanisms. In addition, a feed-forward air pressure with dead-time compensation and an overblowing correction controller were implemented. However, the range of pressure was too limited to reproduce dynamic effects of the sound (i.e. decrescendo, etc.), a delay on the response of the finger mechanism was detected (due to the use of a wire-driven mechanism) and deviations on the pitch during the saxophone playing were observed. Therefore; in this paper, we present the Waseda Saxophonist Robot No. 2 Refined (WAS-2R). In particular the shape of the oral cavity has been re-designed to increase the sound pressure range and potentiometers were embedded on the fingers to reduce the dynamic delay response of the wire-driven mechanism. In addition, a Pressure-Pitch Controller has been implemented to reduce the deviation of the sound pitch by implementing a feedback error learning algorithm for a Multiple-Input Multiple-Output system. A set of experiments were proposed to verify the effectiveness of the re-designed mechanisms and the improved control strategy. From the experimental results, we could confirm the improvements to extend the sound pressure range to reproduce the decrescendo effect, to reduce the response delay from the finger mechanism as well as the deviations on the sound pitch.

The surface Electromyography (sEMG) signal is affected by different sources of noises: current technology is considerably robust to the interferences of the power line or the cable motion artifacts, but still there are many limitations with the baseline and the movement artifact noise. In particular, these sources have frequency spectra that include also the low-frequency components of the sEMG frequency spectrum; therefore, a standard all-bandwidth filtering could alter important information. The Wavelet denoising method has been demonstrated to be a powerful solution in processing white Gaussian noise in biological signals. In this paper we introduce a new technique for the denoising of the sEMG signal: by using the baseline of the signal before the task, we estimate the thresholds to apply to the Wavelet thresholding procedure. The experiments have been performed on ten healthy subjects, by placing the electrodes on the Extensor Carpi Ulnaris and Triceps Brachii on right upper and lower arms, and performing a flexion and extension of the right wrist. An Inertial Measurement Unit, developed in our group, has been used to recognize the movements of the hands to segment the exercise and the pre-task baseline. Finally, we show better performances of the proposed method in term of noise cancellation and distortion of the signal, quantified by a new suggested indicator of denoising quality, compared to the standard Donoho technique.

Performing laparoscopic surgery requires several skills which have never been required for conventional open surgery, surgeons experience difficulties in learning and mastering these techniques. Various training methods and metrics have been developed in order to assess and improve surgeon's operative abilities. While these training metrics are currently widely being used, skill evaluation methods are still far from being objective in the regular laparoscopic skill education.
This paper proposes a methodology of defining a model to objectively evaluate surgical performance and skill expertise in the routine laparoscopic training course. Our approach is based on the processing of kinematic data describing the movements of surgeon's upper limbs. An ultra-miniaturized wearable motion capture system (Waseda Bioinstrumentation system WB-3), therefore, has been developed to measure and analyze these movements. The skill evaluation model was trained by using the subjects' motion features acquired from WB-3 system and further validated to classify the expertise levels of the subjects with different laparoscopic experience. An experiment for training fundamental laparoscopic psychomotor skill was elaborated by using laparoscopic box trainer. Preliminary results show that, the proposed methodology can be efficiently used both for quantitative assessment of surgical ability, and for the discrimination between expert surgeons and novices.

:This paper presents the preliminary performance evaluation of our new wireless ultra-miniaturized inertial measurement unit (IMU) WB-4 by compared with the Vicon motion capture system. The WB-4 IMU primarily contains a mother board for motion sensing, a Bluetooth module for wireless data transmission with PC, and a Li-Polymer battery for power supply. The mother board is provided with a microcontroller and 9-axis inertial sensors (miniaturized MEMS accelerometer, gyroscope and magnetometer) to measure orientation. A quaternion-based extended Kalman filter (EKF) integrated with an R-Adaptive algorithm for automatic estimation of the measurement covariance matrix is implemented for the sensor fusion to retrieve the attitude. The experimental results showed that the wireless ultra-miniaturized WB-4 IMU could provide high accuracy performance at the angles of roll and pitch. The yaw angle which has reasonable performance needs to be further evaluated.

This paper describes an avoidance behavior against unknown forces acting from outside the system on a biped vehicle. External forces that act on a biped vehicle can be divided into two categories: disturbances from the rider of the vehicle and disturbances from outside the system. Disturbances from the rider are measured by a force sensor placed between the rider's seat and the pelvis, while disturbances from outside the system are estimated from zero moment point (ZMP) errors. To guarantee walking stability, the waist position is adjusted to match the measured ZMP to the reference ZMP and the position of the landing foot is adjusted such that the waist trajectory does not diverge. On implementing the developed method on the human-carrying biped robot in an experimental setup, the robot could realize a stable walk even while subjected to unknown external forces in the environment. On applying a pushing force to the walking robot, the robot moved in the pushed direction and away from the source of the externally generated forces. On pushing the robot that was walking forward, the robot stopped moving forward and avoided getting closer to the source of the externally generated forces. We confirmed the effectiveness of the proposed control through these experiments. (C) Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2011

In recent years advanced robotic technology has seen more use in the medical field to assist in the development of efficient training systems. Such training systems must fulfill the following criteria: they must provide quantitative information, must simulate the real-world conditions of the task, and assure training effectiveness. We developed Waseda Kyotokagaku Airway series to fulfill all of those requirements. The WKA series we had developed does not consider external appearance such as patient skin, or internal appearance such as the pharynx, larynx, and esophagus. Moreover, the tongue mechanism of the previous system can not precisely measure the force applied by medical devices and cannot simulate muscle stiffness. In addition, the mandible mechanism of the previous system could not adequately reproduce various airway difficulties or apply force control. For these reasons, we propose the WKA-4, which has high-fidelity simulated human anatomy, and we have improved the mechanism over the previous system. We have also attached a lung to the proposed system to improve simulation of the real-world conditions of the task. In this paper, we present how to design several organs with various embedded sensors and actuators, for a conventional patient model with high-fidelity simulated human anatomy. We also present the control system for the WKA-4. Finally, we present a set of experiments carried out using doctors as subjects, and they gave their valuable opinions about our system.

Many patients suffer from swallowing disorders (dysphagia). There are many treatments for these disorders, such as swallowing therapy, surgery, and dietary modification. In our study, we focuse on dietary modification, a common approach. Normally, the swallowing is affected by food bolus properties such as hardness, stickiness and rheological characteristics, and dietary modifications can prevent swallowing disorder patients from suffering dysphagia (aspiration), as well as promote good nutrition. Based on these facts, our goal is to find foods which do not cause dysphagia, and develop food for swallowing disorder patients accordingly. Therefore, we are proposing an in-vitro Dynamic VFSS (Video Fluorographic Swallowing Study) simulation system which uses advanced robotics technology to mimic the dynamic process of swallowing and monitors the status and movement of the food bolus inside the system, for objective evaluation of the swallowing process. The dynamic VFSS simulation system consists of a head, mandible, neck, tongue, pharynx, and larynx which reproduce human anatomy. It is driven by 16 actuators with wire driving mechanisms. In this paper, we will present the dynamic VFSS simulation unit in detail. In addition, we will detail a set of the experiments carried out to determine whether food bolus properties can affect dysphagia or not. To observe the movement of the food bolus, we use a Video Fluoroscopy (VF) unit. The results of the experiments show that thickened boluses have a tendency to leave residue in the epiglottic vallecula. In contrast, liquids cause less residue, and increase the risk of dysphagia (aspiration). Moreover, this study shows that the frontal image, as well as the lateral image, is important for evaluating residual food in the oral-pharyngeal space.

The Simulation Model which can visualize the shape of commercial colonoscope is proposed. This model uses kinematic chain which approximates the shape of colonoscope by serially connected multiple joint-link pairs. As the input to the model, orientation information is used. Orientation information is extracted from the Sensor Network. The sensor network consists of connecting a number of sensor units with CAN bus. Each sensor unit also has two kinds of sensor: triad of accelerometer and triad of magnetometer. Roll and pitch angle are estimated based on the accelerometer signals. Yaw angle is estimated based on the magnetometer signals. By using kinematic chain model and orientation as input, we estimate the key points which are positions of sensor units on the colonoscope. Then, we implement spline interpolation to find the intermediate points which constitutes the shape of colonoscope. We made experiment in order to check whether model has enough accuracy. Firstly, we compared estimated curve with sine curve which is used as a ground truth. Secondly, we investigated the effect of number of sensor on the accuracy. Final result says that it has enough estimation ability.

3D Visualization method of shape of flexible colonoscopy in simulated computing environment is proposed. Signals from sensor network are used to calculate the orientation of the body of each sensor. Position of each sensor is estimated from the orientation using assumption of forward kinematics in robotics. This data are then interpolated with curve fitting method to give natural impression of shape to surgeon who are watching monitor. The resulting simulated curve shows that motion of shape of colonoscopy can be simulated at it is.

Up to now, there are different kinds of robot-assisted ultrasound diagnostic systems proposed in the last decade. However, the compensation of the ultrasound probe position according to the patient movement is still one of the most important and useful functions required for those systems. For this purpose, in this research, we aim at developing an automated diagnostic system for the measurement of the wave intensity which is usually measured at the common carotid artery. In particular, in this paper, we focus on proposing a robust visual servoing method for tracking out-of-plane motion for a robot-assisted medical ultrasound diagnostic system by using a conventional 2D probe. A robotic device which manipulates the ultrasound probe firstly scans a small area around the target position and records several B-mode images at a regular interval. In order to track the out-of-plane motion, an inter-frame block matching method has been proposed and implemented on the Waseda-Tokyo Women's Medical-Aloka Blood Flow Measurement System No. 2 Refined (WTA-2R). A set of experiments was proposed to verify the effectiveness of the proposed method. From the experimental results, we could confirm its robustness while doing the task with real human tissues.

In this paper we propose the basic concept of a tele-presence system for two (or more) anthropomorphic robots located in remote locations. As one robot interacts with a user, it acquires knowledge about the user's behavior and transfers this knowledge to the network. The robot in the remote location accesses this knowledge and according to this information emulates the behavior of the remote user when interacting with its partner. © 2011 IEEE.

This paper describes a fast turning method for a humanoid robot by using slipping motion with both feet. The humanoid robot, WABIAN-2R, has achieved human-like walking with heel contact and toe off motions by using a human-like foot mechanism with a passive toe joint. The human-like foot enables a robot to turn by using slipping motion between the feet and the ground because it can switch ground contact conditions such as heel contact, sole contact and toe contact. To realize a slipping turn, we develop an attitude control. Verification of the proposed method is conducted through experiments with a biped humanoid robot WABIAN-2R. WABIAN-2R realized a quick turn by using slipping motion with both feet. We also confirmed that the energy consumption of a slipping turn is less than that of a stepping turn.

A four degrees of freedom (DoF) waist and trunk mechanism, as well as human-like foot, enable the humanoid robot WABIAN-2R to perform human-like walk with stretched knees, and heel-contact and toe-off gait phases. The inverse kinematics (IK) method, used in the present system, requires specification of not only task space reference trajectories, but also reference trajectories for all redundant DoFs. In this paper, we propose a novel, unified inverse kinematics method significantly simplifying the pattern generation. The method enables generation of the above described gait by specifying only the task space trajectories. We divide the forward locomotion task into subtasks with different priorities and combine them in the single IK equation. We also perform experiments in simulation environment as well as on WABIAN-2R, which prove that the method can be used to calculate IK for human-like gait. The equation evaluated in this paper is applied to the forward locomotion task, however it can be easily modified to perform other tasks on humanoid robots with different kinematic structures.

One of the important tasks required for sonographers is an accurate positioning of ultrasound probe. Especially, the measurement of the diameter of the blood vessel is affected by the positioning error of the probe. For this purpose, we have been developing a robot system for the medical ultrasound diagnosis, which composed of a 6-DOFs probe manipulator and supporting arm. In this paper, we present an implementation of fully automated positioning algorithm of the ultrasound probe on the carotid artery, by means of image feedback. A probe holding robot firstly detects the patient skin, then scans and detects the longitudinal section of the carotid artery, guide the probe towards the position where the tissue layers of the artery walls are most clearly observed. Furthermore, a new method of the visual servoing for tracking the out-of-plane motion for the medical ultrasound is presented. Automated positioning algorithm is tested in eleven volunteers and the results show that the system successfully completed the task in 91% of the trials. Visual servoing algorithm is also tested and the experimental results show its effectiveness.

This research proposes to design and develop a novel robot involved in the general and famous animal experimental method called Social Interaction Test (SIT). Aiming at increased movement range of the waist and improved interoperability, we have developed a novel small animaroid robot WR-4 (Waseda Rat No.4). The waist of WR-4 endowed with a multi-bendable 6-bar linkage mechanism makes the robot able to rotate around ±130° horizontally, meeting required movement range. Integrating with a 4-bar linkage mechanism in the neck, this 6-bar linkage mechanism achieves the bending posture as living rats, allowing the imitation of behavior such as rotating. Furthermore, ultrasonic motors (USM) used to drive forelegs greatly reduce the weight of upper body, resulting in quicker acting of rearing behavior. WR-4 consists of 10 active DOFs (two 1-DOF wheels for locomotion, two 2-DOF forelegs for interaction, one 1-DOF neck for swing, one 2-DOF waist for rearing and body grooming and one 1-DOF reserved for tail) and 2 passive DOFs in the paws. The evaluation tests on motion performance show that WR-4 could act both rearing (reaching 60°) and rotating (reaching ±100° respectively) behaviors approximately 0.1s quicker than mature rats. Preliminary SIT between WR-4 and mature rats have been conducted strictly following psychological rules. Experimental results reveal that the frequencies of rearing behavior in rats were increased significantly when WR-4 reared periodically, and the activities of rats were decreased after WR-4 reared. © 2011 IEEE.

This paper presents the design and development of a bio-inspired mobile robot called WR-3 (Waseda Rat no. 3). The purpose of the robot is to work as an experimental tool to study social interaction between rats and robots. According to the results of the analysis of the motion of rats, their behavior can be divided into two phases: movement and interaction. Therefore, a novel hybrid mechanism that uses wheels during the movement phase and legs while interacting has been designed to actuate WR-3. Consequently, the robot can move at a high speed using its wheels, and reproduce the rat&apos;s interaction behavior using its legs and other parts. Based on body structure of a mature rat, WR-3 has been designed with similar dimensions and shape as a mature rat, and the quality of the shape imitation has been verified by the experiments of a rat&apos;s interestingness to the robot and stuffed rat. Evaluation experiments show that WR-3 is capable of reproducing a rat&apos;s actions such as chasing, rearing, grooming, mounting, etc., similar to a real rat. Furthermore, preliminary social interaction tests with living rats reveal that WR-3 is to some extent able to evoke natural reactions form a real rat and is therefore able to perform a certain level of realistic interaction. (C) Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2011

In this paper we present a general strategy for the calculation of the effective Center of Mass (CoM) of humanoid robots, allowing the reduction of the error between the virtual robot model and the real platform. The method is based on an algorithm that calculates the real position of the CoM of a biped humanoid robot using only 2 force/torque sensors located on the feet of the robot. By means of this algorithm, it is possible to reduce the gap between the real and the virtual posture of the robot and consequently the errors between the ZMP trajectory calculated by the offline pattern generator and the ZMP trajectory calculated by the real-time pattern generator of the humanoid robot. Thus, the influence of the real-time control in the static and dynamic balance of a humanoid platform is minimized. Experimental results using SABIAN platform are provided to validate the proposed method. The results support the applicability of the method to more complex systems. © 2011 IEEE.

Humanoid robots are becoming an important factor for the future work. Future planes are made for the use of humanoid robots for space and planetary exploration application. The development of humanoid robot to work in such environment for the purpose of human assisting is becoming highly demanded. The challenge of developing a bipedal robot to walking on other planets and moons is really high due the different in gravity compare to earth. The difference in the gravity might have a great effect on the robot locomotion. In order to know this effect some basic study needed to be conducted. This research studies the effect of different gravity on the locomotion. The approach for dealing for the different gravity is purposed in this study. © 2011 IEEE.

We present an autonomous goal-directed strategy to learn how to control a redundant robot in the task space. We discuss the advantages of exploring the state space through goal-directed actions defined in the task space (i.e. learning by trying to do) instead of performing motor babbling in the joints space, and we stress the importance of learning to be performed online, without any separation between training and execution. Our solution relies on learning the forward model and then inverting it for the control
different approaches to learn the forward model are described and compared. Experimental results on a simulated humanoid robot are provided to support our claims. The robot learns autonomously how to perform reaching actions directed toward 3D targets in task space by using arm and waist motion, not relying on any prior knowledge or initial motor babbling. To test the ability of the system to adapt to sudden changes both in the robot structure and in the perceived environment we artificially introduce two different kinds of kinematic perturbations: a modification of the length of one link and a rotation of the task space reference frame. Results demonstrate that the online update of the model allows the robot to cope with such situations. © 2011 IEEE.

Personal robots and Robot Technology (RT)-based assistive devices are expected to play a substantial role in our society largely populated by the elderly
they will play an active role in joint works and community life with humans. In particular, these robots are expected to play an important role in the assistance of the elderly and disabled people during normal Activities of Daily Living (ADLs). To achieve this result, personal robots should better be capable of making emotional expressions like human. In this perspective we developed a whole body bipedal humanoid robot named KOBIAN that is capable of expressing humanlike emotions. In this paper we present the development and evaluations of KOBIAN.

Since 1990, at Waseda University the development on the Anthropomorphic Flutist Robot has been focused on mechanically reproducing the physiology of the organs involved during the flute playing (i.e. lungs, lips, etc.) and implementing basic cognitive capabilities to interact with flutist beginners. As a results of the research efforts done until now, the Waseda Flutist Robot is considered to play the flute nearly similar to the performance of a intermediate human player. However, we consider that in order to extend the interaction capabilities of the flutist robot with musical partners, further research efforts should be done. In this paper, we propose as a long-term goal to enable the flutist robot to interact more naturally with musical partners on the context of a Jazz band. For this purpose a Musical-Based Interaction System (MbIS) is proposed to enable the robot the process both visual and aural cues coming throughout the interaction with musicians. In particular, in this paper, the details of the implementation of the visual tracking module on the Waseda Flutist Robot No. 4 Refined IV (WF-4RIV) is presented. The visual tracking module is composed by two levels of interaction: basic (visual interface for the musician based on controlling virtual buttons and faders) and advanced (instrument tracking system so that the robot can process motion gestures performed by the musical partner in real-time which are then directly mapped into musical parameters of the performance of the robot). The experiments carried out were focused in verifying the effectiveness and usability of the proposed levels of interaction. In particular, we focused on determining how well our the WF-4RIV dynamically changes musical parameters while interacting with a human player. From the experimental results we observed that the physical constraints of the robot play an important role during the interaction. Although further improvements should be done to overcome such constrains, we expect that the interaction experience may become more natural. © 2010 Springer Science+Business Media, LLC.

Recently, the number of people of dentists increases every year. However, the lack of skills of graduates of schools of dentistry is obvious. The problem seems to lie in the fact that the dentists have no sufficient experience of treating patients. The present study was made in order to develop a patient-robot for use in an actual clinical training. The patient has the possibility of making an unexpected motion while treating. This motion often surprises the dentist. Therefore, it is important to develop a leg of the patient-robot so that the development of the whole body motion may make the patient-robot more like a real patient.

Our research aims to develop an anthropomorphic saxophone-playing robot; as an approach to understand the human motor control from an engineering point of view. In this paper, we present the Waseda Saxophonist Robot No. 2 (WAS-2) which is composed of 22 degrees of freedom (DOF). In particular, he functioning of the lips, fingers, tongue, oral cavity and lungs have been mechanically simulated to enable WAS-2 to play an alto saxophone. Furthermore, in order to ensure the accuracy of the air pressure control, a feed-forward control system with dead time compensation has been implemented. A set of experiments were carried out to verify the effectiveness of the proposed system. From the experimental results, the range of sound pressure was increased and the air pressure control was improved.

This paper describes an online walking pattern generation method for biped humanoid robots which is based on a preview control method. Depending on the walking parameters, a 3-step pattern and reference ZMP are generated, and one step in the pattern is selected for walking. If another 3-step pattern is created, it will connect with the previous step using linear interpolation. This pattern generation method is able to deal with forward, sideward and forward-sideward mixed walking. In order to confirm the pattern generation method, various walking simulations are conducted using MATLAB/Simulink and ADAMS.

Even though the market size is still small at this moment, applied fields of robots are gradually spreading from the manufacturing industry to the others as one of the important components to support an aging society. For this purpose, the research on human-robot interaction (HRI) has been an emerging topic of interest for both basic research and customer application. The studies are especially focused on behavioral and cognitive aspects of the interaction and the social contexts surrounding it. As a part of these studies, the term of oroboethicso has been introduced as an approach to discuss the potentialities and the limits of robots in relation to human beings. In this article, we describe the recent research trends on the field of humanoid robotics. Their principal applications and their possible impact are discussed.

In the medical literature, the ultrasound diagnosis is a quite well user-friendly method due to its non-invasiveness, portability and real-time imaging capabilities. Recently, some fatigue issues (including musculoskeletal injuries) with sonographers have been reported. Most of those issues are mainly due to the physical stress on the sonographers during their considerably long time task. During the diagnosis, the sonographers usually hold their wrist without touching the patients. Moreover, they are sometimes required to apply a force for the probe to push abdomen of the patients in order to obtain clearer ultrasound image. Therefore, our research aims in developing a probe supporting robot to reduce the fatigue of sonographers during the abdominal diagnosis. In this paper, we describe the design of the Waseda-Tokyo Women's Medical-Aloka System No. 2 (WTA-2) which is composed of an ultrasound diagnosis system, an actuated 3-DOFs robot arm with two different interchangeable end-effectors. One is for power assist of applied force, and the other is for supporting sonographer's wrist. The design of the robot, a force sensing method using photo sensors and the control of the robot are detailed. A set of experiments were carried out in order to verify the effectiveness of the proposed system to support sonographers while performing the diagnosis.

Since 2007, the research on the anthropomorphic saxophonist robot at Waseda University aims in understanding the human motor control from an engineering point of view as well as an approach to enable the interaction with musical partners. As a result of our research, last year we have introduced the Waseda Saxophonist Robot No. 1 (WAS-1), composed of 15-DOFs that reproduced the lips (1-DOF), tonguing (1-DOF), oral cavity, lungs (2-DOF) and fingers (11-DOFs). However, even that the mouth mechanism of WAS-1 was useful in order to adjust the pitch of the saxophone sound, the range of sound pressure was too narrow. Thus, no dynamic effects of the sound can be reproduced (i.e. crescendo and decrescendo). Moreover, the finger mechanism was designed only to play from C3-C#5. On the other hand, a cascade feedback control system has been implemented in the WAS-1; however, a considerable delay in the attack time to reach the desired air pressure was detected. Therefore, in this paper, the Waseda Saxophone Robot No. 2 (WAS-2) which is composed by 22-DOFs is detailed. The lip mechanism of WAS-2 has been designed with 3-DOFs to control the motion of the lower, upper and sideway lips. In addition, a human-like hand (16 DOF-s) has been designed to enable to play all the keys of the instrument. Regarding the improvement of the control system, a feed-forward control system with dead-time compensation has been implemented to assure the accurate control of the air pressure. A set of experiments were carried out to verify the mechanical design improvements and the dynamic response of the air pressure. As a result, the range of sound pressure has been increased and the proposed control system improved the dynamic response of the air pressure control.

The Waseda Flutist Robot WF-4RIV is a humanoid robot that is able to imitate a human flute performance. In the recent years the mechanical construction of the robot has been improved, so that the robot's playing capabilities have reached the level of an intermediate human instrument player. To make the robot able to play at this performance level, careful calibration of its musical parameters is necessary. Using the flutist robot's core control software, this procedure is very complicated to perform. In this paper we present the implementation of a visual control interface that allows also non-technical users to calibrate the sound settings. The newly developed control interface enables a musician to adjust certain parameters of the robot performance while the robot is playing. Experiments in which we verify the functionality of this sound calibration system are presented. We examine the visual processing system's perception of the instrument movements of a human performer and analyze their effect on the performance of the robot.

In this paper, we present our research on the development of an automated medical ultrasound scanning system for the carotid artery using probe a supporting manipulator (parallel link mechanism). In particular, we detail the mechanism design of the manipulator and a real-time image processing algorithms to detect the carotid artery and tissue layer of its walls (in the B-mode of ultrasound image). Several sequential patterns of ultra-sound probe trajectory were implemented in order to enable the manipulator to scan the surface of neck effectively. A set of experiments has been carried out to verify the effectiveness of the proposed system.

To increase the maximum payload, the joint arrangement of the Stewart platform type leg mechanism for a biped walking vehicle is optimized by a dynamic simulation and a real-coded genetic algorithm. Using effective joint arrangement, the maximum HMS (root-mean-square) value of the current will be able to be reduced. A new prototype of a biped walking vehicle, WL-16RIV, was developed by using the optimal joint arrangement method. Weight saving in some parts was also conducted. Through walking experiments, the maximum R,MS value of the current, was reduced, and the maximum payload was increased. The effectiveness of the proposed method was confirmed

This paper describes a disturbance avoidance control from environments for a biped walking vehicle. To distinguish between external forces from passenger and those from environments, we use the data of a force sensor mounted on foot to generate an avoidance behavior. To guarantee a walking stability against external forces. a compensation motion around a reference ZMP is generated. Then, external forces are estimated from ZMP errors. By implementing the developed method on the human-carrying biped robot, the robot realized a stable walk under unknown external forces from environments.

This paper describes about an online pattern generation based on FFT (Fast Fourier Transform). Until now, authors have adopted the offline FFT-based pattern generation. However, it's needed to regard the compensated moment from starting walking to stopping as a periodic function and it's difficult to generate a part of walking pattern. As a solution, it's found that the compensatory waist trajectory for the compensated moment which is cut out with a window of predetermined duration is proper only in the center part of the window. That means the whole trajectory is obtained as a series of the partial ones. Therefore, the online pattern generation is realized by generating a partial trajectories in the proposed way while walking.

This study investigates the effects of semi-passive dynamics bipedal walking on humanoid robots using a simulation approach. WABIAN-2R is a human size robot developed to be used as human motion simulator. It has 39 degrees of freedom of rigid joints and is selected for this study. The actuator of the ankle joint and its harmonic drive is replaced with an elastic joint. This configuration creates a semi-passive bipedal walker, since the rest of the joints are actively controlled to track a desired gait pattern. The passive movement of the elastic ankle joint stores part of the energy of the robot during the collision phase into an elastic form and returns that energy during the rebound phase. The robot can successfully finish a limited number of walking steps.

We have developed a biped humanoid robot, WABIAN-2R as a human motion simulator. However, it was difficult to walk stably on terrain with unevenness of several millimeters. So, we propose an attitude compensation control and a landing pattern modification control (LPMC) to deal with uneven terrain. The LPMC modifies the motion of the landing foot according to the ground surface while the attitude control compensates posture angles of the body based on the 3-axis gyro sensor's data. By integrating two controls, WABIAN-2R is able to walk on outdoor terrain with 5 degree inclination slope and height variations of several millimeters.

Purpose: Oral disorders such as temporomandibular joint disorders (TMD) and dry mouth are common and often require treatment. Maxillofacial massage is used as a complementary and alternative therapy for these disorders. We developed an oral rehabilitation robot that massages the maxillofacial tissues for this purpose. In this paper, we propose a control system for oral rehabilitation robots. Method: The control system consists of a massage path generator, virtual compliance calculator, and inverse kinematics calculator. The massage path generator computes a target massage path based on a human head model obtained from a reference MRI image of an adult male. The head model includes the shape and elastic modulus of each component, all of which were obtained experimentally. Virtual compliance control is used to control manipulators with position servo actuators. The manipulators, which have a force sensor at their end-effectors, move actively in the direction of the external force applied to their sensors via virtual compliance control. We implemented this control in WAO-1, our first prototype oral rehabilitation robot. Results: WAO-1 provided massage to three adult male subjects with and without virtual compliance control. One of the subjects was the adult male whose MRI image was used to synthesize the head model in the massage path generator. Without virtual compliance control, the actual massage force was greater than the target massage force, while that with virtual compliance control was less than the target massage force. Furthermore, with virtual compliance control, the massage paths conformed to the head shape of each patient. Conclusion: Implementation of virtual compliance control in the WAO-1 massage robot is feasible and useful for implementation of safe and potentially effective maxillofacial massage therapy. © 2009 CARS.

This paper reports on the development of an Airway Management Training System. Airway management is a standard operation executed in emergency and operating rooms. However, medical accidents occur due to unskilled operations. In order to avoid accidents, medical doctors undergo to mannequin-based training. However, traditional training techniques do not provide quantitative information on the trainees performance and are not capable to assess the trainees performance based on the quantitative information. In this context, we proposed a novel airway management training system, dubbed WKA-3. This work presents both the electromechanical and the control sub-systems of the WKA-3. The results of preliminary experiments carried out by medical doctors to doctors to verify the training system are also provided.

Our research is related to the development of an anthropomorphic saxophonist robot, which it has been designed to mechanically reproduce the organs involved during the saxophone playing. Our research aims in understanding the motor control from an engineering point of view and enabling the communication between humans and robots in musical terms. In this paper, we present the Waseda Saxophone Robot No. 2 (WAS-2) which is composed by 22-DOPs. In particular, the lip mechanism of WAS-2 has been designed with 3-DOFs to control the motion of the lower, upper and sideways lips to increase the sound range and to reproduce the dynamic effect of the sound (i.e. crescendo and decrescendo). In addition, a human-like hand (16-DOFs) has been designed to enable to play all the keys of the instrument. A set of experiments were carried out to verify the effectiveness of the mechanical design and the control system improvements.

Personal robots and Robot Technology (RT)-based assistive devices are expected to play a substantial role in our society, largely populated by elders; they will play an active role in joint works and community life with humans. In particular, these robots are expected to play an important role for the assistance of elderly and disabled people during normal activities of daily living (ADLs). To achieve this result, personal robots should be also capable of human-like emotion expressions. In this perspective we developed a whole body bipedal humanoid robot, named KOBIAN, which is also capable to express human-like emotions. In this paper we present the mechanical and modular design of KOBAIN.

This paper describes an avoidance behavior from unknown external forces for a biped walking vehicle. To distinguish between external forces from passenger and those from environments, we use the data of a force sensor mounted on foot, and external forces are estimated from ZMP errors. To guarantee a walking stability, the waist position is adjusted to match the measured ZMP to the reference ZMP, and the position of landing foot is adjusted so that the waist trajectory does not diverge. By implementing the developed method on the human-carrying biped robot, the robot realized a stable walk under unknown external forces from environments. When pushing the robot stepping, the robot moved backward and moved away from the generation source of external forces about 400 mm. When pushing the robot walking forward, the robot stopped going forward and prevented from coming closer to the generation source of external forces. We confirmed the effectiveness of the proposed control through these experiments.

We have developed a new biped foot mechanism capable of detecting ground surface to realize stable walking on uneven terrain. The size of the foot mechanism is 160 mm x 277 mm and its weight is 1.5 kg. The foot system consists of four spikes each of which has an optical sensor to detect ground height. The foot makes a support polygon on uneven terrain by using three or four spikes. We have conducted several experiments on the outdoor ground surface that has a slope of 7.0 degrees and a maximum height of 15 mm bumps, and the effectiveness of the foot mechanism is confirmed.

Purpose Fibre optic colonoscopy is usually performed with manual introduction and advancement of the endoscope, but there is potential for a robot capable of locomoting autonomously from the rectum to the caecum. A prototype robot was designed and tested. Methods The robot colonic endoscope consists in a front body with clockwise helical fin and a rear body with anticlockwise one, both connected via a DC motor. Input voltage is adjusted automatically by the robot, through the use of reinforcement learning, determining speed and direction (forward or backward). Results Experiments were performed both in-vitro and in-vivo, showing the feasibility of the robot. The device is capable of moving in a slippery environment, and reinforcement learning algorithms such as Q-learning and SARSA can obtain better results than simply applying full tension to the robot. Conclusions This self-propelled robotic endoscope has potential as an alternative to current fibre optic colonoscopy examination methods, especially with the addition of new sensors under development. © CARS 2010.

The research on the Waseda Flutist Robot, since 1990, is an approach to understand human motor control from an engineering point of view, as well as introducing novel ways of musical teaching. More recently, the authors have proposed as a long-term goal the aim to enable musical performance robots to interact with musical partners. For this purpose, we present two research approaches: implementing more advanced cognitive capabilities on the Waseda Flutist Robot no. 4 Refined IV (WF-4RIV) (i.e., visual/aural processing) and developing a new musical performance robot (i.e., duet performance). In this paper, we have focused our research on developing an anthropomorphic saxophonist robot as a benchmark to better understand how the interaction with musical partners can be facilitated. As a result, we have developed the Waseda Saxophonist Robot no. 1 (WAS-1) with 15 d.o.f. that mechanically simulates the organs involved during saxophone playing. In this paper, we present the details of the mechanical design of the simulated organs, as well as the implementation of the musical performance control system based on air pressure feedback control. A set of experiments was proposed to verify the effectiveness of the designed simulated organs to produce the saxophone sound and to verify the effectiveness of the proposed air pressure feedback control by comparing the saxophone performance of WAS-1 against an intermediate saxophonist. Finally, a preliminary experiment was carried out to analyze the feasibility of realizing a duet performance with the WF-4RIV. From the experimental results, we have confirmed that WAS-1 is capable of producing a saxophone sound nearly similar in terms of pitch and volume to the performance of a human player. (C) Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2010

Problem statement: Jaw movement analysis, as a clinical aid, can provide an objective basis for understanding and diagnosing jaw musculoskeletal disorders. Therefore, the use and development of devices for quantitatively measuring and analyzing jaw movement have become more common and popular in the clinic. Many types of jaw tracking devices have been developed, but most of them are still not handy and easy to be used. Approach: To improve the handiness and utility of the jaw movement analysis devices, we developed a simple to be used jaw tracking prototype by using a new ultra-miniaturized Inertial Measurement Unit (IMU) named WB-3. The WB-3 IMU was composed by 3-axis gyroscope, 3-axis accelerometer and 3-aixs magnetometer, which can not only measure the acceleration and angular speed of jaw movement, but also can measure mouth opening angle. The IMU's extremely reduced weight and size allowed it to be easily adhered to mandible during normal tests without physical restriction to the subjects. A preliminary experiment for jaw movement analysis during free chewing of three types of food with different shapes and hardness was evaluated. A group of 15 healthy subjects aged from 21-36 years old kindly participated in the experiment. Results: The parameters of chewing time, chewing frequency, power spectrum density of jaw's angular speed and acceleration, cumulative distribution function of jaw's acceleration and mouth opening angle were presented. The experimental results clearly showed that the subjects used less chewing time, less chewing frequency, less acceleration cumulative distribution and energy to eat soft food
higher values were found in the case of hard food and there was no significant difference in mouth opening angle while eating these three foods. Conclusion: Our jaw movement analysis prototype using IMU WB-3 was proved to be a valid and handy method for jaw movement and pattern analysis which may be used clinically as an assistant system for dental therapy. © 2010 Science Publications.

Recently, in medical field, different training methods for medical staff have been proposed. However, the lack of knowledge on the real improvements of trainees makes difficult the real effectiveness of those proposed methods. Therefore, we are proposing an Active Training system for the effective medical training. The Active training system is characterized by providing quantitative information of the trainee's performance of the task to the trainee, simulating real-world conditions of the task, and assuring training effectiveness. In order to fulfill each of these characteristics, we have developed Waseda Kyotokagaku Airway No. 3 (WKA-3) which makes it possible to obtain quantitative information for the trainee's performance and reproduce the various cases, individual differences for the airway difficulties for the simulating real-world conditions of the task. In this paper, we are proposing a patient scenario generation which can reproduce the characteristics of the patient simulating real-world conditions of the task for WKA-3. In emergent situation or surgical operation, the characteristics of patients are presented in the three parameters such as: patient initial conditions, time variant status change, and reflex action. By adjusting, and combining each of the three parameters, we can reproduce the various patient scenarios. In this paper, we also state how to generate the Patient Scenario Generation using the position control and virtual compliance control. Finally, a set of experiments has been carried out to the doctor subjects in order to verify effectiveness of the proposed Patient Scenario Generation, and discuss the doctors about the result of the experiments.

An active training system is characterized by providing quantitative information of the trainee's performance of the task to the trainee, simulating real-world conditions of the task, and assuring training effectiveness. For this purpose, the authors have been developing an Airway management training system. In particular, we have previously presented an evaluation model system to acquire quantitative information for the trainee's performance, and an actuated model system for real-world conditions of the task. In order to fulfill all of the characteristics of the active training system; in this paper, we would like to propose an integrated system, Waseda Kyotokagaku Airway No. 3 (WKA-3) which integrates the function of both system models. For this reason, we have focused on embedding sensors and actuators with the link drive mechanism and the wire drive mechanism to a conventional patient model towards the development of a patient robot. In this paper, we present WKA-3 how to design the mechanism and how to redesign several organs to embed the sensors for the measurement of the trainee's performance. A set of experiment have been carried out to doctor subjects using the WKA-3 to verify the effectiveness of the proposed system by asking doctors to evaluate the proposed system.

The number of patients with mental disorders is increasing in advanced countries. Many researchers are working to develop mental disorder model animals that contribute to development of new psychotropic drugs. However, we have some doubts about conventional mental disorder models. Therefore, the purpose of this study is to develop an experimental setup to create novel mental disorder model animals. We then developed a small mobile robot and a control system for the robot. Using them, we performed an experiment to develop a mental disorder model rat. In the experiment, we succeeded in developing a new depression model rat and also high activity model rat. These disorder models must be useful in the screening of new psychotropic drugs. In addition, the methodology we developed in this research will contribute to clarifying mechanisms of mental disorders.

In the domain of psychology and medical science, many experiments have been conducted referring to research on animal behaviors, to study the mechanism of mental disorders and to develop psychotropic drugs to treat them. Rodents such as rats are often chosen as experimental subjects in these experiments. However, according to some researchers, the experiments on social interactions using animals are poorly-reproducible. Therefore, we consider that the reproducibility of these experiments can be improved by using a robotic agent that interacts with an animal subject. We have developed a novel quadruped rat-inspired robot, the WR-2 (Waseda Rat No. 2), based on the dimension and body structure of a mature rat. It is capable of reproducing the behaviors such as walking, mounting, rearing and grooming of the rat.

This paper presents the design and development of a bio-inspired mobile robot called WR-3 (Waseda Rat No. 3), as an experimental tool to study social interaction between rats and robots. According to the motion analysis of rats, their motion can be divided into two phases: moving and interaction. Therefore, a novel hybrid mechanism in which wheels are used for moving and legs are used for interaction has been designed to actuate the WR-3. Consequently, the robot can move at a high speed using its wheels and reproduce the rats' interaction using its legs and other parts. Based on the dimension and body structure of a mature rat, WR-3 has been designed with dimensions of 240x70x90[mm] and is the same shape as a rat. It consists of 18 DOFs in total: two 1-DOF wheels, four 3-DOF legs (including passive DOFs), a 2-DOF waist, and a 2-DOF neck. Preliminary interaction experiments with rats demonstrate that WR-3 is capable of reproducing interactions such as following, rearing, grooming, mounting, etc. similar to a real rat.

Robot Technology should contribute to the progress of other research fields. We'd like to propose one example of it. In psychology, basic medicine and biological science, several experiments on animal behavior have been performed to clarify brain functions or mechanisms of learning. These experiments have been playing very important role to understand human mind. Rats and mice have been well used in these experiments. Therefore, we have been developing quadruped robots that reproduce animal behavior as new experimental tools. We developed a quadruped robot that has 4 legs and reproduces some social behaviors. Each leg has 3 DOFs. The robot also has 2 DOF at the neck and 2 DOF at the waist.

This paper presents the comparison of the WB-3 ultra-miniaturized inertial measurement unit (EMU), developed by our group, with the commercial EMU IntertiaCube by InterSense and the Vicon motion capture system. WB-3 is provided with a 32-bit microcontroller and 9-axis inertial sensors (miniaturized MEMS accelerometer, gyroscope and magnetometer). We implemented an Extended Kalman Filter (EKF) based on quaternion for the sensor fusion to retrieve the attitude. A new methodology for the automatic estimation of the measurement covariance matrix on the EKF is presented (R-Adaptive Algorithm). The preliminary results showed that WB-3 performance is comparable with Vicon. The R-Adaptive Algorithm improves the attitude reconstruction in case of non-static condition compared with the commercial IMU. © 2010 IEEE.

Performing laparoscopic surgery requires several skills which have never been required for conventional open surgery, surgeons experience difficulties in learning and mastering these techniques. Various training methods and metrics have been developed in order to assess and improve surgeon's operative abilities. While these training metrics are currently widely being used, skill evaluation methods are still far from being objective in the regular laparoscopic skill education. This study proposes a methodology of defining a processing model to objectively evaluate surgical performance and skill expertise in the routine laparoscopic training course. Our approach is based on the analysis of kinematic data describing the movements of surgeon's upper limbs. An ultra-miniaturized wearable motion capture system (Waseda Bioinstrumentation system WB-3), therefore, has been developed to measure and analyze these movements. The skill evaluation model was trained by using the subjects' motion features acquired from WB-3 system and further validated to classify the expertise levels of the subjects with different laparoscopic experience. Experimental results show that, the proposed methodology can be efficiently used both for quantitative assessment of surgical performance, and for the discrimination between expert surgeons and novices. © 2010 IEEE.

Mastication analysis can provide an objective basis for studying and diagnosing jaw musculoskeletal disorders. Therefore, the use and development of devices for quantitatively measuring and analyzing jaw movement have become very popular in the consulting room. This paper proposes a simple to be used jaw tracking prototype by using the new miniaturized wireless Inertial Measurement Unit (IMU) named WB-4. The WB-4 IMU primarily contains a mother board, a Bluetooth module and a Li-Polymer battery. The mother board is provided with a microcontroller and 9-axis inertial sensors (miniaturized MEMS accelerometer, gyroscope and magnetometer) to measure the jaw motion. The data transmission between WB-4 and PC is based on the Bluetooth module to realize the wireless communication. The IMU's extremely reduced weight and size allows it to be easily attached to mandible during normal mastication tests without physical restriction to the subjects. Three pilot experiments for mastication analysis of chewing gum were elaborated. A group of 9 healthy subjects kindly participated in the experiment. The preliminary results show that WB-4 IMU can efficiently evaluate the jaw movement and mastication pattern of different subjects, which could provide quantitative information to the doctors for the diagnosing and clinical treatment of different jaw diseases. ©2010 IEEE.

Real-time tracking of human body motion is an important technology in synthetic environments, robotics, and other human-computer interaction applications. This paper presents an ultra-miniaturized inertial measurement unit (IMU) named WB-3 for real-time attitude estimation of human limb segments. The WB-3 IMU is provided with a 32-bit microcontroller and 9-axis inertial sensors (miniaturized MEMS accelerometer, gyroscope and magnetometer). The quaternion-based Extended Kalman Filter (EKF) was implemented for the sensor fusion to retrieve the attitude of the human segment. An upper body motion capture system with 12 WB-3 IMUs was elaborated for tracking human movements in real time scenarios. ©2010 IEEE.

Personal robots anticipated to become popular in the future are required to be active in joint work and community life with humans. These personal robots must recognize changing environment and must conduct adequate actions like human. Visual tracking can be said as a fundamental function from the view point of environmental sensing and reflex reaction against it. The authors developed a visual tracking motion algorithm by using upper body. Then, we integrated it with an online walking pattern generator and developed a visual tracking biped locomotion. Finally, we conducted an experimental evaluation with emotion expression.

The research on Music Playing-Instrument Humanoid Robots (MP-HRs) has a long tradition in the research field of robotics since the development of the humanoid pianist robot WABOT-2 developed at Waseda University (1984). Since then, several researchers have been aiming for the better understanding of the human musical performance. For this purpose, different mechanical designs and cognitive functions have been implemented on them. A particular interest was given to wind instruments as a research approach for understanding human breathing mechanism. Nowadays, different kinds of automated machines and humanoid robots have been developed for playing wind instruments to understand the human motor control from an engineering point of view. Moreover, the importance of studying the ways of enabling the interaction between musicians-humanoid is being attracting several researchers from different research fields. As a long-term research goal, we are aiming to enable wind playing-instrument humanoid robots to display motor dexterities and high-level perceptual capabilities to interact with other musician partners. In this paper, we present our current research achievements on the development of an anthropomorphic saxophonist robot and the implementation of a musical-based interaction system tested on an anthropomorphic flutist robot.

Our research aims in developing an anthropomorphic saxophonist robot designed to mechanically reproduce the human organs involved during the saxophone playing. In this paper, the (Wa) under bar seda (S) under bar axophone Robot No. (2) under bar (WAS-2) which is composed by 22-DOFs is detailed. The lip mechanism of WAS-2 has been designed with 3-DOFs to control the motion of the lower, upper and sideway lips. In addition, a human-like hand (16 DOF-s) has been designed to enable to play all the keys of the instrument. Regarding the improvement of the control system, a feed-forward control system with dead-time compensation has been implemented to assure the accurate control of the air pressure. In addition, the implementation of an auditory feedback control system has been proposed and implemented in order to adjust the positioning of the physical parameters of the components of the robot by providing a pitch feedback and defining a recovery position (off-line). A set of experiments were carried out to verify the mechanical design improvements and the dynamic response of the air pressure. As a result, the range of sound pressure has been increased and the proposed control system improved the dynamic response of the air pressure control.

The flutist robot WF-4RIV at Waseda University is able to play the flute at the level of an intermediate human player. So far the robot has been able to play in a statically sequenced duet with another musician, individually communicating only by keeping eye-contact. To extend the interactive capabilities of the flutist robot, we have in previous publications described the implementation of a Music-based Interaction System (MbIS). The purpose of this system is to combine information from the robot's visual and aural sensor input signal processing systems to enable musical communication with a partner musician. In this paper we focus on that part of the MbIS that is responsible for mapping the information from the sensor processing system to generate meaningful modulation of the musical output of the robot. We propose a two skill level approach to enable musicians of different ability levels to interact with the robot. When interacting with the flutist robot the device's physical capabilities / limitations need to be taken into account. In the beginner level interaction system the user's input to the robot is filtered in order to adjust it to the state of the robot's breathing system. The advanced level stage uses both the aural and visual sensor processing information. In a teaching phase the musician teaches the robot a tone sequence (by actually performing the sequence) that he relates to a certain instrument movement. In a performance phase, the musician can trigger these taught sequences by performing the according movements. Experiments to validate the functionality of the MbIS approach have been performed and the results are presented in this paper.

Humanoid robots are developed to be used in many areas in the human environment, especially area where it is highly dangerous for human to work or live in. Outer space or even the moon surface is one of the areas where are people trying to explore, but it is highly risky and costly. Sending humanoid robot to the moon could one of the solution to explore the moon surface and research on the real effect of the moon gravity on human walking motion. Using dynamic simulation we can have an approach to imitate human walking gait and analyze the effect of the low gravity which could result on the walking velocity.

Humanoid robots are becoming an important factor for the future work. The researches in this field are focusing on the ability of using Humanoid robots in many areas where human live and work. Future planes are made to explore the surface of the moon for different purposes which requires long present and existing by human. The development of humanoid robot to work in such environment for the purpose of human assisting is becoming highly demanded. The challenge of developing a bipedal robot to walking on the moon is really high due the low gravity compare to earth. The effect of the low gravity may result in unstable walking which will require lower walking velocity. In order to have higher velocity it is better to switch to running gait instead of walking gait. In the paper we investigate the ability to perform a jumping motion on the moon gravity as a first step toward developing a running gait motion. © 2010 IEEE.

The main goal of this paper is to report a successful attempt of monitoring the stiffness behavior of a biped walking vehicle during its dynamic operation. In particular, a suitable procedure has been developed and implemented for estimating the stiffness performance of WL-16RV as based on previous experiences at LARM with Milli-CaTraSys design. The proposed experimental set-up is composed of six linear encoder wire sensors and two force/torque sensors embedded in each foot. Experimental tests are conducted on a biped walking vehicle WL-16RV under static and dynamic conditions. The experimental tests provide useful information for both design and control purposes.

In this paper, we present a robotic system which automatically searches and detects the longitudinal section of the carotid artery using a conventional medical ultrasound diagnostic system. In order to obtain a clear image of the carotid artery ready for medical diagnosis, the authors developed real-time image processing algorithms to detect the carotid artery and tissue layers of its walls in the B-mode ultrasound images. Sequential patterns of the ultrasound probe trajectory for scanning the surface of the neck and searching the carotid, were implemented and tested on the Waseda-Tokyo Women's Medical-Aloka Blood Flow Measurement Robot System No. 1 Refined II (WTA-1RII). An experiment with eleven volunteers was carried out and the results show that the system obtained clear images of the carotid artery in 91% of the trials.

We have developed a mechanical talking robot, Waseda Talker No. 7 Refined II, to study the human speech mechanism. The conventional control method for this robot is based on a concatenation rule of the phoneme-specific articulatory configurations. With this method, the speech mechanism of the robot is much slower than is required for human speech, because the robot requires momentary movement of motors. To resolve this problem, we have developed a control method that mimics human articulatory trajectory data. The human trajectory data for continuous speech was obtained by using an electromagnetic articulography (EMA) system. The EMA data was converted to the robot control parameters by applying inverse kinematics as well as geometric transformation. Experimental results show that the robot can produce continuous speech with human-like speed and smooth movement.

Heart and cerebrovascular diseases such as arteriosclerosis and myocardial ischemia dysfunction are currently among the main causes of death in developed countries. Recently, wave intensity (WI), which is an index used to obtain the force of cardiac contraction, has been investigated as a method for early-stage diagnosis of the above-mentioned diseases. Nevertheless, experimental tests have proven that the manual measurements of WI by means of commercial ultrasonic diagnostic systems require too much time and can be affected by the operator&apos;s skills. For this purpose, the introduction of robotic-assisted technology has advantages in terms of repetitiveness and accuracy of the measurement procedure. Therefore, at Waseda University, the development of a carotid blood flow measurement system has been proposed to support doctors while using ultrasound diagnostic equipment to measure the WI. This robotic system is composed of a serial robot with a wrist having a six-degree-of-freedom (6-DOF) parallel mechanism. The main focus is to obtain a suitable workspace performance of the 6-DOF parallel mechanism wrist. In this paper, a workspace analysis is carried out on a wrist prototype built for the Waseda-Tokyo Women&apos;s Medical Aloka Blood Flow Measurement System No. 1 Refined (WTA-1R). Then, mechanical design enhancements are proposed and validated to provide a suitable workspace performance both as reachable workspace and dexterity, and a refined prototype WTA-1RII has been built.

人間の発話運動は複雑な流体音響現象を含んでおり，その解明のために物理モデルを構築することは有効な手段である．ロボット技術を用いた物理モデルとして，われわれは人間形発話ロボットWT-7R（Waseda Talker No.7 Refined）を構築した．WT-7Rは声帯・舌などの発声に重要な器官を，これまでの機械モデルよりも人間の機構に近い形で構築したロボットである．

We have developed an oral-rehabilitation robot WAO-1 (Waseda Asahi Oral-rehabilitation robot No. 1) for use in cases of oral disorders such as temperomandibular joint (TMJ) disorder and dry mouth. WAO-1 is the first robot designed to provide massage to the facial tissues of a patient with oral disorders. This robot provides massage to the masseter and temporal muscles and to the parotid gland and duct with simple operation. It consists of two six-degree-of-freedom arms with plungers, a body with headrest, a control box, a PC, and an automatic massage trajectory generation system with virtual compliance control. Two evaluation experiments were performed to verify the effectiveness of the oral massages of WAO-1 compared with the massages given by doctors. In the experiments, the massage to the parotid gland and duct by WAO-1 increased the amount of saliva in the subjects, and the massage to the masseter muscle by WAO-1 increased facial skin temperature and width of the masseter muscle in the subjects. We consider that these results indicate that massage by WAO-1 can be effective for patients with oral disorders.

WAO-1（Waseda Asahi Oral-rehabilitation robot No. 1）は，顎顔面領域のマッサージ治療を行う目的で開発されたロボットである。WAO-1は，6自由度をもつ2本のアームと，顔表面を擦るプランジャにより構成され，プランジャの力と位置を制御することにより精密なマッサージを行う。臨床応用試験の一部として，咀嚼筋へのマッサージを試みた。健常人に施行した結果，ロボットマッサージが安全かつ快適であることがわかったので，顎関節症患者37名にマッサージを行った。その結果，3回以上マッサージを受けた患者の73％で疼痛の減少が，50％で開口度の改善が認められた。ロボットによる咀嚼筋のマッサージは，顎関節症における疼痛軽減と開口障害の改善に有効なことが示唆された。<br>

We developed an oral-rehabilitation robot WAO-1 for use in cases of oral disorders such as TMJ (Temporomandibular Joint) disorder and dry mouth. WAO-1 is the first robot designed to provide massage to the facial tissues of a patient with oral disorders. This robot provides massage to the masseter and temporal muscles and to the parotid gland and duct with simple operation. It consists of two 6-DOF arms with plungers, a body with head rest, a control box, a PC, and an automatic massage trajectory control system with virtual compliance control. The massage trajectories are generated using the face shape model of an adult male before the massage. During the massage, compliance displacement xcc is calculated based on the reaction force from the face in real time. Using the virtual compliance control, it is possible to apply the massage trajectories made from the facial shape model of an adult male to many people without modification of the model.

Objectives: This study determined suitable conditions for masseter and temporal muscle massage using a specially fabricated robot and evaluated its effects on patients with TMJ dysfunction associated with myofascial pain. Methods: The robot was designed with two arms with six degrees-of-freedom, and equipped with plungers. A phase-1 trial examined 22 healthy volunteers to determine its safety and suitable massage pressure, examining three different pressures. The volunteers evaluated their comfort, warmth, and ease of mouth opening by use of a visual analogue scale (VAS). A phase-2 trial examined the safety, suitable dose regimen, and efficacy in 12 patients. Maximal mouth opening was measured, and muscle pain and massage were evaluated subjectively. Results: The robot was safe in the phase-1 trial, except for two massages in which the pressure was excessive. Massages at 6-10 N were given the highest VAS scores. In phase 2, the massage pressure was arbitrary and each muscle was massaged seven times for 1 min, three times every two weeks. After evaluating the efficacy, additional treatments were performed at a greater pressure or for longer. The massage treatment was very effective for most patients. Conclusion: The massage treatment was safe and effective for most patients when administered at a pressure of 6-10 N seven times for 1 min per muscle every two weeks. The robot may constitute a useful tool for treating TMJ dysfunction associated with myofascial pain. © 2009 Japanese Society for Oral and Maxillofacial Radiology and Springer.

Up to now, different kinds of musical performance robots (MPRs) and robotic musicians (RMs) have been developed. MPRs are designed to closely reproduce the required motor skills displayed by humans (i.e. anthropomorphic robots) in order to play musical instruments. MPRs are then usually conceived as benchmarks to study the human motor control from an engineering point of view and to better understand the human-robot interaction from a musical stand point. In contrast, RMs are conceived as automated mechanisms designed for the creation of new ways of musical expression from the musical engineering perspective. Our research on the anthropomorphic flutist robot, at Waseda University, has been focused on clarifying the human motor control while playing the flute, proposing novel applications for humanoid robots and enabling the communication with humans at the emotional level of perception. In this paper, we are presenting the details of the development of the Waseda flutist robot No. 4 Refined IV (WF-4RIV). The WF-4RIV is composed by 41-DOFs that reproduce the anatomy and physiology of the organs involved during the flute playing. In particular, we describe the new mechanical design of the artifical organs; such as lips, tonguing, vibrato and lungs, which are related to the production of a clear sound. A set of experiments were proposed to verify the effectiveness of each of the mechanisms to imitate the human flute playing. From the experimental results, the WF-4RIV is able of producing clear sound with smoother transitions between notes. (c) 2008 Elsevier Ltd. All rights reserved.

Personal robots and robot technology (RT)-based assistive devices are expected to play a major role in our elderly-dominated society, with an active participation to joint works and community life with humans, as partner and as friends for us. In particular, these robots are expected to be fundamental for helping and assisting elderly and disabled people during their activities of daily living (ADLs). To achieve this result, personal robots should be also capable of human-like emotion expressions. To this purpose we developed a new whole body emotion expressing bipedal humanoid robot, named KOBIAN, which is also capable to express human-like emotions. In this paper we presented three different evaluations of the emotional expressiveness of KOBIAN. In particular In particular, we presented the analysis of the roles of the face, the body, and their combination in emotional expressions. We also compared Emotional patterns created by a Photographer and a Cartoonist with the ones created by us. Overall, although the experimental results are not as good as we were expecting, we confirmed the robot can clearly express its emotions, and that very high recognition ratios are possible. © 2009 IEEE.

The research on human-robot interaction (HRI) has been an emerging topic of interest for both basic research and customer application. The studies specially focus on behavioral and cognitive aspects of the interaction and the social contexts surrounding it. HRI issues have long been a part of robotics research because the goal of fully autonomous capability has not been met yet. One of the most challenging problems is giving the robots an understanding of how to interact with human beings at the same logical level so that they may function not as passive tools, but rather as active agents that can drive the human interaction, instead of merely reproducing a sequence of movements. Hence, these robots must have higher level cognitive functions that include knowing how to reason, when to perceive and what to look for, how to integrate perception and action under changing conditions, etc. These functions will enable robots to perform more complex tasks which require tight human interaction; consequently, the robots can perform high level interactions such as teaching motor skills to unskilled people. In this paper, the development of active training systems for medical training purposes designed to provide quantitative information as well as to provide feedback to medical students are detailed.

It is well known that the massage therapy is useful for the rehabilitation of various diseases (i.e. oral health problems, etc.). Although various apparatus have been developed for the massage of the torso and limbs, there is still little knowledge about their real effectiveness. For this purpose, authors have proposed the development of a robotic system that provides massage therapy of the maxillofacial region to patients with temporomandibular joint disorders. As a result of our research, we have developed the Waseda-Asahi Oral-Rehabilitation No.1 (WAO-1), which it is composed by two six-degrees of freedom arms with plungers attached at their end-effector. Preclinical tests were carried out to confirm the effectiveness of the proposed system. In order to evaluate the safety measures of the applied forces during the massage therapy, we have based our analysis on the Visual Analogue Scale (VAS) which is a conventional subjective evaluation methods commonly used in the medical field. From the experimental results, we could confirm the effectiveness of the therapy provided by WAO-1.

It is well known that the massage therapy is useful for the rehabilitation of various diseases (i.e. oral health problems, etc.). Although various apparatus have been developed for the massage of the torso and limbs, a machine to perform precise massage therapy to maxillofacial region is not developed yet. The ability of a robotic system to exert itself without fatigue aims in providing more hours of therapy per day, resulting in an increased number of patients that can be treated. This increased potential for treatment would benefit the elderly persons as well allowing more frequent treatments and more convenience in scheduling. For this purpose, the authors have developed the Oral-Rehabilitation Robot which provides massage of the maxillofacial region as a therapy to patients with temporomandibular joint disorders, etc. Then, we developed the Waseda-Asahi Oral-Rehabilitation Robot No.1 Refined (WAO-1R) by redesigning the arms of WAO-1 to increase variety of massage. By this improvement, the angular limitation of end-effector is increased from 60 degrees to 360 degrees. In order to assess the effectives of the massage provided by the robotics system, different performances indexes were proposed based on the medical literature and from our discussion with experts. A set of experiments were carried out to confirm if the mechanical improvements enhanced or not the effect of the massage provided by the WAO-1R. From the experimental results, we could detect increasing the thickness of masseter muscle on volunteers and the amount of mouth-opening after providing the massage with WAO-1R compared with the previous robot.

The emerging field of medical robotics aims to introduce intelligent tools to assist a physician. The main challenges for developing efficient medical robotic training systems are simulating real-world conditions of the task and assuring training effectiveness. High anatomic fidelity has been achieved in current systems. However, those training systems are designed to reproduce specific conditions of the task (passive training). In this research, we are focusing in developing an airway management training systems designed to reproduce various cases of difficult airway. Such difficulties (i.e. restricted mouth opening, various shapes of oral cavity including tongue swallowing, etc) may provoke traumas on different organs of the patient during an emergency situation. For this purpose, the authors have proposed the development of more advanced training tools. For this purpose, we have focused in embedding sensors and actuators to a conventional patient model towards the development of a patient robot (in previous research, authors have presented the evaluation model which embeds sensors). In this paper, we present an airway training system which embeds actuators into a mannequin. In particular, the mechanism design of the Waseda Kyotokagaku Airway No.2 (WKA-2) is detailed. The WKA-2 is composed of twelve active and one passive degrees of freedom; which are designed to reproduce the various cases of difficult airway. For this purpose, the WKA-2 reproduces the human muscles around the upper airway based on a wire driving mechanisms (a total of sixteen wires are used). In particular, the head of the model is composed of a tongue and mandible with translational and rotational movements around kinematic axis. In addition, we present the details of the kinematic model of WKA-2 which enable the robot to reproduce the airway difficulties. Finally, we presented the design of a tension sensor designed to measure the applied tension on each of the wire driving mechanism of WKA-2. As preliminary experiments, we reproduce several cases of difficult airways using WKA-2.

Up to now, different kinds of medical training systems have been developed which were designed to reproduce the human anatomy in high fidelity. However, these kinds of systems are limited to provide quantitative information of the trainees' operation, only provide subjective assessment to them, and finally to provide few feedbacks to them. Therefore, we would like to propose the advanced medical training method using RT which enables us to not only provide quantitative information of the trainees' operation, but also objective evaluation to them from the quantitative information. For the purpose of these facts, we developed Waseda Kyotokagaku Airway-No.1 Refined (WKA-1R) which embeds many sensors in order to provide quantitative information of the trainees' skill as well as an evaluation unit for them. However, the force sensor of WKA-1R has three problems, such as a limited measurement of the applied force, calibration, and maintenance for practicality. In this paper, we propose newly developed Tension/Compression Detection Sensor System (TCDSS) which not only reinforces calibration and maintenance for practicality, but also enables us to measure tension, compression, and torque. In addition, we also propose a Tactile Detection Sensor System (TDSS) which enables us to obtain the information of tactile sensation of the robot. Finally, preliminary experiments have been proposed to obtain the characteristic curve on the TCDSS.

In recent years there has been an ever increasing amount of research and development of technologies and methods to improve the quality and the performance of advanced surgery. In several fields, such as laparoscopy, various training methods and metrics have been proposed, both to improve the surgeon's abilities and also to assess her/his skills. For neurosurgery, however, the extremely small movements and target operating space involved have prevented until now the development of similar methodologies and systems.
In this paper we present the development of an ultra-miniaturized Inertial Measurement Unit (IMU) and its application for neurosurgery skill assessment in a simple pick and place scenario. This analysis is a preliminary yet fundamental step to realize a better training/evaluation system for neurosurgeons, and to objectively evaluate and understand how the neurosurgery is performed.

The bipedal humanoid robot WABIAN-2R is developed to simulate human locomotion. Performing a walking motion requires a high torque at the ankle joint. WABIAN-2R consists of harmonic gears in its driveline system which increases the weight of each leg and respectively decreases the energy economy. Therefore, a new idea is proposed and developed in this paper through computer simulation to modify the design of the ankle joint by adding a spring mechanism instead of high gear ratio transmission. The spring stiffness could be controlled by twisting the joint to set the required torque. This helps reduce the energy consumed while walking; by storing and returning part of the energy. Research presented in this paper proposes an important step toward developing the passive dynamics walking into the advanced complex humanoid robots.

The bipedal humanoid robot WABIAN-2R is developed to simulate human locomotion. Performing a walking motion requires a high torque at the ankle joint. WABIAN-2R consists of harmonic gears in its driveline system which increases the weight of each leg and respectively decreases the energy economy. Therefore, a new idea is proposed and developed in this paper through computer simulation to modify the design of the ankle joint by adding a spring mechanism instead of high gear ratio transmission. This helps reduce the energy consumed while walking; by storing and returning part of the energy. Research presented in this paper proposes an important step toward developing the passive dynamics walking into the advanced complex humanoid robots.

This paper investigates mechanical design improvements for a carotid blood flow measurement robotic system. This robotic system is composed of a serial robot with a wrist having a 6-DOF parallel mechanism. Main focus is to enhance the workspace performance of the wrist. Thus, a workspace analysis is carried out by referring to a built prototype that is named as WTA-1R (Waseda-Tokyo women's medical Aloka blood flow measurement system no.1 Refined). Then, mechanical design enhancements are proposed.

In recent years there has been an ever increasing amount of research and development of technologies and methods to improve the quality and the performance of advanced surgery. In other fields several training methods and metrics have been proposed, both to improve the surgeon's abilities and also to assess her/his skills. For neurosurgery, however, the extremely small movements and sizes involved have prevented until now the development of similar methodologies and systems. In this paper we present the development of an ultra-miniaturized Inertial Measurement Unit and its application for the evaluation of the performance in a simple pick and place scenario. This analysis is a preliminary yet fundamental step to realize a better training/evaluation system for neurosurgeons, and to objectively evaluate and understand how the neurosurgery is performed.

The emerging field of medical robotics is aiming in introducing intelligent tools to perform medical procedures. In particular, robotic researchers have been proposed advanced medical training systems to enhance motor dexterities of trainees. An efficient medical training system should be designed to simulate real-world conditions and to assure their effectiveness as the representation of the motor skills often differs among trainees. Up to now, several training simulators have been developed by medical companies designed to reproduce with high fidelity the human body. However, such devices are not designed to provide any information to trainees. Therefore, we have proposed the development of a Patient Robot which embeds sensors and actuators into a conventional human model. Due to its complexity, as a first approach; we are presenting the development of a suture training system designed to simulate the real-world task conditions as well as providing quantitative assessments. In particular; the Waseda-Kyotokagaku Suture No.2 Refined II is presented, which includes a new evaluation function to provide more detailed information of the task. A set of experiments were proposed to analyze the performance of trainees. From the experimental results, we could confirm its effectiveness to detect differences of the performance of trainees.

The research on the development of musical performance robots has been particularly intensified on the last decades. In fact, the development of anthropomorphic robots able of playing musical instruments have been served as a mean for understanding the human motor control from an engineering point of view as well as understanding how to enable the communication between human and robots from an emotional point of view. In particular, our research aims in the development of an anthropomorphic saxophonist robot which is able not only of performing a musical score; but also to interact with other musical performance robots (i.e. Waseda Flutist Robot) at the emotional level of perception. In this year, we have focused on the mechanical design of an anthropomorphic robot Waseda Saxophonist Robot No. 1 (WAS-1); which has been designed for playing an alto saxophone. WAS-1 has a total of 15-DOFs which mechanically reproduces the following organs involved during the saxophone playing: lips (1-DOF), tongue (1-DOF), oral cavity, lungs (air pump: 1-DOF and air valve: 1-DOF) and fingers (11-DOFs). In order to verify the effectiveness of the production of sound, a set of experiments have been proposed. In particular, the characteristics of air flow-pressure, level of mechanical noise, and the ripple effect ratio are presented. Finally, a qualitative evaluation of the sound produced by WAS-1 is presented and discussed. From the experimental results, we have confirmed the effectiveness of the proposed mechanisms to produce the saxophone sound.

Many researchers have studied on walking stability controls for biped robots. Most of them are highly accurate acceleration controls based on the mechanics model of the robot. However, the control algorithms are difficult to be used for human-carrying biped robots due to modeling errors. In the previous report, we proposed the landing pattern modification method, but it had a problem that a foot landing impact increased when a walking cycle was short. So, we propose a new terrain-adaptive control reducing a landing-impact force. To increase a concave terrain adaptation, we set a target landing position beneath a reference level. To reduce the landing-impact force, we change the position gain control value to a small value at a swing phase. Moreover, we set landing-foot speed at zero when the foot landing is detected by the force sensor mounted on a foot. To follow uneven terrain, a virtual spring is applied along the vertical direction after detecting a foot-landing on a ground, and a virtual compliance control is applied to the roll and pitch axes. In a stable walk while carrying a 65 kg human on uneven terrain, the new control method decreased the landing-impact force than the previous terrain-adaptive control.

The rapid increase of personal robotic platforms and their applications in Japan represents a great challenge for universities to introduce undergraduate students the basic knowledge required to develop intelligent automated mechanisms. For this purpose; in this paper, we are presenting our approach to introduce first year undergraduate students of the Department of Modern Mechanical Engineering the basics of robotics systems. In particular, the details of the inverted pendulum system based on the robotic education kit RoboDesigner and the development of a two-wheeled inverted pendulum mobile robot are detailed. The first system is basically used by students of the Mechatronics Laboratory (2) where they receive lectures of the content of each proposed topic and then, a set of practical experiments are done. On the other hand, in order to foster the creativity of undergraduate students of engineering fields, we focused in developing an education tool designed to introduce at different educational levels the principle of developing mechatronic systems. In particular, the development of an inverted pendulum mobile robot Waseda Wheeled Vehicle No. 1 (WV-1) has been proposed. Different kinds of experiments were proposed to confirm the possibility of implementing controllers as well as changing physical properties of the system to observe differences on the response of the system. From the experimental results, we could confirm the effectiveness of the proposed systems to control the angle of pendulum respect to the body base.

In recent years, due to the increasing rate of elderly people in Japan, the needs to detect adults' diseases at the early stage becomes a high priority. In particular, an increased interest in detecting heart and cerebrovascular diseases at an early stage may allow clinicians to begin treatment sooner (when more treatment options are available), when interventions are generally more effective and less expensive. For this purpose, the introduction of robotic-assisted technology has advantages in terms of repetitiveness and accuracy of the measurement procedure. Therefore, at Waseda University, we have proposed the development of a carotid blood flow measurement system to support doctors while using ultrasound diagnostic equipments to detect arteriosclerosis and myocardial ischemia by measuring wave intensity. In this paper, the Waseda-Tokyo Women's Medical-Aloka Blood Flow Measurement System No. 1 Refined II (WTA-1RII) is detailed. The WTA-1RII is composed by an ultrasound diagnostic system and a probe-supporting robotic device. The robotic device is composed by a parallel link manipulator (for fine adjustment) and a passive arm (for rough positioning). The WTA-1RII has improved the design of the gravity compensation mechanism (composed by a constant force spring attached to a slide guide). In addition, a genetic algorithm has been implemented to determine the optimal link's position of the 6-DOF parallel manipulator to increase the workspace. Finally, a set of experiments were carried out to determine the usability of the proposed system.

The bipedal humanoid robot WABIAN-2R is developed to simulate human locomotion. Performing a walking motion requires a high torque at the ankle joint. WABIAN-2R consists of harmonic gears in its driveline system which increases the weight of each leg and respectively decreases the energy economy. However, using a spring mechanism instead of high gear ratio transmission could decrease the energy used during walking motion. Therefore, the idea of installing the dynamic walking techniques to WABIAN-2R is proposed. Using computer simulation the design of the ankle joint is modified by adding a spring mechanism and controlled by twisting the joint to set the required torque. Based of dynamic simulation an important step toward developing the passive dynamics walking into the advanced complex humanoid robots is been purposed.

The purpose of this study was to develop a robotic endoscope that is low invasive, easy to operate and capable of locomotion from the rectum to the appendix in the human body. We believe that it would contribute to relieving pain in patients. We therefore developed a robotic endoscope that consists of a front and rear body with clockwise and anticlockwise helical fins, respectively. The front and rear bodies are connected via a DC motor. This robot moves forward in the colon by rotating the front body in the clockwise direction and the rear body in the anticlockwise direction. In addition, the radius of each helical fin can be changed by blowing air into a balloon implemented under each fin using an air compressor. Before experiments with animals, we performed experiments to evaluate the mechanical performance and safety of the robot. We confirmed that the maximum radius of the fins was less than the maximum radius of the colon by blowing air continuously into the balloons. We then confirmed that the robot can locomote in the colon without invasion of scratch and make short hole by performing an in-vivo experiment in live swine.

The rapidly increase of personal robotic platforms and their applications in Japan represents a great challenge for universities to introduce undergraduate students the basic knowledge required to develop intelligent automated mechanisms. For this purpose; in this paper, we are presenting our approach to introduce first year undergraduate students of the Department of Modern Mechanical Engineering the basics of robotics systems. In particular, the details of curricula of the Mechatronics Laboratory (1) and (2) are explained. In both lessons, the students receive lectures of the content of each proposed topic and then, a set of practical experiments are done. On the other hand, in order to foster the creativity of undergraduate students of engineering fields, we focused in developing an education tool designed to introduce at different educational levels the principle of developing mechatronic systems. In particular, the development of an inverted pendulum mobile robot Waseda Wheeled Vehicle No. 2R (WV-2R) has been proposed. Regarding the Mechatronics Laboratory, questionnaires were proposed to obtain information from the students about their impressions of the lessons. From the comments collected from the questionnaires, we observed the advantages of the proposed curricula to introduce them about robot technology. On the other hand, different kinds of experiments were proposed to confirm the possibility of implementing controllers as well as changing physical properties of the system to observe differences on the response of the system.

The rapidly increase of personal robotic platforms and their applications in Japan represents a great challenge for universities to introduce undergraduate students the basic knowledge required to develop intelligent automated mechanisms, by introducing in simple and efficient ways the basic components of robots as well as their application for solving real-world problems. In Japan, the proliferation of amateur robot contests has been introduced to motivate their interest to get involved in the robotics field. This is not only the case for tournaments supported by local governments and private companies. Several universities along Japan have been implementing Project-Based Learning (PBL) within their curricula as introduction for Mechatronic. For this purpose, at Waseda University, we focused in developing an education tool designed to introduce at different educational levels the principle of developing mechatronic systems. In particular, the development of an inverted pendulum mobile robot Waseda Wheeled Vehicle No. 2 (WV-2R) has been proposed. In this paper, an overview of the research results is detailed. Even that in many universities around the world has been promoting the introduction of robotic technology, little discussion has been done to analyze from an ethical point of view. In this paper, some issues related to both Robot Education and Engineering Ethical Education are give based on experiences carried out in Japan. Then, some points regarding the integration of RoboEthics Education are pointed out for discussion.

The Waseda Flutist Robot is able to play the flute at the level of an intermediate human player. This ability opens a wide field of possibilities to research human-robot musical interaction. This research is focused on enabling the flutist robot to interact more naturally with musical partners in the context of a Jazz band. For this purpose a Musical-Based Interaction System (MbIS) has been proposed to enable the robot to process both visual and aural cues coming throughout the interaction with musicians. In a previous publication, we have concentrated on the implementation of visual communication techniques. We created an interaction interface that enabled the robot to detect instrument gestures of partner musicians during a musical performance. Two computer vision approaches were implemented to create a two-skill-level interface for visual human-robot interaction in a musical context. In this paper we focus on the aural perception system of the robot. The method introduced here enables the robot to, a suitable environment provided, detect the tempo and harmony of a partner musician's play, with a specific focus on improvisation. We achieve this by examining the rhythmical and harmonic characteristics of the recorded sound. We apply the same approach to amplitude and frequency spectrum, thus, in the former case tracking amplitude transients. In the latter case, as we focus on communication with monophonic woodwind instruments, we follow the most prominent peak in the frequency spectrum. We specifically use a similar technique for the audio analysis as we did for our previous research on motion tracking. From the experimental results, we have shown that after implementing our algorithm the robot is able to correctly recognize a number of rhythms and harmonies. It is able to engage in a simple form of stimuli and reaction play with a human musician.

The rapidly increase of personal robotic platforms and their applications in Japan represents a great challenge for universities to introduce undergraduate students the basic knowledge required to develop intelligent automated mechanisms. For this purpose; in this paper, we are presenting our approach to introduce first year undergraduate students of the Department of Modern Mechanical Engineering the basics of robotics systems. In order to foster the creativity of undergraduate students of engineering fields, we focused in developing an education tool designed to introduce at different educational levels the principle of developing mechatronic systems. In particular, the development of an inverted pendulum mobile robot Waseda Wheeled Vehicle No. 2 (WV-2R) has been proposed. Different kinds of experiments were proposed to confirm the possibility or implementing controllers as well as changing physical properties of the system to observe differences on the response of the system. From the experimental results, we could confirm the effectiveness of the proposed systems to control the angle of pendulum respect to the body base as well as by changing the radius of the wheel.

During several decades, the research at Waseda University has been focused on developing anthropomorphic robots able of performing musical instruments. More recently, the authors have succeeded in developing a human-like robot able of playing the alto saxophone. As a result of our research efforts, the Waseda Flutist Robot WF-4RIV and the Waseda Saxophonist Robot WAS-1 have been designed to reproduce the human player performance. Therefore, as a long-term goal, we tire proposing to enable the interaction between musical performance robots (i.e. robots orchestra). Such approach may enable us not only to propose new ways of musical expression, but also we may contribute to the better understanding of some of the mechanisms that enable the communication of humans in musical terms. In general terms, the communication of humans within an orchestra is a special case of conventional human social behavior. Rhythm, harmony and timbre of the music played represent the emotional states of the musicians. Of course, we are not considering a musical performance robot (MPR) just as a mere sophisticated MIDI instrument. Instead, its human-like design and the integration of perceptual capabilities may enable to act on its own autonomous initiative based on models which consider its own physical constrains. Due to the complexity of our long-term goal, in this paper, we sire presenting our first steps towards enabling the interaction between musical performance robots. In particular, the details of the musical performance control systems are detailed.;flanks to the use of MIDI data, we performed preliminary experiments to enable a duet performance between the WF-4RIV and the WAS-I. We expect in the future; as a result of our research, we may enable a single anthropomorphic robot to perform different kinds of woodwind instruments as well as liable to interact at with level of perceptual capabilities (like human does).

The research on the Waseda Flutist Robot
since 1990, has been carried out as an approach to understand the human motor control from an engineering point of view as well as introducing novel ways of musical teaching. Thanks to the improvements on the technical skills of WF-4RIV, we have enabled the flutist robot to enhance its musical expressiveness. As authors have being developing basic cognitive capabilities on the WF-4RIV
we have proposed as a long-term goal to enable musical performance robots (MPRs) to interact with musical partners. For this purpose, we have proposed two approaches: implementing more advanced cognitive capabilities on the WF-4RIV and developing a new musical performance robot. In this paper, we have focused our research on developing an anthropomorphic saxophonist robot as a benchmark to understand better how the interaction with musical partners can be facilitated. Thanks to our experience on developing the flutist robot, we have succeeded in developing the WAseda Saxophist Robot no. 1 (WAS-1), which is composed of 15-DOFs. In this paper, in particular, we present the details of the mechanical and control systems. A set of experiments were proposed to compare the saxophone performance as well as the production of vibrato of the WAS-1 compared with human players. ©2009 IEEE.

Many researchers have studied on walking stability controls for biped robots. Most of them are highly accurate acceleration controls based on the mechanics model of the robot. However, the control algorithms are difficult to be applied to human-carrying biped robots due to modeling errors. In the previous report, we proposed the landing pattern modification method, but it had a problem that a foot landing impact increased when a walking speed became fast. So, we propose a new terrain-adaptive control that can reduce a landing.. impact force. To increase a concave terrain adaptation, e set a target landing position beneath a reference level. To reduce the landing-impact force, we change the position gain control value to a small value at a swing phase. Moreover, we set landing-foot speed at zero after detecting a foot-landing by the force sensor mounted on a foot. To follow uneven terrain, a virtual spring is installed to the vertical direction after detecting a foot-landing on a ground, and a virtual compliance control is applied to the roll and pitch axes. In a stable walk while carrying a 65 kg human on uneven terrain, the new control method decreased the landing-impact force than the previous terrain-adaptive control.

We have developed a new, three dimensional vocal tract mechanical model for an anthropomorphic talking robot WT-7R (Waseda Talker No. 7 Refined), to improve the resonance of the vocal tract. The Waseda Talker robot series aims to reproduce the human speech mechanism with three-dimensional accuracy. The tongue of the previous model, WT-7 (Waseda Talker No. 7), was made of rigid links and covered with a thermoplastic rubber (Septon). This mechanism could deform the tongue shape and work as a part of the vocal tract, however, the cover thickness was not sufficient enough to prevent sound leakage, and did not have sufficient resonance. As a result, the produced sounds were unclear. To resolve this problem, the inner area of the tongue was filled with liquid. We experimented to select the filling liquid which is minimizes damage to the Septon cover and provides adequate resonance characteristics. The ethylene glycol was selected because it does little damage to the Septon and is relatively non-flammable. An oil seal and liquid gasket prevent leakage into the robot. WT-7 also has problems with its tongue link deformation range and open lip control range-these problems were also addressed. The improvements made the vowel production of WT-7R clearer than that of the previous robot, and the bandwidth of the formant peak in spectral analysis became sharper.

In recent years, due to the increasing rate of elderly people in Japan, the needs to detect adults' diseases at the early stage becomes a high priority. In particular, an increased interest in detecting heart and cerebrovascular diseases at an early stage may allow clinicians to begin treatment sooner, when interventions are generally more effective and less expensive. Recently, the Wave Intensity (WI) has been proposed as a new hemodynamic index that provides information about the dynamic behavior of the heart and the vascular system and their interaction. However; the repetitiveness and accuracy of the WI measurement depend on the precision of the positioning of the ultrasound probe. Therefore a positioning device for ultrasound probe is required. Such a device should not only be used to keep the position but also for the fine positioning of the probe. For this purpose, at Waseda University, we have proposed the development of a robot system to assist a carotid blood flow measurement using ultrasound diagnostic equipments. In this paper, the development of Waseda-Tokyo Women's Medical-Aloka Blood Flow Measurement System No. 1 Refined II (WTA-1RII is detailed. The system consists of an ultrasound diagnostic device, a 6-DOFs parallel link manipulator, a serial link passive arm, ball joint, and a joystick type controller. The WTA-1RII has improved the design of the gravity compensation mechanism. In addition, a genetic algorithm has by implemented to determine the optimal link's position of the 6-DOFs parallel manipulator to increase the workspace. Finally, a set of experiments were carried out to determine the usability of the proposed system.

Up to now, different kinds of musical performance robots (MPRs) have been developed. MPRs are designed to closely reproduce the required motor skills displayed by humans in order to play musical instruments. Our research at Waseda University has been focused on developing an anthropomorphic flutist robot. As a result of our research, the Waseda Flutist Robot No. 4 Refined IV (WF-4RIV) has been designed to mechanically reproduce the human organs involved during a flute-playing performance. Although the WF-4RIV is able to play the flute nearly similar to the performance of an intermediate player, further improvements in terms of cognitive capabilities are still required (i.e., autonomously improve the quality of the sound during performance based on the sound processing). For this purpose, in this paper, we present the implementation of an Auditory Feedback Control System (AFCS) designed to enable the flutist robot to analyze the flute sound during a performance (in a similar way professional flutists practice before a performance is held). The AFCS is composed of three subsystems (which are detailed in this paper): WF-4RIV&apos;s Control System, Expressive Music Generator and Pitch Evaluation System. A set of experiments was proposed to verify the effectiveness of the proposed AFCS to control the air pressure and to detect/correct faulty notes during a performance. From the experimental results, we confirm the improvements on the flute sound produced by the robot. (C) Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2009

We developed an anthropomorphic talking robot, Waseda Talker No. 6 (WT-6), which generates speech sounds by mechanically simulating articulatory motions and aero-acoustic phenomena. WT-6 possesses 17 degrees of freedom (DOF): a 5-DOF tongue, 1-DOF jaws, 4-DOF lips, a nasal cavity, and a 1-DOF soft palate as articulators
and 5-DOF vocal cords and 1-DOF lungs as vocal organs. The vocal cords, tongue, and lips are made from the thermoplastic rubber Septon, whose elasticity is similar to that of human tissue. WT-6 has three-dimensional (3D) lips, tongue, jaw, and velum, which form the vocal tract structure. It also has an independent jaw opening/closing mechanism. The previous robot in the series had a two-dimensional tongue and could not produce human-like tongue shape. The new tongue can form 3D shapes, and thus, is able to produce more realistic vocal tract shapes. The vocal cord model consists of two folds, and is constructed with a structure similar to the biomechanical structure of human vocal cords. These vocal cords can vibrate in complex phases, similar to those of a human. With these mechanisms, the robot can reproduce human speech in a more biomechanical manner, and thus, can produce a voice closer to that of a human. © 2008 Trans Tech Publications, Switzerland.

Up to now, there is no widely accepted quantitative evaluation scheme. Nowadays, an objective structured clinical examination has been proposed as a modern type of examination often used in medicine to test skills such as medical procedures, etc. The assessment of skills is realized by practical exams, in which students are evaluated by experienced examiner using a check list. However, the examiner lacks of information which cannot be obtained trough the simple observation of the task. Thanks to the recent advances in robot technology in embedded systems, etc.; more advanced evaluation tools can be conceived. For this reason, at Waseda University, we have proposed the development of a patient robot as an advanced evaluation tool to provide more detailed information of the task. As a first approach of our long-term research target, we have proposed the development of a suture/ligature training system which provides quantitative information of the movement of a dummy skin as well as information of the quality of task. In this paper; we describe the functionalities of the newest version, the Waseda-KyotoKagaku Skin No.2 Refined (WKS-2R), which has been designed to provide quantitative information of the task. In addition, we are proposing a new evaluation function which includes performance indexes and weighting coefficients. As a first approach, the weighting coefficients were determined by using the discriminant analysis. A set of experiments were proposed to confirm the effectiveness of the proposed evaluation function. From the preliminary results, the evaluation function was useful in detecting differences among different levels of expertise as well as detecting improvements during the training process by computing the learning curve.

In the aging society, more effective rehabilitation/welfare instruments to support seniors and disabled persons are required. However, it becomes difficult the evaluation of such instruments for safety reasons. Therefore, we suggest the use of a humanoid robot, which is able to display human motions, instead of a human to evaluate such instruments as an experimental subject. The use of robots for measurement purposes is safe and gives us the quantitative data for improving rehabilitation/welfare instruments. Recently, we have developed the new humanoid robot as a human motion simulator, WABIAN-2. This robot can walk autonomously with the knees stretched like a human by using waist motion, and also it can walk by physically interacting with a walk-assist machine. In this paper, the experiments are focused verifying if the WABAIN-2 can be considered as a human motion simulator to move a walk-assist machine while walking.

This paper describes the mechanism of a 16 d.f. biped walking machine, Waseda biped humanoid robot-2 lower limb (WABIAN- 2LL), which has two 7 d.f. legs and a 2 d.f. waist actuated by DC servo motors with reduction gears. WABIAN-2LL is designed with large movable angle ranges like those of a human. Its height and weight are 1200 mm and 40 kg, respectively. It is able to walk with its knees stretched using the redundancy of the legs and to move around an object using a hip-bending motion without touching the object. A knee-stretched locomotion pattern generation is also proposed in this paper, which separately creates joint angles in a supporting and a swinging phase. During knee-stretched walking, the joint rate of the knee will approach infinitely when the knee is stretched. This singularity problem is solved by using the motion of the waist, not the posture of the trunk. The effectiveness of the mechanisms and pattern generations of WABIAN-2LL is verified through dynamic walking experiments.

The aim of this paper is to create an interface for human-robot interaction. Specifically, musical performance parameters (i.e. vibrato expression) of the Waseda Flutist Robot No.4 Refined IV (WF-4RIV) are to be manipulated. Our research is focused on enabling the WF-4RIV to interact with human players (musicians) in a natural way. In this paper, as a first approach, a vision processing algorithm, that is able to track the 3D-orientation and position of a musical instrument, was developed. In particular, the robot acquires image data through two cameras attached to its head. Using color histogram matching and a particle filter, the position of the musician's hands on the instrument are tracked. Analysis of this data determines orientation and location of the instrument. These parameters are mapped to manipulate the musical expression of the WF-4RIV, more specifically sound vibrato and volume values. We present preliminary experiments to determine if the robot may dynamically change musical parameters while interacting with a human player (i.e. vibrato etc.). From the experimental results, we may confirm the feasibility of the interaction during a performance, although further research must be carried out to consider the physical constraints of the flutist robot

A new humanoid bipedal robot WABIAN-2R was developed to simulate human motion. WABAIN-2R is able to perform similar human-like walking motion. Moreover, the robot is able to perform walking motions with a passive walk-assist machine. However, walking with an active walk-assist machine is expected to be unstable. Conducting this experiment is highly risky and costly. Therefore, we had developed a dynamic Simulator in order to test walking robot with walk-assist machine before conducting it in real simulation.