Robust stability bounds for discrete system reduced-order dynamic compensator designs

Stability robustness is discussed for optimal reduced-order dynamic compensator designs for linear discrete systems. Robust stability of the controller design in the presence of perturbations (modeling errors) of the system matrices is investigated. These results are based on a recently developed bound on elemental (structured) time-varying perturbations of an asymptotically stable linear time-invariant discrete-time system. The system and compensator equations are combined into an augmented homogeneous state equation. The augmented perturbation matrix is determined, and the perturbation bound is applied. Simple examples illustrate these results.<>