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

• Published in: European journal of control Vol. 49; pp. 15 - 25
• Main Author: Kchaou, M.
• Format: Journal Article
• Language: English
• Published: Philadelphia Elsevier Ltd 01.09.2019; Elsevier Limited
• Subjects: Adaptive control; Adaptive systems; Control systems design; Controllers; Delay; Design specifications; Fault diagnosis; Input non-linearity; Linearity; LMI; Motivation; Nonlinear control; Nonlinear systems; Nonlinearity; Observer; Ordinary differential equations; Output feedback; Robust control; Singular systems; Sliding mode control; Time-varying delay; Uncertainty; LMI; Singular systems; Time-varying delay; Sliding mode control; Input non-linearity; Observer
• ISSN: 0947-3580; 1435-5671
• DOI: 10.1016/j.ejcon.2018.12.007

•An observer-based SMC is designed for a non-linear singular system with time-varying delay and non-linear input.•A new sufficient and less conservative condition is established such that the sliding mode dynamics is admissible.•An adaptive control law is designed to adapt the parameters of the NL input slope as well the bounds of perturbations. 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.