A novel approach to the nonlinear H∞ regulator problem

This paper presents a theoretical approach to the nonlinear H_∞ regulator problem. From a fixed point theoretic point of view, it is shown that the nonlinear H_∞ state feedback law is characterized as a fixed point of a mapping and its suboptimal solution can be obtained using standard optimization techniques. A simple numerical example is included to verify that the resulting feedback law actually enhances the robustness of a system.