A Fuzzy Sliding Mode Control Based on Model Reference Adaptive Control for Permanent Magnet Synchronous Linear Motor

In order to meet the demands of high-acceleration/high-deceleration and high-precision motion control system, the direct-drive linear motor as the prime motion actuator is widely used in modern motion control systems such as machine tools, ranging from mass transportation to factory automation etc. Among these applications, permanent magnet synchronous linear motor (PMSLM) owing to their simple structure, easy of manufacture and simple control are more frequently used. The advantage of using PMSLM is that it can provide high performance motions with reduced mechanical components, but unlike conventional ball-crew drive, the PMSLM system eliminates the mechanical coupling, rotary-to-linear translators, and reduction gears. Therefore, any change or disturbance in the load will be directly reflected back to the motor and control system, which will cause large deterioration in motion control. In this paper, the model of PMSLM is established firstly; Secondly, a fuzzy sliding mode control based on model reference adaptive control (MRAC) for permanent magnet synchronous linear motor (PMSLM) system, which combines the merits of MRAC, the sliding-mode control and the fuzzy inference mechanism, is proposed. In order to reduce the complex identification of MRAC, the sliding mode control (SMC) is employed in the controller design, which makes the response of the PMSLM system can strictly track the reference mode, and is less sensitive to external load disturbance and the system uncertainties. The introduction of fuzzy control effectively minimized the chattering of SMC. At last, the result of simulation using proposed method is illustrated, which illuminate the proposed method has good tracking characteristic and strong robustness for external load disturbance and the system uncertainty.