Journal of the Robotics Society of Japan
Online ISSN : 1884-7145
Print ISSN : 0289-1824
ISSN-L : 0289-1824
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  • Masanori Sekiguchi, Naoyuki Takesue
    2019 Volume 37 Issue 8 Pages 711-717
    Published: 2019
    Released: October 18, 2019
    JOURNALS FREE ACCESS

    This paper proposes a new numerical solution of prioritized inverse kinematics using the method of sections. First of all, this paper shows the differential kinematics of the manipulator whose one of link is virtually disconnected. The proposed method is based on the differential kinematics. Next, the problems of applying the method of sections to the prioritized inverse kinematics are pointed out, and solutions of the problems are described. Finally, simulation experiments to compare the proposed method with the conventional method are performed, and the result shows that the proposed method is superior to the conventional method in terms of computation time.

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  • Takayuki Osa, Masaya Sato, Kazuya Moriki, Satoshi Sugiyama, Naohiko Su ...
    2019 Volume 37 Issue 8 Pages 718-725
    Published: 2019
    Released: October 18, 2019
    JOURNALS FREE ACCESS

    Motion planning for robotics manipulation is an essential component for automating various tasks. In this study we discuss optimization-based motion planning methods for robotic manipulation. The optimization-based method can compute smooth and collision-free trajectories with relatively short computational cost. Although existing methods are often designed to output a single solution, the objective function is often multimodal and there exist multiple solutions to achieve a given task. On such a task, obtaining multiple solutions gives a user an opportunity to choose one of the solutions based on factors which are not encoded in the objective function. To address this issue, we propose a motion planning framework that finds multiple solutions. The proposed method is validated in simulated environments with a four-link manipulator in 2D space and a 6 DoFs manipualtor in 3D space.

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  • Masanori Sekiguchi, Naoyuki Takesue
    2019 Volume 37 Issue 8 Pages 726-734
    Published: 2019
    Released: October 18, 2019
    JOURNALS FREE ACCESS

    Angle-axis vector, which is also called axis-angle representation or rotation vector, can be applied to represent an orientation or orientation error with minimal three parameters. However, it has a problem about singular points. Therefore, this paper shows a method for calculating angle-axis vector at singular points. In addition, this paper proposes an extended angle-axis vector. Conventional angle-axis vector cannot represent an orientation error that is greater than π due to the range of inverse trigonometric function. The extended angle-axis vector can express the orientation that cannot be represented by the conventional method. The results of this study are expected to give a new method for expressing an orientation error which is needed for numerical solution of inverse kinematics or some attitude controls.

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  • Toshiaki Kami, Yuki Harata, Tomoka Yamaguchi, Yoshito Okada, Kazunori ...
    2019 Volume 37 Issue 8 Pages 735-743
    Published: 2019
    Released: October 18, 2019
    JOURNALS FREE ACCESS

    In our study, we developed AED Gripping System for AED transport UAV in order to deliver quickly to remote places. This system is structured by grippers and a gripping determination system. We introduced Permanent Electromagnets as gripper. The gripping determination system is necessary to confirm that the AED is delivered at the destination, because AED transport UAV flies to remote places which the pilot cannot see the UAV. We developed a new gripping determination system which use the difference of convergence time of counter-electromotive force between gripping or not. We conducted flight experiments and confirmed that the AED Gripping System do not drop the AED accidentally and can confirm gripping status during flight.

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