Experimental verification of a hybrid fuzzy control strategy for a high-performance brushless DC drive system

This paper describes the design and experimental verification of a hybrid fuzzy control system for a high-performance brushless DC motor drive. Both the design of the fuzzy controller and its integration with the proportional-integral (PI) in a global control system are discussed. The principle, of the proposed control system is to use a PI controller, which performs satisfactorily in most cases, while keeping in the background, a fuzzy controller, which is ready to take over the PI controller when severe perturbations occur. Strategies of the switching control for the hybrid controller is such that the fuzzy controller is activated whenever the resident system exhibits an oscillatory and/or overshoot behavior. Thus, the PI and fuzzy controllers can be managed to take advantage of their positive attributes. Performance of the hybrid fuzzy-PI controller is evaluated through a laboratory implementation. The laboratory implementation is based on a linguistic fuzzy controller whose design is derived from the expert knowledge gained during disturbances. Experimental results have shown excellent tracking performance of the proposed control system, and have convincingly demonstrated the usefulness of the hybrid fuzzy controller in high-performance drives with uncertainties.