With the increase in the aging population, the demand for healthcare devices has increased. Among the aging population, many experience joint pain, muscle weakness, or poor balance. Without external help, such persons may have difficulty walking, fall easily, or experience poor quality of life. To provide this category of the population with the opportunity to exercise and walk safely and take care of themselves in daily activities, a stepper motor-powered walking assistive device is proposed and built. The device enables users with different heights to walk in suitable gaits; assists users to stand up, sit down, and step up or down stairs; automatically detects user’s intention using pressure sensors and potentiometers; and can be used outdoors for long periods. In this study, the effectiveness of the device is verified using muscle-activity measurements.

Owing to aging populations, the number of elderly people with limb dysfunction affecting their daily lives will continue to increase. These populations have a great need for rehabilitation training to restore limb functions. However, the current numbers of rehabilitation hospitals and doctors are limited. Moreover, people often cannot go to a hospital owing to external conditions (e.g., the impacts of COVID-19). Thus, an urgent need exists for telerehabilitation system for allowing patients to have training at home. The purpose of this study is to develop an easy-to-use system for allowing target users to experience rehabilitation training at home and to remotely receive real-time guidance from doctors. The proposed system only needs a monocular camera to capture 3D motions. First, the 2D key joints of the human body are detected; then, a simple baseline network is used to reconstruct 3D key joints from the 2D key joints. The 2D detection only has an average angle error of 1.7% compared to that of a professional motion capture system. In addition, the 3D reconstruction has a mean per-joint position error of only 67.9 mm compared to the real coordinates. After acquiring the user’s 3D motions, the system synchronizes the 3D motions to a virtual human model in Unity, providing the user with a more intuitive and interactive experience. Generally, many telerehabilitation systems require professional motion capture cameras and wearable equipment, and the training target is a single body part. In contrast, the proposed system is low-cost and easier to use and only requires a monocular camera and computer to achieve real-time and intuitive telerehabilitation (even though the training target is the entire body). Furthermore, the system provides a similarity evaluation of the motions based on the dynamic time warping; this can provide more accurate and direct feedback to users. In addition, a series of evaluation experiments verify the system’s usability, convenience, feasibility, and accuracy, with the ultimate conclusion that the system can be used in practical rehabilitation applications.

As the population ages, the number of elderly people suffering from systemic diseases such as stroke increases. To address this problem, various wearable walking assistive robots have been developed to promote physical exercise for stroke prevention. Wearable assistive robots have shown the ability to improve human mobility. However, most of these robots are heavy, bulky, and impractical. In this study, we developed a compact ankle assistive robot for elderly users to promote walking exercise. By informing the user of correct motion and timing, the robot can guide the user to achieve a healthy gait by only assisting their ankle joint. The robot provides faster-than-ankle motion to allow the user to feel supported while walking. Users can adjust the robot’s assistance parameters through a graphical user interface (GUI) according to their needs. Furthermore, we proposed a gait-adaptive method for ankle assistive robots to adapt to the user’s changing gait. Hence, the robot can automatically adjust the parameters to provide more accurate walking assistance. Finally, the results of an evaluation experiment demonstrated the feasibility of human gait adaptation. The proposed methods have the advantages of low cost and easy implementation.

This paper proposes a three-layer elastic cloth fabric mechanism for an assistive suit with adjustable structure (based on a two-layer non-adjustable structure) to achieve different assistive force profiles. This increases the assistive force on the lower-back muscle group and alleviates the undesired pre-tension that acts on a user when the rubber belt located on the back is pulled to provide a higher assistive force. With the lower pre-tension, users would not encounter body fatigue as rapidly as in the past. The adjustable feature enables the structure to provide a force that increases gradually to a high level over a short distance without pre-tension. An experiment involving the measurement of muscle activities is conducted to evaluate the variation in assistive force in the lower back by comparing the three-layer suit to the two-layer non-adjustable suit. The experimental results show that the new three-layer structure successfully assists without pre-tension in the lower-back muscle group similar to the two-layer structure with pre-tension. A simple questionnaire is also administered to collect feedback from participants on the differences between the three-layer suit and two-layer suit in terms of wearing perception. Over half of the participants reported that the perception of pre-tension in the three-layer suit is lower than that in the two-layer suit.

In response to the shortage, uneven distribution, and high cost of rehabilitation resources in the context of the COVID-19 pandemic, we developed a low-cost, easy-to-use remote rehabilitation system that allows patients to perform rehabilitation training and receive real-time guidance from doctors at home. The proposed system uses Azure Kinect to capture motions with an error of just 3% compared to professional motion capture systems. In addition, the system provides an automatic evaluation function of rehabilitation training, including evaluation of motion angles and trajectories. After acquiring the user’s 3D motions, the system synchronizes the 3D motions to the virtual human body model in Unity with an average error of less than 1%, which gives the user a more intuitive and interactive experience. After a series of evaluation experiments, we verified the usability, convenience, and high accuracy of the system, finally concluding that the system can be used in practical rehabilitation applications.

The world’s aging population is increasing. The number of elderly individuals having walking impairments is also increasing. Adequate exercise is becoming necessary for them. Therefore, several walking assistive devices have been developed or are under development. However, elderly individuals may have low motivation for exercising, or they may experience physical damage by excessive fatigue. This study proposed a method to enable elderly individuals to exercise with a positive emotion and prevent damage such as muscle fatigue. We proposed a 3D human condition model to control the walking assistive device. It includes the arousal, pleasure, and fatigue dimensions. With regard to the arousal and pleasure dimensions, we used heartbeat and electromyography (EEG) signals to train a deep neural network (DNN) model to identify human emotions. For fatigue detection, we proposed a method based on near-infrared spectroscopy (NIRS) to detect muscle fatigue. All the sensors are portable. This implies that it can be used for outdoor activities. Then, we proposed a walking strategy based on a 3D human condition model to control the walking assistive device. Finally, we tested the effectiveness of the automatic control system. The wearing of the walking assistive device and implementation of the walking strategy can delay the fatigue time by approximately 24% and increase the walking distance by approximately 16%. In addition, we succeeded in visualizing the distribution of emotion during each walking method variation. It was verified that the walking strategy can improve the mental condition of a user to a certain extent. These results showed the effectiveness of the proposed system. It could help elderlies maintain higher levels of motivation and prevent muscle damage by walking exercise, using the walking assistive device.

Ankle foot orthoses are mainly applied to provide stability in the stance phase and adequate foot clearance in the swing phase; however, they do not sufficiently assist during the entire gait cycle. On the other hand, robotic-controlled orthoses can provide mechanical assistance throughout the phases of the gait cycle. This study investigated the effect of ankle control throughout the gait cycle using an ankle joint walking assistive device under five different robotic assistance conditions: uncontrolled, dorsiflexion, and plantar flexion controlled at high and low speeds in the initial loading phase. Compared with the no-control condition, the plantar flexion condition enhanced knee extension and delayed the timing of ankle dorsiflexion in the stance phase; however, the opposite effect occurred under the dorsiflexion condition. Significant differences in the trailing limb angle and minimum toe clearance were also observed, although the same assistance was applied from the mid-stance phase to the initial swing phase. Ankle assistance in the initial loading phase affected the knee extension and ankle dorsiflexion angle during the stance phase. The smooth weight shift obtained might have a positive effect on lifting the limb during the swing phase. Robotic ankle control may provide appropriate assistance throughout the gait cycle according to individual gait ability.

Extended roles of robots for activities of daily living (ADL) lead to researchers’ increasing attention to human-robot interaction. Emotional recognition has been regarded as an important issue from the human mental aspect. We are developing an assistive walking device which considers the correlation between physical assistance and mental conditions for the user. To connect the assistive device and user mental conditions, it is necessary to evaluate emotion in real-time. This study aims to develop a new method of two-dimensional valence-arousal model emotion evaluation with multiple physiological signals. We elicit users’ emotion change based on normative affective stimuli database, and further extract multiple physiological signals from the subjects. Moreover, we implement various algorithms (k-means, T method of MTS (Mahalanobis Taguchi System) and DNN (deep neural network)) for determining the emotional state from physiological data. Finally, the findings indicate that deep neural network method can precisely recognize the human emotional state.

Emotion is an internal and subjective experience that plays a significant role in human life. There are several methods of recognizing emotions in people, the most authentic of which is using physiological signals, as they are beyond one's control and strongly correlated with human emotions. This study aims to develop an emotion recognition system based on three physiological signals, namely, brainwave, heartbeat, and facial muscular activity. It utilizes deep neural network (DNN) and the T method of Mahalanobis-Taguchi system (MTS) to process the multiple physiological signals and further recognize the states of human emotion. As such, nine emotions are effectively recognized on a two-dimensional model through the DNN, then compared against several other algorithms, such as MTS, SVM, Naive Bayes, and K-means, where its superior accuracy is validated. Moreover, although the T method only improves the classification accuracy on the valence state, it rather obtains the intensity of emotion in different states. Furthermore, in this study, the proposed DNN is implemented into a wide range of applications for an accurate understanding of the human emotional states, whereas the T method is utilized to respond to the emotional intensity in different states. Finally, a real-time emotion recognition system is developed with DNN as the classifier; this system can directly monitor the variation of the human emotion through reliable and objective emotion analysis results from the physiological signals. Thus, the method can provide useful treatment effect information for robots or assistive apparatus serving activities of daily living.

This chapter presents authors development work on walking assistant exoskeletons for gait training of patients and promotion exercise of the elderly. The first exoskeleton is a whole leg assisting device using a special parallel link mechanism. For gait training of motor palsy patients, a weight bearing lifter was attached, and an impedance control was tuned by using frequency entertainment. For the elderly, a torque controller taken into account the dynamics of both a user and the apparatus with real time acceleration data is developed. The second exoskeleton is a whole body assisting suit was developed by adding arm assistance to the whole leg apparatus. By assisting not only legs but also swinging arms, an increased cerebral activity of all areas can be expected via rehabilitation with the whole body exoskeleton. Finally, we developed a close-fitting type exoskeleton assisting only ankle joint, which leads to a product RE-Gait® in 2016. By utilizing the structure of bi-articular muscle and physiological phenomenon of stretch reflex, the user’s leg can be raised assisting only ankle joint. Experiments with by hemiplegic patients are enclosed, which show that abduct variation of the hip joint is decreased while the stride length is increased by using the device.

A walking assistance device for apoplexy patients has been developed. We developed a walking assistance device RE-Gait®, which assists the motion of the ankle joint while walking. The motor is controlled according to the walking phase grasped with the pressure sensors under the sole. It is already utilized as a product, for the gait training by so many hemiplegic patients. By using the technology of RE-Gait®, a new device for the able-bodied elderly to promote exercise was also developed. This is RE-Gait®Light, which is lower cost, very light, and easy to move. We proposed a new control method for this device, which is automatically tuned according to the condition of the emotion of the user. In this chapter, the evaluation results using this method are introduced.

Wearable assistive devices have been receiving considerable attention in academic circles. To make these devices efficient, we need additional research on the service lives of the mechanical elements used in these devices. The wearers of these devices frequently encounter unexpected movements that lead to motor failure in the devices. The purpose of this study is to develop an overload protection mechanism using a torque limiter, which can eliminate the overload torque delivered in the reverse direction to effectively prevent the device from breaking and ensure the safety of the user. To improve the service life of assistive walking devices, we designed a sandwich mechanism for the final gear of the servo motor. We made the material from rubber and configured it between a pair of circular plates. The surface tractive force delivered the required torque. When the surface load exceeded the maximum friction force, the circular plates slipped and protected the device. In this paper, we implement a torque limiter and prove its durability by performing experiments using two circular plate designs, one with grooves type and another without grooves type. We also use various materials to assess the applicability of the assistive walking device. The findings indicate that the with grooves type gives better torque performance
it achieves the same rated torque as the servo motor. Thus, this study recommends that with grooves type is particularly suitable for the elderly who require high assistive power. On the other hand, without grooves type is suitable for users who employ the device for extended periods because this type has an excellent service life. Our experiment proves that the torque limiter that we developed can withstand the load torque over 300 times for situations involving the loss of balance such as stumbling and slipping. Finally, we experimentally validate the improvement of walking performance by using this torque limiter.

Due to the growing elderly population in many developed countries like Japan, assistive devices are increasingly needed to overcome the difficulties of their activities of daily living (ADL). The motion of standing up places a particular burden on the ankle and knee joints and connects static motions (e.g., sitting and lying) and kinetic motions (e.g., walking and climbing up/down the stairs). In our previous research, two types of standing-up assistance apparatuses were introduced according to the suitable standing-up motions. However, these devices are bulky and cannot be widely used in practical settings such as bus terminals. Regarding the suitable standing-up motions of the elderly in the previous literature, a standing-up apparatus with a pantograph mechanism is introduced to diminish the size of the mechanism based on three design principles: (1) the trajectory of the user's COG is an arc
(2) the trajectory of the user's hip joint while standing up is a straight line at an angle of 45 [deg] from the horizon
and (3) the user is supported until the knee angle reaches 60 [deg]. Simulations showed that the load on knee and ankle joint is decreased, and user may stand up easily with our proposed apparatus. A prototype of the apparatus that may be installed on various chairs in public was fabricated. Considering that the apparatus may be used in places without electric power supply, the apparatus is made simply with links and a gas spring instead of electric actuators. Experimental measurements of the trajectories of the center of gravity (COG) and hip joints show that the proposed apparatus may help users to stand in a way that minimizes stress on their lower-body joints.

We proposed a method that promotes walking which uses a two-dimensional emotion map. In this method, a subject listened to a beat sound while walking. The beat was adjusted according to the condition of the subject, based on his/her comfortable walking frequency. Simultaneously, the walking velocity, the stride length, and the heart beat of the subject while walking was measured, and LF/HF was calculated from the result of measured heart beat. Furthermore, we asked them to give information on the condition of their feelings, from pleasant or not by 5 levels in each case of the beat sound. By using these data, a two-dimensional walking condition map and two-dimensional emotion map were made and we found the relation between these two maps. Therefore, according to the emotional condition of the targeted person while walking, this method can promote or restrain walking adequately, only adjusting the beat sound.

In the current study, we formulated ontological descriptions for emotional states of users using motion assistance apparatus. In our previous studies, we developed apparatus that assists the ankle joints of patients in neuro-rehabilitation. Although we have confirmed the apparatus can improve the gait of the patient while walking, we have to capture and manage patients’ emotions as feedback of the usage. The ontological descriptions provide a feasible framework for common understanding while sharing and using this knowledge. In future work, we will develop a subset of this framework for more practical usage, in addition to expanding the descriptions of emotional states. After that, we will assess the validity and utility for design and implementation of software and hardware applications using this subset.

Recently, the viewpoint of service has become widespread. In learning domains, service providers have been required to adopt the viewpoint and to provide values co-created by teachers and learners. However, production by a service provider means the generation of potential value, whereas usage by a service receiver implies the generation of real value. That is, a receiver creates value independent of the value generated by a provider. Indeed, value co-creation takes place in a joint sphere where providers and customers interact with each other. Thus, service providers must attempt to generate the potential value through service design and play a role of co-producer of the real value in the interactions between the providers and the receivers. In the current study, we developed an ontology to share the knowledge on value co-creation and the information related to the interactions between the providers and the receivers. In concrete terms, we proposed ontological descriptions of receiver states for sharing knowledge in learning service design, and conceptualized elements of consensus building and value co-creation, according to the conceptual model of value co-creation proposed in a previous study. In addition, concepts pertaining to academic emotions are also described to represent contents of consensus building. Then, we demonstrated instances of a consensus building, which is extracted from conversations during counseling by a teacher (mentor) and a learner. As a result, we obtained a metamodel for co-design processes in the learning service design, and a conceptual framework of the knowledge sharing on learning states including academic emotions by the ontological descriptions.

<p>We developed a new power assistance suit without the need for electricity. This suit is to support care worker's assistance behavior, e.g. lifting-up and holding motion. It is made of only rubber and nylon belts. This suit can assist the equipped person's arms and back with two kinds of equipped belts. One is for the waist, attached from the shoulder to the back of the knee via his/her back. The other is for the arms, attached from equipped person's forearm to the back of the knee via his/her back. To confirm the possibility of this suit, first, we interviewed medical doctors and physical therapists. Their comments were, it is important to adjust the length of each belt for an equipped person adequately, and it is effective for the assistance of motion in a half-sitting posture and in transfer motions between a bed and a wheel chair. Furthermore, we measured the variation of maximum output force and %MVC of the entire body muscles during lifting and holding motions using the suit and not. From the result, by using this suit, the maximum lifting weight of the equipped person was increased by over 8kg, and the arms and back of the equipped person were assisted effectively.</p>

We developed a device that promotes walking which uses a two-dimensional emotion map for the exercise of the elderly. This map was made with two axes, the horizontal axis was pleasant or unpleasant, with the vertical axis being arousal or not, same as the circumplex model of affect (J. A. Russell (1980)). This device has two means to promote walking. One is an ankle joint assistance system, which consists of a servo motor and a controller which can adjust the targeted walking cycle, the targeted angle of the ankle joint, and the sensitivity of the sensors which was attached under the sole. The other is a beat listening system. The beat listening system makes the beat sound, which is decided for the purpose of the user, and based on the walking cycle. The user listens to the beat sound using head phones. By combining and using these two means simultaneously, users can change their gait and emotion, therefore, they can continue to walk for a long time.

We developed a walking assistance apparatus RE-Gait® for not only the elderly but also apoplexy patients, which assist the ankle joint of the equipped person. By only assisting the ankle joint, the equipped person’s leg can be raised. To keep up the user’s motivation for exercise using this apparatus, it is necessary to assist not only physically but also mentally. Therefore we suggested the new method of promotion walking, using the walking assistance apparatus while listening to the beat sound, which was adjusted according to a two-dimensional emotion map. In this paper, the relation between emotion map and walking condition map is shown.

We developed a new method that can diagnose damage on a gear tooth surface using a laser beam without a rotary encoder. The method procedure is as follows: 1) The tooth bottom, the tooth tip and their two median values are detected using the differential values of the laser reflection data. 2) The gear rotation speed is calculated with these four positions, and interpolated according to the rotation fluctuation. 3) Using the calculated gear rotation speed, the measured data can be converted to the corresponding gear rotation angles. Thus we can diagnose the damage of the gear tooth surface precisely and can easily set up the experimental measurements without being influenced by rotational fluctuation. To confirm the validity of the method, we conducted the diagnosis experiment and we created contour maps to show the diagnosis accuracy variation according to the fluctuations of the amplitude and cycle. Based on these maps, we found that the diagnosis accuracy of the damage size is the same irrespective of the presence or absence of a rotary encoder. The diagnosis accuracy of the damage location without using a rotary encoder is lower than the result obtained using a rotary encoder because we assumed that the detection of the damage start point is delayed using this new method. Furthermore, we defined the limit using the conditions of this method from the sampling theorem; the validity of this definition could also be confirmed from the contour map.

We developed a motion assistance apparatus which can be used for neuro-rehabilitation of patients and for the promotion of exercise for the elderly. This apparatus assists only the ankle joints of the equipped person according to the posture of him/her while walking, getting up, sitting, and standing. By using this apparatus, the dorsiflexion and plantarflexion of the ankle joint of the equipped person can increase while walking. Therefore, this apparatus can prevent stumbling and promote walking and various motions.

We developed a method which can diagnose damage on a gear tooth surface by using laser beam without a rotary encoder. This method is as follows: 1) The tooth bottom, the tooth tip and their two medians are detected by the differentials of the laser reflection data. 2) The gear rotation speed is calculated with these four positions, and interpolated according to the rotation fluctuation. 3) By using the calculated gear rotation speed, the measured data can be converted corresponding to the gear rotation angle. Thus we diagnose gear tooth surface damage without being influenced by rotational fluctuation. We did diagnosis experiments and we made contour maps show diagnosis accuracy. From these maps, we got the following conclusions: 1) The accuracy of damage diagnosis is the same level regardless of the presence or absence of a rotary encoder. 2) The cycle of rotational fluctuation hardly affects the accuracy. 3) Bigger fluctuation amplitude makes the range accuracy worse, however the position accuracy improves.

We developed a walking assistance apparatus which can be used for neuro-rehabilitation of patients. This apparatus assists only the ankle joints of the equipped person while walking. The apparatus attaches the motor on the waist of the equipped person and the flexible shaft transmits the torque of the motor to the self lock less worm gear on the ankle joint. By using this apparatus, the dorsiflexion and plantarflexion of the ankle joint of the equipped patients could be increased while walking. Therefore, the heel contact could be recovered and stumbling could be prevented. Furthermore, the length of the stride of the equipped patients was increased and the posture was raised according to gait training with the apparatus. We found that this apparatus can improve the gait of the equipped person while walking.

This assistance apparatus for upper limbs was developed for patients who can control their fingers but they cannot lift up their arms themselves, for example myopathy and hemiplegic patients. The purposes of the research in this paper are as follows: 1) to design the simple shaped arm and make the easy control system taking into account the practical use of patients, 2) to confirm the decrease of muscle activity while using the apparatus as an ADL assistance device for myopathy patients, 3) to grasp the tendency of the cerebral activity while using the apparatus as a Neuro-Rehabilitation assistance device for hemiplegic patients. The mechanism of assistance is utilizes the differential gears to lose the weight and volume of the mechanical arm. That enabled us to configure three motors to drive two DOFs (Degrees of freedom) for the shoulder and one DOF for the elbow around the root of the mechanical arm. The arm can lift up to 4 kgf (39.2 N) at the tip of the extended arm, and each maximum angle velocity is 1.57 rad/sec. This arm has two support trays, for wrist and upper arm. Each tray is equipped with a pressure sensor at the contact point to the user's arm, and by using the measured result of these four sensors, the control computer can learn the status of the user's arms. Furthermore, to realize other ADL (activities of daily living) motions (for instance, eating, writing, putting on making up, wiping his/her face, and so on) themselves, we proposed to control the device using the targeted posture map for the mechanical arm. At first, various desired or necessary postures of the assisted arms for the equipped person are determined, and each posture is defined as a control target. Next, each target (which is relatively close) is mutually connected, and the map can be accomplished. However, most of user can use the device without watching the map, because each target in the map is connected with the input signal of the same direction, which the user wants to move his/her hand. To be able to choose the appropriate input for each patient, various input interfaces, for example, joy-stick, push buttons, sensor glove using bending sensors, and so on, are equipped. The muscle activity while using the device was measured, and compared the %MVC data between using the device or not. As a result, the activity decreased up to 60%, and the effectiveness of this device could be confirmed. Finally, to expand the usage of this apparatus to encompass Neuro-Rehabilitation as well, the cerebral activity while using the device for rehabilitation with a near-infrared spectroscopy (NIRS) was measured. Then the data from using the device or not, and input motion from a third person were compared. By using this device, the cerebral activity decreased especially when the target motion was complex. However, when the subject input the motion themselves, the cerebral activity increased more than the data is input by a third person, especially, according to the complexity of the target motion. Therefore, for use in Neuro-Rehabilitation, we found it was important for the subject to input the target motion him/herself.

We developed a new whole body motion support type mobile suit. This suit can be used separately for supporting the upper and/or lower limbs, for assisting in ADL (Activities of Daily Living). We also developed a mobile lifter system which can bear both the equipped person and the suit. This suit and the lifter can be used by motor palsy patients, people who have suffered a stroke, spinal-cord-injury patients, and people with central nerve disorders. Using this device, these patients can recover normal gait with no risk of falling. In this paper, the cerebral activity during walking using the suit and normal gait without the suit are compared. According to multiple trials with the suit on a treadmill, the activities of the premotor area sensory motor cortex decreased. Especially, while walking using the suit for supporting lower limbs without swinging arms, the cerebral activities of most of the areas decreased. This data shows that it bcomes ineffective for patients accustomed to the suit in rehabilitation. However, on the contrary, by walking while swinging bilateral arms (even though these arms were assisted by the suit), the activity in the supplementary motor area increased (this area of the brain is related with memory of motion). Furthermore, the cerebral activities while walking on a treadmill and while walking in a corridor with an outside view were compared using NIRS (Near-Infrared Spectroscopy). From the results of this experiment, we found it is most effective for gait training to actually walk and not stay fixed in one location. We also found it is important for patients to swing their arms during gait training in rehabilitation.

We have developed a method to diagnose damage using a laser beam. Our method can be explained as follows: First, a tooth surface is irradiated by a zonal laser beam from an oblique direction, and then the irradiated laser beam line is shifted along the surface of the tooth according to gear revolution. The variations of the laser reflection between the initial and the present conditions are compared. And then it can estimate the condition on the tooth surface such as initial or abnormal abrasion, pitting, spalling, etc. To apply this method for a helical gear, the arm for setting the laser sensor was assumed as the special closed-loop serial-linkage, and the structure of the arm was proposed. By using these proposals, the data calculated from laser reflection and measured with caliper were compared. As a result, we could diagnose the helical and/or profile shifted gear as well as a spur gear, and the difference was up to 8 [%].

We developed a new diagnostic method by using a laser beam. A tooth surface is irradiated by the zonal laser beam from an oblique direction, and then the irradiated laser beam line is shifted along the height of the tooth according to gear rotation. The variation of the voltage proportional to laser reflection between initial and present conditions are compared, and the condition of the tooth surface can be diagnosed for things such as initial or abnormal abrasion, pitting, etc. Furthermore, we developed a method of automatic and remote damage diagnosis on a gear tooth surface according to various gear specifications by using the angle-distance relation map which made from pre-measured data of same material and heat treatment, and taking into account the influence of adjacent teeth. The measured data agreed well with the predicted data made with this method, therefore we can diagnosis the condition of various products automatically.

We have developed a prototype for a walking-assistance apparatus that serves as a next-generation vehicle or a movable neuro-rehabilitation training appliance for the elderly or motor palsy patients. Our prototype uses a novel spatial parallel link mechanism with a weight-bearing lift. Flat steps of the apparatus move in parallel with the ground
the apparatus supports the entire leg alignment (including soles of the feet) and assists walking behavior at the ankle, knee, and hip joints simultaneously. To estimate the walking phase of each leg of the equipped person, pressure sensors were attached under the thenar eminence and the heel of the sole and the pressure variation at each sensing point was measured. To determine the direction in which the equipped person is walking, a pressure sensor was attached to the flexible crural link. Motor palsy patients and those with muscle weakness can walk with the assistance of the apparatus. Patients who have ambulation difficulty can also use the apparatus with a weight-bearing lift that we developed. Using the apparatus with the weight-bearing lift prevents stumbling and enables input of walking movement to the brain motor area. The validity of the weight-bearing lift can be confirmed from the results of the measured % maximum voluntary contraction (MVC). © (2012) Trans Tech Publications, Switzerland.

The repletion rate of guide dogs for visually handicapped persons is roughly 10% nationwide. The reasons for this low rate are the long training period and the expense for obtaining a guide dog in Japan. Motivated by these two reasons, we are developing guide-dog robots. The major objective is to develop an intelligent human-robot interface. This paper describes two novel interface algorithms and strategy to guide visually handicapped person. We developed new leading edge searching method, which uses a single laser range finder (LRF) developed to find the center of the corridor in an indoor environment. We also developed a new twin cluster trace method that can recognize the led-person's walking conditions measured by the LRF. The algorithm allows the guide-dog robot to accurately estimate and anticipate the led-person's next move. We experimentally verified these algorithms. The results show that the algorithms are reliable enough to enable the guide-dog robot and the led-person to maneuver in a complex corridor environment. © 2011 Springer-Verlag.

A prototype for a walking assistance apparatus for the elderly or rehabilitants of motor palsy patients was developed as a next-generation vehicle or movable neuro-rehabilitation training appliance, using a novel spatial parallel link mechanism and a bearing lift. The flat steps of the apparatus move in parallel with the ground
the apparatus can support entire leg alignment (including soles) and assist
walking behavior at ankle, knee and hip joints simultaneously. To respond to the variation of equipped person's walking velocity, the length of stride and walking cycle while walking with wearing the apparatus were compensated by using walking ratio. Therefore the apparatus can be controlled in response to equipped person's will. Next, we developed a control method of the apparatus by using impedance control, taking into account the dynamics of the apparatus and the legs of an equipped person, and assist ratio for the equipped person. By adjusting the value of natural angular frequency of the desired dynamic equation for the equipped person, this apparatus can assist walking according to the equipped person's desired response of the apparatus. Furthermore, motor palsy and muscle weakness patients can walk by themselves by using the apparatus
patients who have ambulation difficulty can use the apparatus with weight bearing lift that we developed. Using the apparatus with the weight bearing lift prevents stumbling and enables input of walking movement to the brain motor area. From the results of measured %MVC, the validity of the weight bearing lift was shown. Copyright © 2011 by ASME.

A prototype for a walking assistance apparatus for the elderly or motor palsy patients was developed as a next-generation vehicle or movable neuro-rehabilitation training appliance, using a novel spatial parallel link mechanism and a bearing lift. The flat steps of the apparatus move in parallel with the ground
the apparatus can support entire leg alignment (including soles) and assist
walking behavior at ankle, knee and hip joints simultaneously. In order to respond the variation of equipped person's walking velocity, the length of stride and walking cycle while walking with wearing the apparatus were compensated by using the relation of walking ratio. Therefore the apparatus can be controlled in response to equipped person's will. Motor palsy and muscle weakness patients can walk by themselves by using the apparatus
patients who have ambulation difficulty can use the apparatus with weight bearing lift that we developed. Using the apparatus with the weight bearing lift prevents stumbling and enables input of walking movement to the brain motor area. It is very effective for rehabilitation to use the apparatus with the weight bearing lift. This newly developed system facilitates motor palsy and muscle weakness patients in the rehabilitation program. © 2011 IEEE.

Walking assistance is necessary for elderly and persons who engage a heavy activity. In order to meet the social requests, a walking assistance apparatus used a spatial parallel link mechanism have been newly developed in this research. Without making special constraints on person's legs the proposed apparatus can assist whole legs of a person including soles. To utilize the apparatus for elderly in their life, it has to output the angle velocity same as the data of able bodied person. And the equipped person has to be able to walk in various environments (inclined road and stairs, and so on) at will. Therefore the apparatus was equipped an inclination sensor and an ultrasonic sensor, then the angle of the slope and the size of stairs are measured to generate the control signal. The apparatus was equipped a control unit and lithium-ion batteries, and could drive over one hour period. To stabilize the equipped parson's posture for horizontal direction, leaf springs were attached to prevent over-adduction of hip joint. To examine the effectiveness of the proposed apparatus, the muscle fatigue while walking with wearing the apparatus was evaluated for one hour by mean power frequency (MPF) of the measured data of electromyography. As a result, the MPF wearing the apparatus was on maintenance tendency, while the MPF without wearing the apparatus was shifted from high-frequency range to low-frequency range. Moreover, the muscle activity in walking up the stairs was evaluated by IEMG. Therefore, the effectiveness of the apparatus could be confirmed.

A walking assistance device using a flexible shaft was developed. A combination of the flexible shaft with a worm gear was successfully adopted on this device to modify its appearance simple and its size compact. This device is controlled with a hybrid-control system both torque and angle at ankle and knee joints. In this system, the torsional spring constant of the flexible shaft is taken into account to the control power and the rotating angle of the motor. To expand the area of where an equipped parson can walk with the device, a self-contained system that controlled with SH-4 microcomputer and actuators, which consisted of motors and gears, were put in the small backpack, and Lithium-ion battery was utilized. Therefore, the equipped parson and patient can freely walk both in and out of doors environment.

In this paper, we develop a baby buggy with new functions which improve road safety. For the development, we decide the concept of policy based on questionnaire survey for users. The questionnaire survey was carried out around the shopping mall close to Minami-Senju station in Arakawa-ku, Tokyo-Metropolitan. The survey point has some characteristics e.g., there is a large number of the vehicle traffic; there is a road connected with train stations; the baby buggy come and go with bicycles on a walkway, and so on. As the result of survey, we can found expectations for improvements of “the single-hand operation” which include a function of single-hand open/fold and straightforward progress. If the single-hand operation is possible, the user is possible to hold children in another hand. In same time, it is expected that the improvement of usability make user available to attend on children for road safety. Then, we developed new functions based on a buggy in the market. Those are the function of single-hand folding, the function of improved straightforward progress and the function of new self-standing. The first, we install a kick-bar. By this development, the single-hand folding is remarkably improved. Also, the kick-bar work as the leg of the self-standing when the buggy is folded. The second, we develop a function of handle-revolution. By this function, straightforward progress will be improved due to tentative combination of handles.

An apparatus to assist elderly patients to stand up, as well as leaning forward the upper body, has been developed. The mechanism of the apparatus enables to shift the person's center of gravity along an adequate trajectory during the standing up process, so as not to cause strain on the joints of the user's leg. The apparatus also assists a person to alter from standing or sitting posture to lying posture. Although the mechanism has multiple links and joints, only one actuator is required to transform the apparatus between aforementioned three postures. The length of each link of the mechanism has been determined from their effect on the backrest angle when each link in the mechanism length is changed. The torque of the hip and knee joints while using the apparatus can be calculated and compared with the data of a user not using the apparatus. We hypothesize that the output torque of the user while standing is decreased by using the apparatus.

We propose herein an in situ method to remotely diagnose gear-tooth damage using scattering of a laser beam. The proposed method provides early and accurate diagnosis of the gear-tooth-surface condition. A tooth surface is first irradiated at oblique incidence by a zone-covering laser beam, and the zone is scanned along the surface of the gear tooth by the rotation of the gear. By analyzing variations in laser scattering between benchmark data and the current data, we can estimate the condition of the gear-tooth surface in terms of abnormal abrasion, pitting, spalling, etc. To test the method, we used it to remotely detect gear-teeth pitting in an experiment during which we simultaneously measured the vibration and sound of the gearbox and pedestal. Our analysis shows that the laser-scattering measurements reveal pitting more clearly and at an earlier stage than does the vibration and noise measurements. Therefore, we conclude that the proposed method estimates the tooth-surface condition with sufficient accuracy to assess the lifetime of the gear. Furthermore, we used the proposed method to diagnose real gear-teeth in situ in practical gearboxes to verify that the method yields an accurate diagnosis of the tooth surface of a lubricated gear. We found that by attaching a cover to the laser receiver; the remote measurements were unaffected by the choice or method of lubrication. For force-feed lubrication, pitting was detected for every speed range under 1800 rpm. These results demonstrate that the proposed method can diagnose the tooth surface of lubricated gears in practical gearboxes. Finally, we developed an automatic damage diagnosis method that is capable of detecting pitting by analyzing the laser-scattering signal from damaged teeth combined with that from the same teeth prior to the damage.

モビルスーツ型自立歩行支援ロボットを使って，免荷時のロボット使用時の歩行と通常歩行の健常者における脳活動を比較し，脳機能の視点から月面歩行のシミュレーションとしての可能性を検討した．月面歩行のシミュレーションを歩行と捉えるか，ジャンプと捉えるかでシミュレーションの方法が変わってくるものと考えられる．月面歩行のシミュレーションの技術開発は，ニューロリハビリテーションやスポーツ医学等の隣接学術領域にも多くの知見を与えるものと思われる．

An apparatus to assist elderly patients to stand up, as well as leaning forward the upper body, has been developed. The mechanism of the apparatus enables to shift the person's center of gravity along an adequate trajectory during the standing up process, so as not to cause strain on the joints of the user's leg. The apparatus also assists a person to alter from a standing or sitting posture to lying posture. Although the mechanism has multiple links and joints, only one actuator is required to transform the apparatus between aforementioned three postures. The length of each link of the mechanism has been determined from their effect on the backrest angle when each link in the mechanism length is changed. The torque of the hip and knee joints while using the apparatus can be calculated and compared with the data of a user not using the apparatus. We hypothesize that the output torque of the user while standing is decreased by using the apparatus.Mechanical Design

We have developed a walking assistance apparatus using a spatial parallel link mechanism. This apparatus was designed to assist in the rehabilitation of patients who have difficulty walking. The apparatus utilizes a compensating gravity mechanism that helps center gravity during the stance phase of walking. To confirm the effectiveness the mechanism, we compared the measured data of the height of the hip joint on the apparatus while walking between with the mechanism and without the mechanism, and measured the value of the force which lifted the upper body with the mechanism. From these results, it can be verified that the mechanism output the lifting force during the stance phase of walking, and the hip joint kept the adequate height while walking by using the mechanism.

We have developed two kinds of power assistance suits. One is for support a patient's activities of daily living, which was united two apparatuses between for the upper limbs and for the legs; these were driven with a motor. These apparatuses were already developed, and characterized in that equipped person can be assisted for arms and legs without fixation with the apparatuses. By using this suit, we can input the entire body motion to the equipped patient for the neuro-rehabilitation. The other is for support a helper's assistance behavior, which was made with rubber belt, and without electricity. This suit can assist lifting motion, especially for equipped person's arms and waist. To confirm the validity of this suit, we measured the variation of maximum output force, IEMG and %MVC of the entire body while lifting and holding motion. By using this suit, the maximum lifting weight of equipped person was increased by 8kg, and the arm and leg of the equipped person were assisted effectively.

A conceptual Guide-Dog Robot prototype to lead and to recognize a visually-handicapped person is developed and discussed in this paper. Key design features of the robot include a movable platform, human-machine interface, and capability of avoiding obstacles. A novel algorithm enabling the robot to recognize its follower's locomotion as well to detect the center of corridor is proposed and implemented in the robot's human-machine interface. It is demonstrated that using the proposed novel leading and detecting algorithm along with a rapid scanning laser range finder (LRF) sensor, the robot is able to successfully and effectively lead a human walking in corridor without running into obstacles such as trash boxes or adjacent walking persons. Position and trajectory of the robot leading a human maneuvering in common corridor environment are measured by an independent LRF observer. The measured data suggest that the proposed algorithms are effective to enable the robot to detect center of the corridor and position of its follower correctly.

In Japan, repletion rate of guide dogs for visually-handicapped persons is at very low percentage of roughly 10% nationwide due to required long training period as well as uneconomic price in obtaining a guide dog. Motivated by these two reasons, we are currently developing a Guide-Dog Robot with major objective given to developing intelligence in human-guide-dog robot interface. In this paper, novel human-machine interface algorithm and strategy to lead visually-handicapped people is proposed. A new leading edge searching method intelligently incorporated with one leaser range finder (LRF) is developed and implemented in our prototype guide-dog robot. It is demonstrated in our experiment that with the new method, the robot not only is able to effectively recognize the led-person's walking conditions but also is able to accurately estimate the person's next move. With the new method and a LRF, robustness is improved and validated to allow the guide-dog robot and the led-person to maneuver in complex corridor environment.

There are many persons who lost their sight or hearing. And They want to get more flexibility for their activities. But there are very low supply assistance-dog. So, we started to serve a assistance-dog robot for handicap persons. In this paper, algorithm of obstacle detection with image processing and avoidance are proposed. Especially, the potential method is applied to Bar-Shape obstacles for estimating the coordinate. These validity of methods are shown with simulation and also experiment by using prototype robot with real-time processing. As a result, we found the choice of getting around Bar or not is easily to control with height of Bar with persons safety.

We developed a walking assist machine, which machine used a spatial parallel link mechanism for the elderly or workers. The flat steps of the assist machine move in parallel with the ground and can support the legs of a person including the soles. The machine was equipped various sensors, could turn around during walking and walk in a slope or stairs. Furthermore, the machine was mounted self-contained control system used a SH-4 microcomputer and Lithium-ion batteries. As a result, the equipped person can walk without limitation of the area where the machine can be used. The EMG while the equipped person walked on the stairs was measured, and the ratio of IEMG between the data while wearing and without wearing the machine, and MVC were calculated. As a result, the machine was effective to use during walking on the stairs for the lower leg (crural leg) of the equipped person.

We developed a new diagnostic method by using a laser beam from the point of view of remote diagnosis. Our method can be explained as follows : first, a tooth surface is irradiated by a zonal laser beam from oblique direction, and then an irradiated laser beam line is shifted along the height of the tooth according to gear revolution. The variations of the laser reflection between the initial and the present conditions are compared, and it can estimate a condition on the tooth surface such as normal or destructive wear, pitting, spalling, etc. To confirm the validity of our method, a pitting experiment was carried out, and at the same time the laser reflection was measured. As a result, the data of the laser reflection experiment revealed occurrence of the pitting apparent and early. Thus, it can be concluded that our method can accurately estimate the condition of a tooth surface and sufficiently assess the duration of the gear life.

Ankle-foot orthoses (AFOs) are used in people who have difficulty of working as ankle contracture splints and foot drop splints. Although utilization of AFOs has been expanding, it is still questionable if functions and structures of AFOs are suitable. In this paper, a new active ankle-foot orthosis (AAFO), which is dynamically controlled linked with muscle activities, is proposed. To discuss functions of the AAFO, using the electromyographies (EMGs), muscle activities during dynamic balancing of a body and changing of muscle activities with fatigue are considered. As the results, it's shown that to assist femoris muscles additionally to the tibialis anterior muscle is important as the function of the AAFO.

This paper proposes a walking assist machine for the elderly or rehabilitants, which uses a spatial parallel link mechanism. Its flat steps move in parallel with the ground and can support the whole legs of a person including his/her soles. A prototype was developed, which was designed to assist the halfpower of walking. Its performance was evaluated by experimental load tests corresponding to the half weight of each leg. Furthermore, to confirm the validity of our supporting method, muscle activity of the leg while wearing the walking assist machine was evaluated by using the surface electromyography (EMG) and calculating the ratio of the integrated EMG (IEMG) with and without the walking assist machine. The experimental results show that the activities of the rectus femoris muscle and the tibialis anterior muscle were particularly decreased to approximately sixty percent by wearing the walking assist machine.

Ankle-foot orthoses (AFOs) are used in people who have difficulty of working as ankle contracture splints and foot drop splints. Although utilization of AFOs has been expanding, it is still questionable if functions and structures of AFOs are suitable. In this paper, a new active ankle-foot orthosis (AAFO), which is dynamically controlled linked with muscle activities, is proposed. To discuss functions of the AAFO, using the electromyographies (EMGs), muscle activities during dynamic balancing of a body and changing of muscle activities during fatigue are considered. As the results, it's shown that to assist femoris muscles additionally to the tibialis anterior muscle is important as the function of the AAFO.

A method for predicting gear noise produced by a gear system was developed. This method calculates the distribution of sound pressure around the gearbox and identifies the areas from which noise radiates intensely. According to the sound-power level calculated from this pressure distribution, a low-noise gearbox was designed by adding ribs. The appropriate adding points were then calculated from the viewpoint of mass variation. It was found that to decrease the noise, ribs should be added in two places : (i) along the line with maximum curvature through the antinode of the gearbox's vibration mode or (ii) the minimum-length line which crosses the most contour lines through the maximum point of the sound-pressure contour map. It was also found that in the case of a gearbox with a vibration mode in which the gearbox side faces vibrate in opposite directions, noise can be effectively reduced by connecting the ribs on both side faces.

A method for predicting gear noise from the vibration step to the sound-generation step of a complete gear system, including a gearbox, was developed. This method consists of three separate steps: gear-vibration analysis by an in-house program, gearbox-vibration analysis by an FEA program, and sound-radiation analysis by a commercial software. By using this method, it can obtain the vibration behavior of the gear and gearbox, and the distribution of the sound-pressure around the gearbox and identify the areas from which noise radiates intensely. To validate the method, we measured the displacement of a gear shaft, the acceleration of points on the surface of the gearbox, and the sound-pressure levels around the gearbox. The measured results agreed well with the corresponding calculations. According to the calculated noise, a low-noise gearbox was designed by adding ribs near the antinodes of the gearbox's vibration mode.

The increasing demand for quiet gear systems has created the need for precise analysis of gear-drive vibration. Furthermore, these days, noise should be predicted during product design. In response to these needs, the authors have developed a new method for predicting the vibration and noise of a total gear system, including not only multi-stage gear pairs but also shafts, pedestals, and a gearbox. The method consists of three separate analyses : three-dimensional gear-vibration analysis, FEA (finite element analysis) of gearbox vibration, and BEA (boundary element analysis) of the sound field. To verify the effectiveness of the method, sound-pressure levels at two points in the horizontal and the vertical directions from the experimental apparatus's gearbox were measured. These measurements agreed well with the corresponding calculated levels by developed analysis method. It can thus be concluded that the method can accurately predict vibration and noise and sufficiently assess the noise radiated and propasated through air. It can therefore be utilized for designing a low-noise gearbox by determining the area from which the noise is radiated intensively.

We have developed a new method for building a vibration model of an actual gear-drive system. Each gear has six degrees of freedom: three translational and three rotational motions. Stiffness matrixes representing each gear shaft and tooth meshing were made and overlapped into one stiffness matrix for the whole system. This enabled easy modelling of complex gear-drive systems such as multi-stage gears and branched gears. The results are in good agreement with experimental results with respect to the major resonance frequencies and vibration modes.

A new method for calculating the three-dimensional vibration behavior of a multi-stage helical gear system including a gearbox has been developed. This method utilizes three-dimensional multi -stage gear vibration analysis and FEM analysis. The calculated three-dimensional vibration of gears is used in a FEM model, which gives the vibration responses of the gearbox. The calculated and measured eigen frequencies and vibration responses of the gearbox agree well. For obtaining precise vibration responses of the gearbox, therefore, it is shown to be effective to consider the modeling of gear shaft, gear meshing, bearing and leg of gearbox in FEM analysis.

The increasing demand for quiet gears has created an increasing demand for precise analysis of gear drive vibration. There has been a lot of research on gear vibration analysis; most of which was dealt with a single gear pair. This report shows a new method for building a vibration model for an actual gear drive system. Each gear has six degrees of freedom; three translational motions and three swing motions. Stiffness matrixes for each gear shaft and for tooth meshing were made and overlapped into a stiffness matrix for the total system. This enabled easy modelling of the complex gear drive systems; such as multistage gears and branched gears. The results are in good agreement with experimental results with respect to the major resonance frequencies and vibration modes.

This paper discusses design and control issues for a robot with integrated locomotion and manipulation which can take various postures. This work is motivated by the fact that persons can take various postures and can work while being in those postures. We show a prototype of four legged twelve joint robot employing timing-belt mechanism. Each leg can be used as a manipulator when it is free from providing the support to the body of the robot. At most two legs are free when the robot stands on its knees. This paper formulates feasible motions of the robot maintaining contact with a supporting plane or the floor. This kinematic analysis is useful to determine whether the robot needs to lift its legs in order to change its postures or not.