Application of auto-disturbance rejection controller for pneumatic servo system

To improve the robustness of control systems,a nonlinear auto-disturbance rejection control(ADRC) technique for pneumatic servo systems was developed and a parameter setting method was given.The nonlinear controller is mainly composed of an extended state observer(ESO),an input reference signal tracking-differentiator(TD) and a nonlinear state error feedback(NLSEF) control law.The extended state observer can track successfully the states and extended state of the system,and it is possible to realize the state feedback and handle the model uncertainty and external disturbance compensation.The design of ADRC is independent of controlled system model,and it shows its good adaptability and robustness in whole operation areas.The simulation results show that ADRC is robust against modeling uncertainty and external disturbances for pneumatic servo systems.The dynamic performance of the system using ADRC can be improved as well.