Robust observer-based sliding mode control for nonlinear uncertain singular systems with time-varying delay and input non-linearity

Abstract

This article focuses on the output-feedback sliding mode control design problem for a class of non-linear singular systems with time-varying delay and uncertainties. More precisely, we aim to design an adaptive observer-based sliding mode controller for such class of systems. The appealing aspects of this approach include (i) based on an appropriate Lyapunov–Krasovskii functional, a delay-dependent sufficient condition is established to guarantee the autonomous singular system to be admissible and (ii) by constructing an observer to estimate the system states, an integral sliding mode surface and an adaptive observer-based sliding mode controller are designed to ensure the closed-loop singular system to be insensitive to all admissible uncertainties and satisfies the reaching condition. The developed results are tested on three representative examples to illustrate the theoretical developments.