Simple PI-PD tuning rules based on the centroid of the stability region for controlling unstable and integrating processes

Abstract

Designing the parameters of a PI-PD controller is very challenging. Consequently, the centroid of the convex stability boundary locus approach was employed to overcome this challenge. Unfortunately, this approach requires deriving several equations for constructing the stability regions of the PI-PD controller. Also, it computes the centroid of the stability region based on visual observations without using any analytical methods. Therefore, it is time-consuming, and the accuracy of its computations is questionable. This paper suggests simple tuning rules for computing the gains of PI-PD controllers based on the centroid of the stability region to handle the limitations of the centroid of the convex stability boundary locus approach. A robustness analysis has also been conducted to gauge the performance of the proposed tuning rules. Moreover, several simulation examples and a real-time application have been considered for evaluating the effectiveness and the feasibility of the suggested approach.