Quality indices for the autotuning of industrial regulators

With reference to the model-based autotuning of industrial regulators, like PIs or PIDs, this study proposes some indices to evaluate the obtained tuning, including its robustness against model errors, in a more informative and straightforward way with respect to traditional ones such as the phase margin. As a by-product, the proposed indices allow one to express the regulator in alternate ways, so as to ease the possible optimisation-based tuning procedures (a matter just sketched herein owing to space limitations). Some example tuning methods are presented to illustrate the idea. Simulation tests and a laboratory application are reported.