Study of phase/frequency-locked servo system by fuzzy control technique

A novel fuzzy pulse pump controller (FPPC) is proposed to achieve a fuzzy-control-based phase/frequency-locked servo system (FC-PFLS). Three sets of membership functions are constructed according to the locking performance indexes, position error, discrete time change of position error, and the output crisp value. A set of fuzzy rules is built in the fuzzy-logic controller (FLC) to process the detected position error and provide a suitable pump voltage for the motor drives. The FPPC can fuzzically provide the motion profiles, such as acceleration, constant, and deceleration for the motor in a fast response without overshoot and with nearly zero steady-state error. The physical model and the linearized model of the presented FC-PFLS are built. A design example of realizing an X-Y mode FC-PFLS is constructed. The experiments of the FC-PFLS comparing with DPPLS and SPSCS are conducted. In comparison with the DPPLS, the acquisition times of the presented FC-PFLS for the short, middle and long distance servos are improved by 30%, 53% and 57%, respectively. For the SPSCS, the acquisition times are improved by 30%, 14%, and the same, respectively.