Output feedback ultimate boundedness control for uncertain dynamic systems with structured uncertainty

This paper considers the problem of constructing a linear dynamic output feedback controller such that when applied to a given uncertain system, the resulting closed-loop uncertain system is globally uniformly ultimately bounded. The uncertain systems under consideration contain multiple uncertain nonlinearities, each subject to a non-homogeneous norm bound condition. The approach taken is to apply standard results from H-infinity control theory to the problem. The main result is a sufficient condition for the existence of such a controller. This condition is given in terms of the existence of suitable solutions to a pair of parameter-dependent algebraic Riccati equations.