Efficient Internal Model Control Based on Smith Predictor for PMLSM Servo System Considering Time Delay via Extended State Observer

The tracking, positioning and anti-interference performance of Permanent Magnet Linear Synchronous Motor (PMLSM) servo systems are affected by time delay. In this paper, an Enhanced Internal Model Controller (EIMC) based on Smith Predictor (SP) with a Synchronous Model Extended State Observer (SMESO) is proposed, which is named the EIMC-SP-SMESO method. In this method, a PMLSM dynamic model considering time delay is established, and a SMESO that matches the control input and system output is designed to achieve accurate estimation and real-time compensation of unknown total disturbances. Considering the approximation error introduced by the time delay expansion in existing frameworks, this paper compensated the time delay of the feedback signal by an SP and derived an EIMC to achieve high-precision control. The experimental results confirmed the effectiveness of the proposed method in improving the accuracy of motion tracking, positioning, and disturbance suppression.