Evaluation and redesign of decouplers for TITO processes using relay experiment

In this paper the decoupling control of two-inputs two-outputs (TITO) processes using a simplified dynamic decoupler is considered. A frequency-domain identification technique that uses a relay experiment to estimate a first-order plus dead-time (FOPDT) TITO model is presented. The resulting FOPDT TITO model is accurate around at the frequency of interest and is used to design a simplified decoupler. A new decoupler evaluation and redesign method to reach effective decoupling at the frequency of interest is proposed. Simulation examples are used to illustrate the method.