Theoretical and Experimental Study on In-Orbit Capture Operation With Satellite Mounted Manipulator

Abstract

This paper treats both theoretical and experimental study on a control problem of a space free-flying space manipulator. The authors' main target is to develop a new control method for trajectory tracking or target capturing, considering the dynamical interaction between the manipulator arm and the base vehicle in space micro-gravity environment. In the theoretical study, the Generalized Jacobian Matrix (GJM) concept is introduced. By means of this new matrix, the conventional control methods for ground-fixed manipulators is directly applicable for space manipulators. In the experimental study, a laboratory model of robot satellite supported on air bearings is developed in order to simulate the flee-flying behavior of mechanical links in micro-gravity environment. The model comprises a base satellite and a two-link manipulator arm. An on-line Resolved Motion Rate Control scheme with vision feedback is developed for experimenting capture operations, utilizing the GJM. The manipulator can properly chase and capture both a standing target and a moving target in spite of complex satellite/manipulator dynamical interaction. The experimental results confirm the validity of the GJM concept and the proposed control method.