Browsing by Author "Zribi M."

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Guaranteed cost observer-based control of uncertain time-lag systems
(Elsevier Ltd, 2003) Mahmoud M.S.; Zribi M.; October University for Modern Science and Arts; Amer Street; Mesaha Square; Dokki-Giza; Egypt; Department of Electrical Engineering; College of Engineering and Petroleum; Kuwait University; P.O. Box 5969; 13060 Safat; Kuwait
This paper investigates the design of robust observer-based controllers for a class of uncertain linear time-lag systems. The uncertainties are assumed to be norm-bounded. We extend the previous results on quadratic-cost control to the case of observer-based control for uncertain systems with unknown state and input time-lags. By introducing an appropriate definition of quadratic stability for uncertain time-lag systems, it is shown that observer-based controllers can be constructed via solutions of linear-matrix inequalities. A simulation example is given to illustrate the theoretical developments. 2002 Elsevier Science Ltd. All rights reserved.
Passive control synthesis for uncertain systems with multiple-state delays
(2002) Mahmoud M.S.; Zribi M.; Faculty of Engineering; MSA University; Amer Street; Mesaha Square; Dokki; Egypt; Department of Electrical and Computer Engineering; Kuwait University; P.O. Box 5969; Safat 13060; Kuwait
In this paper, we investigate the robust passivity synthesis problem for a class of uncertain systems with multiple state delays. Both the delay-independent and the delay-dependent cases are treated. In each case, a sufficient condition for which the uncertain multi-state delay system is robustly stable and strictly passive (SP) for all admissible uncertainties is provided in terms of a linear matrix inequality. Then, we propose a dynamic feedback design methodology based on either state measurements or output measurements. For both types of controllers, it is proven that the closed-loop uncertain time-delay system is asymptotically stable and SP for all admissible uncertainties. A detailed simulation example is given to illustrate the theoretical developments. � 2002 Published by Elsevier Science Ltd.
Robust control of a class of nonlinear uncertain time-delay systems
(2002) Mahmoud M.S.; Zribi M.; MSA University; Amer Street; Mesaha Square; Dokki; Egypt; Department of Electrical and Computer Engineering; Kuwait University; PO Box 5969; Safat-13060; Kuwait
The robust ?? control problem of a class of uncertain nonlinear time-delay systems is considered in this paper. The parametric uncertainties are real time-varying and norm-bounded and the nonlinearities are state-dependent and cone-bounded. The delays are time-varying and bounded both in the state and at the input. We provide sufficient conditions for robust stability and robust state-feedback stabilization with disturbance attenuation. Then, we establish sufficient conditions for designing a linear dynamic observer-based controller which stabilizes the uncertain time-delay system and guarantees an ??-norm bound constraint on the disturbance attenuation for all admissible uncertainties and unknown delays. Several examples are simulated to illustrate the developed theory. � 2002 Taylor & Francis Ltd.