Attitude Control Method for Flexible Spacecraft Based on Disturbance Observer

Considering the influence of disturbance and flexible solar panel vibration, the attitude stability control of spacecraft is studied. Based on traditional PD controller, a nonlinear disturbance observer based on sliding mode control is designed to estimate the sum of environmental disturbance, flexible vibration and model uncertainty. The Lyapunov method is used to prove that estimation errors are uniformly bounded and the closed-loop system is globally asymptotically stable. Simulation results show that the proposed method can effectively estimate and compensate the total disturbance, and then achieve high precision and high stability attitude control performance.