Computation of Stabilizing Decentralized PI Controllers for TITO Systems with Simplified and Inverted Decoupling

In this paper, all stabilizing decentralized PI controllers for Two Input-Two Output (TITO) systems using simplified and inverted decoupling methods are calculated in parameter plane. Two Single Input-Single Output (SISO) systems (independent subsystems) are determined from simplified and inverted decoupling configurations and stability regions of both subsystems are calculated in an illustrative example. Test points selected from different regions to examine stability of both subsystems are used to design decentralized PI controllers. Using selected points from intersection of both stability regions provide a limited region to search the controller parameters guaranteeing the stability for both output of TITO systems. In addition to this advantage, a pair of controller parameters with the same values may be sufficient for both decentralized PI controllers.