Journal of the Robotics Society of Japan
Online ISSN : 1884-7145
Print ISSN : 0289-1824
ISSN-L : 0289-1824
Volume 6, Issue 6
Displaying 1-16 of 16 articles from this issue
  • Tsutomu HASEGAWA, Didier GIVERT
    1988 Volume 6 Issue 6 Pages 471-479
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    This paper describes an interactive system for geometric modeling of a manipulation environment. In man created environment, CAD models of geometric shape description for each object are often available. Therefore a geometric model of a real scene can be constructed by finding a position and orientation of each object. Geometric reasoning is developed to reduce necessary interactions by a human operator in the modeling process. This reasoning also enables to efficiently cope with a complicated real environment. The user of the system designates each object by its name and three points belonging to its different faces. The system calculates 3-D position of each point, and then together with the geometric shape description of the object the system generates all the possible position and orientation as location hypotheses. Erroneous location hypotheses are automatically discarded by actively testing presence in the scene of features of the hypotheses. Geometrical constraints induced by the environment are also used to reduce possible uncertainty of the model. Examples of secne modeling are given.
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  • Masahiko KUROKI, Genki YAGAWA, Hideki KAWATE
    1988 Volume 6 Issue 6 Pages 480-488
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    Microcomputer-based A. M. F. C (Adaptive Model Following Control) for a robotic manipulator that is equipped with a UT (Ultrasonic Testing) transducer as well as a pressure sensor is developed. The transducer must be scanned smoothly with a moderate contact pressure on the surface of structural components such as pipes and pressure vessels for a successful NDT (Non-Destructive Testing) . To avoid instability of surface contact, springs have been used between the transducer and the surface. However, they are not enough to control contact pressure precisely. Then the authors have developed a new pressure sensor having a function of spring, and developed a trajectory/pressure control system based on the A. M. F. C. technique.
    Since 6 D. O. F. (Degrees Of Freedom) are required for the perfect trajectory control, one more D. O. F. must be added for the trajectory/pressure control. In the present study, the authors have reduced from 7 D. O. F. to 6 D. O. F. by using the pressure sensor, and constructed an efficient trajectory/ pressure control system.
    The A. M. F. C. technique, which was applied to robotic manipulator by Balestrino, is suitable for the trajectory/pressure control system because it can adjust robotic parameters automatically. However, it requires fine parameter choice and shorter sampling time for the perfect control. In the present study, the A. M. F. C. technique has been applied to a practical robotic manipulator controlled by a 16 bits microcomputer with a slower computing speed.
    The developed system was applied to experiments of trajectory/pressure control of a robotic manipulator. In non-scanning mode where no perturbation occurs, controlled pressure was demonstrated to follow model pressure precisely. In scanning mode where some perturbation can be seen, the hybrid control of A. M. F. C. and feedback control was successfully used.
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  • Koichi KONDO
    1988 Volume 6 Issue 6 Pages 489-498
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    This paper describes a general method using configuration space for planning the collision-free path of a manipulator with 6 d. o. f. The basic approach taken in this method is to restrict the free space concerning path planning and to avoid executing unnecessary collision detections, based on the idea that the collision-free path can be planned using only partial information of the configuration space. The configuration space is equally quantized into cells, and cells concerning path planning are efficiently enumerated based on a heuristic graph search algorithm. A heuristic function which characterizes the search strategy can be defined to give priority to the gross motion using the first few joints. A bi-directional search strategy is also introduced to improve efficiency. Consequently, the total amount of necessary data representing the free space defined in the 6 dimensional configuration space is greatly restricted, and necessary collision detections are reduced. The memory is allocated only to the portion of the configuration space concerning path planning, and the data of the free space defined in the 6 dimensional configuration space can be efficiently stored. This algorithm of free space enumeration is independent of the kinematic characteristics of the manipulator. Therefore, this method is generally applicable to any type of manipulator. This method has been actually implemented and has been applied to a 6 d. o. f. articulated manipulator.
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  • Takashi SUEHIRO, Kunikatsu TAKASE
    1988 Volume 6 Issue 6 Pages 499-506
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    In assembly tasks, motion of a robot hand or an object grasped by a robot is constrained by the contacting environmental objects. This paper proposes the use of the concept of the instantaneous center of motion to analyze such constrained motion in contact. By the analysis, the following methods which are indispensable in realizing assembly-like tasks are obtained: a contorol method of the motion in contact, a method for observing the state of contact, a method of getting into and detaching from the contact state. Applications of these methods to assembly tasks are also discussed.
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  • Kinya TAMAKI, Yukio HASEGAWA, Tatsuji ISHIDATE
    1988 Volume 6 Issue 6 Pages 507-516
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    The workspace of robots is one of the most important performances. The relations between robot joint configurations and the workspace need to be specified for designing kinematic mechanisms of the robots. The authors discuss classification of the arm joint configurations by geometric characteristics of the workspace, dealing with fundamental tables of the arm joint configurations which exclude duplicate or ineffective joint configurations. The classification of the arm joint configurations provides useful data-base for selecting the appropriate arm according to the characteristics of the operation.
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  • [in Japanese]
    1988 Volume 6 Issue 6 Pages 517
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
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  • Yoichiro MAEDA, Morikazu TAKEGAKI
    1988 Volume 6 Issue 6 Pages 518-522
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    This paper presents a collision avoidance method for a mobile robot which applied fuzzy reasoning and production rules. In the first step of this method, a mobile robot recognizes the static and dy namic degree of danger between a robot and an obstacle by the fuzzy reasoning. In the second step, using the degree of danger a mobile robot decides the direction of avoidance by the decision table. This method can realize the heuristic avoidance among moving obstacles for a mobile robot. Some results of computer simulation are shown to prove the effectiveness of this method proposed in this paper.
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  • Kiyoji ASAI
    1988 Volume 6 Issue 6 Pages 523-527
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
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  • Masaharu MIZUMOTO
    1988 Volume 6 Issue 6 Pages 528-535
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
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  • 1988 Volume 6 Issue 6 Pages 535
    Published: 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
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  • Toshiaki MUROFUSHI, Michio SUGENO
    1988 Volume 6 Issue 6 Pages 536-541
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
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  • Shuta MURAKAMI
    1988 Volume 6 Issue 6 Pages 542-548
    Published: December 15, 1988
    Released on J-STAGE: December 09, 2010
    JOURNAL FREE ACCESS
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  • Tomoyoshi TAKEUCHI
    1988 Volume 6 Issue 6 Pages 549-556
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
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  • Kaoru HIROTA
    1988 Volume 6 Issue 6 Pages 557-562
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
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  • 1988 Volume 6 Issue 6 Pages 563-572
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
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  • [in Japanese]
    1988 Volume 6 Issue 6 Pages 576
    Published: December 15, 1988
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    Download PDF (126K)
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