en 3-Nonlinear Control Systems Nonlinear Control Systems Research Paper Research Paper <div style="text-align: justify;"><span style="font-family:times new roman;"><span style="font-size:14px;"><span style="color:#000000;">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 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 the 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 numerical examples.</span></span></span></div> Sliding-Mode Control,Discrete-Time System,Chattering-Free and Lyapunov Stability, 453 461 http://ijeee.iust.ac.ir/browse.php?a_code=A-10-2842-1&slc_lang=en&sid=1 V. Ghaffari vghaffari@pgu.ac.ir 180031947532846008281 180031947532846008281 Yes Department of Electrical Engineering, School of Engineering, Persian Gulf University, Bushehr, Iran.