Attitude dynamics modeling and control of large flexible solar sail spacecraft

The problems of rigid-flexible coupling dynamics modeling and control are proved to be hard to resolve owing to the large size and super-flexible structure of the solar sail spacecraft. This paper utilizes moment of momentum theorem to deduce rigid-flexible coupling dynamics equations including the attitude dynamics and vibration equations for super-flexible solar sail spacecraft with control vanes, and then the dynamics equations solutions of solar sail on super-synchronous transfer orbit are presented combining with the unconstrained modes conception. Based on the proposed dynamics models, the PD control law incorporating the Bang-Bang control technique is designed to study the yaw axis earth-pointing problems of solar sail. Simulation results demonstrate that the solutions of the rigid-flexible coupling dynamics equations can truly describe the dynamical characteristics of the solar sail spacecraft and the attitude controller can perform the yaw axis earth-pointing mission exactly and quickly.