IMC-based controller design for MIMO systems

In this paper, a design method for multivariable controllers in a unit output feedback configuration is presented. With the internal model control (IMC) principles, the objective closed-loop transfer functions are characterized in terms of process unavoidable non-minimum phase elements. A multivariable controller for best achievable performance is obtained with block diagram analysis and model reduction. The proposed design provides users with an option to choose between PID and high-order controllers to suit applications better. Stability and robustness are analyzed and simulation is provided to substantiate the superior performance of the proposed method.