Research on sliding mode control algorithm of permanent magnet synchronous linear motor based on fuzzy switching gain adjustment

Permanent magnet synchronous linear motors (PMLSM) are widely used in chip packaging, aerospace, CNC machine tools and other related fields due to their high speed and high precision performance and simple structure. However, PMLSM also omits the traditional "ball screw + rotary motor" structure, which makes PMLSM unusually sensitive to external disturbances and internal parameter changes, and poorly adapts to the complex surrounding environment, thus making the system difficult to control accurately and seriously affecting the servo performance. The conventional PID controller has the disadvantages of poor robustness, low accuracy and high coupling, which is difficult to meet the requirements of highspeed and high-precision motion control. The sliding mode variable structure control has strong anti-regulation and anti-disturbance capability, which can significantly enhance the immunity and control accuracy of PMLSM servo system, and reduce the complexity of the system parameter identification, while for the inherent jitter problem of the sliding mode control method, fuzzy control is used to achieve online adjustment of the switching gain of the sliding mode controller based on fuzzy rules, thus greatly reducing the jitter brought by the sliding mode control. And soften the control signal, so that the control system to ensure the strong robustness of the sliding mode control, but also can play a good role in reducing jitter. The PI controller is used for both the speed and current loops, which can quickly offset the disturbance and eliminate the static difference. Finally, the designed control scheme is simulated using MATLAB software. The simulation results verify that the sliding mode control strategy possesses a good suppression effect on the disturbance of the system, and also show that compared with the sliding mode controller and PID controller, the designed fuzzy sliding mode controller can significantly improve the anti-load anti-disturbance capability of the system, which is insensitive to external disturbances and further improves the position control accuracy of the system.