Design of decentralized PI controller based on Characteristic Ratio Assignment method For TITO process

In this paper, a decentralized PI controller design based on Characteristic Ratio Assignment (CRA) method for Two-Input-Two-Output (TITO) interacting processes is proposed. The design methodology uses decoupler to reduce the interaction between the variables, and the First Order Plus Dead Time (FOPDT) model is obtained for each decoupled subsystem. The independent diagonal controllers are computed for each reduced order FOPDT decoupled subsystem using CRA method. To verify the performance and stability of controllers two simulation examples are presented. To indicate the robustness of the controller the 20% uncertainty is added to the original system and controller performance is evaluated. The performance of the proposed controller is compared with prevalent controllers in the literature.