Stability design of control system for satellite laser communication

The stability of a satellite laser communication terminal control system is a critical performance index in the construction and maintenance of a communication link. Based on the internal loop of the terminal antenna and fast steer mirror (FSM) controllers, a complete control system model is established for the case when the charge coupled device (CCD) detector receives the position of the cooperative terminal to form a closed laser loop. The sufficient condition of system asymptotic stability is induced according to the time delay dependent stability theorem. In order to revise the unstable internal loop design, a state feedback is proposed which combined the sufficient condition and the cone complementary algorithm. The simulation proves that the controller achieved through this scheme is able to keep system stability and provide proper system bandwidth to both coarse and fine loops for their coordination.