Decentralized variable structure control for stability of flexible satellite attitude suitable for engineering application

The introduction of the full paper points out that, in our opinion, the stability research results in Refs.1 through 3 are not suitable for engineering application because the control output is limited. Sections 1, 2 and 3 explain the decentralized variable structure control we designed. Their core is: ″We first establish the attitude dynamics model of the satellite with a rigid body and a large flexible solar panel. The attitude dynamics model can be expressed in displacement and modal coordinate forms. We then study the decentralized variable structure control system of the attitude of the flexible satellite. The control system is divided into the subsystem whose states can be measured directly and the subsystem whose states can not be measured directly. We design the sliding mode control law for the control system. The control law is simplified by considering the control output limits in engineering practice. After that, the stability of the decentralized variable structure control system with limited control output is proved. The performance of the control system in the sliding mode is discussed. The control system is stable when control output satisfies the sliding mode reaching conditions. The stability of the system whose control output can not satisfy the sliding mode reaching conditions is also proved.″ Section 4 presents in Fig. 2 the results of flexible satellite control simulation experiments; of course, the control torque of the system is limited. The simulation experimental results and their analysis show preliminarily that the variable structure control system can reach the sliding mode and that the precision of the satellite attitude is within 0.05°, indicating that our control system is effective.