Global robust H-infinity control of a class of nonlinear systems

This paper considers the problem of robust disturbance attenuation for a class of systems with both Lipschitz bounded and nonlinear uncertainties. The nonlinear uncertainty is assumed to satisfy a 'matching condition' and bounded by a known nonlinear function. The Lipschitz bounded one could be with any mismatched uncertainties. We develop a Riccati equation approach for designing a state feedback controller such that the so-called L(2)-gain from the exogenous input noise to the state is minimized or guaranteed to be no larger than a prescribed value.