Integrated design of trajectory tracking and inertia property identification for post-capture of non-cooperative target

Abstract

This paper investigates the post-capture control problem associated with trajectory tracking and inertia property identification for a six degree-of-freedom (6DOF) combined spacecraft system subject to input saturation. Post-capture of non-cooperative target will cause a large shift in the dynamics of combined spacecraft mainly resulting from the change of inertia properties. An adaptive tracking control law for combined spacecraft is designed based on the terminal sliding mode and dynamic surface control techniques, and the inertia properties can be identified simultaneously. To estimate mass and inertia matrix, the expression of parameter estimation error is obtained by introducing a group of auxiliary filtered variables. A saturation compensator is employed to deal with the input saturation. Within the Lyapunov framework, the proposed controller is proved to guarantee the finite-time convergence of both trajectory tracking and inertia property identification driven by continuous control forces. Numerical simulations are finally performed to demonstrate the effectiveness of the designed control law.