Mixed H/sub 2//H/sub /spl infin// optimal guaranteed cost control of uncertain linear systems

The mixed H/sub 2//H/sub /spl infin// guaranteed cost control problem via state feedback control law is considered in this paper for linear systems with norm-bounded parameter uncertainty. Based on the linear matrix inequality (LMI) approach, sufficient conditions are derived from the existence of guaranteed cost controllers which guarantee not only a prespecified H/sub /spl infin// disturbance attenuation level on one controlled output for all admissible parameter uncertainties, but also the worst case H/sub 2/ performance index on the other controlled output to be no more than a specified bound. Furthermore, a convex optimization problem is formulated to design an optimal H/sub 2//H/sub /spl infin// guaranteed cost controller.