Abstract: A new robust adaptive sliding-mode tracking scheme based on the concept of variable structure control (VSC),is proposed with respect to bounded disturbances.A key feature of this scheme is that the dead zone is used but no knowledge of the upper bounded on the disturbances is required a priori.The controller is shown to be robust with respect to the unknown but bounded disturbance and  the global stability of the scheme is established.

Key words: variable structure control (VSC), uncertain, minimum-phase