Motion Control of a Three-Link Space Robot to Reduce the Base Attitude Disturbance Experimental Verification by Using Two-Degree-of-Freedom Control

• Published in: Transactions of the Japan Society of Mechanical Engineers Series C Vol. 70; no. 693; pp. 1409 - 1416
• Main Authors: WENG, Zhiqiang, TAMURA, Yoshiaki, NISHIMURA, Hidekazu, TAKAHASHI, Shinya
• Format: Journal Article
• Language: English; Japanese
• Published: The Japan Society of Mechanical Engineers 2004
• Subjects: d'Alembert Principle; Enhanced Disturbance Map; Final-State Control; Linear Parameter Varying System; Nonholonomic Constraint; Space Robot
• ISSN: 0387-5024; 1884-8354
• DOI: 10.1299/kikaic.70.1409

In this paper, we deal with a three-link space robot moving in planar space without controls for the base attitude. Our experimental setup of the three-link space robot can levitate by use of compressed air. Using d'Alembert principle, it is shown that the state equation of the three-link space robot can be reconstructed as a first-order nonholonomic system with the constraint condition that the rotational velocity of the base is set to be zero. The suitable final postures corresponding to the desired position of the end effector can be determined using the concept of the enhanced disturbance map. Based on the state equation, the feedforward torque inputs can be obtained by the final-state control in order to bring the end effector from an initial position to the desired position. The torque inputs and trajectories obtained are smooth. We designed a two-degree-of-freedom control to follow the obtained trajectory. It is verified from simulation and experiment that the proposed method of motion control is useful.