Fixed-time Attitude Control and Active Vibration Suppression for Flexible Spacecraft based on the Fully-actuated System Approach

This paper investigates attitude control with high accuracy and active vibration suppression for flexible spacecraft with external disturbances and inertia uncertainty. A novel control scheme is technically proposed based on the fully-actuated system approach. Firstly, based on the 3-dimensional Special Orthogonal Group, a second-order fully-actuated system described by exponential coordinates is constructed and then converted into a constant linear system with an arbitrarily eigenstructure. After that, a fixed-time sliding mode control scheme is proposed to ensure the fixed-time convergence of the error exponential coordinates and the flexible mode simultaneously. By using Lyapunov approach, the stability of the closed-loop system is analysed. Finally, a numerical simulation is carried out to vindicate the effectiveness of the controller.