a novel approach to designing of chattering-free sliding-mode control in second-order discrete-time systems

In this paper, a chatteringfree slidingmode control is mainly proposed in a secondorder discretetime system. for achieving this purpose, firstly, a suitable control law would be derived by using the discretetime lyapunov stability theory and the slidingmode concept. then the input constraint is taken into account as a saturation function in the proposed control law. in order to guarantee the closedloop system stability, a sufficient stability condition would be addressed in the presence of unstructured uncertainties. hence the states of the discretetime 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 discretetime systems (i.e. regulation and tracking problems). the effectiveness of the proposed method will be verified via numerical examples.