Robust Control for Free-Floating Space Robot in Inertial Space Based on Adaptive Estimation of the Upper Bounds

摘要

In this paper, the robust control problems were discussed for space-based robot system whose base was not controlled and parameter variations with external disturbances in inertial space. The under-actuated dynamic equations of the system were derived through the Lagrange method and linear momentum conservation of the system.With the augmentation approach, it is demonstrated that the augmented generalized Jacobian matrix and the dynamics equation of the system can be linearly dependent on a group of inertial parameters.Based on the results ,a improved robust control scheme is proposed for Free-Floating Space Robot. The assumption that the bounds of uncertainties must be a peiori known which is the restrictive condition of the general robust control is overcome by making adaptation laws for the upper bounds on the norm of parameter variations and external disturbances. The asymptotic stability of the control scheme is proved with Lyapunov method.A planar freefloating single-arm space robot system with one payloads is simulated to verify the proposed control scheme.