Modified Anti-windup Control for High Precision Motion System

This study aims to solve the windup problem caused by the actuator saturation of the high precision motion system after the acceleration process. We propose two anti-windup control methods by adding anticipatory saturation units to the traditional anti-windup controllers, hence the actuator saturation is suppressed when control inputs are approaching the actuators' limits. One of the two anti-windup controllers is based on modified back-calculation, and the other one modifies the variable structure. Simulation results show that the two modified controllers can both improve the scanning accuracy greatly, decease the settling time and overshoot evidently, and have a smooth and stable scanning speed. Moreover, the controller with modified variable structure performs even better than that with modified back-calculation.