Improved Sliding Mode Control of Permanent Magnet Synchronous Linear Motor Based on Model-Assisted Linear Extended State Observer

Abstract

Aiming at the problem that generalized disturbance such as parameter perturbation, load disturbance and unmodeled dynamics will reduce the performance of the mover speed control of the permanent magnet synchronous linear motor (PMSLM), an improved sliding mode control (ISMC) strategy of PMSLM based on model-assisted linear extended state observer (MALESO) is proposed. Firstly, a speed mathematical model of PMSLM considering generalized disturbance is established, then the speed tracking error signal is introduced into the traditional exponential reaching law (TERL) as the system state variable, and the improved exponential reaching law (IERL) based on the system state variable is designed and applied to the integral sliding mode surface to obtain the control variable with generalized disturbance. Secondly, MALESO is designed to estimate the generalized disturbance and its estimated value is feedforward compensated to the output signal of the improved sliding mode speed controller (ISMSC). Finally, the speed control of PMSLM under the generalized disturbance is realized. The simulation results show that the proposed control strategy can significantly optimize the dynamic and static quality, anti-disturbance ability and robustness of the system, and at the same time effectively weaken the chattering phenomenon of sliding mode control.