Robust permanent magnet linear synchronous motor servo system based on disturbance observer

This paper presents a new position controller for permanent magnet linear synchronous motor (PMLSM), which is robust against load disturbance, torque ripple and parameter variations. A disturbance observer based on an acceleration control loop is used. The disturbance observer estimates the disturbance and parameter variations using current and position information. Both the feedback controller and disturbance observer adopt a fuzzy variable-structure scheme to suppress the observer noise. The effectiveness of the proposed controller is verified by experimental result