Robust position control of AC servo motors

In this paper, we propose a robust position control scheme for AC servo motors. We adopt a disturbance torque suppresser to eliminate the effects of the disturbance torque and variation in moment of inertia, thus the proposed controller has improved robustness. We can, thereby, reduce position errors due to the disturbances. Some simulation and experimental results are presented to demonstrate the superior position tracking performance of the proposed controller over the conventional proportional-integral (PI) and feedforward controller.