Control of permanent magnet AC servo motors via fuzzy reasoning

A control method which drives the permanent magnet AC servomotor without the detection of the rotor position by an absolute position transducer such as an absolute encoder or a resolver is described. An incremental encoder is only coupled to the motor shaft in order to obtain the information for electrical commutation, motor speed, and motor position. A fuzzy algorithm based on the min-max compositional rule of inference is developed for the estimation of the absolute rotor position which is essential to electrical commutation. The proposed control algorithm was implemented on a microprocessor control system. Experimental results show that the proposed control system can be effectively used to control the permanent magnet AC servo motor with high dynamic performance