Performance optimization of PID controllers using fuzzy logic

The controllers extensively used in the control industry are of the PID type. The performance of these controllers depends on the values of the Proportional, Integral and Derivative, (P, I and D) parameters. Tuning of these parameters is a tedious task which requires experience and expert knowledge of the calibration engineer. This paper proposes a fine tuning method for these parameters using fuzzy logic. The PID Controller is initially tuned using Ziegler Nichols Closed Loop method and Relay auto tuning and then finely tuned using fuzzy logic. The output response is drastically improved when fuzzy logic is used for fine tuning and the results validating the same are simulated using MATLAB/Simulink.