Abstract
This paper investigates the observer design problem for a class of nonlinear systems. The square integrable noise signal to the nonlinear systemsis is considered. It is shown that such an observer gain can be obtained by a solution of Riccati inequality that the observer error system is asymptotically stable with noise attenuation. It is also shown that the observer gain matrix obtained in this paper is equivalent to the solution of H∞ problem with constant scaling matrix.
