Discrete sliding mode control using uncertainty and disturbance estimator

Abstract

This paper details design and validation of δ-operator based discrete sliding mode control (DSMC) algorithm for uncertain dynamical systems. A unifying sliding condition is used and control is designed for model-following. The control law is synthesized by estimating states and uncertainties using UDE. The UDE used in combination with SMC makes it possible to use a smooth control without having to employ a smoothing approximation. The proposed control affords control over the magnitude of sliding width for a given sampling period. The stability of system is assured using Lyapunov criterion. The control design is validated on a benchmark motion control problem.