Reduced-order dynamic compensator design for stability robustness of linear discrete-time systems

A reduced-order dynamic compensator design for stability robustness of linear discrete-time systems is presented. The controller determination includes a stability robustness component in addition to the standard quadratic state and control terms in the performance criterion. The robustness component is based on a recently developed unstructured perturbation bound for time-varying perturbations using the Lyapunov approach. The controller design is based on the parameter optimization technique. The resulting controller involves the solution of five algebraic matrix equations, four of which are discrete-time Lyapunov matrix equations. These equations can be solved using gradient-based algorithms. An example illustrates the results