The Research On The Control Algorithm And Stimulation Of Two-stage Servo System

As a kind of control system which can change timely according to the outside given input signals,the servo system is widely applied in various fields.With a continuously increased requirement for control accuracy,response speed and robustness,the traditional single-stage servo system has difficulties in meeting these requirements.Aiming at the laser positioning platform with high precision,a two stage servo system which is different from the traditional positioning platform is designed.Firstly,the overall structure of the two-stage servo system is designed according to the operating principle and technical criteria of the laser system,including the design of the coarse and fine channel driven structures.Secondly,the three-loop simulation model of the coarse channel platform based on the direct drive motor is built in the Simulink simulation environment,and the position loop of the three-loop control system is designed in particular.Because of the poor anti-interference of PID controller,we apply the ADRC controller into the position loop control and make a mainly comparison of the anti-interference with PID controller according to the simulative interference.At the same time,the modeling and analysis of the fast mirror structure based on the piezoelectric ceramic drive are carried out.The fine channel model is built in the Simulink simulation environment;the compound control is adopted and its performance is compared with the traditional PID control.Then,because of the difficulties in the tuning of the controller parameters,two parameters tuning methods are designed,including the compound parameter tuning method and the fusion particle swarm algorithm optimization.Both of the two methods are used in the parameter tuning of the fine channel controller and achieve excellent results by experiments saving time from cut and try manually.Finally,the coordinated control module of the two-stage driven servo system is designed,and the double-threshold switching strategy is implemented with S-function.Meanwhile,because of the hysteresis and unsteadiness phenomenon produced during fine channel's compensation of the errors in coarse channel,the curve fitting least squares method,the weighted filtering algorithm and the output linearization algorithm are introduced into the coordination control module.Meanwhile,a simulation model of the two-stage servo system is built in the Simulink simulation environment,and the typical signal is input for testing.The result of the debugging shows that the model meets the requirements of high-speed and high-precision of the system.