Self-tuning fuzzy PI+PD controller for PMSM servo system

In order to overcome the parameter uncertainties, enhance the fast tracking performance of PMSM servo system, a self-tuning fuzzy PI+PD controller is proposed first in this paper. The self-tuning fuzzy PI+PD controller is fast; computing on-line easily and can reduce stability error, especially fitting for application in the speed control of the PMSM servo system. Then an observer is adopted to observe load torque and the observed load torque is also feedforward through a weighting factor to compensate the load torque disturbance. To demonstrate the advantages of the fuzzy PI+PD controller and the load torque feedforword control, the simulation was executed in this research. The simulation results show that the proposed control scheme not only enhances the fast tracking performance, but also increases the robustness of the synchronous motor drive system.