Comparison of fuzzy logic based tuning methods for PID controllers

In this paper, different methods based on fuzzy logic for the tuning of Proportional- Integral-Derivative (PID) controllers are analyzed and compared. The easiness of implementation and the effectiveness of the examined control schemes for a wide range of processes is discussed. Comparisons are made with respect to performances in the set-point following (step response) where the parameters of the employed fuzzy inference systems have been optimally selected by means of genetic algorithms. Moreover, step signals have also been applied as a load disturbance in order to test the load disturbance attenuation capabilities and to verify if stability problems may arise.