Doctorat
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Item Control against faults of dynamical systems(Universite M'Hamed Bougara Boumerdès : Institut de Génie Eléctrique et Eléctronique, 2025) Azizi, Abdesamia; Kouadri, Abdelmalek(Directeur de thèse)Modern industrial systems have become increasingly complex, making them more vulnerable to faults in critical components such as actuators and sensors. The objective of this thesis is to develop robust control strategies capable of managing faults in actuators and sensors while maintaining the stability and desired performance of complex systems, even in the presence of faults and external disturbances. To achieve this, the work combines advanced fault estimation techniques with robust fault-tolerant control (FTC) strategies designed for both linear and nonlinear systems. Specifically, for linear systems, Unknown Input Observers (UIO) and output feedback fault-tolerant controllers are developed, with their gain matrices obtained by optimizing a multi-objective function using a genetic algorithm. Similarly, for nonlinear systems, UIO and output feedback sliding mode faulttolerant controllers are designed. Stability is ensured through the use of Linear Matrix Inequalities (LMIs) based on Lyapunov functions. Additionally, the LMI region is employed to control the poles of the overall closed-loop system, allowing for greater flexibility in achieving desired performance levels. The proposed framework not only detects and isolates faults but also compensates for them to ensure smooth operation. Simulations involving systems such as wind turbines and DC motors demonstrate the effectiveness of these methods. This research contributes to safer and more efficient industrial processesItem Faults location in distributed-parameter systems(Université M'Hamed Bougara : Institut de génie électrique et électronique, 2021) Bendjabeur, Abdelhamid; Kouadri, Abdelmalek(Directeur de thèse)Cette th ese propose de nouvelles techniques pour localiser les d efauts qui se produisent dans les syst emes a param etres distribu es. Les lignes de transmission electriques sont l'un des syst emes a param etres distribu es, compte tenu de la nature distribu ee de leurs param etres electriques, qui sont g en eralement sujets a di erents types de d efauts qui coupent leurs op erations et peuvent endommager leurs dispositifs electriques. sont d evelopp es en r esolvant num eriquement l' equation di erentielle partielle de ligne dont la solution et les param etres doivent ^etre d etermin es. En cons equence, de nouvelles m ethodes d'estimation pr ecise des param etres du mod ele de ligne et de calcul rigoureux de la localisation des d efauts le long de la ligne sont pr esent ees, test ees et discut ees a travers diverses simulations de MATLAB. Mots cl es: Localisation des d efauts, syst emes a param etres distribu es, lignes de transmission electrique, equations di erentielles partielles (PDE), m ethodes num eriques, estimation des param etres de ligne, simulations MATLABItem Design and management of industrial alarm systems(Université M'Hamed Bougara : Institut de génie électrique et électronique, 2021) Kaced, Radhia; Kouadri, Abdelmalek(Directeur de thèse)