Adaptive sliding control of precision permanent magnet linear motors
ZHAO Hu~1, LI Rui~2 (1. Department of Control Science and Technology, Huazhong University of Sci. & Tech.,Wuhan 430074,China;2. Management School, Huazhong University of Sci. & Tech.,Wuhan 430074,China)
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 than 10 μm is achieved which is a much better performance compared to conventional PID control.