Дисертації з теми "Détection des modes mécaniques"
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Rabenimanana, Toky Harrison. "Modélisation, fabrication et caractérisation expérimentale de réseaux MEMS faiblement couplés pour la détection de masse." Thesis, Bourgogne Franche-Comté, 2020. http://www.theses.fr/2020UBFCD062.
A study on mass microsensors using Anderson localization is conducted in this thesis. Different ways allowing to enhance their performances are proposed and demonstrated through two MEMS devices. Both devices use the same system composed of two mechanically coupled cantilevers, but the vibrations are generated in two different ways: the first device is actuated with an attractive electrostatic force while the second device is actuated with a repulsive electrostatic force. In order to get rid of initial imbalance due to manufacturing defects, the electrostatic softening effect is used by tuning the DC voltage of the actuation. For the first device, a concept with an asymmetric system including two cantilevers of different lengths is proposed. We thus reduce the effective stiffness of the short cantilever to balance the system. With the second type of actuation, the weak electrostatic softening effect forces us to use two microbeams of the same length. But the system is still balanced with the same approach. Thanks to the functionalization of electrostatic nonlinearities, the first device shows an enhanced sensitivity, which is 67% higher than the maximum sensitivity reachable in the linear regime. Concerning the second device, it shows the absence of electrostatic nonlinearities, which allows to increase the linear dynamic range by up to 70% of the gap. It should improve not only the mass resolution of the sensor, but also the accuracy of the mass sensing. All of these concepts are first theoretically investigated with the developed analytical model based on the Euler-Bernoulli beam theory. They are then experimentally demonstrated after the sensors are manufactured with the MUMPS
Guirardel, Matthieu. "Conception, réalisation et caractérisation de biocapteurs micromécaniques résonants en silicium avec actionnement piézoélectrique intégré : détection de l'adsorption de nanoparticules d'or." Phd thesis, Université Paul Sabatier - Toulouse III, 2003. http://tel.archives-ouvertes.fr/tel-00003314.
Guirardel, Matthieu. "Conception, réalisation et caractérisation de biocapteurs micromécaniques résonants en silicium avec actionnement piézoélectrique intégré : détection de l'absorption de nanoparticules d'or." Toulouse 3, 2003. http://www.theses.fr/2003TOU30159.
Harder, Thomas. "Atténuation des instabilités paramétriques basée sur la pression de radiation dans les détecteurs d’ondes gravitationnelles." Thesis, Université Côte d'Azur, 2022. http://www.theses.fr/2022COAZ4005.
Direct detection of Gravitational Waves was demonstrated for the first time in 2015 with km-scale Michelson interferometers. In order to reduce the shot noise at high frequency of these detectors high optical power in the arm cavities is needed. At that high circulating power a nonlinear optomechanical phenomenon called parametric instability (PI) may occur that induce the amplification of mirror’s eigenmodes. It limits the optical power and can cause the loss of the interferometer’s control if notmitigated.Several PI mitigation strategies have been proposed and already implemented in current gravitational wave detectors. These schemes keep them working without PI at the current optical power level in the cavities but they are not adapted to PI involving any kind of mechanical mirror modes, which needs to be considered when the optical circulation power is increased further. Next generation detectors aim at increasing their sensitivity of a factor of ten compared to current detectors. This can be achieved, inter alia, through the increase of the optical power in the arm cavities which will imply more PI.In this thesis an active and flexible PI mitigation strategy based on radiation pressure of a movable laser beam is proposed. The idea is to apply a damping force to mitigate PI. Fast beam steering is required to point at different positions of the cavity mirror with a small laser spot during one period of the mechanical mode with frequencies in the kHz-range. A sensitive sensing method is required to detect PI at the level ofthermal excitation.First experimental studies of a table-top setup are presented: rapid beam deflection based on acousto-optic modulators is investigated. A final configuration with 2D arbitrary beam steering with a maximal deflection rate of 10 MHz is demonstrated for a maximal optical power of 3.6 W, corresponding to a radiation pressure force of 24 nN. It satisfies the requirements of the laser beam that should be used as radiation pressure force for our proposed PI damping scheme.Sensing of mechanical mirror modes is investigated with the 2D beam steering system based on a Michelson interferometer. A sensitivity corresponding to a differential arm length change of δL = 4.8 · 10^-14 m/√Hz is achieved for a fixed beam position on the mirror. It is around one order of magnitude higher than the expected displacement of the mirror due to thermally excited mirror modes. Propositions are given to improve the sensitivity of the interferometer and to use the same setup to investigate active damping of mirror modes via radiation pressure
Ben, Attia Houda. "Détection et localisation de défauts mécaniques d'un entraînement électrique à vitesse variable." Toulouse, INPT, 2003. http://www.theses.fr/2003INPT012H.
Boubanga, Tombet Stéphane Albon. "Modes plasmoniques dans les transistors à effet de champ et détection THz." Montpellier 2, 2008. http://www.theses.fr/2008MON20118.
Gillet, Aymeric. "Détection des modes par opérateurs morphologiques flous pour la segmentation d'images couleurs." Lille 1, 2004. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2004/50376-2004-Gillet.pdf.
Valès, Frédéric. "Modes de déformation et d'endommagement de roches argileuses profondes sous sollicitations hydro-mécaniques." Phd thesis, Ecole Polytechnique X, 2008. http://pastel.archives-ouvertes.fr/pastel-00004758.
Blanchin, Marie-Dominique. "Etude de nouveaux modes de détection en chromatographie liquide pour l'analyse des céphalosporines." Montpellier 1, 1988. http://www.theses.fr/1988MON13524.
Cardenas, Cabada Edouard. "L'imagerie acoustique au service de la surveillance et de la détection des défauts mécaniques." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI124/document.
Vibration analysis is mainly used in condition monitoring and fault detection of rotating machine domain. The success of the diagnosis is strongly related to the position of the accelerometers. However, the machine geometry sometimes prevents the sensors to be placed close enough to the faulted part causing the diagnostic failure. The sound emitted by a mechanism and its condition are related. Using microphones to optimize condition monitoring is then justified. Acoustic imaging techniques (acoustic holography, beamforming, etc…) are mainly used as a source localization and quantification tool but they can be turned into a powerful diagnosis tool. Several strategies based on the beamforming algorithm are developed in this work. Firstly, diagnosis features commonly used in condition monitoring of rotating machinery are mapped as a function of space. Kurtosis allows localizing impulsive sources which eventually can be related to a mechanism failure. New features based on the squared envelope spectrum of the focused signals are also introduced. They aim toward the detection of inner and outer race fault in roller element bearings. On the other hand, angular synchronous average is used to extract the acoustic field synchronous with one component rotation. The sources related to a fault are localized in the residual field mappings. Finally, a new imaging technique based on the vibroacoustic transfer functions between a few accelerometers placed on the machine and the microphone array is developed. It allows obtaining the mappings of the radiated pressure on the machine surface only thanks to the accelerometers. It is tested as a fault detection tool on a test bench
Rastegar, Fatemi Mohammad Javad. "Détection des défauts mécaniques dans les entraînements électromécaniques complexes : application aux systèmes de levage." Amiens, 2011. http://www.theses.fr/2011AMIE0113.
As part of predictive maintenance and safe operation of electromechanical systems, the objective of this thesis is to propose some methods for diagnostics and monitoring of mechanical faults. In this work, these methods have been proposed and applied for predictive maintenance in a hoisting winch system driven by an induction machine. The monitoring and fault detection of complex electromechanical systems by using non-invasive sensors is an interesting approach due to simplicity of implementation and its level of reliability. It can be performed with minimal changes for the implementation. The stator current or the stray flux signals can detect the electromechanical faults by non-invasive measurements. The proposed methods do not use these types of sensors. Hence, we have been analyzed these types of sensors for the study of mechanical faults. For an application where the stator current is not available, another alternative using the stray flux of the machine has been considered for the system condition monitoring. In this thesis, five new diagnostic methods have been proposed and have been presented with their experimental results. A method using the stray flux is proposed to monitor the gearbox. It is based on the stator current signature, which directly affects the stray flux. Other mechanical parts of an electrical machine like bearings and the rotor shaft eccentricity are monitored by the stray flux in comparison to the stator current. It is also verified the influence of the load on the output torque and on the stator current in case of the planetary gearbox and misalignment faults in a hoisting winch system. A novel non-invasive method has been presented to detect defective conditions of the wire rope of a hoisting winch system using the stator current and the output torque of an induction machine. In addition, an other non-invasive method has been presented for detection of the hanging load effect in the stator current and the output torque
Navizet, Isabelle. "Modélisation et analyse des propriétés mécaniques des protéines." Paris 6, 2004. http://www.theses.fr/2004PA066309.
Halimi, Meriem. "Observation et détection de modes pour la synchronisation des systèmes chaotiques : une approche unifiée." Phd thesis, Université de Lorraine, 2013. http://tel.archives-ouvertes.fr/tel-00942426.
Cès, Maximin. "Etude théorique et expérimentale des résonances mécaniques locales de modes guidés par des structures complexes." Phd thesis, Université Paris-Diderot - Paris VII, 2012. http://tel.archives-ouvertes.fr/tel-00986632.
Ces, Maximin. "Etudes théorique et expérimentale des résonances mécaniques locales de modes guidés par des structures complexes." Paris 7, 2013. http://www.theses.fr/2013PA077271.
This PhD thesis is about Zero Group Velocity Lamb modes. For these peculiar modes, the group velocity (c 1 cohlk) vanishes and the phase velocity (coi k) remains finite, giving rise to narrow local resonances whose properties are very interesting. Attractive prospects in non destructive evaluation can be found because the frequency of those modes depends on the thickness and the mechanical properties of the plate. The behavior of the modes has primarily been explained. The experimental study have been lead using a non-contact optical set up including a pulsed laser source and an interferometric probe for the generation and the detection of those modes. The resonances have been used to determine the thickness and elastic constants of plates and of an anisotropic pipe. Then, the lateral resolution of the thickness measurement has been studied. The influence of the plate edge has been explored: an abrupt transition between the first ZGV resonance and the edge resonance has been observed at the distance of one thickness to the edge. The effect of the deposit of a thin layer on the ZGV resonances has then been numerically studied, which permitted to measure the thickness of a few hundreds nanometers thin gold layers deposited on a millimetric substrate. Finally, the function of the losses has been examined for two different cases, the intrinsic attenuation and the radiation of a fluid in contact with one face
Li, Weikang. "Propriété mécaniques, electriques, et de détection des composites comportant des renforts hybrids nano/micro nanotube de carbone/microrenforts." Phd thesis, Ecole Centrale Paris, 2013. http://tel.archives-ouvertes.fr/tel-00997409.
Déjous, Corinne. "Capteurs acoustiques à modes de plaque transverses horizontaux : application à la détection en milieux liquides et gazeux." Bordeaux 1, 1994. http://www.theses.fr/1994BOR10654.
Cabrera, Gutiérrez Naty Citlali. "Modes de Laguerre-Gauss et canalisation d’atomes froids." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112360/document.
Laguerre-Gaussian modes of light are one of the solutions to the propagation equation of light in the paraxial approximation in cylindrical coordinates. These modes are characterized by two indices (azimuthal and radial) and present particular properties: ring-shaped structure and a helical phase. These properties have been put to use in several applications going from microscopy to astronomy. This work has been devoted to the study of these modes and their application in the cold atom domain. Initially, the purity of such modes generated by numerical holography was studied, as well as the role played by the purity in their propagation. These modes were then used to obtain a bright source of cold atoms. For more than 20 years, considerable efforts have been made to create sources of cold atoms as bright and compact as possible. A two dimensional magneto-optical trap (2D-MOT) is currently used to obtain a continuous source of cold atoms with high flux of the order of 1010 atomes/s. Nevertheless, the source of cold atoms thereby achieved show a divergence of about 40 mrad which constrains the user to work by output but with a limited optical access or far from the output but at the cost of lower density. An alternative is presented, in which a Laguerre-Gaussian mode of light is used to channel the atoms at the output of a 2D-MOT. The Laguerre-Gaussian mode of light carries out a dipole trapping that confines the atoms in the black center of the mode, which has the advantage of limiting the heating due to absorption/emission of light. Thus, since the Laguerre-Gaussian modes of light keep their ring-shape along their propagation, the atoms are channeled over a distance of several decimeters. We studied the functioning of this system for different orders of the Laguerre-Gaussian mode and at different frequencies, and we showed that this system is efficient and allows to achieve a density gain of a factor 200 compared to a conventional 2D-MOT. A particular case is also presented, in which the frequency of the Laguerre-Gaussian mode of light is chosen to carry out not only the channeling of the atoms, but also their repumping, which leads to an important simplification of the system. Laguerre-Gaussian modes of light are also of great interest in the domain of quantum information and quantum cryptography because they can be used to encode and store information. In order to do that, it is crucial to be able to detect them in an unequivocal way. In this context, we are interested in the determination of these modes. Until now, different detection techniques have measured the azimuthal index, but few of them have been able to measure the radial index. If we are able to measure the radial index, it can be used as a new variable to encode and store information. Under this motivation, a technique based on the transformation of a Laguerre-Gaussian mode of light by an astigmatic system has been extended to determine the two indices characterizing them. We showed that this technique can also be used to experimentally optimize the generation of the purest possible Laguerre-Gaussian modes of high order
Arbona, Jean-Michel. "Origami d’ADN : étude des propriétés mécaniques et du processus de formation." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14585/document.
DNA origami are new nanostructures (2006) whose physical properties are still to be understood. In this work we were first interested in their mechanical properties. The first approach of this study was through the use of polymer physics, as it is the classical way to study DNA. We then used computer simulations to model the system in a more detailed manner and to extract general rules on the mechanical behaviour of DNA constructs. The other aspect that we studied is the process of formation of DNA origamis. We first realised an experimental study of the process of formation of the simplest origami that we could envision. This study was intended to investigate basic principles on the process of formation of DNA structures. A coarse grain model is then developed to have a first insight onto the formation process. Then an experimental study on large origamis follows with a modeling of the annealing and melting curves based on the principles determined from the study of the simplest origami. We also worked on the development of a SERS platform
Beylat, Laurence. "Étude des modes de déformation d'alliages d'aluminium sous sollicitations monotone et cycliques (chargements proportionnels et non proportionnel)." Compiègne, 1991. http://www.theses.fr/1991COMPD364.
Paquet, Alex. "Biodétection au moyen des modes de galerie de microsphères fluorescentes." Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/28672/28672.pdf.
Touzani, Abderrahmane. "Classification automatique par détection des contours des modes des fonctions de densité de probabilité multivariables et étiquetage probabiliste." Lille 1, 1987. http://www.theses.fr/1987LIL10058.
Reserbat-Plantey, Antoine. "Nanosystèmes graphitiques : cavités optiques ajustables et détection spectrale des contraintes dans un nanorésonateur mécanique." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00767927.
Smati, Cherif Besma. "Gouvernance et performance des services publics : cas des entreprises de remontées mécaniques." Thesis, Nice, 2014. http://www.theses.fr/2014NICE0018.
Public-Private Partnership is a tool for modernization and renewal of public intervention, its main goal is to achieve very high levels of performance. This doctoral work is therefore in the context of public management that focuses on studying the impact of public-private modes of governance on the technical efficiency of ski lifts. To answer our questions, an empirical study was conducted among 68 ski lift companies over five years (2006-2010). These data have been processed using a quantitative confirmatory study using a statistical model. To test the validity of the two models proposed by the literature, a quantitative research has been conducted. The first stochastic frontier model consists of three variables (capital productivity, labor productivity and power momentum), and three control variables (size, altitude and staff) and a dependent variable (the skier day). The second model of technical inefficiency consists of two explanatory variables (“time and materials » and SEM) and an explanatory variable (technical inefficiency). The results of this research outline, among other things, the importance of modes of governance (“time and materials » or SEM) in the process of increasing the technical efficiency of ski lifts. The second empirical study (2011-2013) which approaches the competitiveness of the French winter sports resorts by the measure of the productivity of the operators of ski lifts. By means of the indication of productivity of Malmquist and its two constituents, we look to arrest the changes of productivity then, this productivity is decomposed into two elements. Then, the relation between size and variation Technical efficiency is verified
Dalmas, Davy. "Adhérence et propriétés mécaniques de dépôts obtenus par projection thermique : application de l'émission acoustique à l'étude des modes d'endommagement." Compiègne, 2001. http://www.theses.fr/2001COMP1346.
Blanco, Éric. "L'émergence du produit dans la conception distribuée : vers de nouveaux modes de rationalisation dans la conception de systèmes mécaniques." Grenoble INPG, 1998. http://www.theses.fr/1998INPG0159.
Wood, Thomas. "Application des techniques d’optique guidée à la détection de gaz." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4321/document.
In a world suffering from increasing air pollution due to spiraling industrial activity, the detection of toxic gasses in the atmosphere is of paramount importance. The gas detector market is already well developed, and features a wide variety of detection technologies and techniques, each presenting its own set of intrinsic advantages and drawbacks. In this thesis, a combination of two or more technologies typically used independently has been studied in order to improve the global performances of gas detection systems. To this length, we have conceived and studied detector architectures based upon optical transduction systems, coupled with a material presenting a specific sensitivity to the target gas. More precisely, we have for the first time integrated a catalyst designed to accelerate the oxidation rate of chemical species (such as carbon monoxide or hydrogen) with an optical component capable of absorbing the heat generated by the oxidation reaction. The associated increase in temperature is translated to a variation of the optical intensity comprising the exit signal of the detector. The work carried out measuring the chromatic and temperature dispersion of the refractive index of the materials comprising the optical transduction component by guided mode techniques, ellipsometry and photometric techniques is presented. The optical probing of the electrical properties of semiconductor materials has also been studied, including the variations of these properties following interactions with oxidizing, reducing, or combustible gasses
Abou, Younes Fayez. "Détection des changements des propriétés mécaniques des tissus au contact d'un biomatériau : développement d'une nouvelle méthode basée sur les ultrasons." Compiègne, 2001. http://www.theses.fr/2001COMP1367.
Fournier, Etienne. "Protocole de diagnostic des entraînements asynchrones par références : application à la détection des déséquilibres mécaniques et des défauts de courroies." Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/15546/1/E_Fournier.pdf.
Joussemet, Lionnel. "Approche évolutionniste pour la détection des collisions au sein d'environnements virtuels denses." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2006. http://tel.archives-ouvertes.fr/tel-00128675.
Petrolli, Vanni. "Confinement induced transition between wave-like cellular migration modes." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAY056.
The ability of organisms to spontaneously generate order relies on the intricate interplay of mechanical and bio-chemical signals. If the general consensus is that chemical signaling governs the behavior of cells, an increasing amount of evidence points towards the impact of mechanical factors into differentiation, proliferation, motility and cancer progression. In this context, several studies recently highlighted the existence of long-range mechanical excitations (i.e. waves) at the supra-cellular level.Here, we investigate the origins of those velocity waves in tissues and their correlation with the presence of boundaries. Practically, we confine epithelial cell mono-layers to quasi-one dimensional geometries, to force the almost ubiquitous establishment of tissue-level waves. By tuning the length of the tissues, we uncover the existence of a phase transition between global and multi-nodal oscillations, and prove that in the latter regime, wavelength and period are independent of the confinement length. Together, these results demonstrate the intrinsic origin of tissue oscillations, which could provide cells with a mechanism to accurately measure distances at the supra-cellular level and ultimately lead to spatial patterning. Numerical simulations based on a Self-propelled Voronoi model reproduce the phase transition we measured experimentally and help in guiding our preliminary investigations on the origin of these wave-like phenomena, and their potential role for the spontaneous appearance of hair follicles in mouse skin explants
Humbert, Claude. "Couplage d'un filtre numérique sur FPGA avec une microbalance à quartz pour la détection de masse par localisation de modes." Thesis, Bourgogne Franche-Comté, 2020. http://www.theses.fr/2020UBFCD051.
There is an ever growing interest in ultra-accurate mass detection in the health, environment and agri-food fields. In this context, the last decade has seen the emergence of resonant sensors based on Anderson localization in an array of weakly coupled resonators. Known to be highly sensitive to mass perturbations, this phenomenon however requires identical and coupled resonators, which is a challenge due to microfabrication constraints. In order to overcome this limitation, we present in this thesis an alternative solution based on a hybrid system, where a hardware (field programmable gate array) plays the role of a resonator as well as the coupling in closed loop with a quartz cristal microbalance (QCM) having a Q-factor greater than 100000. The digital aspect of the system allows maximum sensitivity to be achieved with a fine tuning of the different parameters. In addition, this system can be adapted to the geometry of the physical resonator, indeed allowing the implementation of mode localization in shear waves resonant structures such as the QCM which is widely used in biosensing for its high Q-factor and large binding surface. This solution has been designed, implemented and tested with digital and mass perturbations, and the results are consistent with theoretical models. Finally, the experimental sensitivities achieved in this work are at least an order of magnitude higher than those found in the literature, which is promising for the design of a new generation of ultrasensitive sensors based on Anderson localization. However, these results have yet to be confronted with signal-to-noise ratio problems, as suggested by the theoretical studies carried out in the framework of this thesis
Rabus, David. "Résonateurs à ondes élastiques de volume à modes harmoniques élevés (HBARs) pour mesures gravimétriques : application à la détection de gaz." Thesis, Besançon, 2013. http://www.theses.fr/2013BESA2038/document.
The demand for compact and autonomous systems devoted to field detection of gaseous compounds is still persisting in arapidly changing international context (food-processing, sustainable development, security, and so on). The thesis reportedin this manuscript, supported by the Délégation Générale de l’Armement, develops new resonant sensor solutions basedon high overtone bulk acoustic waves (so-called HBARs) for chemical compound detection and more specifically explosivesubstances. These high compactness resonators are built using a transducer bound or deposited onto a resonant cavity,yielding a comb spectrum modulating its own frequency response. They are used generally as dipoles, but a quadrupolestructure allowing for transverse mode coupling has been particularly used for our developments. A theoretical study ofthe behaviour of these devices based on lithium niobate-on-quartz or qluminum nitride-on-silicon material stack has beenachieved to determine the gravimetric properties of these configurations accounting for their mode specificities. Variouscalibration techniques have been implemented to confirm the theoretical analysis and to define the most appropriate structurefor a given application. The produced results have been compared to those of a quartz guided-wave micro-balance toemphasize the strength (compactness, reduced chemical kinetics, multiphysics measurements) and weakness (gravimetricsensitivity requiring device thickness less than 100 μm) of our devices. An embedded signal processing electronics alsohas been developed to treat the information provided by our sensors, offering fast or accurate (millidegree range) detectionprotocols. The dedicated electronics aims at providing the flexibility needed to track multiple modes at variaous fixed frquencieswhile getting rid of the long sweep time of general purpose network analyzers. A eight-channel version of thissystem has been set to process several sensor in parallel or to monitor several modes of two HBAR sensors for effectivemuti-physics measurements in a reduced analysis domain (a few cubic mm). Phase noise is the limiting factor determiningthe detection limit. The system has been deployed for gas detection as well as for monitoring other physical parameters suchas temperature or viscosity under various experimental condition including fluid media
Harmouche, Mohamed. "Contribution à la théorie de la commande par modes glissants d'ordre supérieur et à la commande des systèmes mécaniques sous-actionnés." Thesis, Belfort-Montbéliard, 2013. http://www.theses.fr/2013BELF0214/document.
Nonlinear systems are so diverse that generalized tools for control are difficult to develop. Nonlinear control theory requires rigorous mathematical analysis to justify its conclusions. This thesis addresses two distinct, yet important branches of nonlinear control theory: control of uncertain nonlinear systems and control of under-actuated systems.In the first part, a class of Lyapunov-based robust arbitrary higher order sliding mode (HOSM) controllers is developed for the control of uncertain nonlinear systems. This class of controllers is based on a class of controllers for finite-time stabilization of pure integrator chain, and requires the limits of the system uncertainty to be known a-priori. Then, in order to eliminate the dependence on the knowledge of these limits, an adaptive arbitrary HOSM controller is developed. Using this new class, a universal homogeneous arbitrary HOSM controller is developed and it is shown that the homogeneity degree can be manipulated to obtain additional advantages in the proposed controllers, such as bounded control, minimum amplitude of discontinuous control and fixed time convergence. The performance of the controllers has been demonstrated through simulations and experiments on a fuel cell system.In the next part, the control of two under-actuated systems is studied. The first control problem is the global path following of car-type robotic vehicle, using target-point. The second problem is the precise tracking of surface marine vessels. Both these problems are distinct in nature; however, they are subjected to similar physical constraints. The solutions proposed for these control problems use saturated controls, taking into account the physical bounds on the control inputs. Simulations have been performed to demonstrate the performance of these controllers
Zejli, Hasnae. "Détection et localisation par émission acoustique de fils rompus dans les ancrages des câbles d'ouvrage d'art." Compiègne, 2007. http://www.theses.fr/2007COMP1669.
The objective of this study is the development of a method based on acoustic emission (AB) for detection and localization of broken wires in the cables anchorages. The analysis of the behavior mechanical of a broken wire in a tented strand, anchored at its two ends and subjected to a dynamic bending contributed 10 understand the physical phenomenon detected by AB. The development of an analytical model allowed to determine the most favourable conditions of vibration for detection of broken wires. The control method used is based on the acoustic emissions of the cable under dynamic bending. The broken wire generates on acoustic emission due to friction by slip over its recovery length. However, the healthy wire starting from certain deviation amplitude, can slip and constitute an additional source of AB. These phenomena sources were identified thanks to the analysis methodology of the AB parameters. The work showed that the acoustic signature of interwire friction depends on the surface state, the number of vibration cycles and on the degree damage of the cable (a number of broken wires inside anchorage). The acoustic emission is a technique able to give a diagnosis on the degradation state of a cable inside its anchorage, at least in the laboratory conditions
Nguyen, Tien Minh. "Dynamique non linéaire des systèmes mécaniques couplés: réduction de modèle et identification." Phd thesis, Ecole des Ponts ParisTech, 2007. http://pastel.archives-ouvertes.fr/pastel-00002994.
Esteban, Irène. "Etude et intégration de capteurs acoustiques à modes de plaque transverses horizontaux (SH-APM) : application à la détection de gaz organophosphorés." Bordeaux 1, 1999. http://www.theses.fr/1999BOR10510.
Rahme, Sandy. "Détection et estimation d'anomalies dans un réseau de communication." Phd thesis, Université Paul Sabatier - Toulouse III, 2011. http://tel.archives-ouvertes.fr/tel-00667420.
Mathe, Carole. "Etude de résines naturelles : caractérisation par CLHP et CPG couplées à divers modes de détection : UV/Visible, fluorimétrique et spectrométrie de masse." Avignon, 2003. http://www.theses.fr/2003AVIG0216.
This work concerns the study of two natural vegetable resins : olibanum and dragon's blood. Olibanum, is a oleo-gommo-resin only exuded by certain species of Boswellia (family of Burseraceae). The dragon's blood corresponds to a particular resin coloured in red. It is currently admitted, it is allowed that the true dragon's blood belongs to both species Daemonorops and Dracaena. Consequently, two samples were analyzed corresponding to Daemonorops draco (Indonesia) and Dracaena cinnabari (endemic species of Socotra's island, Yemen). Only the resin part (terpenic) of these substances was analyzed : the mono ones and sesquiterpenes (essential oils), the diterpenes and especially the triterpenes (ursane, oleanane, lupane and tirucallane skeletons). Various chromatographic techniques (LC/PDA/Fluorimetry, LC/SM and GC/MS) were employed to characterize these substances. The main goal of this work is to determine the specific chemical markers of these materials. Thus, seventeen molecules were isolated or hemisynthetized from commercial olibanum "Erytrean" type , as for example boswellic acids and their corresponding acetylated derivative, and a novel compound named lupeolic acid. Thermal degradation assays were also carried out ; studies of the released fume and the resinous residue obtained indicate the presence of products resulting from degradations : 24-noroléana-3,12-diene, 24-norursa-3,12-diene and 24-norlupa-3(20)29-diene. The thermal resistance of our standard compounds was also highlighted. Various geographical samples was also investigated to correlate the chemical composition and geographical origin. The species Boswellia carteri, Boswellia sacra and Boswellia frereana were differentiated. Moreover, our chromatographic methods also allowed the determination of fraud. Note that, the extrapolation of the results obtained on contemporary resins, allowed the characterization of olibanum in samples coming from the 18th century pharmacy or samples dating from ancient Egypt. Concerning the dragon's blood, both species considered were differentiated
Zouari, Talel. "Diagnostic des systèmes dynamiques hybrides à modes non linéaires." Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10071/document.
This thesis deals with the diagnosis of switching systems (a special class of hybrid dynamical systems) with nonlinear modes. Some modes correspond to the normal operation, i.e. the fault-free case. The other modes may represent the system behavior in the presence of sensors, actuators or internal component faults. A general representation called multimode/multimodels is proposed. It models each nonlinear mode by a set of linear models. A weighting function is used to determine the contribution of each local model. A design method of robust residuals based on projection techniques is proposed. It uses only inputs/outputs data and the weighting functions. The knowledge of local parameters is not needed to compute the residuals. The fault detection and isolation with the data projection method includes firstly, the sensor faults in a nonlinear mode and secondly, the actuator faults or internal faults by detecting the mode switching and by recognizing, at each time-instant, the active mode.Discernability conditions between modes are established and a discernability index computed online is introduced in order to reduce the complexity of the current mode identification method. Academic examples are taken all along the thesis in order to illustrate the effectiveness of the different proposed methods and tools
Paris, Pierre-Alain. "Identification directe des rigidités de flexion de plaques composites à partir de la mesure de leurs modes propres en vibrations libres : principe théorique, simulations et mise en œuvre expérimentale." Lyon 1, 1997. http://www.theses.fr/1997LYO10048.
Deligne, Philippe. "Etude comparative de différents modes de sollicitations mécaniques (statique, quasi-statique, cyclique) sur le comportement d'un acier inoxydable austhénitique en milieu chloruré chaud." Bordeaux 1, 1986. http://www.theses.fr/1986BOR10548.
Riachy, Samer. "Contribution à l'estimation et la commande de systèmes mécaniques sous-actionnés." Phd thesis, Ecole Centrale de Lille, 2008. http://tel.archives-ouvertes.fr/tel-00370270.
La deuxième partie de cette thèse parle de techniques de différenciations qui sont de nature algébrique. On présentera des résultats expérimentaux de la commande d'un pendule inversé avec estimation algébrique des vitesses connaissant les positions respectives. Ensuite, nous proposerons une extension multidimensionnelle de ces techniques de dérivation, i.e. des techniques d'estimation des dérivées partielles d'une fonction multidimensionnelle. Ces techniques peuvent être appliquées en traitement d'image par exemple, ce que nous laisserons au titre de perspectives.
Hedayati, Kia Shahin. "Méthodes avancées de traitement du signal pour la détection de défauts électriques et mécaniques dans les machines à induction : Application aux systèmes de traction ferroviaire." Amiens, 2009. http://www.theses.fr/2009AMIE0116.
The monitoring and diagnosis of the electrical and mechanical faults in railway traction systems have been studied in this dissertation. The railway traction system works in complex condition in which traditional techniques of signal processing cannot be used intensively. Initially, different methods such as non-parametric, parametric and subspace techniques have been examined and finally a method based on MUSIC (MUltiple SIgnal Classification) has been proposed to improve diagnosis of broken bar fault in induction machine, by detecting a large number of frequencies in a given bandwidth. This method is called zoom-MUSIC. The broken bar fault diagnosis in induction machines needs the speed information in order to localize the side-band frequencies around the fundamental in the stator current spectrum. The accurate slip estimation needs also advance signal processing. This fact has been used to define a new technique of broken bar fault detection based on discrete wavelet transform without slip estimation. The non-invasive techniques for mechanical system monitoring are interesting alternatives leading to low cost diagnosis systems. In this way, a theoretical framework has been proposed to show all the effects of a gearbox-based mechanical system torsional vibration on mechanical torque and then on the stator current of the driving machine. This study has been carried out with a basic modeling approach based on the realistic dynamic behavior of a healthy gearbox to show the influence of transmission error, eccentricities of pinion/wheel and teeth contact stiffness variation in the electromagnetic torque and the stator current signatures. In order to test the effectiveness of proposed methods under healthy and faulty mechanical conditions, a unique reduced-scale set-up based on a real railway traction system has been realized and instrumented. The diagnostic methods validated in this reduced-scale, will be in the near future implemented in a scale 1 industrial experimental set-up
Monjo, Florian. "Contrôle prédictif des effets mécaniques de la fatigue musculaire : implication dans l'étude des modèles internes et des modes de coordination entre posture et mouvement." Thesis, Saint-Etienne, 2015. http://www.theses.fr/2015STET014T.
Muscle fatigue is a transient and commonly experienced phenomenon. It is mainly associated with loss of force and leads to higher effort to produce a particular force level. The increased discharge rate of the nociceptive afferents (group III and IV) during fatiguing contractions alters motor command expression and finally motor production. An issue that has never been addressed in the literature is the Central Nervous System (CNS) capacity to anticipate muscle fatigue effects in a predictive fashion. This predictive capacity will be investigated thanks to experimental paradigms involving postural predictive processes of control, namely Anticipatory Postural Adjustments (APAs). Because numerous works show that APAs are modulated as a function of the mechanical properties of the upcoming movement, the induction of muscle fatigue at the levels of the focal muscles allowed us to appreciate the CNS capacity to predict muscle fatigue effects. We will demonstrate that this capacity is condition-dependent, i.e. it depends on the nature of the fatiguing contractions performed (voluntary vs. electro-induced) and on the level of cognitive and temporal constraints during movement preparation
Gauthier, Christophe. "Recherches sur de nouveaux modes de détection des spectres d'absorption X exploitant l'excitation de la fluorescence X, de la luminescence visible et la photoémission." Nancy 1, 1992. http://www.theses.fr/1992NAN10025.
Kerkeni, Leila. "Analyse acoustique de la voix pour la détection des émotions du locuteur." Thesis, Le Mans, 2020. http://www.theses.fr/2020LEMA1003.
The aim of this thesis is to propose a speech emotion recognition (SER) system for application in classroom. This system has been built up using novel features based on the amplitude and frequency (AM-FM) modulation model of speech signal. This model is based on the joint use of empirical mode decomposition (EMD) and the Teager-Kaiser energy operator (TKEO). In this system, the discrete (or categorical) emotion theory was chosen to represent the six basic emotions (sadness, anger, joy, disgust, fear and surprise) and neutral emotion.Automatic recognition has been optimized by finding the best combination of features, selecting the most relevant ones and comparing different classification approaches. Two reference speech emotional databases, in German and Spanish, were used to train and evaluate this system. A new database in French, more appropriate for the educational context was built, tested andvalidated
Abdul-Nour, Faraj. "Étude et conception des pompes implantables mécaniques pour l'administration de médicaments." Compiègne, 1988. http://www.theses.fr/1988COMPD149.
Trajin, Baptiste. "Analyse et traitement de grandeurs électriques pour la détection et le diagnostic de défauts mécaniques dans les entraînements asynchrones. Application à la surveillance des roulements à billes." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2009. http://tel.archives-ouvertes.fr/tel-00554240.
Gheorghe, Anca. "Détection robuste et précoce de l'embarquement et du grippage dans le système de commandes de vol." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00879224.