A PID tuning approach to find the optimal compromise among robustness, performance and control effort: implementation in a free software tool

Abstract

A PID tuning approach is presented to achieve an optimal compromise among robustness, performance and control effort in terms of measurement noise amplification. The tuning strategy is based on the concept of fixed robustness tuning line, in which the derivative filter parameter is a key point in finding the compromise between control effort due to noise and performance. The approach allows to find the controller that optimises the performance while fulfils a prescribed robustness constraint and a permitted control effort due to noise. The tuning procedure has been implemented in a software tool that can be freely downloaded from https://sites.google.com/a/uji.es/freepidtools/. The robustness can be defined in three different ways, involving the phase margin, the gain margin and the sensitivity peak. The performance can be defined in several ways, including the IAE, ITAE, ISE and other. Some examples show the validity of the approach and the use of the tool.