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Challouf A.,Unite de Recherche Modelisation | Challouf A.,Institute Superieur Des Systemes Industriels Of Gabes Issig | Abdelkrim N.,Unite de Recherche Modelisation | Tellili A.,Unite de Recherche Modelisation | And 4 more authors.
2010 7th International Multi-Conference on Systems, Signals and Devices, SSD-10 | Year: 2010

This work aims at the adaptive fault tolerant control using output feedback. Fault tolerant adaptive control is developed for N-interconnected subsystems with unknown sensors failures. Such sensors failures are characterized by some unknown inputs stuck at some unknown fixed values at unknown time instants. An effective output feedback controller structure is proposed for sensors failures compensation. The FTC scheme has an additive control in the adaptive controller which has an intrinsic robustness in terms of the stability and performance of the estimation sensors failure. This work is an extension of the additive control method presented in [8] to the interconnected subsystems. Numerical and simulation results are provided to demonstrate the effectiveness of the proposed controller. Source


Challouf A.,Unite de Recherche Modelisation | Tellili A.,Institute Superieure Des Etudes Technologiques Of Djerba | Abdelkrim M.N.,Unite de Recherche Modelisation | Aubrun C.,Nancy Research Center for Automatic Control
International Review of Automatic Control | Year: 2012

This paper presents a class of centralized and decentralized adaptive fault tolerant control (FTC) for N-interconnected subsystems which can make up a global system coupling. An integrated model for the combined dynamics of two interconnected subsystems is developed which provides an ideal frame work for the design of centralized and distributed FTC controllers. The additive FTC schemes obtained consist of an on-line estimation of faulty parameters for overall interconnected system and N-interconnected subsystems. Then, the estimated parameters are used to compute the feedback controller gains. The fault estimation and compensation is handled in this paper using the Singular Values Decomposition (SVD). Many strong points of the different architecture of FTC techniques are noted such as the possibility of making appropriate selection of control schemes based on specific representations (overall interconnected system/distributed N-subsystems coupling) of plant, as well as the facility of implementation by distributed processing FTC approach and some characteristics to realize improved performance of decentralized control. Numerical and simulation results are provided to demonstrate the effectiveness of the proposed fault tolerant controls. © 2012 Praise Worthy Prize S.r.l. - All rights reserved. Source


El Harabi R.,Lille University of Science and Technology | Ould Bouamama B.,Lille University of Science and Technology | Abdelkrim M.N.,Unite de Recherche Modelisation | Gayed M.B.,Unite de Recherche Modelisation
International Conference on Integrated Modeling and Analysis in Applied Control and Automation | Year: 2011

In this paper, robust Fault Detection and Isolation (FDI) design in nonlinear uncertain dynamic system, with chemical and thermodynamic phenomenon, is addressed. The methodology using a Bond Graph (BG) representation in linear fractional transformation (LFT) form is shown to be a valuable tool for developing dynamic threshold generators and achieving robustness against model uncertainty in combination with sensitivity to faults. The proposed FDI method is illustrated through an equilibrated reaction occurred in a continuous reactor coupled with a heat exchanger. Simulations are given to support the theoretical development and demonstrate the potential of the developed procedure. Source


Yahia M.,Unite de Recherche Modelisation | Yahia M.,University of Limoges | Yahia M.,National School of Hydraulic Engineering, Blida | Tao J.W.,National School of Hydraulic Engineering, Blida | And 3 more authors.
International Journal of Microwave and Optical Technology | Year: 2011

We propose a hybrid neural network/modal method computer-aided design (CAD) tool to the analysis of uniaxial discontinuities in rectangular waveguides. The neural network is trained using the continuity conditions of the transverse electric and magnetic fields in the discontinuity plane. Unlike the conventional modal methods, the performances of the proposed neuromodel are controlled by the operator and can outperform the classical modal methods in CPU time. The parallel nature of the proposed hybrid CAD tool makes it an interesting solution for parallel implementation in hardware and software. © 2011 ISRAMT. Source


Yahia M.,Unite de Recherche Modelisation | Yahia M.,University of Limoges | Yahia M.,CNRS LAPLACE Lab | Tao J.W.,CNRS LAPLACE Lab | And 3 more authors.
European Microwave Week 2010, EuMW2010: Connecting the World, Conference Proceedings - European Microwave Conference, EuMC 2010 | Year: 2010

We propose a hybrid finite element method (FEM) and a modified multimodal variational formulation (MMVF) to the analysis of cascaded uniaxial complex 2D discontinuities in rectangular waveguides. The finite element method characterizes waves in the arbitrarily shaped discontinuities and the total response of the circuit is obtained by applying the modified multimodal variational formulation. The proposed hybrid method is successfully applied to the full-wave analysis of filters with great practical interest (i.e., multimode filters), thus improving CPU time and memory storage against several full-wave finite element method based computer aided design (CAD) tools. © 2010 EuMA. Source

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