2024/03/24 更新

写真a

マエカワ タカシ
前川 卓
所属
理工学術院 理工学術院総合研究所
職名
上級研究員(研究院教授)
学位
Ph.D. ( マサチューセッツ工科大学(アメリカ合衆国) )
ホームページ

経歴

  • 2019年04月
    -
    継続中

    早稲田大学   理工学術院総合研究所   上級研究員(研究院教授)

  • 2019年04月
    -
    継続中

    横浜国立大学   名誉教授

  • 2003年04月
    -
    2019年03月

    横浜国立大学 大学院工学研究院 システムの創生部門 教授

  • 1999年07月
    -
    2003年03月

    マサチューセッツ工科大学 工学部 海洋工学科 主席研究員

  • 1994年09月
    -
    1999年06月

    マサチューセッツ工科大学 工学部 海洋工学科 研究員・講師

  • 1993年07月
    -
    1994年08月

    マサチューセッツ工科大学 工学部 海洋工学科 ポスドク

  • 1989年08月
    -
    1993年06月

    マサチューセッツ工科大学 工学部 海洋工学科 リサーチ・アシスタント

  • 1978年04月
    -
    1989年07月

    (株)ブリヂストン 技師

▼全件表示

学歴

  •  
    -
    1993年

    マサチューセッツ工科大学   工学部   海洋工学科  

  •  
    -
    1976年

    早稲田大学   理工学部   機械工学科  

委員歴

  • 2012年03月
    -
    継続中

    Computer-Aided Design  Editor

所属学協会

  • 2020年08月
    -
    継続中

    日本応用数理学会

  •  
     
     

    日本機械学会

研究分野

  • 設計工学

受賞

  • Solid Modeling Fellow Award 2023

    2023年07月   Solid Modeling Association  

    受賞者: Takashi Maekawa

  • The Best Paper Award 1st Place

    2021年09月   Solid Modeling Association SPM 2021  

    受賞者: Felix Scholz, Takashi Maekawa

  • 貢献賞

    2019年09月   日本機械学会 設計工学・システム部門  

    受賞者: 前川 卓

  • 発明表彰

    2019年05月   横浜国立大学  

    受賞者: 前川 卓

  • 120周年記念功労者表彰

    2017年11月   日本機械学会  

    受賞者: 前川 卓

  • 特別研究員等の書面審査 表彰

    2016年08月   日本学術振興協会  

    受賞者: 前川 卓

  • 設計・システム部門 業績賞

    2014年09月   日本機械学会  

    受賞者: 前川 卓

▼全件表示

 

論文

  • Approximation of doubly curved surfaces by analysis-suitable piecewise surfaces with high developability

    Felix Scholz, Soma Nishikawa, Masahito Takezawa, Takashi Maekawa

    The Visual Computer    2022年12月  [査読有り]

    担当区分:最終著者

    DOI

    Scopus

  • Accurate High-Order Derivatives of Geodesic Paths on Smooth Surfaces

    Felix Scholz, Takashi Maekawa

    Computer-Aided Design   140   103082 - 103082  2021年11月  [査読有り]

    担当区分:最終著者

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • Fabrication of doubly-curved CFRP shell structures with control over fiber directions

    Masahito Takezawa, Yuto Otoguro, Kohei Matsuo, Tadahiro Shibutani, Akio Sakurai, Takashi Maekawa

    Computer-Aided Design   136   103028 - 103028  2021年07月  [査読有り]

    DOI

    Scopus

    11
    被引用数
    (Scopus)
  • Two-Lane Path Planning of Autonomous Vehicles in 2.5D Environments

    Riku Usami, Yuji Kobashi, Taiki Onuma, Takashi Maekawa

    IEEE Transactions on Intelligent Vehicles   5 ( 2 ) 281 - 293  2020年06月  [査読有り]

    DOI

  • Control of lines of curvature for plate forming in shipbuilding

    M. Takezawa, K. Matsuo, T. Maekawa

    Computer Aided Geometric Design   75  2019年11月  [査読有り]

  • Automatic Two-Lane Path Generation for Autonomous Vehicles Using Quartic B-Spline Curves

    Taketoshi Suzuki, Riku Usami, Takashi Maekawa

    IEEE Transactions on Intelligent Vehicles   3 ( 4 ) 547 - 558  2018年12月  [査読有り]

    DOI

  • Embedding QR codes onto B-spline surfaces for 3D printing

    Ryosuke Kikuchi, Sora Yoshikawa, Pradeep Kumar Jayaraman, Jianmin Zheng, Takashi Maekawa

    CAD Computer Aided Design   102   215 - 223  2018年09月  [査読有り]

     概要を見る

    Recent advance of Additive Manufacturing technologies allows us to manufacture various parts used in real-world products. Consequently, product tracking of such 3D printed parts is an important issue. Quick Response (QR) code which is a two-dimensional matrix barcode invented by Denso, a Japanese automotive industry, in 1994, can be used for this purpose. It can store more data than the 1D barcode in a smaller space, and using a smartphone as a scanner, one can directly visit a website where all the information of the parts is stored. However, QR codes require secondary procedures to add them to products and are also vulnerable to wear and tear. Moreover, QR codes cannot be added to freeform surfaces, but only to developable surfaces. In this paper we propose a novel technique to embed QR codes onto CAD models consisting of freeform surfaces represented by B-spline surfaces, which produces 3D QR codes. 3D QR codes work similar to 2D QR codes and can be read by existing QR scanners, but are designed by grooving the surface to obtain light and dark regions caused by ambient occlusion. Unlike conventional QR codes, 3D QR codes do not fall off from the part and can even be painted if necessary. Furthermore, we do not need to prepare dark-colored and light-colored materials for 3D printing as the dark color is provided by the grooving. We demonstrate the effectiveness of our technique with various examples.

    DOI

    Scopus

    33
    被引用数
    (Scopus)
  • An image processing approach to feature-preserving B-spline surface fairing

    Taro Kawasaki, Pradeep Kumar Jayaraman, Kentaro Shida, Jianmin Zheng, Takashi Maekawa

    CAD Computer Aided Design   99   1 - 10  2018年06月  [査読有り]

     概要を見る

    Reverse engineering of 3D industrial objects such as automobiles and electric appliances is typically performed by fitting B-spline surfaces to scanned point cloud data with a fairing term to ensure smoothness, which often smooths out sharp features. This paper proposes a radically different approach to constructing fair B-spline surfaces, which consists of fitting a surface without a fairing term to capture sharp edges, smoothing the normal field of the constructed surface with feature preservation, and reconstructing the B-spline surface from the smoothed normal field. The core of our method is an image processing based feature-preserving normal field fairing technique. This is inspired by the success of many recent research works on the use of normal field for reconstructing mesh models, and makes use of the impressive simplicity and effectiveness of bilateral-like filtering for image denoising. In particular, our approach adaptively partitions the B-spline surface into a set of segments such that each segment has approximately uniform parameterization, generates an image from each segment in the parameter space whose pixel values are the normal vectors of the surface, and then applies a bilateral filter in the parameter domain to fair the normal field. As a result, our approach inherits the advantages of image bilateral filtering techniques and is able to effectively smooth B-spline surfaces with feature preservation as demonstrated by various examples.

    DOI

    Scopus

    15
    被引用数
    (Scopus)
  • Survey on geometric iterative methods and their applications

    Hongwei Lin, Takashi Maekawa, Chongyang Deng

    CAD Computer Aided Design   95   40 - 51  2018年02月  [査読有り]

     概要を見る

    Geometric iterative methods (GIM), including the progressive–iterative approximation (PIA) and the geometric interpolation/approximation method, are a class of iterative methods for fitting curves and surfaces with clear geometric meanings. In this paper, we provide an overview of the interpolatory and approximate geometric iteration methods, present the local properties and accelerating techniques, and show their convergence. Moreover, because it is easy to integrate geometric constraints in the iterative procedure, GIM has been widely applied in geometric design and related areas. We survey the successful applications of geometric iterative methods, including applications in geometric design, data fitting, reverse engineering, mesh and NURBS solid generation.

    DOI J-GLOBAL

    Scopus

    84
    被引用数
    (Scopus)
  • 反復幾何処理手法を用いた船体曲面表現手法に関する研究

    竹澤正仁, 松尾宏平, 前川 卓

    日本船舶海洋工学会論文集   27   149-160  2018年  [査読有り]

    DOI CiNii

  • Adaptive direct slicing of volumetric attribute data represented by trivariate B-spline functions

    Yuhi Sasaki, Masahito Takezawa, Seungki Kim, Hiroshi Kawaharada, Takashi Maekawa

    International Journal of Advanced Manufacturing Technology   91 ( 5-8 ) 1791 - 1807  2017年07月  [査読有り]

     概要を見る

    We introduce a framework for modeling of heterogeneous objects in terms of trivariate B-spline functions and a method for slicing them directly for additive manufacturing. We first fit volumetric attribute data associated with the geometry in terms of trivariate B-spline functions under the assumption that the geometric volume is already defined by the trivariate B-spline functions. Then, the B-spline volume and the associated attribute data are directly sliced without converting them to stereo-lithography format, resulting in a tool path with fewer errors. Furthermore, adaptive ray shooting is introduced in the slicing plane so that the zigzag tool path passes through all the tangential intersection points of the heterogeneous objects to represent all the feature points in the fabricated model. Complex examples illustrate the effectiveness of our method.

    DOI

    Scopus

    24
    被引用数
    (Scopus)
  • Curvature sensitive analysis of axially compressed cylindrical tubes with corrugated surface using isogeometric analysis and experiment

    Takuma Imai, Tadahiro Shibutani, Kazumi Matsui, Seitoku Kumagai, Dang Tien Tran, Kaiyuan Mu, Takashi Maekawa

    COMPUTER AIDED GEOMETRIC DESIGN   49   17 - 30  2016年12月  [査読有り]

     概要を見る

    We study the effects of curvature on the energy absorption characteristics of cylindrical corrugated tubes under compression by isogeometric analysis and experiments. The corrugated volume is constructed by revolving a wavelike B-spline profile surface about the vertical axis. The curvature at peaks of the profile curve is gradually increased from a smaller value to a larger value while the wavelength and amplitude are kept unchanged. This leads to three curvature distribution patterns, which are found to significantly affect the energy absorption characteristics of the corrugated tube. Examples show that the tube with the largest curvature pattern absorbs around 21% more energy than that with the smallest curvature pattern. (C) 2016 Elsevier B.V. All rights reserved.

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • Fabrication of freeform objects by principal strips

    Masahito Takezawa, Takuma Imai, Kentaro Shida, Takashi Maekawa

    ACM Transactions on Graphics   35 ( 6 ) 1 - 12  2016年11月  [査読有り]

    DOI

    Scopus

    23
    被引用数
    (Scopus)
  • Tool path generation for chamfering drill holes of a pipe with constant width

    Takato Sato, Youichi Sato, Takashi Maekawa

    COMPUTER-AIDED DESIGN   78 ( SI ) 26 - 35  2016年09月  [査読有り]

     概要を見る

    When drilling circular holes into metal circular pipes, burr is generated at the hole entrance as well as at the hole exit. The burrs generated at the edge curves associated with the outer and inner pipe surfaces must be removed by constant chamfering. Geometrically, the two edge curves can be defined as cylinder to-pipe intersection curves. In this paper, we employ differential geometric properties of the surface-to-surface intersection curves in order to generate an interference-free tool path with constant chamfering for a ball-end cutter. We demonstrate the effectiveness of our method by conducting experiments with physical pipe models. (C) 2016 Elsevier Ltd. All rights reserved.

    DOI

    Scopus

    4
    被引用数
    (Scopus)
  • 反復照度差ステレオ法を用いた微細形状計測装置の開発

    井本 治孝, 町田 賢一郎, 山浦 佑介, 蓼沼 周, 前川 卓

    日本機械学会論文集 2016   82 ( 835 ) 15-00512 - 00512-15-00512  2016年02月  [査読有り]

     概要を見る

    In the manufacturing process of machine products, it is important to automate the manual visual inspection in detecting microscopic surface defects in order to improve the efficiency and eliminate human errors as well. The basic hardware system consists of a high-resolution camera equipped with a telecentric lens, and a device to change light directions using 60 LED light bulbs. We introduce an accurate automatic system to detect such surface defects based on the novel hardware system and the iterative photometric stereo techniques, which iteratively improve the quality of the estimation of the surface shape. Complex examples are provided to demonstrate the effectiveness of the proposed system.

    DOI CiNii J-GLOBAL

  • Automatic generation of LEGO building instructions from multiple photographic images of real objects

    Takuya Kozaki, Hiroshi Tedenuma, Takashi Maekawa

    COMPUTER-AIDED DESIGN   70   13 - 22  2016年01月  [査読有り]

     概要を見る

    We introduce a system to reconstruct large scale LEGO models from multiple two dimensional images of objects taken from different views. We employ a unit voxel with an edge length ratio of 5:5:6 for the shape from silhouette method that reconstructs an octree voxel-based three dimensional model with color information from images. We then convert the resulting voxel model with color information into a LEGO sculpture. In order to minimize the number of LEGO bricks, we use a stochastic global optimization method, simulated annealing, to hollow the model as much as possible but keep its strength for portability. Several real complex LEGO models are provided to demonstrate the effectiveness of the proposed method. (C) 2015 Elsevier Ltd. All rights reserved.

    DOI

    Scopus

    14
    被引用数
    (Scopus)
  • Shape reconstruction from a normal map in terms of uniform bi-quadratic B-spline surfaces

    Yusuke Yamaura, Takaki Nanya, Harutaka Imoto, Takashi Maekawa

    COMPUTER-AIDED DESIGN   63   129 - 140  2015年06月  [査読有り]

     概要を見る

    This paper studies the recovery of the height field function of an object from its surface normal vectors in terms of uniform bi-quadratic B-spline surfaces. The study is motivated by two modern technological needs namely, the recovery of the height field function of an object from its surface normal vectors obtained by photometric stereo techniques, and the introduction of new design methodology of streamlined aesthetic surfaces through the direct editing of normal vectors. Our mathematical formulation for explicit surface reconstruction is based on differential geometry and geometric modeling techniques. Complex examples are provided to demonstrate the effectiveness of the proposed method. (c) 2015 Elsevier Ltd. All rights reserved.

    DOI

    Scopus

    10
    被引用数
    (Scopus)
  • Surface design based on direct curvature editing

    Yuki Kineri, Shuhei Endo, Takashi Maekawa

    COMPUTER-AIDED DESIGN   55 ( 10 ) 1 - 12  2014年10月  [査読有り]

     概要を見る

    This paper presents a novel method for modifying the shapes of existing uniform bi-cubic B-spline surfaces by interactively editing the curvatures along isoparametric curves. The method allows us to edit the curvatures of the two intersecting isoparametric curves at each knot with specified positions, unit tangents, and unit normals. The user adjusts the radii of circles, representing the radii of curvature in the u and v isoparametric directions directly via a GUI without having to work with control points and knots. Such shape specifications are converted into iterative repositionings of the control points on the basis of geometrical rules. Using these point-based curvature-editing techniques, we successfully embedded log-aesthetic curves into existing surfaces along their isoparametric curves. Moreover, we were able to distribute the cross curvature with log-aesthetic variation along the isoparametric curves. We applied our technique to the design of automobile hood surfaces to demonstrate the effectiveness of our algorithms. (C) 2014 Elsevier Ltd. All rights reserved.

    DOI J-GLOBAL

    Scopus

    19
    被引用数
    (Scopus)
  • Differential geometry properties of lines of curvature of parametric surfaces and their visualization

    Han Kyul Joo, Tatsuya Yazaki, Masahito Takezawa, Takashi Maekawa

    GRAPHICAL MODELS   76 ( 4 ) 224 - 238  2014年

     概要を見る

    We present algorithms for computing the differential geometry properties of lines of curvature of parametric surfaces. We derive a unit tangent vector, curvature vector, binormal vector, torsion, and algorithms to evaluate their higher-order derivatives of lines of curvature of parametric surfaces. Among these quantities, it is shown that the curvature and its first derivative of the lines of curvature lend a hand for the formation of curved plates in shipbuilding. We also visualize the twist of lines of curvature, which enables us to observe how much the osculating plane of the line of curvature turns about the tangent vector. (C) 2014 Elsevier Inc. All rights reserved.

    DOI

    Scopus

    14
    被引用数
    (Scopus)
  • B-spline surface fitting by iterative geometric interpolation/approximation algorithms

    Yuki Kineri, Mingsi Wang, Hongwei Lin, Takashi Maekawa

    COMPUTER-AIDED DESIGN   44 ( 7 ) 697 - 708  2012年07月  [査読有り]

     概要を見る

    Recently, the use of B-spline curves/surfaces to fit point clouds by iteratively repositioning the B-spline's control points on the basis of geometrical rules has gained in popularity because of its simplicity, scalability, and generality. We distinguish between two types of fitting, interpolation and approximation. Interpolation generates a B-spline surface that passes through the data points, whereas approximation generates a B-spline surface that passes near the data points, minimizing the deviation of the surface from the data points. For surface interpolation, the data points are assumed to be in grids, whereas for surface approximation the data points are assumed to be randomly distributed. In this paper, an iterative geometric interpolation method, as well as an approximation method, which is based on the framework of the iterative geometric interpolation algorithm, is discussed. These two iterative methods are compared with standard fitting methods using some complex examples, and the advantages and shortcomings of our algorithms are discussed. Furthermore, we introduce two methods to accelerate the iterative geometric interpolation algorithm, as well as a method to impose geometric constraints, such as reflectional symmetry, on the iterative geometric interpolation process, and a novel fairing method for non-uniform complex data points. Complex examples are provided to demonstrate the effectiveness of the proposed algorithms. (C) 2012 Elsevier Ltd. All rights reserved.

    DOI

    Scopus

    71
    被引用数
    (Scopus)
  • Point-tangent/point-normal B-spline curve interpolation by geometric algorithms

    Shu-ichi Gofuku, Shigefumi Tamura, Takashi Maekawa

    COMPUTER-AIDED DESIGN   41 ( 6 ) 412 - 422  2009年06月

     概要を見る

    We introduce a novel method to interpolate a set of data points as well as unit tangent vectors or unit normal vectors at the data points by means of a B-spline curve interpolation technique using geometric algorithms. The advantages of our algorithm are that it has a compact representation, it does not require the magnitudes of the tangent vectors or normal vectors, and it has C-2 continuity. We compare our method with the conventional curve interpolation methods, namely, the standard point interpolation method, the method introduced by Piegl and Tiller, which interpolates points as well as the first derivatives at every point, and the piecewise cubic Hermite interpolation method. Examples are provided to demonstrate the effectiveness of the proposed algorithms. (C) 2009 Elsevier Ltd. All rights reserved.

    DOI J-GLOBAL

    Scopus

    60
    被引用数
    (Scopus)
  • 3D shape reconstruction from 2D images

    Daisuke Hirano, Yusuke Funayama, Takashi Maekawa

    Computer-Aided Design and Applications   6 ( 5 ) 701 - 710  2009年

     概要を見る

    We present a method of reconstructing a 3D model from several 2D images of an object taken from different views. The data acquisition system consists of a camera on a tripod, and a computer-controlled turntable. We employ the Shape-From-Silhouette (SFS) method, which constructs a voxel-based 3D model from silhouette images. The concave shapes are further carved by using the space carving technique. In order to make the resulting model compatible with the CAD/CAM system, the voxel model is converted into a triangular mesh using the Marching Cubes algorithm. Since the mesh generated from the voxel model by using the Marching Cubes algorithm inherits the staircase effect, the mesh is adjusted to recover the object precisely by using silhouette images. Finally, we evaluate the accuracy of the proposed method. The reconstructed models of complex objects show the effectiveness of the proposed inexpensive 3D shape reconstruction system.© 2009 CAD Solutions, LLC.

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • Computation of the Solutions of Nonlinear Polynomial Systems in the Barycentric Bernstein Basis

    M. Reuter, T. Mikkelsen, E. Sherbrooke, T. Maekawa, N. M. Patrikalakis

    The Visual Computer   24 ( 3 ) 187-200  2008年  [査読有り]

  • Approximation of involute curves for CAD-system processing

    Fumitaka Higuchi, Shuuichi Gofuku, Takashi Maekawa, Harish Mukundan, Nicholas M. Patrikalakis

    ENGINEERING WITH COMPUTERS   23 ( 3 ) 207 - 214  2007年09月  [査読有り]

     概要を見る

    In numerous instances, accurate algorithms for approximating the original geometry is required. One typical example is a circle involute curve which represents the underlying geometry behind a gear tooth. The circle involute curves are by definition transcendental and cannot be expressed by algebraic equations, and hence it cannot be directly incorporated into commercial CAD systems. In this paper, an approximation algorithm for circle involute curves in terms of polynomial functions is developed. The circle involute curve is approximated using a Chebyshev approximation formula (Press et al. in Numerical recipes, Cambridge University Press, Cambridge, 1988), which enables us to represent the involute in terms of polynomials, and hence as a Bezier curve. In comparison with the current B-spline approximation algorithms for circle involute curves, the proposed method is found to be more accurate and compact, and induces fewer oscillations.

    DOI J-GLOBAL

    Scopus

    11
    被引用数
    (Scopus)
  • Interpolation by Geometric Algorithm

    Takashi Maekawa, Yasunori Matsumoto, Ken Namiki

    Computer Aided Design   39 ( 4 ) 313-323  2007年04月  [査読有り]

    DOI J-GLOBAL

    Scopus

    85
    被引用数
    (Scopus)
  • Surface Faring Using Circular Highlight Lines

    Yu Nishiyama, Yoh Nishimura, Takayuki Sasaki, Takashi Maekawa

    Computer-Aided Design and Applications   4 ( 1-4 ) 405 - 414  2007年  [査読有り]

     概要を見る

    We herein propose a novel method for removing irregularities of B-spline surfaces via smoothing circular highlight lines. A circular highlight line is defined as a set of points on a surface such that the distance between a circular light source and an extended surface normal to be zero. Circular highlight lines allow us to capture the surface fairness in all directions, whereas conventional method, which uses a family of parallel straight lines for light sources, can capture the surface irregularity only in one direction. This method of correcting surface irregularities through circular highlight lines is intuitive and allows non-skilled persons to generate surfaces that can satisfy requirements imposed by downstream applications. Nonlinear equations that relate the difference between the circular highlight lines of the current surface and the target curves in the parameter space are formulated in terms of control points of the surface to be modified. The nonlinear governing equations are solved by Newton’s method. The effectiveness of these algorithms is demonstrated through examples. © 2007 by CAD Solutions.

    DOI

    Scopus

    6
    被引用数
    (Scopus)
  • Algorithms for optimal partial matching of free-form objects with scaling effects

    KH Ko, T Maekawa, NM Patrikalakis

    GRAPHICAL MODELS   67 ( 2 ) 120 - 148  2005年03月  [査読有り]

     概要を見る

    A free-form object matching problem is addressed in this paper. Two methods are proposed to solve a partial matching problem with scaling effects and no prior information on correspondence or the rigid body transformation involved. The first method uses umbilical points, which behave as fingerprints of a surface and their qualitative properties can be used for matching purposes. The second method uses an optimization scheme based on the extension of the KH curvature matching method [Comput. Aided Design 35 (2003) 913], first introduced in the context of a matching problem without scaling effects. Two types of curvatures, the Gaussian and the mean curvatures, are used to establish correspondences between two objects. The curvature matching method is formulated in terms of minimization of an objective function depending on the unknown scaling factor, and the rigid body transformation parameters. The accuracy and complexity of the proposed methods as well as the convergence for the optimization approach are analyzed. Examples illustrate the two methods. (C) 2004 Elsevier Inc. All rights reserved.

    DOI J-GLOBAL

    Scopus

    17
    被引用数
    (Scopus)
  • Circular Highlight/Relfection Lines

    T. Maekawa, Y. Nishimura, T. Sasaki

    Computer-Aided Design and Applications   2 ( 1-4 ) 291-300  2005年  [査読有り]

  • Methods for feature-based design of heterogeneous solids

    H Liu, T Maekawa, NM Patrikalakis, EM Sachs, W Cho

    COMPUTER-AIDED DESIGN   36 ( 12 ) 1141 - 1159  2004年10月  [査読有り]

     概要を見る

    This paper presents a parametric and feature-based methodology for the design of solids with local composition control (LCC). A suite of composition design features are conceptualized and implemented. The designer can use them singly or in combination, to specify the composition of complex components. Each material composition design feature relates directly to the geometry of the design, often relying on user interaction to specify critical aspects of the geometry. This approach allows the designer to simultaneously edit geometry and composition by varying parameters until a satisfactory result is attained. The identified LCC features are those based on volume, transition, pattern, and (user-defined) surface features. The material composition functions include functions parametrized with respect to distance or distances to user-defined geometric features; and functions that use Laplace's equation to blend smoothly various boundary conditions including values and gradients of the material composition on the boundaries. The Euclidean digital distance transform and the Boundary Element Method are adapted to the efficient computation of composition functions. Theoretical and experimental complexity, accuracy and convergence analyses are presented. The representations underlying the composition design features are analytic in nature and therefore concise. Evaluation for visualization and fabrication is performed only at the resolutions required for these purposes, thereby reducing the computational burden. (C) 2003 Elsevier Ltd. All rights reserved.

    DOI J-GLOBAL

    Scopus

    80
    被引用数
    (Scopus)
  • Surface to Surface Intersections

    N. M. Patrikalakis, T. Maekawa, K. H. Ko, H. Mukundan

    Computer-Aided Design and Applications   1 ( 1-4 ) 449 - 457  2004年

     概要を見る

    This paper presents an overview of surface intersection problems and focuses on the rational polynomial parametric/rational polynomial parametric surface intersection case including transversal and tangential intersections. Emphasis is placed on marching methods with a discussion of the problems with conventional tracing algorithms. An approach using a validated interval ordinary differential equation system solver is outlined and illustrated with examples, which offers significant advantages in robustness over conventional marching schemes. © 2004 by CAD Solutions Company Limited.

    DOI

    Scopus

    17
    被引用数
    (Scopus)
  • Shape Intrinsic Properties for Free-Form Object Matching

    K. H. Ko, T. Maekawa, N. M. Patrikalakis, H. Masuda, F. E. Wolter

    Journal of Computing and Information Science in Engineering   3 ( 4 ) 325 - 333  2003年12月  [査読有り]

     概要を見る

    Despite extensive research and rapid increase of computing power, free-form object matching still remains a challenging problem in CAD/CAM areas. In this paper, various object features are discussed, and matching methods which use these features are introduced along with robust computational algorithms for umbilical points and intrinsic wireframes. The similarity of matched objects is assessed with three proposed tests. Each algorithm is demonstrated with examples.

    DOI

    Scopus

    25
    被引用数
    (Scopus)
  • An algorithm for optimal free-form object matching

    KH Ko, T Maekawa, NM Patrikalakis

    COMPUTER-AIDED DESIGN   35 ( 10 ) 913 - 923  2003年09月  [査読有り]

     概要を見る

    A novel method of matching for 3-D-free-form objects (points vs. surface and surface vs. surface) is proposed. The method formulates the problem in terms of solution of a non-linear polynomial equation system, which can be solved robustly by the Interval Projected Polyhedron (IPP) algorithm. Two intrinsic surface properties, the Gaussian and the mean curvatures, are used as object features for matching. The related iso-curvature lines are used to establish the correspondence between two objects. The intersection points of these iso-curvature lines are calculated and sorted out to satisfy the Euclidean constraints from which the translation and rotation transformations are estimated. The performance of the proposed algorithm is also analyzed. This approach can cover global and partial matching, and be applied to automated inspection, copyright protection of NURBS models, and object recognition. Examples illustrate our technique. (C) 2003 Elsevier Science Ltd. All rights reserved.

    DOI J-GLOBAL

  • Surface Construction by Fitting Unorganized Cureves (Jointly worked)

    K. H. Ko, T.Maekawa

    Graphical Models   64 ( 5 ) 316-332  2002年  [査読有り]

  • Shape Interrogation for Computer Aided Design and Manufacturing

    N. M, Patrikalakis, T.Maekawa

    Springer-Verlag    2002年

  • Efficient simulation of shell forming by line heating

    G Yu, RJ Anderson, T Maekawa, NM Patrikalakis

    INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES   43 ( 10 ) 2349 - 2370  2001年10月  [査読有り]

     概要を見る

    A simplified thermo-mechanical model for the prediction of angular deformations of metal plates due to line heating is presented. The model utilizes a semi-analytically determined temperature distribution, which incorporates the effects of heat loss and a distributed moving heat source, to find the dimensions of a critical heat-affected region. The dimensions of this region are used to find the angular deformation by an analytic solution method. Predicted values of angular deformation compare well with corresponding values from experimental results. This model is also compared with thermo-mechanical analysis based on the three-dimensional finite element method. The comparisons indicate that the simplified model is fairly accurate and much more efficient in comparison to the finite element solution. (C) 2001 Elsevier Science Ltd. All rights reserved.

    DOI

    Scopus

    54
    被引用数
    (Scopus)
  • FEM simulation of laser forming of metal plates

    G Yu, K Masubuchi, T Maekawa, NM Patrikalakis

    JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME   123 ( 3 ) 405 - 410  2001年08月  [査読有り]

     概要を見る

    A finite element model is developed for thermo-mechanical analysis of the process of metal plate forming by laser line heating. A rezoning technique is adopted to greatly reduce the simulation time. The effects of the refinement of mesh size on temperature distribution and final distortion are studied. Comparison between numerical and experimental results shows a good agreement in final distortion of the formed plate. Finally, edge effects in the laser forming process are studied.

    DOI

    Scopus

    55
    被引用数
    (Scopus)
  • Self-Intersections of Offset Curevs and Surfaces

    J. Wallner, T. Sakkalis, T. Maekawa, H. Pottmann, G. Yu

    International Journal of Shape Modelling   7 ( 1 ) 1-21  2001年06月  [査読有り]

  • CNC tool path in terms of B-spline curves

    C Lartigue, F Thiebaut, T Maekawa

    COMPUTER-AIDED DESIGN   33 ( 4 ) 307 - 319  2001年04月  [査読有り]

     概要を見る

    We present an accurate and efficient method to generate a CNC toot path for a smooth free-form surface in terms of planar cubic B-spline curves which will be fed into a free-form curve interpolator. We assume the use of a three-axis CNC machine tool with a ball end-mill cutter. We first interpolate break points, which art: generated by computing the offset surface-driving plane intersection curve reflecting the curvature, by a planar cubic B-spline curve. We then evaluate the maximum scallop height along a scallop curve by computing the stationary points of the distance function between the scallop curve and the design surface. Furthermore, we compute the maximum pick feed such that the maximum scallop height along a scallop curve coincides with the prescribed tolerance. illustrative examples show the substantial improvements this method achieves over conventional methods where the tool path consists of linear or circular paths. (C) 2001 Elsevier Science Ltd. All rights reserved.

    DOI

    Scopus

    76
    被引用数
    (Scopus)
  • Optimal development of doubly curved surfaces

    GX Yu, NM Patrikalakis, T Maekawa

    COMPUTER AIDED GEOMETRIC DESIGN   17 ( 6 ) 545 - 577  2000年07月  [査読有り]

     概要を見る

    This paper presents algorithms for optimal development (flattening) of a smooth continuous curved surface embedded in three-dimensional space into a planar shape. The development process is modeled by in-plane strain (stretching) from the curved surface to its planar development. The distribution of the appropriate minimum strain field is obtained by solving a constrained nonlinear programming problem. Based on the strain distribution and the coefficients of the first fundamental form of the curved surface, another unconstrained nonlinear programming problem is solved to obtain the optimal developed planar shape. The convergence and complexity properties of our algorithms are analyzed theoretically and numerically. Examples show the effectiveness of the algorithms. (C) 2000 Elsevier Science B.V. All rights reserved.

    DOI

    Scopus

    58
    被引用数
    (Scopus)
  • Differential geometry of intersection curves of two surfaces

    XZ Ye, T Maekawa

    COMPUTER AIDED GEOMETRIC DESIGN   16 ( 8 ) 767 - 788  1999年09月  [査読有り]

     概要を見る

    We present algorithms for computing the differential geometry properties of intersection curves of two surfaces where the combination of two surfaces can be parametric-parametric, implicit-implicit and parametric-implicit. We derive unit tangent vector, curvature vector, binormal vector, curvature, torsion, and algorithms to evaluate the higher-order derivatives for transversal as well as tangential intersections for all three types of intersection problems. (C) 1999 Elsevier Science B.V. All rights reserved.

    DOI J-GLOBAL

    Scopus

    58
    被引用数
    (Scopus)
  • An overview of offset curves and surfaces

    T Maekawa

    COMPUTER-AIDED DESIGN   31 ( 3 ) 165 - 173  1999年03月  [査読有り]

     概要を見る

    A literature survey on offset curves and surfaces up to 1992 was carried out by Pham (Pham B, Offset curves and surfaces: a brief survey. Computer Aided Design 1992; 24(4): 223-229). The objective of this article is to overview the literature after 1992 and those which were not cited in aforementioned paper. The article focuses on five active areas of research on offsets: (1) representing exact offsets in Bezier/B-spline format, (2) approximations, (3) self-intersections, (4) geodesic offsets and (5) general offsets. (C) 1999 Elsevier Science Ltd. All rights reserved.

    DOI J-GLOBAL

    Scopus

    220
    被引用数
    (Scopus)
  • Computation of inflection lines and geodesics on developable surfaces

    T Maekawa, JS Chalfant

    MATHEMATICAL ENGINEERING IN INDUSTRY   7 ( 2 ) 251 - 267  1999年

     概要を見る

    A developable surface can be formed by bending or rolling a planar surface without stretching or tearing; in other words, it can be developed or unrolled isometrically onto a plane. This paper describes two main differential geometry properties of developable surfaces that have industrial applications. First, a method for identifying the inflection line of a developable surface is described. Second, geodesic lines between two points on a developable surface are found as an initial value problem, which is easier to solve than the boundary value problem that is normally required.

  • Design for manufacturing using B-spline developable surfaces

    JS Chalfant, T Maekawa

    JOURNAL OF SHIP RESEARCH   42 ( 3 ) 207 - 215  1998年09月  [査読有り]

     概要を見る

    A developable surface can be formed by bending or rolling a planar surface without stretching or tearing; in other words. it can be developed or unrolled isometrically onto a plane. Developable surfaces are widely used in the manufacture of items that use materials that are not amenable to stretching such as the formation of ducts, shoes, clothing and automobile parts including upholstery and body panels (Frey & Bindschadler 1993). Designing a ship hull entirely of developable surfaces would allow production of the hull using only rolling or bending. Heat treatment would only be required for removal of distortion, thus greatly reducing the labor required to form the hull. Although developable surfaces play an important role in various manufacturing applications, little attention has been paid to implementing developable surfaces from the onset of a design. This paper investigates novel. user friendly methods to design complex objects using B-spline developable surfaces based on optimization techniques. Illustrative examples show the substantial improvements this method achieves over previously developed methods.

  • Design and tessellation of B-Spline developable surfaces

    T Maekawa, J Chalfant

    JOURNAL OF MECHANICAL DESIGN   120 ( 3 ) 453 - 461  1998年09月  [査読有り]

     概要を見る

    Developable surfaces are widely used in various engineering applications. However, little attention has been paid to implementing developable surfaces from the onset of a design. The first half of the paper describes a user friendly method of designing developable surfaces in terms of a B-Spline representation whose two directrices lie on parallel planes. The second half of the paper investigates a new method for development and tessellation of such B-Spline developable surfaces which is necessary for plate cutting and finite element analysis.

    DOI

    Scopus

    47
    被引用数
    (Scopus)
  • Efficient and reliable methods for rounded-interval arithmetic

    SL Abrams, W Cho, CY Hu, T Maekawa, NM Patrikalakis, EC Sherbrooke, Ye, X

    COMPUTER-AIDED DESIGN   30 ( 8 ) 657 - 665  1998年07月  [査読有り]

     概要を見る

    We present an efficient and reliable method for computing the unit-in-the-last-place (ulp) of a double-precision floating-point number, taking advantage of the standard binary representation for floating-point numbers defined by IEEE Std 754-1985. The ulp is necessary to perform software rounding for robust rounded-interval arithmetic (RIA) operations. Hardware rounding, using two of the standard rounding modes defined by IEEE-754, may be more efficient. RIA has been used to produce robust software systems for the solution of systems of nonlinear equations, interrogation of geometric and differential properties of curves and surfaces, curve and surface intersections, and solid modeling. (C) 1998 Elsevier Science Ltd. All rights reserved.

    DOI

    Scopus

    30
    被引用数
    (Scopus)
  • Analysis and applications of pipe surfaces

    T Maekawa, NM Patrikalakis, T Sakkalis, GX Yu

    COMPUTER AIDED GEOMETRIC DESIGN   15 ( 5 ) 437 - 458  1998年05月  [査読有り]

     概要を見る

    A pipe (or tubular) surface is the envelope of a one-parameter family of spheres with constant radii r and centers C(t). In this paper we investigate necessary and sufficient conditions for the nonsingularity of pipe surfaces. In addition, when C(t) is a rational function, we develop an algorithmic method for the rational parametrization of such a surface. The latter is based on finding two rational functions alpha(t) and beta(t) such that /C'(t)/(2) = alpha(2)(t) + beta(2)(t) (Lu and Portmann, 1996). (C) 1998 Elsevier Science B.V.

    DOI

    Scopus

    71
    被引用数
    (Scopus)
  • Self-intersections of offsets of quadratic surfaces: Part II, implicit surfaces

    T Maekawa

    ENGINEERING WITH COMPUTERS   14 ( 1 ) 14 - 22  1998年

     概要を見る

    The paper investigates self-intersections of offsets of implicit quadratic surfaces, The quadratic surfaces are the simplest curved objects, referred to as quadrics, and are widely used in mechanical design. In an earlier paper, we have investigated the self-intersections of offsets of explicit quadratic surfaces, such as elliptic paraboloid, hyperbolic paraboloid and parabolic cylinder, since not only are they used in mechanical design, but also any regular surface can de locally approximated by such explicit quadratic surfaces. In this paper, we investigate the rest of the quadrics whose offsets may degenerate, i.e, the implicit quadratic-surfaces (ellipsoid, hyperboloid, elliptic cone, elliptic cylinder and hyperbolic cylinder). We found that self-intersection curves of offsets of all the implicit quadratic surfaces are planar implicit conics and their corresponding curve on the progenitor surface can be expressed as the intersection curve between an ellipsoid, whose semi-axes are proportional to the offset distance, and the implicit quadratic surfaces themselves.

    DOI

    Scopus

    7
    被引用数
    (Scopus)
  • Self-intersections of offsets of quadratic surfaces: Part I, explicit surfaces

    T Maekawa

    ENGINEERING WITH COMPUTERS   14 ( 1 ) 1 - 13  1998年

     概要を見る

    Although offset surfaces ape widely used in various engineering applications, their degenerating mechanism is not well known in a quantitative manner. Offset surfaces are functionally mole complex than their progenitor surfaces and may degenerate even if the progenitor surfaces are regular. Self-intersections of the offsets of regular surfaces may be induced by concave regions of surface where the positive offset distance exceeds the maximum absolute value of the negative minimum principal curvature or the absolute value of the negative offset distance exceeds the maximum value of the positive maximum principal curvature.
    It is well known that any regular surface can be locally approximated in the neighborhood of a point p by the explicit quadratic surface of the form r(x, y) = [x, y, 1/2 (alpha x(2) + beta y(2))](T) to the second order where -alpha and -beta are the principal curvatures at point p. Therefore investigations of the self-intersecting mechanisms of the offsets of explicit quadratic surfaces die to differential geometry properties lead to an understanding of the self-intersecting mechanisms of offsets of regular parametric surfaces. in this paper, we develop the equations of the self-intersection curves of an offset of an explicit quadratic surface. We also develop an algorithm to detect and trace a small loop of a self-intersection curve of an offset of a regular parametric surface based on our analysis of offsets of explicit quadratic surfaces. Examples illustrate our method.

    DOI

    Scopus

    9
    被引用数
    (Scopus)
  • Robust interval algorithm for surface intersections

    CY Hu, T Maekawa, NM Patrikalakis, XZ Ye

    COMPUTER-AIDED DESIGN   29 ( 9 ) 617 - 627  1997年09月  [査読有り]

     概要を見る

    In this paper, we develop robust algorithms for computing interval polynomial curve-to-surface and surface-to-surface intersections. These include well-conditioned transversal intersections as well as ill-conditioned non-transversal intersections. Key components of our methods are the reduction of the intersection problems into solving balanced or unbalanced systems of non-linear interval polynomial equations. These systems are solved using an interval non-linear polynomial solver based on Bernstein subdivision coupled with rounded interval arithmetic, documented in a series of earlier papers. The solver provides results with numerical certainty and verifiability. Examples illustrate our techniques. We also provide a theoretical analysis of degenerate interval polynomial curve-to-surface and surface-to-surface ill-conditioned non-transversal intersections. (C) 1997 Elsevier Science Ltd.

  • Computation of self-intersections of offsets of Bezier surface patches

    T Maekawa, WJ Cho, NM Patrikalakis

    JOURNAL OF MECHANICAL DESIGN   119 ( 2 ) 275 - 283  1997年06月  [査読有り]

     概要を見る

    Self-intersection of offsets of regular Bezier surface patches due to local differential geometry and global distance function properties is investigated. The problem of computing starting points for tracing self-intersection curves of offsets is formulated in terms of a system of nonlinear polynomial equations and solved robustly by the interval projected polyhedron algorithm. Trivial solutions are excluded by evaluating the normal bounding pyramids of the surface subpatches mapped from the parameter boxes computed by the polynomial solver with a coarse tolerance. A technique to detect and trace self-intersection curve loops in the parameter domain is also discussed. The method has been successfully tested in tracing complex self-intersection curves of offsets of Bezier surface patches. Examples illustrate the principal features and robustness characteristics of the method.

  • Robust interval algorithm for curve intersections

    CY Hu, T Maekawa, EC Sherbrooke, NM Patrikalakis

    COMPUTER-AIDED DESIGN   28 ( 6-7 ) 495 - 506  1996年06月  [査読有り]

     概要を見る

    In this paper, we develop and study a robust algorithm for computing intersections of two planar interval polynomial curves. The intersection problems include well-conditioned transveral intersections as well as ill-conditioned cases such as tangential and overlapping intersections. Key components of our methods are the reduction of the intersection problems into solving systems of nonlinear interval polynomial equations which consist of m equations with n unknowns. An earlier interval nonlinear polynomial solver for balanced system based on Bernstein subdivision method coupled with rounded interval arithmetic is extended to solve unbalanced systems. The solver provides results with numerical certainty and verifiability. Examples illustrate our techniques. Copyright (C) 1996 Elsevier Science Ltd

  • Towards robust geometric modelers, 1994 Progress Report

    NM Patrikalakis, W Cho, CY Hu, T Maekawa, EC Sherbrooke, J Zhou

    PROCEEDINGS OF THE 1995 NSF DESIGN AND MANUFACTURING GRANTEES CONFERENCE     139 - 140  1994年  [査読有り]

  • COMPUTATION OF SINGULARITIES AND INTERSECTIONS OF OFFSETS OF PLANAR CURVES

    T MAEKAWA, NM PATRIKALAKIS

    COMPUTER AIDED GEOMETRIC DESIGN   10 ( 5 ) 407 - 429  1993年10月  [査読有り]

     概要を見る

    The objective of this paper is to compute the singularities of a normal offset of a planar integral polynomial curve and the intersections of two specific normal offsets of two planar integral polynomial curves. Singularities include irregular points (such as isolated points and cusps) and self-intersections. The key element in the above techniques is the computation of all real roots within a finite box of systems of nonlinear equations involving polynomials and square roots of polynomials. The curves that we are investigating are described by polynomial functions, but their offset curve representations involve polynomials and square roots of polynomials. A methodology based on adaptive subdivision techniques to solve the resulting systems of nonlinear equations is investigated. Key components of our methods are the reduction of the problems into solutions of systems of polynomial equations of higher dimensionality through the introduction of auxiliary variables and the use of rounded interval arithmetic in the context of Bernstein subdivision to enhance the robustness of floating point implementation. Examples illustrate our techniques.

▼全件表示

書籍等出版物

  • Shape Interrogation for Computer Aided Design and Manufacturing

    前川 卓( 担当: 共著)

    Springer-Verlag  2002年02月

  • Handbook of Computer Aided Geometric Design Chapter 25 Intersection Problems

    ( 担当: 共著)

    Elsevier Science Publisher  2002年

講演・口頭発表等

  • 掘削面に対する油圧ショベル作業具正対手法に関する研究

    佐藤 隆人, 前川 卓

    第 26 回設計工学・システム部門講演会   (慶應義塾大学 日吉キャンパス)  日本機械学会  

    発表年月: 2016年10月

  • From CAD Models to Toy Brick Sculptures: A 3D Block Printer

    Y. Maeda, O. Nakano, T. Maekawa, S. Maruo

    RSJ International Conference on Intelligent Robots and Systems (IROS)   (Daejeon, Korea)  2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)  

    発表年月: 2016年10月

  • 法線マップ直接編集による流線型形状曲面の設計

    蓼沼 周, 前川 卓  [招待有り]

    情報処理学会 グラフィクスとCAD研究会  

    発表年月: 2015年11月

  • 自立性と安定性を考慮したレゴモデル組み立て図の自動生成

    狐崎 拓哉, 竹澤 正仁, 佐々木 雄飛, 前川 卓  [招待有り]

    情報処理学会 グラフィクスとCAD研究会  

    発表年月: 2015年11月

  • 照度差ステレオ法を用いた検査システムの開発

    町田賢一郎, 井本治孝, 前川卓  [招待有り]

    第 25 回設計工学・システム部門講演会  

    発表年月: 2015年09月

  • 照度差ステレオ法を用いた3次元物体の復元

    蓼沼 周, 井本治孝, 町田 賢一郎, 前川 卓  [招待有り]

    第 25 回設計工学・システム部門講演会  

    発表年月: 2015年09月

  • 曲率線展開法に基づく自由曲面を有するペーパークラフトの作成方法

    竹澤正仁, 佐藤隆人, 前川卓  [招待有り]

    第 25 回設計工学・システム部門講演会  

    発表年月: 2015年09月

  • Isogeometric 解析による前縁半径をパラメータとした二次元翼周りの流体解析

    志田 健太朗, 遠藤 修平, 蓼沼 周, 前川 卓  [招待有り]

    第 25 回設計工学・システム部門講演会   (信州大学工学部) 

    発表年月: 2015年09月

  • 幾何処理によるB-SPLINE VOLUME フィッティングとその可視化

    金 勝基, 佐々木 雄飛, 竹澤 正仁, 前川 卓  [招待有り]

    関東学生会第54回学生員卒業研究発表講演会   日本機械学会  

    発表年月: 2015年03月

  • 波形管軸圧縮時に波形曲率が最大応力に及ぼす影響の研究

    今井 琢麻, 熊谷 盛徳, 前川 卓  [招待有り]

    関東学生会第54回学生員卒業研究発表講演会   (波形管軸圧縮時に波形曲率が最大応力に及ぼす影響の研究)  日本機械学会  

    発表年月: 2015年03月

  • 組み立てやすさを考慮したレゴブロックモデルによる複雑な物体の再構築

    狐崎 拓哉, 前川 卓  [招待有り]

    関東支部第21期総会・講演会   日本機械学会  

    発表年月: 2015年03月

  • 微分幾何学に基づくNACA 翼型形状のB-spline 曲線による近似方法

    蓼沼 周, 遠藤 修平, 前川 卓  [招待有り]

    関東学生会第53回学生員卒業研究発表講演会  

    発表年月: 2015年03月

  • 露天掘り鉱山の形状設計

    狐崎 拓哉, 安里 翼, 前川 卓

    第 24 回設計工学・システム部門講演会   日本機械学会  

    発表年月: 2014年09月

  • 幾何処理による離散データの B-spline volume 補間

    佐々木 雄飛, 竹澤 正仁, 金 勝基, 前川 卓

    第 24 回設計工学・システム部門講演会   日本機械学会  

    発表年月: 2014年09月

  • 複雑な物体の複数画像からのレゴブロックによる再構築

    林慧, 前川卓

    情報処理学会研究報告グラフィクスとCAD (第153回グラフィクスとCAD研究発表会)  

    発表年月: 2013年11月

  • 照度差ステレオを用いた2.5D物体の高精度復元

    山浦 佑介, 南谷 崇輝, 井本 治孝, 前川 卓

    第23回設計工学・システム部門講演会  

    発表年月: 2013年10月

  • 鉱山における3D-GEO Map生成

    小橋 裕司, 前川 卓

    第23回設計工学・システム部門講演会  

    発表年月: 2013年10月

  • 美的曲線を取り入れた意匠曲面の曲率コントロール

    遠藤 修平, 前川 卓

    第23回設計工学・システム部門講演会  

    発表年月: 2013年10月

  • Isogeometric解析用 3D NURBSソリッドの生成方法

    チャン ダン ティエン, 前川 卓

    第23回設計工学・システム部門講演会   (沖縄県読谷村)  日本機械学会  

    発表年月: 2013年10月

  • Constrained B-spline Surface Fitting by Iterative Geometric Approximation Algorithm

    Y. Kineri, W. Choi, T. Maekawa

    ACDDE2012, Niseko Japan, December 2012  

    発表年月: 2012年12月

  • 幾何アルゴリズムによる拘束条件付きB-spline曲面フィッティング

    木練 佑樹, 前川 卓

    第22回設計工学・システム部門講演会  

    発表年月: 2012年09月

  • ボクセルの統合を用いた,複雑なモデルのリバースエンジニアリング

    南谷 崇輝, 吉原 宏貴, 前川 卓

    第22回設計工学・システム部門講演会  

    発表年月: 2012年09月

  • コンピュータビジョンによるマイクロ製品の形状評価方法

    末安 秀匡, 前川 卓

    第146回グラフィクスとCAD研究発表会  

    発表年月: 2012年02月

  • SFS法と合焦判定法を用いたマイクロ製品形状評価

    末安 秀匡, 前川 卓

    発表年月: 2011年12月

  • レベルセット法による点群からの位相頑強なメッシュ生成

    吉原 宏貴, 吉井 達哉, 澁谷 忠弘, 前川 卓

    日本機械学会 第21回設計工学・システム部門講演会  

    発表年月: 2011年10月

  • 空間曲線の微分幾何学に基づく高速道路のコンピュータ支援設計

    鈴木 絢也, 前川 卓

    日本機械学会 第21回設計工学・システム部門講演会  

    発表年月: 2011年10月

  • B-splineにより曲率が精確に表現されているシェルモデルのisogeometric 解析

    穆 凱圓, 澁谷 忠弘, 松井 和己, 前川 卓

    日本機械学会 第21回設計工学・システム部門講演会  

    発表年月: 2011年10月

  • ボクセルの統合による3 次元物体の全体形状復元

    南谷 崇輝, 篤 幸太郎, 末安 秀匡, 前川 卓

    Visual Computing / グラフィクスとCAD 合同シンポジウム  

    発表年月: 2011年

  • 三角形メッシュの主曲率と主効率方向の計算方法

    岡庭翔一, 前川 卓

    日本機械学会 第20回設計工学・システム部門講演会  

    発表年月: 2010年10月

  • 高速化された幾何アルゴリズムによるB-spline曲面近似

    良知 鷹彦, 王 銘思, 前川 卓

    日本機械学会 第20回設計工学・システム部門講演会  

    発表年月: 2010年10月

  • レベルセット法による三次元モデルの再構築

    金 東俊, 良知 鷹彦, 三橋 郁, 澁谷 忠弘, 前川 卓

    日本機械学会 レベルセット法による三次元モデルの再構築  

    発表年月: 2010年03月

  • レベルセット法と幾何アルゴリズムを用いた点群からのポリゴンメッシュ生成

    金 東俊, 良知 鷹彦, 安藤 嘉章, 澁谷 忠弘, 前川 卓

    Visual Computing / グラフィクスとCAD 合同シンポジウム  

    発表年月: 2010年

  • 幾何処理と線形解法による細分割曲面補間の比較

    安藤 嘉章, 岡庭 翔一, 前川 卓

    日本機械学会 第19回設計工学・システム部門講演会  

    発表年月: 2009年10月

  • 幾何処理によるB-spline曲線・曲面補間の高速化

    町田 賢一郎, 良知 鷹彦, 前川 卓

    日本機械学会 第19回設計工学・システム部門講演会  

    発表年月: 2009年10月

  • SFS法を用いたマイクロ製品評価方法

    船山裕輔, 篤 幸太郎, 前川卓

    Visual Computing /グラフィクスとCAD 合同シンポジウム  

    発表年月: 2009年

  • B-spline曲線による無人車両の準最適走行経路生成

    田村 重文, 尾崎 友紀, 野田哲也, 前川 卓

    日本機械学会 第18回設計工学・システム部門講演会  

    発表年月: 2008年09月

  • 膨大な点群からなる形状の細分割曲面近似

    森岡真之, 西山 悠, 前川 卓

    日本機械学会 第18回設計工学・システム部門講演会  

    発表年月: 2008年09月

  • 視体積交差法を用いた3D-CADモデルの作成

    船山裕輔, 平野大輔, 前川 卓

    日本機械学会 第18回設計工学・システム部門講演会  

    発表年月: 2008年09月

  • マイクロ製品の3次元形状評価方法

    船山 裕輔, 平野 大輔, 前川 卓

    日本機械学会 2008年度年次大会講演会  

    発表年月: 2008年08月

  • 幾何処理によるB-スプラインフィッティング

    呉服 秀一, 田村 重文, 梶原 健, 前川 卓

    日本機械学会 第17回設計工学・システム部門講演会  

    発表年月: 2007年11月

  • 視体積交差法による三次元モデル復元装置

    安倍 史朗, 平野 大輔, 船山 裕輔, 前川 卓

    日本機械学会 第17回設計工学・システム部門講演会  

    発表年月: 2007年11月

  • 幾何アルゴリズムによる区分平滑曲面補間

    宮崎 達矢, 西山 悠, 前川 卓

    日本機械学会 第17回設計工学・システム部門講演会  

    発表年月: 2007年11月

  • 幾何処理による細分割曲面補間

    並木 謙, 松本 泰典, 前川 卓

    日本機械学会 第16回設計工学・システム部門講演会  

    発表年月: 2006年11月

  • 幾何処理によるB-spline補間

    樋口 文隆, 呉服 秀一, 前川 卓

    日本機械学会 第16回設計工学・システム部門講演会  

    発表年月: 2006年11月

  • 円形ハイライト線によるB-Spline曲面のフェアリング

    西山 悠, 前川 卓

    日本機械学会 第16回設計工学・システム部門講演会  

    発表年月: 2006年11月

  • タービンブレードの線切削加工における工具経路の算出方法

    平野 大輔, 前川 卓

    日本機械学会 関東学生会第45回学生員卒業研究発表講演会  

    発表年月: 2006年03月

▼全件表示

共同研究・競争的資金等の研究課題

  • 炭素繊維刺しゅう機によるCFRP自由曲面成形方法の開発と応用

    日本学術振興会  科学研究費助成事業 基盤研究(B)

    研究期間:

    2018年04月
    -
    2021年03月
     

    前川 卓, 松尾 宏平, 澁谷 忠弘, 竹澤 正仁

     概要を見る

    1)曲面を伸ばしたり切込みを入れたりせずに、曲げ変形のみで平面に展開できる曲面を可展面という。可展面のガウス曲率はゼロであることから、ガウス曲率がゼロに近い値を取る領域では曲率線を止め、基布に無駄な切込みを抑えるようにすることにより、切込み量の少ないガラスクロス基布を作成することができた。
    2)プリフォームの基布上に炭素繊維束を刺しゅうするための一筆書きツールパスを生成する基礎アルゴリズムを開発した。開発手法を自動車フード曲面に適用することで、平面展開図上において1本で繋がったツールパスを生成することができた。また生成したツールパスCADデータを刺しゅう機に適したデータ形式に変換して入力することで、生成したツールパスに沿って炭素繊維束をプリフォーム基布上に縫い付けることができた。
    3)改良型曲率線展開法で展開した短冊状の基材を張り合わせることで曲面を有する製品形状を再構築できることを利用して、設計形状の雌型を必要としない新たなCFRP成形手法の実用化に向けて開発を開始した。本年度は、プリフォームに比較的剛性の高いガラスロービングクロスを用いて成形試験を行うことで、より実用的な成形が可能であることを示した。しかし成形中の自重による変形、ならびに成形後の製品表面の平滑性については改善する必要がありこれらの課題について、引き続き取り組む。
    4)数値シミュレーションを通してその妥当性を検証した。標準的なプロペラを対象に、モード解析と静解析を実施して、炭素繊維による効率的な強化方法について検討した。炭素繊維を任意の曲線に沿って配置することで、より軽量かつ高強度なプロペラ構造が期待できる。また、主応力分布をもとに炭素繊維の配置を決定するための試行として、ボンネットのシェル要素モデルを対象に主応力分布から応力線を作成するための基礎検討を行った。

  • 3Dマルチマテリアル・ブロックプリンティング技術の開発と応用

    日本学術振興会  科学研究費助成事業

    研究期間:

    2015年04月
    -
    2018年03月
     

    丸尾 昭二, 廣田 誠, 前田 雄介, 前川 卓

     概要を見る

    本研究では、マイクロ光造形・鋳型技術を用いて多彩なセラミックスブロック群を作製し、これらを3D 形状モデリングとロボット工学を駆使して最適構造に組み立てることで、3次元機能デバイスを作製する「3D マルチマテリアル・ブロックプリンティング技術」の開発に取り組んだ。マイクロ光造形によって作製したシリコーン樹脂鋳型を用いて、微小なバイオセラミックス製ブロックを作製した。微小ブロックを組み立てたブロック群の重心位置を考慮しながら、安定して自動組立を行うためのアルゴリムズを開発した。さらに、作製した微小ブロックをロボットアームと画像処理を組み合わせて、ブロックを自動的に組み立てるシステムを構築した。

  • 曲率線展開法に基づくCFRP成形技術の開発と応用

    日本学術振興会  科学研究費助成事業

    研究期間:

    2015年04月
    -
    2018年03月
     

    前川 卓

     概要を見る

    地球の温暖化に伴い、今後CO2排出量の規制強化がますます進むと予測される中、自動車、航空機、船舶等日常的に使用される乗り物の軽量化は、CO2排出量の削減に直接的に大きく貢献することができる。このような背景の中、炭素繊維強化プラスチック(CFRP)は鉄と比較して高価ではあるものの、重さが約4分の1、強度が10倍の高機能材料であり、鉄の代替材料として注目を集めている。その中でもとりわけ、自動車、航空機の翼と胴体とのブレンド曲面、新幹線のノーズ、船舶のプロペラ、ハル等の形状は意匠性や流体力学特性を満たさなければならない複雑な曲面をしており、各層毎のCFRPの切り込みをどのように決めれば高強度でかつ、仕上げ工程の少ない製品に仕上がるのかという統一された基準がない。本研究ではこれらの複雑な曲面に曲率線展開法に基づいた新たな成形加工方法を適用することにより様々なCFRP曲面を作製し、その用途に応じた強度試験や数値シミュレーションを通

  • 幾何処理による曲面曲率コントロールとそのIsogeometric解析への応用

    日本学術振興会  科学研究費助成事業

    研究期間:

    2012年04月
    -
    2015年03月
     

    前川卓

  • 幾何処理による点群の位置並びに法線ベクトルのフィッティング

    日本学術振興会  科学研究費助成事業

    研究期間:

    2008年04月
    -
    2011年03月
     

    前川 卓

  • ポリゴンメッシュで形成された3次元ソリッドモデルの電子指紋に関する研究

    日本学術振興会  科学研究費助成事業

    研究期間:

    2004年04月
    -
    2007年03月
     

    前川 卓

▼全件表示

Misc

  • 1108 照度差ステレオ法を用いた検査システムの開発(OS2-3 デジタルエンジニアリング3,OS2 デジタルエンジニアリング)

    町田 賢一郎, 井本 治孝, 前川 卓

    設計工学・システム部門講演会講演論文集   2015 ( 25 ) "1108 - 1"-"1108-6"  2015年09月

     概要を見る

    In the manufacturing process of machine products, it is very important to automate the manual visual inspection in detecting microscopic surface defects in order to improve the efficiency and eliminate human errors as well. We present an automatic system to detect such surface defects based on iterative photometric stereo techniques. Our system consists of a high-resolution camera equipped with a telecentric lens, and a device to change light directions using 60 LED light bulbs. In this paper, we propose a convergence condition based on the change of amount of albedo. Examples are provided to demonstrate the effectiveness of the proposed method.

    CiNii

  • 1106 曲率線展開法に基づく自由曲面を有するペーパークラフトの作成方法(OS2-2 デジタルエンジニアリング2,OS2 デジタルエンジニアリング)

    竹澤 正仁, 佐藤 隆人, 前川 卓

    設計工学・システム部門講演会講演論文集   2015 ( 25 ) "1106 - 1"-"1106-5"  2015年09月

     概要を見る

    We introduce a method to generate developed paper craft patterns of free-form surfaces based on lines of curvature. Objects that consist of free-form surfaces can be developed onto a plane by expanding the surfaces along the lines of curvature. If we remove all the expanded areas, paper crafts can be constructed by connecting the corresponding edges of the removed areas. Several real paper crafts are provided to demonstrate the effectiveness of the proposed method.

    CiNii

  • 1105 Isogeometric解析による前縁半径をパラメータとした二次元翼周りの流体解析(OS2-2 デジタルエンジニアリング2,OS2 デジタルエンジニアリング)

    志田 健太朗, 遠藤 修平, 蓼沼 周, 前川 卓

    設計工学・システム部門講演会講演論文集   2015 ( 25 ) "1105 - 1"-"1105-5"  2015年09月

     概要を見る

    Finite element analysis and NURBS-based computer-aided design had been developed independently until isogeometric analysis (IgA) was introduced by Hughes et al. in 2005. Unlike FEA, in isogeometric analysis the CAD geometry represented by NURBS curves/surfaces/volumes are converted to NURBS elements exactly without any approximations. On the other hand, in aerodynamics it is well known that the leading edge radius of the wing profile plays an important role on the aerodynamic performance of the wing. In this paper, we represent the curvature-controlled 2D wing profile in terms of planar B-spline curve, and construct the 2D B-spline surface outside the wing profile and perform IgA in order to examine the aerodynamic performance of the wing under various leading edge radius.

    CiNii

  • 1107 照度差ステレオ法を用いた3次元物体の復元(OS2-3 デジタルエンジニアリング3,OS2 デジタルエンジニアリング)

    蓼沼 周, 井本 治孝, 町田 賢一郎, 前川 卓

    設計工学・システム部門講演会講演論文集   2015 ( 25 ) "1107 - 1"-"1107-5"  2015年09月

     概要を見る

    This paper studies an automatic 3D shape reconstruction of objects using images taken by a camera from different views based on photometric stereo technique. The automated data acquisition system consists of a camera, lighting system that consists of 60 LED bulbs, and a turntable rotated by a computer-controlled stepping motor. We use photometric stereo techniques, which recover surface normals of an object on a per-pixel basis from a set of images captured from a fixed viewpoint under various lighting directions, and then recover the height field function from the normals. Finally we merge all the height field function to reconstruct the object. Examples are provided to demonstrate the effectiveness of the proposed method.

    CiNii

  • 20311 組み立てやすさを考慮したレゴブロックモデルによる複雑な物体の再構築

    狐崎 拓哉, 前川 卓

    日本機械学会関東支部総会講演会講演論文集   2015 ( 21 ) "20311 - 1"-"20311-2"  2015年03月

     概要を見る

    We introduce a system to reconstruct LEGO models from multiple two-dimensional images of complex objects taken from different views based on shape from silhouettes (SFS) technique. We employ a unit voxel with edge length ratios 5:5:6 for the SFS method, and convert the resulting voxel models with color information to LEGO models. In order to minimize the number of LEGO bricks, we remove interior voxels as much as possible before the conversion so that the thickness of the voxel model is uniform from the surface voxels. We also add supporting bricks to interior as well as exterior of the model to strengthen or ease the difficulty of construction. Complex examples are provided to demonstrate the effectiveness of the proposed algorithms.

    CiNii

  • 2415 幾何処理による離散データのB-spline volume補間(OS3 デジタルエンジニアリング)

    佐々木 雄飛, 竹澤 正仁, 金 勝基, 前川 卓

    設計工学・システム部門講演会講演論文集   2014 ( 24 ) "2415 - 1"-"2415-5"  2014年09月

     概要を見る

    In the past, tremendous amount of research has been conducted to fit point clouds using B-spline curves and surfaces. However, there are few studies on fitting scientific volume data using the trivariate B-spline functions. In this paper, an iterative geometric approximation method, which iteratively repositions B-spline control points on the basis of geometrical rules, is introduced to fit the scientific volume data.

    CiNii

  • 複雑な物体の複数画像からのレゴブロックによる再構築

    林 慧, 前川 卓

    研究報告コンピュータビジョンとイメージメディア(CVIM)   2013 ( 9 ) 1 - 6  2013年11月

     概要を見る

    レゴブロックは楽しみながら作品を組み立てることを通して創造力を養うことができることから,子供から大人まで幅広い世代の人々に親しまれている.その中でも,基本ブロックのみで組立てられる大きな立体作品はレゴスカルプチャーと呼ばれ,世界中の人々を魅了している.しかし,初心者が同じようなものを組立図なしに組立てることは困難である.本研究では,複雑な形状の物体を多視点から撮影した複数の画像から,レゴの単位ブロックである縦,横,高さの比が 5:5:6 の直方体を単位ボクセルとして Shape From Silhouette 法を用いて色情報を含んだボクセルモデルを構築し,レゴブロックに変換する.その際,表面ボクセルからの厚さが一様となるように,内部ボクセルを削除し,出来る限り最少ブロック数で組立図を自動的に生成する方法を提案する.We introduce a system to reconstruct LEGO models from multiple two-dimensional images of complex objects taken from different views. We employ a unit voxel with edge length ratios 5:5:6 for the Shape from silhouette method, and convert the resulting voxel models with color information to LEGO sculptures. In order to minimize the number of LEGO blocks, we remove inside voxels as much as possible before the conversion so that the thickness of the voxel model is uniform from the surface voxels.

    CiNii

  • 2113 照度差ステレオを用いた2.5D物体の高精度復元

    山浦 佑介, 南谷 崇輝, 井本 治孝, 前川 卓

    設計工学・システム部門講演会講演論文集   2013 ( 23 ) "2113 - 1"-"2113-6"  2013年10月

     概要を見る

    This paper studies the recovery of the height field function of an object from its surface normal vectors in terms of uniform bi-quadratic B-spline surfaces. Our mathematical formulation for explicit surface reconstruction is based on differential geometry and geometric modeling techniques. Complex examples are provided to demonstrate the effectiveness of the proposed method.

    CiNii

  • 3307 幾何アルゴリズムによる拘束条件付きB-spline曲面フィッティング(OS3-1 デジタルエンジニアリングI)

    木練 佑樹, 前川 卓

    設計工学・システム部門講演会講演論文集   2012 ( 22 ) "3307 - 1"-"3307-8"  2012年09月

     概要を見る

    Recently, the advancement of the laser range scanner has made it possible to provide dense and accurate range data of 3D objects. From these point clouds, one can reconstruct a CAD model of the existing old mechanical parts, which is called reverse engineering. However, if we fit the point cloud without any constraints on geometric characteristics, these features will be easily lost on the reconstructed surface. In this paper we introduce novel methods to impose geometric constraints on the B-spline approximants during the iterative geometric fitting process. The geometric constraints include reflectional symmetry of the surfaces of industrial products and feature curves on the aesthetic surfaces provided by designers.

    CiNii

  • 3308 ボクセルの統合を用いた,複雑なモデルのリバースエンジニアリング(OS3-1 デジタルエンジニアリングI)

    南谷 崇輝, 吉原 宏貴, 前川 卓

    設計工学・システム部門講演会講演論文集   2012 ( 22 ) "3308 - 1"-"3308-7"  2012年09月

     概要を見る

    We present a method for reconstructing complete 3D models from a number of images of an object taken from multiple viewpoints under the circular motions. We employ the shape from silhouette (SFS) method which constructs a voxel-based 3D model from the silhouettes of 2D images. In general, a single camera with an object's circular motion cannot capture the entire object with one orientation. Accordingly, we need to change the orientation of the object at least one time to capture the whole object. In this paper, we discuss a novel method to merge the two incomplete reconstructed voxel models into a single complete voxel model. Complex examples are provided to demonstrate the effectiveness of the proposed algorithms.

    CiNii

  • 2111 空間曲線の微分幾何学に基づく高速道路のコンピュータ支援設計(OS3-1 デジタルエンジニアリングI,OS3 デジタルエンジニアリング)

    鈴木 絢也, 前川 卓

    設計工学・システム部門講演会講演論文集   2011 ( 21 ) 176 - 179  2011年10月

     概要を見る

    In the current highway design, a center curve of a highway is designed in three steps. In the first step the projection of the center curve onto the horizontal plane is designed with planar curves, i.e. x=x(t), y=y(t) consisting of straight lines, circular arcs, and clothoid curves. Secondly, the elevation z=z(t) is designed separately. Finally, the super elevation, which is the tilting of the road to account for the centripetal forces as the vehicle goes around a curve, is considered. Therefore, the resulting 3D curve may pass through the desired positions and tangents, however, in general, it does not have the correct normal and binormal vectors. In this research, we introduce a new method to generate the center curve with correct positions, tangents and curvature vectors at the input positions. Then, the section curves are generated along the normal vector at each input position, and blended together to form a lofted surface.

    CiNii

  • 2112 レベルセット法による点群からの位相頑強なメッシュ生成(OS3-2 デジタルエンジニアリングII,OS3 デジタルエンジニアリング)

    吉原 宏貴, 吉井 達哉, 澁谷 忠弘, 前川 卓

    設計工学・システム部門講演会講演論文集   2011 ( 21 ) 180 - 185  2011年10月

     概要を見る

    In this paper, we propose a novel method for approximating a set of scattered data points by a quadrilateral mesh using level set methods followed by geometric algorithms. The level set method is used to capture the topology of the point clouds, and the geometric algorithm using Catmull-Clark subdivision surface is employed to generate high quality meshes. Finally the Catmull-Clark control mesh is converted to B-spline representation. The reconstructed models of topologically complex models show the effectiveness of the proposed algorithm.

    CiNii

  • 2110 B-splineにより曲率が精確に表現されているシェルモデルのisogeometric解析(OS3-1 デジタルエンジニアリングI,OS3 デジタルエンジニアリング)

    穆 凱圓, 澁谷 忠弘, 松井 和己, 前川 卓

    設計工学・システム部門講演会講演論文集   2011 ( 21 ) 171 - 175  2011年10月

     概要を見る

    In this research, we introduce a novel method to analyze the axial compression analysis of thin circular shell structures. employing a new analysis framework, called isogeometric analysis, which is based on NURBS surfaces We generate the thin circular shell structures by first designing the profile curve with prescribed positions, normals and curvatures at a number of points using the geometric interpolation algorithm, then generating the NURBS surface by revolving the profile curve.

    CiNii

  • 3308 高速化された幾何アルゴリズムによるB-spline曲面近似(OS4-2 デジタルエンジニアリングII,OS4 デジタルエンジニアリング)

    良知 鷹彦, 王 銘恩, 前川 卓

    設計工学・システム部門講演会講演論文集   2010 ( 20 ) "3308 - 1"-"3308-6"  2010年10月

     概要を見る

    We introduce a new method to approximate a point cloud by B-spline surfaces by the accelerated geometric algorithm. We distinguish two types of fitting, interpolation and approximation. In this paper we present a method to approximate B-spline surfaces that pass near point clouds. Our method takes an approach that the initial shape is updated step by step by moving the control points to approximate point clouds. I relies on a surprisingly simple geometric algorithm which iteratively updates the input control points mesh in a global manner based on a local point-surface distance computation and an offsetting procedure without solving a linear system. We demonstrate the advantages and disadvantages of our proposed methods with some complex examples.

    CiNii

  • 2214 幾何処理によるB-spline曲線・曲面補間の高速化(OS4-2 自由曲面モデリング,OS4 デジタルエンジニアリング)

    町田 賢一郎, 良知 鷹彦, 前川 卓

    設計工学・システム部門講演会講演論文集   2009 ( 19 ) 393 - 396  2009年10月

     概要を見る

    B-spline surface interpolation technique by geometric algorithm iteratively updates the control mesh in a global manner based on a simple point-surface distance computation followed by translations of the control vertices along the error vectors. In this paper we introduce two techniques to accelerate the computation of geometric interpolation algorithm. The first acceleration technique employs the method of Lagrange Multipliers, and the second technique uses the Steepest Descent Method. We demonstrate the effectiveness of our proposed methods with some examples.

    CiNii

  • 3207 幾何処理による法線情報を含むB-スプラインフィッティング(OS4-3 デジタルエンジニアリング-3)意匠曲線・曲面)

    呉服 秀一, 田村 重文, 梶原 健, 前川 卓

    設計工学・システム部門講演会講演論文集   2007 ( 17 ) 307 - 308  2007年10月

     概要を見る

    Interpolation is one of the most typical problems that arise in the application of B-spline curves and surfaces. In this paper we are interested in not only interpolating a set of points, but also normal vectors given at these points by the B-spline curves. Applications of point-normal fitting include design of functional surfaces used in hydrodynamics and aerodynamics, enhancement in the free-form curve design by adding the normal control, and accurate approximation of offset curves/surfaces. Our method relies on a surprisingly simple geometric algorithm which iteratively updates the input control points in a global manner based on a local point-curve distance computation, application of an orthogonality condition of the normal vector, and an offsetting procedure without solving a linear system.

    CiNii

  • 3406 幾何処理によるB-spline補間(OS14 CAD,未来社会を支えるものづくりとひとづくり(設計・システムから))

    樋口 文隆, 呉服 秀一, 前川 卓

    設計工学・システム部門講演会講演論文集   2006 ( 16 ) 380 - 381  2006年11月

     概要を見る

    The purpose of this study is to introduce a new method to fit a set of point by B-spline curves/surfaces by geometric algorithms. Standard B-spline curve/surface fitting algorithms first associate suitable parameter values for each input point, known as parameterization of data, and form a linear system with control points as unknowns. In this paper we propose a geometric algorithm to construct smooth B-spline curves/surfaces that fit a finite set of points. Our method takes an approach that the initial shape is updated step by step by moving the control points to reach the target shape. It relies on a surprisingly simple geometric algorithm which iteratively updates the input control points mesh in a global manner based on a local point-surface distance computation and an offsetting procedure without solving a linear system. The complexity of our algorithm is O(mn) where n is the number of vertices to be interpolated and m is the number of iterations. Therefore it is very fast compared to the conventional fitting methods, as m<<n.

    CiNii

  • 曲面モデルの指紋検出

    前川 卓

    設計工学 = JOURNAL OF JAPAN SOCIETY FOR DESIGN ENGINEERING   39 ( 12 ) 648 - 652  2004年12月

    CiNii

  • MITでの教育に携わってみて

    前川 卓

    日本機械学会誌   98 ( 923 ) 838 - 839  1995年10月

    CiNii

▼全件表示

産業財産権

  • 「曲面生成装置および曲面生成用プログラム」

    土江庄一, 前川 卓

    特許権

  • 運搬車両の管制システム及び運搬車両の管理方法

    前川卓, 鈴木健稔, 宇佐美陸, 小橋裕司, 竹田幸司, 田貫富和

    特許権

  • 「軌道算出プログラム、加工装置、及び、軌道算出方法」

    前川 卓

    特許権

  • 目的面形状物製造方法、目的面形状物製造装置、部材形状取得装置およびプログラム

    前川 卓, 竹澤 正仁

    特許権

  • 「除去部分設定装置、曲面形成装置、除去部分設定方法、曲面形成方法およびプログラム」

    前川 卓, 村富 洋一, 竹澤 正仁

    特許権

  • 補間処理方法および補間処理装置

    特許第4934789号

    前川 卓, 松本泰典, 並木謙

    特許権

     概要を見る

    単線形システムを解かずに純な幾何処理により点群を補間して高品質な曲面を生成する方法。

  • 形状評価方法、形状評価装置、及び形状評価装置を備えた装置

    特許第4876256号

    前川 卓, 西村 遥, 佐々木孝行

    特許権

▼全件表示

 

担当経験のある科目(授業)

  • 応用機械設計製図II

    横浜国立大学  

  • 設計統合CAD

    横浜国立大学  

  • 設計と加工

    横浜国立大学  

  • 機械設計 I

    横浜国立大学  

  • 機構学Ⅰ

    横浜国立大学  

  • 機械要素設計製図Ⅱ

    横浜国立大学  

  • 機械要素設計製図Ⅰ

    横浜国立大学  

  • 機械要素設計・製図Ⅱ

    横浜国立大学  

  • 機械要素設計・製図Ⅰ

    横浜国立大学  

  • 設計統合CAD

    横浜国立大学  

  • 機構学

    横浜国立大学  

  • 機械設計Ⅱ

    横浜国立大学  

  • 機械設計Ⅰ

    横浜国立大学  

  • 形状処理特論

    横浜国立大学  

▼全件表示

 

社会貢献活動

  • Rhinocerosによる3次元CAD理論入門

    工学研究院  (横浜国立大学田町サテライトキャンパス) 

    2006年09月
    -
     

     概要を見る

    3次元CADソフトRhinocerosを使って製品設計を行う際の曲線・曲面理論の基礎知識を習得し、演習や実際の応用事例を通して理解を深める。

  • Rhinocerosによる3次元CAD理論入門

    工学研究院  (横浜国立大学田町サテライトキャンパス) 

    2005年09月
    -
     

     概要を見る

    3次元CADソフトRhinocerosを使って製品設計を行う際の曲線・曲面理論の基礎知識を習得し、演習や実際の応用事例を通して理解を深める。