Feedback linearization control of permanent magnet linear synchronous motor based on adaptive fuzzy controller and nonlinear disturbance observer

A feedback linearization control method based on adaptive fuzzy controller (AFC) and nonlinear disturbance observer (NDO) is proposed for the permanent magnet linear synchronous motor (PMLSM), which is susceptible to nonlinear uncertainties such as external load disturbance, parameter variation and friction. Firstly, a feedback linearization controller (FLC) is designed to linearize the nonlinear system and realize position tracking, so as to stabilize the PMLSM control system. NDO is used to estimate and compensate the uncertainties of the system and reduce the position tracking error of system. However, it is difficult to select the observer gain in the actual operation process, which is very easy to produce large observation error. Therefore, AFC method is used to approach the observation error of NDO, and the fuzzy rules are dynamically adjusted by the adaptive law, so as to improve the learning ability of the fuzzy controller, enhance the robustness of the system, and guarantee the closed-loop stability of the system with Lyapunov theorem. Experiments show that the method not only makes the system have strong robust performance and good tracking accuracy, but also can effectively compensate the uncertainty of the system. © 2021, Editorial Department of Control Theory & Applications South China University of Technology. All right reserved.