Servo system design of direct-drive aerospace linear electro-mechanical actuator

Abstract

According to the high accuracy, broad band and large load demanding for the actuator which put forward by the spacecraft, servo system of direct drive linear electro-mechanical actuator is designed. In order to improve precision and dynamic property of the servo system, direct-drive torque motor combined ball screws are used and high precision optical absolute encoder are used for feedback. SimPowerSystems toolbox is adopted to set up model and simulation which can observe the servo system operation state directly on the basis of close loop servo system math model in order to improve the accuracy of servo system model. Simulation and experimental results show that direct drive linear electro-mechanical actuator with a good ability of servo movement. In the case of load 20Kg, amplitude attenuation in 1 dB, bandwidth lag 10 °, dynamic response is no less than 12Hz and absolute position accuracy is no more than 0.2mm. It can satisfy the servo system requirements of high accuracy, broad band and large load.