Dynamic Output Feedback H∞ controller design for a class of continuous-time nonlinear systems

This paper is concerned with the dynamic output feedback H_∞ controller design for a class of nonlinear continuous-time systems with nonlinear uncertainties. The resulting design is such that the closed-loop system not only is asymptotically stable, but also meets the prescribed H_∞ norm constraint. What´s worth mentioning is that the paper proposes a new method which combines S-procedure approach to solve the nonlinear uncertainties. A sufficient condition for the existence of such a controller is obtained by using appropriate Lyapunov functional and linear matrix inequality (LMI) technique. In addition, based on this result, a convex LMI-based optimization method is developed to optimize the H_∞ performance. A numerical example is provided to demonstrate the effectiveness of the proposed design.