Flexible spacecraft optimal attitude maneuver with SMDO

The SMDO (Sliding Mode Disturbance Observer) is introduced in optimal attitude maneuver control law for high precision attitude control of flexible spacecraft which consists of rigid central body and flexible appendages. First, an theta-D optimal attitude maneuver control law is adopted, then an SMDO is designed based on internal model principle. Furthermore, the attitude control system stability is analyzed based on Lyapunov stability method, and the parameter criteria of the SMDO is derived. By integrating the SMDO with optimal control law, the disturbance can be rejected and the desired dynamic performance can be guaranteed. Simulation results show that, comparing with the classical disturbance observer, the attitude control system performance is improved after introducing SMDO, and the effectiveness of the designed control system is demonstrated.