Motion Control of a Robot Composed of Three Serial Links with Curved Contour (Ist Report; Concept and Dynamic Control of the Robot)
Kazuo Nakakuki, Kazuo Yamafuji and Osamu Shikata*
University of Electro-Communications, 1-5-1, Chofugaoka, Chofu, Tokyo 182, Japan
* Nitto Seiko Co., Ltd., 29, Umegahata, Ayabe, Kyoto 623, Japan
The authors developed several kinds of robots having a smaller number of actuators than links. Motion controls of these robots were successfully accomplished using dynamic interference forces. For example, a swing and mobile robot was developed consisting of pivoted double-link arms and a single motor. This robot is capable of shifting itself from one horizontal bar to another by utilizing vibrational excitation. In this study, we elaborated a robot composed of three serial links with a curved contour and made it perform several dynamic motions. The outer contour of each link has a large curvature, and the links are connected serially. The two outer links of the robot have the same configuration which is different from that of the central link. Two DC servomotors are installed in the two outer links. These links can move freely around the connection joints, and constitute a part of a large arc having a certain angle which is controlled by the motions of the outer links. This robot can induce large vibration on all links by swinging the two outer links while lying on the floor, and can eventually bring itself up to a standing position. On the other hand, the robot can lie down from a standing posture without sustaining a shock on impact. The robot can perform movements like those of young children on the floor. In this paper, we mainly report on the concept of the robot, the simulation procedure and experimental results for the standing-up action.