H∞ Output Feedback Control for a Class of Nonlinear Systems

This paper proposes a convex approach to the H-infinity output feedback problem for a class of uncertain nonlinear systems in which the system matrices are allowed to be rational functions of the state and uncertain parameters. We derive sufficient linear matrix inequality (LMI) conditions for designing full-order output feedback controllers that assure the regional stability of the nonlinear system for a given energy bound on the disturbance input in the sense that the state stays inside a given region, and also minimize an upper-bound on the L2-gain of the input-output operator for the class of admissible disturbance signals. Numerical examples are used to illustrate the proposed methodology.