Fuzzy logic enhancement of antiwindup PID control for servo systems

The enhancement of the conventional antiwindup PID control with a simple fuzzy logic block is presented. The developed combination of fuzzy logic and conventional control shows considerable improvement in stability of the closed-loop system, set-point tracking, disturbance rejection and robustness to improper PID controller tuning. The fuzzy logic block has only 4-rules and acts as an independent control unit which functionally combines proportional and derivative actions in a nonlinear fuzzy fashion. It can be added to the installed PID controllers as a separate block and can be efficiently applied to processes with significant actuator nonlinearity having no deadtime. The Validity of the design is tested in experiments.