The 6-DOF synchronized sliding-mode control for approaching to the slowly rotating satellite

This paper aims at solving the 6-DOF synchronized control problem of effectively approaching arbitrary capture vectors of a slowly rotating satellite. Firstly, relative orbital and attitude dynamic equations, which in detail describe the relative motion between the chaser and the target satellite, are established. Secondly, the reference trajectories and expected attitude for chaser are given based on concrete analyses. In order to complete the approaching task safely and effectively, a synchronized controller based on sliding-mode control is designed. Finally, simulation results show that the presented controller provides a good performance of relative position control, meanwhile guarantee the pointing accuracy of the capture axis of the chaser.