Sliding Mode Prediction Control Based on Improved Reference Trajectory for Active Magnetic Bearing

The sliding mode prediction variable structure control design for uncertain discrete-time systems was studied.To solve the chtterin g problem caused by general sliding mode control in active magnetic bearings control,a new reaching law for sliding model control systems is proposed,which overcomes the shortcomings of the exponential rate reaching law.The modified reaching laws will not only have the advantage of original one,but also eliminate chattering effectively.This paper uses the new reaching law being the reference sliding mode trajectory,and uses a nominal model to predict future sliding mode value,conducts receding optimization,makes feedback correction.The modified algorithm is applied to the active magnetic bearings.The simulation results show that the disadvantage of chatting can be effectively reduced by using the new method,the rotor's quick adjusting and steady levitating are achieved,and the method not only enhances the fast tracking performance,but also has a stronger robustness against parametric variations and resistance disturbances.