Laser Speckle Measurement System for Plant Vigor Detection

Satoshi Shintani,Hiroaki Ishizawa,Takashi Miki,Hiroyuki Kanai 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

This paper describes a new measuring method of plant vigor by using Laser speckle pattern. Furthermore, this proposes a practical application of this presented measurement system. The measuring instrument is consisted by a He-Ne Laser as the light source, and a set of optics, such as reflectors, a beam expander. The speckle pattern could be measured by a CCD camera through lenses. A Japanese morning glory (Ipomoea nil) was used as the sample plant. Their intact leaves were measured the speckle pattern images. The optimal laser light wave length was studied based on the biological concerns. The relationship has been obtained between the feature of the images and the chlorophylldegradation. It would be expected that the symptom of plant could be detected by measuring the Laser speckle pattern.

As-built modeling of piping system from terrestrial laser scanned point clouds using normal-based region-growing

Kazuaki Kawashima,Satoshi Kanai,Hiroaki Date (사)한국CDE학회 2013 한국CAD/CAM학회 국제학술발표 논문집 Vol.2010 No.8

Recently, renovations of plant equipment have been more frequent because of the shorten lifetimes of the products, and as-built models from large-scale laser scanned data is expected to streamline their rebuilding processes. However, the laser scanned data of the existing plant has enormous number of points, captures intricate objects and includes high level of noises, so that the manual reconstruction of a 3D model is very time-consuming and costs a lot. Among plant equipment, piping systems especially account for the greatest proportion of plant equipment. Therefore, the purpose of this research was to propose an algorithm which can automatically recognize a piping system from terrestrial laser scanned data of the plant equipment. The straight portion of pipes, connecting parts and connection relationship of the piping system can be recognized in this algorithm. Normal-based region-growing and cylinder surface fitting can extract all candidates of points of pipes including straight pipes, elbows and junctions. Tracing axes of piping system allows to recognize the positions of these elements and their connection relationship. Using only point clouds, the recognition algorithm can be performed in a fully automatic way. The algorithm was applied to large-scale scanned data of an oil rig. The results of the recognition rate of straight pipes, elbows, junctions were achieved at 93%, 92% and 91% respectively

Variational hand modeling based on image-based 3D model reconstruction

Yulai Xie,Satoshi Kanai,Hiroaki Date (사)한국CDE학회 2013 한국CAD/CAM학회 국제학술발표 논문집 Vol.2010 No.8

A method for variational modeling of individual hands from a template hand model was described. The marked individual hand model was reconstructed based on an image-based multiview 3D model reconstruction technique. The skin surface of the template hand model was partitioned into segments whose boundaries were taken as main creases on palmar side according to the hand surface anatomy. The segments of the template hand model are scaled according to the feature dimensions of the segments of the reconstructed individual hand model. On the other hand, according to hand joint anatomical knowledge, a single axis rotation assumption was proposed for estimating the joint axes and joint centers by the positions of dot markers at the backside of the hand skin in different hand postures. The joint axes and their centers could be estimate from the correspondences of the dot marker positions painted at the back side of the hand in different postures. Finally, the scaled template hand model was in a segment-wise way was registered to the reconstructed hand model by an alignment process. Compared with previous works, the method was more subject-friendly, inexpensive and efficient.

Recognition of Revolved Features using Dynamic Programming and Constraint Fitting for Reverse Engineering

Kazuaki Kawashima,Satoshi Kanai (사)한국CDE학회 2010 한국CAD/CAM학회 국제학술발표 논문집 Vol.2010 No.8

The performance of the three-dimensional non-contact measuring devises (3D laser or industrial X-ray CT scanning devices) have been rapidly developed, and the importance of reverse engineering(RE) increases where 3D CAD model is reconstructed from scanned mesh model measured from real objects. However, existing reverse engineering methods cannot recover the feature-based model representations that might be defined in CAD systems, therefore the reconstructed CAD models cannot be easily faired and modified for the effective use in downstream applications. The purpose of the research is to propose a new algorithm that can robustly recognize 2.5 dimensional features and can detect the defining parameters of them from the scanned meshes including scanning error and noise. Among the features which are popularly used for feature-based solid modeling in commercial CAD systems, revolved features can be recognized in our algorithm. The defining parameters of a revolved feature consist of a rotational axis, a sketch defining plane, a 2D sketch profile and a rotational angle. Firstly, curvature and principle directions are evaluated from vertices of scanned mesh, then, the boundary surface of the scanned mesh is segmented into regions. Then, rotational axes of the regions are estimated from gauss images of maximum principle direction vectors. Same rotational axes are then integrated to the one axis. Then, a sketch defining plane is determined as a plane including the rotational axis, and the vertices are projected to the plane, then, lines and arcs which minimize distance between vertices and the lines or the arcs are fitted to the projected vertices with dynamic programming and Hough transform in order to obtain a 2D sketch profile. Then, the position and orientation of the rotational axis and the 2D sketch profile shape are modified with constraint fitting. Lastly, the defining parameters of the features are transmitted to a commercial CAD system via API functions, and a final feature-based solid model is created in the system. A prototype system was developed. And the algorithm was tested for a scanned mesh obtained from a X-ray CT scanning device and the dimensional accuracy of the defining parameters were verified. Dimension errors of the 2D sketch profile were less than 0.2mm. Given the average edge length of the scanned mesh(1.06mm), the algorithm could recognize revolved features and reconstruct a 3D CAD model in high accuracy.

A-02 : Learning from Cherry Wood Works: Remarkable Mechanical Property and its Biological Significance

( Yoko Ura ),( Satoshi Kimura ),( Kayoko Kobayashi ),( Izumi Kanai ),( Junji Sugiyama ) 韓國木材工學會 2016 한국목재공학회 학술발표논문집 Vol.2016 No.-

Accessibility Evaluation of the as-built two-storey Large-scale Indoor Environments by combining Digital Human Model and Terrestrial Laser Scanners

Tsubasa Maruyama,Satoshi Kanai,Hiroaki Date (사)한국CDE학회 2013 한국CAD/CAM학회 국제학술발표 논문집 Vol.2010 No.8

Motion-capture-based walking simulation of digital human adapted to laser-scanned 3D as-is environments for accessibility evaluation

Maruyama, Tsubasa,Kanai, Satoshi,Date, Hiroaki,Tada, Mitsunori Society for Computational Design and Engineering 2016 Journal of computational design and engineering Vol.3 No.3

Owing to our rapidly aging society, accessibility evaluation to enhance the ease and safety of access to indoor and outdoor environments for the elderly and disabled is increasing in importance. Accessibility must be assessed not only from the general standard aspect but also in terms of physical and cognitive friendliness for users of different ages, genders, and abilities. Meanwhile, human behavior simulation has been progressing in the areas of crowd behavior analysis and emergency evacuation planning. However, in human behavior simulation, environment models represent only "as-planned" situations. In addition, a pedestrian model cannot generate the detailed articulated movements of various people of different ages and genders in the simulation. Therefore, the final goal of this research was to develop a virtual accessibility evaluation by combining realistic human behavior simulation using a digital human model (DHM) with "as-is" environment models. To achieve this goal, we developed an algorithm for generating human-like DHM walking motions, adapting its strides, turning angles, and footprints to laser-scanned 3D as-is environments including slopes and stairs. The DHM motion was generated based only on a motion-capture (MoCap) data for flat walking. Our implementation constructed as-is 3D environment models from laser-scanned point clouds of real environments and enabled a DHM to walk autonomously in various environment models. The difference in joint angles between the DHM and MoCap data was evaluated. Demonstrations of our environment modeling and walking simulation in indoor and outdoor environments including corridors, slopes, and stairs are illustrated in this study.

Mesh Simplification and Adaptive LOD for Finite Element Mesh Generation

Date, Hiroaki,Kanai, Satoshi,Kishinami, Takeshi,Nishigaki, Ichiro Society for Computational Design and Engineering 2006 International Journal of CAD/CAM Vol.6 No.1

In this paper, we propose a new triangular finite element mesh generation method based on simplification of high-density mesh and adaptive Level-of-Detail (LOD) methods for efficient CAE. In our method, mesh simplification is used to control the mesh properties required for FE mesh, such as the number of triangular elements, element shape quality and size while keeping the specified approximation tolerance. Adaptive LOD methods based on vertex hierarchy according to curvature and region of interest, and global LOD method preserving density distributions are also proposed in order to construct a mesh more appropriate for CAE purpose. These methods enable efficient generation of FE meshes with properties appropriate for analysis purpose from a high-density mesh. Finally, the effectiveness of our approach is shown through evaluations of the FE meshes for practical use.

As-built modeling of piping system from terrestrial laser-scanned point clouds using normal-based region growing

Kawashima, Kazuaki,Kanai, Satoshi,Date, Hiroaki Society for Computational Design and Engineering 2014 Journal of computational design and engineering Vol.1 No.1

Recently, renovations of plant equipment have been more frequent because of the shortened lifespans of the products, and as-built models from large-scale laser-scanned data is expected to streamline rebuilding processes. However, the laser-scanned data of an existing plant has an enormous amount of points, captures intricate objects, and includes a high noise level, so the manual reconstruction of a 3D model is very time-consuming and costly. Among plant equipment, piping systems account for the greatest proportion. Therefore, the purpose of this research was to propose an algorithm which could automatically recognize a piping system from the terrestrial laser-scanned data of plant equipment. The straight portion of pipes, connecting parts, and connection relationship of the piping system can be recognized in this algorithm. Normal-based region growing and cylinder surface fitting can extract all possible locations of pipes, including straight pipes, elbows, and junctions. Tracing the axes of a piping system enables the recognition of the positions of these elements and their connection relationship. Using only point clouds, the recognition algorithm can be performed in a fully automatic way. The algorithm was applied to large-scale scanned data of an oil rig and a chemical plant. Recognition rates of about 86%, 88%, and 71% were achieved straight pipes, elbows, and junctions, respectively.

A Multiresolution Mesh Processing System for Efficient CAE

Hiroaki Date,Satoshi Kanai,Takeshi Kishinami,Ichiro Nishigaki 제어로봇시스템학회 2006 제어로봇시스템학회 국제학술대회 논문집 Vol.2006 No.10