Adaptive finite-time sliding mode attitude tracking control laws for flexible spacecraft with actuator saturation

In this paper, attitude tracking control for flexible spacecraft with inertia uncertainty, disturbance and actuator saturation is investigated. First, a switching function is constructed by using attitude velocity tracking errors and quaternion errors. Then, an adaptive finite-time sliding mode controller is derived for the flexible spacecraft to guarantee that the control goals can still be achieved when actuator saturation happens. To verify the effectiveness of the presented control laws, simulations are performed for a flexible spacecraft in the presence of inertia uncertainty, disturbance and actuator saturation. In addition, some existing control strategies are compared with the presented adaptive finite-time sliding mode control laws to demonstrate the superior control performance of the proposed control schemes.