Valiollah Ghaffari

In this paper, a chattering-free sliding-mode control is mainly proposed in a second order discrete-time system. For achieving this purpose, firstly, a suitable control law would be derived by using of the discrete-time Lyapunov stability theory and the sliding-mode concept. Then the input constraint is taken into account as a saturation function in the proposed control law. In order to guarantee the closed loop system stability, a sufficient stability condition would be addressed in presence of unstructured uncertainties. Hence the states of the discrete-time system are moved to a predefined sliding surface in a finite sampling time. Then the system states are asymptotically converged to the origin through the sliding line. The suggested SMC is successfully applied in two discrete-time systems (i.e. regulation and tracking problems). The effectiveness of the proposed method will be verified via the numerical examples.