Research On Fast Steering Mirror System Based On Active Disturbance Rejection And Dynamic Surface Method

With the development of optoelectronic tracking technology and laser beam weapon,the performance requirement of optoelectronic tracking system is more and more strict.Under this background,compound axis control arises at the historic moment.Fast Steering Mirror(FSM)as the core component of precision tracking in composite axis control,How to control the mirror to rotate quickly and accurately is the difficulty of the compound axis control.At the same time,high precision and fast response are two key indicators to judge the performance of precision tracking system.Because of the nonlinear characteristic,environmental factors,internal parameters change and the influence of uncertain disturbances such as atmospheric turbulence on line of sight stability during tracking of FSM system,it is difficult for the controller to achieve fast and stable tracking.In this thesis,a FSM driven by voice coil actuator is used as the controlled object.The control strategy of the system is studied and three control strategies are proposed,which are improved active disturbance rejection control,sliding mode dynamic surface control based on tracking differentiator and dynamic surface active disturbance rejection control.The feasibility of the proposed control algorithm is verified by theoretical analysis and simulation experiments.The specific work is as follows:(1)An improved active disturbance rejection controller is designed which improved the nonlinear state error feedback in traditional active disturbance rejection control.It theoretically proves that the algorithm can greatly improve the rapidity and tracking accuracy of the FSM system and verified by simulation experiments.(2)In order to improve the rapidity further,tracking accuracy and anti-disturbance ability of system,overcome internal unmodeled disturbance and external uncertain disturbance,a sliding mode dynamic surface controller based on tracking differentiator is designed.Using the fast and good tracking ability of the tracking differentiator,combined with the dynamic surface control with excellent stability and the sliding mode control with strong robustness and rapidity,a mirror controller is designed.The control effects of the proposed controller and the traditional dynamic surface controller in the FSM system are compared and analyzed through simulation experiments.(3)Considering the strong robustness of active disturbance rejection control and the high tracking accuracy of dynamic surface control,a dynamic surface active disturbance rejection control controller is designed by combining those two what has just been mentioned above.In the Simulink,the FSM system is used as the controlled object to compare the controller with the traditional dynamic surface and the traditional active disturbance rejection control the results show that the proposed controller has good dynamic performance and steady state performance.