Title: New sliding mode observer design method for a class of time-varying delay systems with matched and unmatched uncertainties

Authors: Iskander Boulaabi; Fayçal Ben Hmida; Anis Sellami

Addresses: Research Laboratory LISIER, Higher National Engineering School of Tunis, University of Tunis, Tunisia ' Research Laboratory LISIER, Higher National Engineering School of Tunis, University of Tunis, Tunisia ' Research Laboratory LISIER, Higher National Engineering School of Tunis, University of Tunis, Tunisia

Abstract: This paper concerns with a new design method of a sliding mode observer (SMO) for a class of linear uncertain time-varying delay systems. This new method builds on the current SMO design methods for linear uncertain systems, but it gives a robust state estimation in spite of the presence of both uncertainties and time delay. In the meantime, the considered uncertainties are matched and unmatched, and the time delay is constant and affects the state system. The basic idea in the design consists to combine the SMO concept with a Lyapunov-Krasovskii functional which is numerically tractable via linear matrix inequalities (LMIs) optimisation. This design approach ensures the stability of the system estimation error. In addition, the dynamic properties of the observer are analysed and the reachability condition is satisfied. A DC-8 aircraft system is included to illustrate the validity and the applicability of the proposed approaches.

Keywords: sliding mode observer; SMO; time delay; uncertain; linear matrix inequalities; LMIs; aircraft system.

DOI: 10.1504/IJSCC.2024.143858

International Journal of Systems, Control and Communications, 2024 Vol.15 No.4, pp.349 - 366

Received: 15 Dec 2023
Accepted: 02 Aug 2024
Published online: 10 Jan 2025 *

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