Modelling and Analysis of Electro-Mechanical Actuator Servo System with Nonlinear Factors

Aiming at an electro-mechanical actuator (EMA) servo system based on a three-closed-loop control strategy with a permanent magnet synchronous motor (PMSM), the models of the PMSM, the current vector control method and planetary roller screw mechanism (PRSM) are established in this paper respectively. The influence of some nonlinear factors such as the PRSM contact stiffness, EMA anchorage stiffness and PRSM clearance on dynamic characteristics of the system are analyzed. The results show that the nonlinear factors would affect the stability, rapidity and steady-state errors of the system responses.