On the Selection of Tuning Methodology of FOPID Controllers for the Control of Higher Order Processes

TL;DR

This paper compares time and frequency domain tuning strategies for fractional order PID controllers applied to higher order processes, introducing a new modeling template and analyzing practical implementation issues.

Contribution

It introduces a new fractional order template for modeling higher order processes and compares various tuning strategies for FOPID controllers.

Findings

Frequency domain tuning advantages demonstrated

Time domain optimal tuning performed with various indices

Practical issues like noise filtration and robustness discussed

Abstract

In this paper, a comparative study is done on the time and frequency domain tuning strategies for fractional order (FO) PID controllers to handle higher order processes. A new fractional order template for reduced parameter modeling of stable minimum/non-minimum phase higher order processes is introduced and its advantage in frequency domain tuning of FOPID controllers is also presented. The time domain optimal tuning of FOPID controllers have also been carried out to handle these higher order processes by performing optimization with various integral performance indices. The paper highlights on the practical control system implementation issues like flexibility of online autotuning, reduced control signal and actuator size, capability of measurement noise filtration, load disturbance suppression, robustness against parameter uncertainties etc. in light of the above tuning methodologies.