Design And Application Of Active Disturbance Rejection Control With Anti-windup Compensation

The phenomenon of actuator saturation is widespread in practical control systems.It is usually assumed that the actuator dynamic is linear in the controller design.When the actuator is restricted,the output signal of the actuator is not consistent with the output signal of the controller,resulting in poor dynamic performance or even instability of the closed-loop system.In recent years,active disturbance rejection control has been widely used in research and practice,and has gradually become an important direction of control theory.In order to guarantee the performance of the closed-loop systems,large parameters of the active disturbance rejection controller are often selected,and the control signal also exceeds the actuator saturation limitation.The antenna servo system with active disturbance rejection control cannot obtain good performance due to the influence of actuator saturation.Thus,the investigation of active disturbance rejection control with anti-windup compensation is of great theoretical and practical significance.This thesis is concerned with active disturbance rejection control with anti-windup compensation.The main contents are listed as follows:First,the controlled system using the relative degree theory is analyzed,and we discuss the design method of linear active disturbance rejection controller with antiwindup compensation.Based on the Lyapunov method,the stability condition of the closed-loop system is given in terms of linear matrix inequalities.Second,we design an anti-windup compensator for the nonlinear active disturbance rejection controller.By analyzing the nonlinear term in the classical controller,an improved active disturbance rejection controller is proposed.Both static and dynamic anti-windup compensators are designed for controllers.And stability criteria of the closed-loop system are established.Simulation examples are provided to illustrate the validity of the results.Finally,we introduce and model the antenna servo control system,and apply the anti-windup active disturbance rejection control algorithm to the actual antenna platform successfully.The performance of the antenna closed-loop system is analyzed by comparing the simulation and experimental results,and the validity of the designed controller is verified.