Discrete Sliding Mode Control Based High-precision Flux tracking of Reluctance Actuator

In linear reluctance actuator, the rate-dependent hysteresis nonlinearity is an essential characteristic, and it pose great challenge for its application in the high precision positioning. In this paper, the rate-dependent hysteresis of the linear reluctance motor is described by Hammerstein structure. In order to achieve the high-precision flux tracking, a new control method, composed by sliding mode control and inverse model compensation, is applied. In the proposed control strategy, an inverse model compensator is used to eliminate the hysteretic nonlinear part of the system, and transforming the system into a linear system with an inverse bias. Further, a sliding mode controller is designed to handle linear dynamics, unmodeled dynamics and disturbances in the system. Finally, the simulation of a protype of linear reluctance actuator is carried out to verify the effectiveness of the proposed control strategy. From the simulation results, we can conclude that the Hammerstein structure can effectively characterize the rate-dependent hysteresis nonlinearity of the reluctance actuator, and the proposed control method can achieve outstanding performance.