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 |
2019 |
Gasmi, Noussaiba; Boutayeb, Mohamed; Thabet, Assem; Aoun, Mohamed Sliding Window Based Nonlinear H∞ Filtering: Design and Experimental Results Article de journal Dans: IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 66, no. 2, p. 302 – 306, 2019, (Cited by: 10). Résumé | Liens | BibTeX | Étiquettes: ARDUINO MEGA 2560, Delayed measurements, Digital control systems, Discrete – time systems, Discrete time control systems, Linear matrix inequalities, Numerical comparison, One-sided Lipschitz condition, Quadratic inner-boundedness, Real time control, Real-time implementations, Sliding window-based @article{Gasmi2019302b,This brief discusses a new linear matrix inequality (LMI)-based $boldsymbol mathcal Hboldsymbol ınfty $ filter for a class of one-sided Lipschitz discrete-time systems. Due to the introduction of a sliding window of delayed measurements, new LMI conditions are proposed. Indeed, the previous measurements allow increasing the number of decision variables in the LMIs, which render it more general and less conservative than those established by using the standard Luenberger structure of the filter. Analytical and numerical comparisons are provided to demonstrate the superiority of the proposed filter with respect to the standard one. Finally, simulation results and real-time implementation have been presented to illustrate the performances of the new filter. © 2004-2012 IEEE. |
Achnib, Asma; Airimitoaie, Tudor-Bogdan; Lanusse, Patrick; Abrashov, Sergey; Aoun, Mohamed; Chetoui, Manel Discrete-time robust control with an anticipative action for preview systems Article de journal Dans: Journal of Dynamic Systems, Measurement and Control, Transactions of the ASME, vol. 141, no. 3, 2019, (Cited by: 8; All Open Access, Green Open Access). Résumé | Liens | BibTeX | Étiquettes: Closed loop systems, Control methodology, Controllers, Digital control systems, Discrete – time systems, Discrete time control systems, Feedback control, Feedback controller, Feedforward filters, Leveling (machinery), Model uncertainties, Motion control, Reference signals, Robust control, Robust controller design, Robust feedback controllers, Robustness (control systems), Signal processing, Uncertainty analysis, Water tanks @article{Achnib2019c,A discrete-time robust controller design method is proposed for optimal tracking of future references in preview systems. In the context of preview systems, it is supposed that future values of the reference signal are available a number of time steps ahead. The objective is to design a control algorithm that minimizes a quadratic error between the reference and the output of the system and at the same time achieves a good level of the control signal. The proposed solution combines a robust feedback controller with a feedforward anticipative filter. The feedback controller’s purpose is to assure robustness of the closed-loop system to model uncertainties. Any robust control methodology can be used (such as μ-synthesis, qft, or crone control). The focus of this paper will be on the design of the feedforward action in order to introduce the anticipative effect with respect to known future values of the reference signal without hindering the robustness achieved through the feedback controller. As such, the model uncertainties are taken into account also in the design of the feedforward anticipative filter. The proposed solution is validated in simulation and on an experimental water tank level control system. © 2019 American Society of Mechanical Engineers (ASME). All rights reserved. |
Gasmi, Noussaiba; Thabet, Assem; Aoun, Mohamed New LMI Conditions for Reduced-order Observer of Lipschitz Discrete-time Systems: Numerical and Experimental Results Article de journal Dans: International Journal of Automation and Computing, vol. 16, no. 5, p. 644 – 654, 2019, (Cited by: 0). Résumé | Liens | BibTeX | Étiquettes: Arduino, Asymptotic stability, Degrees of freedom (mechanics), Digital control systems, Discrete – time systems, Discrete time control systems, Linear matrix inequalities, Lipschitz systems, Performance analysis, Real time control, Reduced order observers @article{Gasmi2019644b,The objective of this paper is to propose a reduced-order observer for a class of Lipschitz nonlinear discrete-time systems. The conditions that guarantee the existence of this observer are presented in the form of linear matrix inequalities (LMIs). To handle the Lipschitz nonlinearities, the Lipschitz condition and the Young′s relation are adequately operated to add more degrees of freedom to the proposed LMI. Necessary and sufficient conditions for the existence of the unbiased reduced-order observer are given. An extension to H∞ performance analysis is considered in order to deal with H∞ asymptotic stability of the estimation error in the presence of disturbances that affect the state of the system. To highlight the effectiveness of the proposed design methodology, three numerical examples are considered. Then, high performances are shown through real time implementation using the ARDUINO MEGA 2560 device. © 2018, Institute of Automation, Chinese Academy of Sciences and Springer-Verlag GmbH Germany, part of Springer Nature. |
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 |
Achnib, Asma; Airimitoaie, Tudor-Bogdan; Lanusse, Patrick; Guefrachi, Ayadi; Aoun, Mohamed; Chetoui, Manel Anticipative Robust Design Applied to a Water Level Control System Conférence 2018, (Cited by: 4). Résumé | Liens | BibTeX | Étiquettes: Controllers, Design, Digital control systems, Discrete – time systems, Discrete time control systems, Experimental test benches, Feedforward filters, Level control, Leveling (machinery), Quadratic errors, Reference signals, Reference-tracking, Robust control, Robust controller design, Robust feedback controllers, Water levels @conference{Achnib2018863b,In this paper, a discrete-time robust controller design method for optimal reference tracking in preview systems is validated on an experimental test bench. In the context of preview systems, it is supposed that future values of the reference signal are available a number of time steps ahead. The objective is to design a control algorithm that minimizes a quadratic error between the reference and the output of the system. The proposed solution combines a robust feedback controller with a feedforward anticipative filter. The theoretical description of this new approach is given and experimental results on a water level control system are presented. © 2018 European Control Association (EUCA). |
Gasmi, Noussaiba; Boutayeb, Mohamed; Thabet, Assem; Aoun, Mohamed H ∞ Sliding Window Observer Design for Lipschitz Discrete-Time Systems Conférence 2018, (Cited by: 0). Résumé | Liens | BibTeX | Étiquettes: Bilinear matrix inequality, Degrees of freedom (mechanics), Design, Design Methodology, Digital control systems, Discrete – time systems, Discrete time control systems, Discrete-time nonlinear systems, Linear matrix inequalities, Lipschitz property, LMI (linear matrix inequality), Luenberger observers, Restrictive constraints @conference{Gasmi2018111b,This paper focuses on the H ∞ observer design for Lipschitz discrete-time nonlinear systems. The main idea consists in using previous measurements in a Luenberger observer through a sliding window to obtain less restrictive constraint. Reformulations of both Lipschitz property and Young’s relation are used to offer greater degree of freedom to the obtained constraint. The presented result is in the form of BMI (Bilinear Matrix Inequality) which is transformed into LMI (Linear Matrix Inequality) through an interesting approach. The resulting constraint can be easily achieved with standard software algorithms. Then, to prove the superiority of the proposed design methodology, a comparison with the classical case is presented. Numerical examples are given to illustrate the effectiveness and the high performances of the proposed filter. © 2018 IEEE. |
2016 |
Gasmi, Noussaiba; Thabet, Assem; Boutayeb, Mohamed; Aoun, Mohamed Observers for nonlinear lipschitz discrete time systems with extension to H∞ filtering design Conférence 2016, (Cited by: 1). Résumé | Liens | BibTeX | Étiquettes: Asymptotic convergence, Differential mean value theorems, Digital control systems, Discrete – time systems, Discrete time control systems, Functions, Linear parameter varying systems, Mathematical transformations, Non-linear error, Nonlinear discrete-time systems, Nonlinear functions, Simulation example @conference{Gasmi2016364b,This note focuses on state observer design for a general class of nonlinear discrete-time systems. The main contribution lies in the use of the differential mean value theorem (DMVT) to transform the nonlinear error dynamics into a linear parameter varying (LPV) system. This has the advantage of introducing a general condition on the non linear functions. An extension to H∞ filtering design is obtained for systems with linear and nonlinear outputs. LMI conditions are presented to ensure asymptotic convergence. Then performances and accuracy of the results are illustrated through simulation examples. © 2016 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). |
2019 |
Sliding Window Based Nonlinear H∞ Filtering: Design and Experimental Results Article de journal Dans: IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 66, no. 2, p. 302 – 306, 2019, (Cited by: 10). |
Discrete-time robust control with an anticipative action for preview systems Article de journal Dans: Journal of Dynamic Systems, Measurement and Control, Transactions of the ASME, vol. 141, no. 3, 2019, (Cited by: 8; All Open Access, Green Open Access). |
New LMI Conditions for Reduced-order Observer of Lipschitz Discrete-time Systems: Numerical and Experimental Results Article de journal Dans: International Journal of Automation and Computing, vol. 16, no. 5, p. 644 – 654, 2019, (Cited by: 0). |
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). |
Anticipative Robust Design Applied to a Water Level Control System Conférence 2018, (Cited by: 4). |
H ∞ Sliding Window Observer Design for Lipschitz Discrete-Time Systems Conférence 2018, (Cited by: 0). |
2016 |
Observers for nonlinear lipschitz discrete time systems with extension to H∞ filtering design Conférence 2016, (Cited by: 1). |