Active Disturbance Rejection Position Control of Permanent Magnet Linear Synchronous Motors Using Feedback Nonlinear State Error

Abstract

Permanent magnet linear synchronous motors (PMLSMs) have the advantages of simple structure, high efficiency, high accuracy, and direct drive. However, the motion accuracy of PMLSMs is hindered due to the negative effect of various disturbances directly acting on the mover, and thus, the development of effective control method against disturbances is a key task for PMLSMs. An active disturbance rejection position control method of PMLSMs using feedback nonlinear state error is proposed to achieve precision motion against disturbances in this paper. The electromagnetic thrust model and the dynamics model of PMLSMs are firstly established. Subsequently, an active disturbance rejection position controller is developed based on the nonlinear state error feedback. In order to reduce the number of control parameters and the jitter of control law, a sliding mode controller based on an improved exponential convergence law is designed to optimize the nonlinear state error feedback control law. In addition, the performance of the extended state observer and an improved nonlinear state error feedback control law are discussed, and the optimal control parameters are determined using the simplex method. Finally, simulation results demonstrate the implementation of high-precision motion and the improvement of anti-interference capability for the PMLSMs, and the effectiveness of the proposed method is verified.