Dynamics and Positioning Control of Space Robot with Structurally Flexible Manipulators.

Abstract

Space robots consist of a free-flying satellite base and manipulators with structural flexibility to meet the requirements of a lightweight system. The motion of the manipulators influences the positions and orientations of the satellite base because the system has no fixed supports. The motion of space robots also induces vibrational motions of structurally flexible manipulators. To control such complicated space robots, their dynamic characteristics should first be understood. A mathematical model of a space robot with structurally flexible manipulators is developed in this paper by using a finite-element method. An extended local PD-control scheme to control the structurally flexible manipulators on the satellite base is proposed. The scheme presented is very simple and the stability of the closed loop system is proved by Liapunov's direct method. The effectiveness of the control scheme is verified by numerical simulation.