Abstract:Aimed at the problem of aircraft electromechanical actuator servo control system, the control method which can effectively suppress transmission mechanism of nonlinear friction was present. The method was constituted by feedforward compensator, proportion integration and differential (PID) feedback controller based on linear quadratic regulator (LQR) and the sliding mode controller. The system fast response could be improved by the feedforward control, and the system antiinterference ability could be enhanced by the PID feedback controller. Aimed at the nonlinear friction design, the sliding mode control was used to weaken the influence of nonlinear friction on the servo actuator. Based on analyzing the structure of the electromechanical actuator servo system, the Stribeck model of nonlinear friction was presented. The system mathematical model was establised, and then the feedforward compensator of structure and parameters were obtained through analysis. The reference input was introduced and state control equation was built based on errors, then the PID controller based on LQR and sliding model controller which supressed interference of nonlinear friction were designed. At last, the simulation experiment with sliding model control was carried out, and then the simulation experiment without sliding model control was also carried out. The experimental results show that by contrast, the control model with sliding model controller can effectively restrain the speed shake of the nonlinear friction and position “ceiling” phenomenon.