Fast Steering Mirror Sliding Mode Control Based on Prescribed Performance

In order to improve the control performance of the fast steering mirror in laser communication, a prescribed performance control method is studied. First, the fast steering mirror system is analyzed, and the model parameters are obtained according to the open-loop step response. Then, the fixed-time extended state observer is used to estimate the angular velocity and disturbance in real time. Next, error transformation function and performance constraint function are introduced to construct a fast nonsingular terminal sliding mode surface, realizing constrained control of the system output error. Furthermore, the stability of the designed controller is proven through Lyapunov theorem. Finally, the effectiveness and feasibility of the proposed method is verified through experiments.