“…Most of the robust stabilization results and investigations focus on the problems of parametric uncertainties or model errors, see, e.g., [11] where the problem of local robust stabilization by means of time-varying control laws have been studied; [7], where a similar problem has been addressed using the class of discontinuous control laws introduced in, e.g., [1] and [6], where several types of hybrid control laws have been used to achieve local robustness against unknown parameters or unmodeled dynamics. On the other hand, the fundamental problems of robustness in the presence of sensor noise, external disturbances and actuator disturbances have been only partially addressed; see, e.g., [3] and [17].…”