Analytical Triangular Decoupling Internal Model Control of a Class of Two-Input, Two-Output (TITO) Systems with Delays

Abstract

The Decoupling Internal Model Control (DIMC) technique is modified to achieve triangular decoupling for a class of two-input, two-output systems with delays. The closed-loop transfer function matrix that guarantees stability and triangular decoupling within the IMC framework is mathematically developed, and the corresponding centralized decoupling internal model controller calculated for systems with delays and right-half-plane zeros. The shifting of inverse responses and interactions is achieved to a single least-desired output so that for non-minimum-phase (NMP) two-input, two-output (TITO) systems with delays, one output has some delay but has no interacting behaviour or inverse response behaviour, while the less-desired output has substantial interaction and inverse response behaviour, with asymptotic tracking of setpoints for both outputs. A simulation example shows the effectiveness of the proposed method.