Fuzzy adaptive PID controller using frequency techniques

A proper tuning method for PID control algorithms is one of the well accepted ways to save control energy as well to achieve both stability and performance robustness under hard environmental situations, like system parameter set points and load variations in most common industrial processes. A method to adjust dynamically the PID controller parameters is presented. Such method comprises two main issues: identifying the mathematical model (phase and magnitude) using FFT procedures associated with the use of a fuzzy rule based diagnostic procedure of the dynamic characteristics of the controlled system, and consequently setting the proper PID parameter values using the frequency techniques.