Robust Attitude Tracking Control and Disturbance Rejection for Flexible Spacecraft

The attitude tracking control problem in the presence of parameter uncertainties and external disturbances for a spacecraft with flexible appendages is investigated in this paper. It is assumed that the external disturbance is generated by some nonlinear exosystems. The MRP is used as the kinematic variables since it is free of singularity. Novel simple robust Lyapunov-based controllers that require only the attitude and angular velocity measurement are proposed. By using the Lyapunov analysis approach, the asymptotical stability of the closed-loop system is proved. Finally, simulation results are presented to illustrate effectiveness of the control strategies.