Design of an adaptive control system for free-flying space robots in joint space

Abstract

Space Robotics has been attracting special interest as a new application field of robotics. Space robots will play an important role in future space projects, such as constructing space structures or servicing satellites. First, an inverse kinematics algorithm to facillitate the joint space control is proposed. We present a joint space dynamic control scheme for free-flying space robots, and investigate the nonlinear parameterization property of the full dynamics using the momentum conservation law. Secondly, under the parameter uncertainty, the extended robot model is used to apply the general adaptive control technique because it is linearly dependent on the dynamic parameters. Then we propose an adaptive control scheme in joint space based on the reaction compensation trajectory generation under the assumption that the vehicle motions are measurable. Finally, to overcome this assumption, it is shown that the vehicle motions are calculated by means of the proposed inverse kinematics algorithm. We propose design techniques of the adaptive control system for free-flying space robots in joint space against parameter uncertainty and unknown payload. Simulation results are presented to show the validity and the effectiveness of the proposed control schemes.