Abstract
This paper presents an approach to design robust nonlinear H∞ controller without any solution of Hamilton-Jacobi inequality or equations. The uncertainty is assumed to be described by nonlinear function on state variable, which is unknown but gain bounded. It is shown that if the zero dynamics of the given system is stable or stabilizable, then the Lyapunov function ensuring robust stability of the overall system and the state feedback controller with changes of the coordinate can be designed by recursive algorithm based on the Lyapunov function of zero dynamics.