Antiunwinding Sliding Mode Control for Rigid Spacecraft Based on Modified Rodrigues Parameters

In this article, attitude maneuver control without unwinding phenomenon is investigated for rigid spacecraft via modified Rodrigues parameters. A novel switching function is constructed by a hyperbolic sine function to guarantee that the sliding surface contains two stable equilibria. A sliding mode controller is developed to ensure that the sliding surface is reachable. Moreover, a dynamic parameter is designed to guarantee unwinding-free performance of the closed-loop system when the system states are outside the sliding surface. In addition, a boundary layer is introduced to deal with the chattering problem. Further, the unwinding-free performance within the boundary layer is guaranteed by imposing some conditions on the parameters of the switching function. Finally, comparison simulations are performed to verify the effectiveness and superiority of the presented control law.