D-STABILITY BOUND ANALYSIS FOR DISCRETE MULTIPARAMETER SINGULARLY PERTURBED SYSTEMS

The D-stability (i.e., the stability in the sense that all the poles o f a system are lying inside the disk D(alpha, r)) problem for discrete multiparameter singularly perturbed systems is considered in this bri ef, A two-stage method is first developed to analyze the stability rel ationship between the discrete multiparameter singularly perturbed sys tems and their corresponding reduced systems. An upper hound of the si ngular perturbation parameters is then derived such that the D-stabili ty of the reduced systems implies that of the original systems, provid ed that the singular perturbation parameters are small enough to be wi thin this bound. This fact enables us to investigate D-stability of th e original systems by establishing that of their corresponding reduced systems.