A Novel Approach to Designing of Chattering-Free Sliding-Mode Control in Second-Order Discrete-Time Systems

• Main Author: V. Ghaffari
• Format: Article
• Language: English
• Published: Iran University of Science and Technology 2019-12-01
• Series: Iranian Journal of Electrical and Electronic Engineering
• Subjects: sliding-mode control; discrete-time system; chattering-free and lyapunov stability.
• Online Access: http://ijeee.iust.ac.ir/article-1-1351-en.html

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.