Design of decentralized PI controller for two-input, two-output processes

This paper addresses the decentralized proportional - integral (PI) controller design for two-input, and two-output (TITO) processes. The controller design is based on the nondimensional analysis. Selection of proper controller is difficult task for multivariable processes because of the interacting dynamic behavior of the process variables in which change in one manipulated variable affects the other controlled variables. In this study, decentralized PI controller with decoupler is selected and designed on the basis of process transfer function matrix and decoupler matrix. Tuned parameters of PI controller are found by non-dimensional tuning (NDT) method (2006). For better understanding, MATLAB simulation results are presented. For showing effective performance of NDT method, the results are compared with Astrom-Hagglund tuning rule (1995), Fruehauf et al. tuning rule (1993) and biggest log modulus tuning (BLT) method (1986).