Recent developments in nonlinear H∞ control

Abstract

The last few years have seen a number of exciting developments in the area known as nonlinear H ∞ control. The aim of work in this area is to design robust controllers for nonlinear systems using generalizations of the highly successful H ∞ methods used in linear systems theory. In this paper we give an overview of the problems and methods of nonlinear H ∞ control, including the H ∞ norm ( L 2 gain), stability, information state methods, and factorization. The development of this area has involved important contributions from a number of researchers using a variety of techniques. In addition, H ∞ control has spurred renewed interest in some traditional areas such as differential games, dissipative systems, and stochastic (risk-sensitive) control.