Feedback control of a permanent magnet stepper motor

This paper is devoted to the feedback control problem of a permanent magnet stepper motor. Under some approximations, a simple linear model is firstly derived. This model is then used to design a controller. Two control techniques are proposed and are shown to guarantee good robustness properties to overcome the effect of nonlinearities and parameter variations. The first technique consists in using H_∞ robust control. The second technique is based on sliding mode control. Simulation results have shown the usefulness and the advantages of the proposed controllers