Unwinding‐Free Multivariable Super‐Twisting Attitude Maneuver Control for Rigid Spacecraft Using MRPs

This paper investigates the attitude maneuver control without unwinding phenomenon for rigid spacecraft using a multivariable super‐twisting algorithm (MVSTA). First, a generalized sliding surface is constructed using a class of functions with specific properties. When the system states are restricted on the proposed generalized sliding surface, the spacecraft system can achieve unwinding‐free performance. Second, taking into account the uncertain input matrix and disturbance, we derive the sliding mode variable equation of the attitude system and present a few crucial features for the equation, allowing the MVSTA to be used. Finally, a second‐order sliding mode controller based on MVSTA is developed based on the generalized sliding surface to assure the robustness of the attitude maneuver control system. A critical feature of the presented attitude control law is the introduction of a dynamic parameter to ensure unwinding‐free performance when the system states are outside the sliding surface. Furthermore, as compared to first‐order SMC with boundary layer, the proposed controller can considerably reduce chattering without sacrificing convergence accuracy. The simulation results show that using the developed generalized switching function and the proposed attitude control method, the unwinding phenomenon is prevented during the attitude maneuver of a rigid spacecraft.