精密永磁直线电机的自适应滑模控制

与一般的回转电机相比,永磁直线电机在需要实现直线运动的应用中有定位精度高、速度快等优点,但是,直线电机对扰动和系统参数变化很敏感,而且由于摩擦力和推力脉动使系统具有明显的非线性.针对这些问题,提出了一种自适应控制器的设计方案,并给出该设计的永磁直线电机的数学模型.该方案用一个滑动模态的控制输入补偿摩擦力和推力脉动.理论分析和仿真实验结果表明,自适应控制器获得的最大误差小于10 μm,其性能远远优于经典的PID控制器.

Adaptive sliding control of precision permanent magnet linear motors

Permanent magnet linear motors offer several advantages over their rotary counterparts in many precision manufacturing applications requiring linear motion, which can achieve a much higher speed and a higher position accuracy. However, linear motors are more sensitive to disturbance and parameter variations. Furthermore, the linear motor systems are subject to significant nonlinear effects due to friction and force ripple. An adaptive control design for permanent magnet linear motors was described to solve these problems, and the mathematic model for a PMLM (Permanent Magnet Linear Motor) is presented on which the control design was given. A sliding mode control input is used to compensate for frictional and ripple forces. Theoretical analysis and full experimental results are provided. A maximum error of less than10 μm is achieved which is a much better performance compared to conventional PID control.