Adaptive Nonlinear Speed Tracking Control of Permanent Magnet Linear Synchronous Motor Based on I&I Theory

The permanent magnet linear synchronous motor is affected by model perturbation, load disturbance, parameter change and other uncertain factors during operation. This impact severely limits the dynamic tracking performance of the system. To solve these problems, an adaptive nonlinear speed tracking controller based on immersion and invariance theory is proposed in this paper. Firstly, a dynamic mathematical model of PMLSM with uncertain factors is established. Secondly, a nonlinear speed controller is designed based on immersion and invariance theory to improve tracking performance, while a disturbance adaptive law is designed to enhance the robustness of the system. Then the stability of the closed-loop system is proved based on Lyapunov stability theory. The selection principle of control parameters to keep the system stable is obtained, and the influence of parameter error on the closed-loop system control performance is analyzed. Finally, the experimental results show that the proposed control method can produce good dynamic tracking performance and strong robustness to load disturbance and parameter change.