Identification and robust tracking control of a single-phase rotary motor with halbach permanent magnet array design

The single-phase electromagnetic motor with the circular permanent magnet Halbach array design, has advantage of large force constant compared with its 3-phase counterpart, if the rotation is within 60 degrees range from its neutral position. However, to authors´ best knowledge, no existing literature mentions on tracking control application using such a single phase rotary motor, probably due to its angular dependent force sensitivity. This paper first models a typical two-pole single phase rotary motor with Halbach circular array, with consideration of back-EMF, friction torque and position dependent characteristic. Followed by this, a dual-relay configuration is applied to closed-loop identification of model-parameters by limit cycle experiments. Later, a composite controller, composes of a model-based controller, a time-delay controller and a sliding mode controller, is capable to achieve the high-speed tracking of reference trajectory with presentation of model uncertainty and disturbances. Simulation based on the actual design parameters shows the practical appeal of the proposed approach.