REAL STRUCTURED SINGULAR-VALUE SYNTHESIS USING THE SCALED POPOV CRITERION

The scaled Popov criterion is used to derive an upper bound for the wo rst-case H-2 norm over a set of linear, time-invariant, norm-bounded, block-structured parameter perturbations. This upper bound provides th e basis for a robust controller synthesis procedure that minimizes the upper bound and guarantees asymptotic stability of the closed-loop sy stem for ail real parameter perturbations in the specified set. Numeri cal examples demonstrate the tradeoff between achievable H-2 performan ce and guaranteed robustness to real parameter perturbations as web as the reduction in conservatism due to the scaling matrix. Controllers designed for flexible structures using this technique are shown to hav e similarities to maximum entropy controllers designed for the same ex amples.