Abstract
This paper treats with the issue of disturbances, noises, uncertainties and sensor faults estimation for uncertain nonlinear systems whose nonlinearity satisfies the Lipschitz condition. The general idea of this approach is to establish an augmented model by supposing the sensor faults as an auxiliary state. In order to ensure the robustness of the proposed observer and guaranteed the convergence conditions, we have used the Lyapunov theory and the H-infinity criterion. So as to illustrate the design approach a control system of satellite attitude is presented.