Novel Dynamic Microactuation Method for Tracking-Error Reduction of Permanent Magnet Linear Synchronous Motors

A permanent magnet linear synchronous motor (PMLSM) is susceptible to system uncertainties and external disturbances, resulting in a tracking error that is difficult to eliminate. To effectively reduce the tracking error of a PMLSM, this paper presents a novel dynamic microactuation (DMA) method through a microactuation unit (MAU)-assisted dual-stage system. In this study, we reduce the tracking error dynamically through MAU-based actuation and use the PMLSM mover as the working end of the dual-stage system. The proposed DMA method finalizes the actuation mechanism of the MAU. Therefore, the method can dynamically actuate the MAU to act on the PMLSM mover with the appropriate actuation amount, and thus reduce the tracking error of the motion system. Moreover, to avoid the coupling effect of MAU-based actuation on the PMLSM controller, the DMA method modifies the feedback error of the PMLSM controller by adding the actuation amount to the position error such that it remains unchanged. Thus, the stability of the electromagnetic thrust of the PMLSM can be maintained for its output. The performance of the proposed DMA method is analyzed theoretically and validated experimentally. The results show that the proposed method can effectively reduce the tracking error of a PMLSM system.