Backstepping Sliding Mode Control for the Displacement Tracking of Permanent Magnet Linear Synchronous Motor Based on Nonlinear Disturbance Observer

Abstract

For the problem that the displacement tracking control accuracy of permanent magnet linear synchronous motor (PMLSM) is prone to be affected by the uncertain factors such as parameter perturbation, and load disturbance, a backstepping sliding mode control method is proposed based on the nonlinear disturbance observer in this paper. Firstly, the nonlinear disturbance observer is developed to observe the uncertainty dynamically, so as to improve the displacement tracking accuracy of the system. Secondly, the displacement tracking controllers of PMLSM are presented by combining the backstepping sliding mode control with the command filter, which enhance the anti-jamming capability of the system, and solve the “explosion of complexity” problem during using the conventional backstepping control. Theoretical analysis shows that all the signals of the resulting closed-loop system are uniformly ultimately bounded. Finally, the proposed control method in this paper is compared with the backstepping control method, and the simulation results verify the effectiveness of the proposed control method.