The Research Of Fuzzy Sliding Mode Velocity Control Of PMLSM

PMLSM is a complex system with characteristics of quiet operation,high stiffness,fast response speed,easy maintenance and high positioning accuracy,at the same time,it is also affected by the change of temperature,magnetic flux leakage and external friction,it is not easy to maintain precise control.On the other hand,because of omitting intermediate mechanical buffer link,it is an external disturbance to a stable system,if the effect of automatic adjustment is not ideal,then the system will be unstable,it will enhance the difficulty of the linear motor control system in the electrical control.Based on the above questions,in order to meet the needs of high performance drive system of PMLSM,this paper adopts a sliding mode control strategy to suppress the effects of system parameter variation and load disturbance.In order to reduce buffeting effectively without compromising robustness,according to the chattering analysis of exponential approach rate control,this paper will propose a design method of a fuzzy sliding mode controller with resistance ability,the controller adopts a new variable exponential approach rate strategy to make the system reach the switching surface quickly,improving the movement quality of sliding mode and developing the static and dynamic characteristics and robustness of the system,fuzzy control is used to replace sliding mode switch in sliding mode,because parameter switching is the main factor to overcome external disturbance,so fuzzy control is adopted to estimate the parameters online and make them as small as possible for reducing the buffeting.Through the speed simulation software of Matlab/Simulink,the fuzzy sliding mode control system model of PMLSM is built for simulation experiment.The velocity loop fuzzy sliding mode controller is compared with PI,ordinary sliding mode and rate of approach sliding mode controller.Simulation results show that fuzzy sliding mode control can effectively suppress chattering caused by sliding mode switching,make the system more stable and improve the dynamic quality of the system without affecting the robustness of sliding mode variable structure control.