Stability analysis of a predictive PI controller

Abstract

Industrial processes are typically regulated by PID controllers. However, for dead time dominating systems, the PID controller is not very applicable. More than two decades ago, a predictive PI controller was introduced for improving control performance of processes having dominating dead times. The predictive PI controller is rather simple to use and implement, intuitively appealing and applicable to delay dominating systems. Yet, its stability analysis has not received attention that it should have, nor its tuning which has been given only one guideline that was presented in the original paper. In this paper, the stability of the predictive PI control loop is analysed in details not only for accurate process models having no model mismatch but also processes having modelling errors and uncertainties. Consequently, some preliminary guidelines for tuning are given.