Design of multi-loop IMC-PID controller for TITO process with dead time

Abstract

This paper describes the performance of PID controllers based on internal model control (IMC) technique for two input and two output (TITO) process with dead time. Centralized inverted decouplers are intended to minimize the interactions between the loops. With appropriate choice of decoupler each decoupled subsystem seems to be first order plus dead time (FOPDT) process in nature. Two separate IMC-PID controllers are designed for each decoupled subsystem. An overall improved response is found from both the loops by using first order filter and suitable choice of close-loop time constant. Performance based comparison with other IMC technique substantiates the competence of the proposed method.