Global convergence of a control system by means of an observer (Q5929420)

Given the nonlinear system \(\dot x= Ax+ Bu+ f(x,u)\), \(y= Cx\), the author proves some sufficient conditions for its global stabilization by using an estimated state feedback law given by the observer \(\dot{\widehat x}=A\widehat x+ Bu+ f(\widehat x,u)- \widetilde K(C\widehat x- y)\), for which the separation principle holds. An example illustrates finally the obtained results.