Attitude Control for Flexible Spacecraft With Disturbance Rejection

The attitude control and disturbance rejection problems are investigated in this paper for a flexible spacecraft during attitude maneuver. Based on the internal model principle, a dynamic disturbance compensator is designed to account for the uncertainty caused by sinusoidal disturbances with known frequencies. With the compensator, a novel robust Lyapunov-based controller that requires only the attitude angle and angular velocity measurement is proposed. Specifically, convergence of modal variables to their set points can be achieved. The result is rigorously proved using the Lyapunov stability theory. The effectiveness and robustness of the proposed controller are demonstrated by numerical simulation.