A higher-order sliding mode controller design for spacecraft attitude tracking system

In order to eliminate bad influence caused by parameter uncertainties and external disturbances in spacecraft tracking system, a higher-order sliding mode control strategy is proposed in this paper. Attitude control system is divided into fast loop and slow loop based on singular perturbation. The sign function is replaced by the norm-type switching function for the continuous virtual control in the slow loop. The fast loop consists of the integral fast terminal sliding mode control, the feedback control and the higher-order sliding mode control. Theoretical analysis and simulation results show strong robustness and weak chattering.