2020 |
Gasmi, Noussaiba; Boutayeb, Mohamed; Thabet, Assem; Aoun, Mohamed; Frej, Ghazi Bel Haj Robust sliding window observer-based controller design for Lipschitz discrete-time systems Conférence vol. 53, no. 2, 2020, (Cited by: 1; All Open Access, Bronze Open Access). Résumé | Liens | BibTeX | Étiquettes: Controllers, Digital control systems, Discrete – time systems, Discrete time control systems, H ∞ criterion, Lipschitz, Lipschitz non-linearity, Observer-based, Observer-based controllers, Observer-based stabilization design, Performance, Sliding Window, Sliding window approach, Stabilization, Uncertain systems @conference{Gasmi20205970b, The aim of this paper is to develop a new observer-based stabilization strategy for a class of Lipschitz uncertain systems. This new strategy improves the performances of existing methods and ensures better convergence conditions. The observer and the controller are enriched with sliding windows of measurements and estimated states, respectively. This technique allows to increase the number of decision variables and thus get less restrictive and more general LMI conditions. The established sufficient stability conditions are in the form of Bilinear Matrix Inequality (BMI). The obtained constraint is transformed, through a useful approach, to a more suitable one easily tractable by standard software algorithms. Numerical example is given to illustrate the performances of the proposed approach. Copyright © 2020 The Authors. This is an open access article under the CC BY-NC-ND license |
2018 |
Gasmi, Noussaiba; Boutayeb, Mohamed; Thabet, Assem; Aoun, Mohamed Enhanced LMI conditions for observer-based H∞ stabilization of Lipschitz discrete-time systems Article de journal Dans: European Journal of Control, vol. 44, p. 80 – 89, 2018, (Cited by: 8). Résumé | Liens | BibTeX | Étiquettes: Control nonlinearities, Controller designs, Controllers, Decoding, Delayed state, Digital control systems, Discrete – time systems, Discrete time control systems, Linear matrix inequalities, Linear matrix inequality approach, Lipschitz systems, Noise analyse, Observer-based controller design, Observer-based controllers, Robustness (control systems), Sliding Window, Sliding window of measurement @article{Gasmi201880b, This paper deals with H∞ observer-based controller design for a class of discrete-time systems with Lipschitz nonlinearities. Usually, the observer-based control synthesis for the considered class of systems leads to the feasibility of a Bilinear Matrix Inequality (BMI). Since, solving a BMI constraint has been an NP-hard optimization problem, then linearizing this constraint to get a convex one is an interesting issue because Linear Matrix Inequalities (LMIs) are easily tractable by numerical softwares (LMI Toolboxes,.). Hence, the aim of this paper is to develop a new Linear Matrix Inequality (LMI) condition, ensuring the H∞ asymptotic convergence of the observer-based controller. Due to the introduction of a slack variable technique, the usual BMI problem is equivalently transformed to a more suitable one, which leads to less conservative and more general LMI condition compared to the existing methods in the literature. Conjointly to the slack variable technique, the Lipschitz property and the Young’s relation are used in a reformulated way to obtain additional decision variables in the LMI. In the aim to further relax the proposed LMI methodology, sliding windows of delayed states and measurements are included in the structures of the controller and the observer, respectively. The obtained LMI is more general and less conservative than the first one, which can be viewed as a particular solution. To show the effectiveness and superiority of the proposed methodology, some numerical examples and comparisons are provided. © 2018 European Control Association |
Gasmi, Noussaiba; Boutayeb, Mohamed; Thabet, Assem; Aoun, Mohamed H∞ Observer-Based Controller for Lipschitz Nonlinear Discrete-Time Systems Conférence 2018, (Cited by: 0). Résumé | Liens | BibTeX | Étiquettes: Bilinear matrix, Controllers, Design Methodology, Design problems, Digital control systems, Discrete time control systems, Linear matrix inequalities, Lipschitz property, Nonlinear discrete-time systems, Observer-based, Observer-based controllers, Robustness (control systems), Slack variables @conference{Gasmi2018771b, Within the paper, a relevant H∞observer-based controller design for a class of Lipschitz nonlinear discrete-time systems is proposed. Usually, Bilinear Matrix Inequaities (BMIs) are obtained from the resolution of the observer-based stabilization design problem for this class of systems. Since, the resolution of a BMI is a hard task, then it is interesting to search for a convenient way to linearize the obtained conditions. Therefore, the objective of this paper is to present new Linear Matrix Inequality (LMI) conditions ensuring the convergence of the observer-based controller in a noisy context. Thanks to the introduction of a slack variable the presented LMI conditions are more general and less conservative than the existence ones. Indeed, reformulations of the Lipschitz property and Young’s relation in a convenient way lead to a more relaxed new LMI. A numerical example is implemented to show high performances of the proposed design methodology with respect to some existing results. © 2018 IEEE. |
Publications
2020 |
Robust sliding window observer-based controller design for Lipschitz discrete-time systems Conférence vol. 53, no. 2, 2020, (Cited by: 1; All Open Access, Bronze Open Access). |
2018 |
Enhanced LMI conditions for observer-based H∞ stabilization of Lipschitz discrete-time systems Article de journal Dans: European Journal of Control, vol. 44, p. 80 – 89, 2018, (Cited by: 8). |
H∞ Observer-Based Controller for Lipschitz Nonlinear Discrete-Time Systems Conférence 2018, (Cited by: 0). |