A novel robust control strategy for spacecraft eigenaxis rotations

This paper addresses the control problem of spacecraft eigenaxis rotations in the presence of parametric uncertainty and external disturbance. We develop a novel robust control strategy for eigenaxis rotation via the time-varying sliding mode control (TVSMC) technique. The general design principle is provided and the characteristic of the eigenaxis rotation is proved mathematically. Modified Rodrigues parameters (MRPs) are utilized as the attitude parameters for the non-redundancy. In particular, a TVSMC eigenaxis algorithm with an exponential timevarying sliding surface is designed to illustrate the main features of the proposed strategy. The effectiveness of the proposed strategy is demonstrated by simulation results.