Abstract:In view of the influence of nonlinearity, model inaccuracy and complex operating conditions on the control accuracy of the electromagnetic levitation system, an improved sliding mode variable structure control strategy was proposed. Through the modeling, analysis and design of the electromagnetic levitation system, a segmented variable speed approach law is designed based on the position outer loop controller based on the sliding mode variable structure control method and the current inner loop controller based on the PI regulator, which reduces the tracking error of the suspension gap and the jitter of the control system, and introduces the velocity state quantity to reduce the excessive approach velocity of the control system in the early stage of the sliding mode. The simulation and hardware experimental results show that after adopting the improved sliding mode variable structure control strategy, the adjustment time of the system is reduced by 60%, the overshoot is reduced by 77%, and the system has smaller steady-state error and jitter, and has stronger anti-disturbance ability under the same interference situation. This method can not only effectively improve the control performance of electromagnetic levitation system, but also has a good reference value for other nonlinear control systems.