Design of Fuzzy-IMC PID Controller for TITO Process with Time Delay

In this paper, we design a multi-loop IMC-PID controller based on fuzzy tuning for a two input two output (TITO) process with time delay. Initially, a decouple is designed to minimize the loop interaction. After decoupling, each decoupled subsystem is considered to be a SISO process having first order plus dead time (FOPDT) model and thereafter IMC-PID controller is designed for them. In the proposed scheme an IMC-PID controller is designed by using first order filter and the proper controller structure is obtained by selecting the appropriate value of closed loop time constant (λ) with the help of a simple fuzzy rule base. The performance improvement of the proposed fuzzy-IMC PID controller is observed due to the set point change as well as load disturbance and compared with other multi-loop PID controllers reported in leading literature.