Dissertations / Theses on the topic 'Estimation de la vitesse du vent'
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Bezerra, Rufino Ferreira Paiva Eduardo. "Wind Velocity Estimation for Wind Farms." Electronic Thesis or Diss., Université Paris sciences et lettres, 2023. http://www.theses.fr/2023UPSLM046.
This thesis designs algorithms to estimate the wind speed and direction for wind turbines and wind farms.First, we propose data-based methods to estimate the Rotor Effective Wind Speed (REWS) for a single turbine without prior knowledge of certain physical parameters of the turbine that might be unknown to an operator.We provide two data-based methods, based respectively on Gaussian Process Regression (GPR) and on an combination of GPR with high-gain observers.Second, grounding on this REWS estimation at the local level of one turbine, we address the question of estimating the free-flow wind at the level of a wind farm.We start by focusing on wind speed estimation, for a given known wind direction. For a wind farm with a simple geometry, we prove that a local speed measurement disturbed by the presence of the turbines can be used to estimate the free-flow wind speed. We ground our estimation methodology on a simplified wake model, which consists of first-order hyperbolic partial differential equations, the transport speed of which is the free-flow wind speed. We propose to use an analytical solution of these equations, involving transport delays, to perform an estimate of the local measurement and to update the free-flow wind speed estimate. We formally prove the convergence of this estimate and numerically illustrate the efficiency of this method.Finally, we move to a more general setup where both the free-flow wind speed and direction are unknown. We propose to use a two-dimensional wake model and to rely on an optimization-based method. This identification problem reveals to be particularly challenging due to the appearance of transport delays, but we illustrate how to circumvent this issue by considering an average value of the free flow wind speed history. Simulation results obtained with the simulator FAST.Farm illustrate the interest of the proposed method
Teysseyre, Raphaël. "Détection homodyne appliquée à la mesure de la vitesse du vent." Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0053/document.
In this thesis, we study the homodyne detection (or self-mixing) applied to wind speed measurements. At the moment, there is no commercially available optical anemometer with a low price point. The objective of this thesis is to develop such a prototype, which will be using the self-mixing phenomenon. Existing anemometers are studied, with a short comparison of advantages and drawbacks of each solution (cup, ultra-sonic and hot-wire anemometers, Pitot probes, PIV/PTV, sodars and lidars). The equations describing the behavior of a self-mixing laser are demonstrated in this thesis. The resulting expressions are nonlinear delayed differential equations. These equations can be reduced to a static model that is commonly used in the relevant literature. This model predicts a periodic variation of the laser power for a linear displacement of the target responsible for self-mixing. If the reflection coefficient of the target is big enough, this model predicts discontinuities in the laser power. We develop a new model from the complete equations. This new model allows for the study of the dynamical behavior of the laser. It notably predicts damped oscillations where the static model presents discontinuities. The characteristics of these oscillations are related to the distance of the target and its reflectivity. The predictions of this new model were confirmed experimentally, and the corresponding results were published in the Optics Letters journal. The main part of this thesis is focused on the acquisition and processing of the self-mixing signal, which is produced by particles carried by the wind in the laser beam. The frequency of the resulting signal is proportional to the speed of the particle projected onto the optical axis. Therefore, we use a discrete Fourier transform to study the signal in the frequency domain. The length of the Fourier transform is a compromise between the necessity of an optimal signal-to-noise ratio that can trigger the detection, the interaction time between the particle and the beam, and the resources available for computing. After choosing the right compromise, we compute the resulting false detection frequency. We study the bias arising from these false detections, and we create an algorithm that can be used to compensate this bias. Finally, we study the optical configurations that allows for the measurement of wind speed in the horizontal plane (it is this data that is interesting for the potential clients). We demonstrate that at least four optical heads are necessary to obtain a reliable acquisition. The tests conducted in a wind tunnel show that the sensor actually measures the wind speed. An autonomous demonstrator with one measuring channel has been put on a measuring mast. The resulting measurements show that the sensor is temperature sensitive. When the measurements are corrected against the temperature, they are well correlated to a reference measurement made by a cup anemometer and a wind vane. This thesis has led to the development of an autonomous demonstrator that measures the wind speed by self-mixing in a laser diode, in outdoor conditions
Le, Chat Gaétan. "Étude du vent solaire à grande échelle." Phd thesis, Université Paris-Diderot - Paris VII, 2010. http://tel.archives-ouvertes.fr/tel-00547571.
Cierco, François-Xavier. "Étude des instationnarités du transport de neige par le vent." Phd thesis, Grenoble 1, 2007. http://www.theses.fr/2007GRE10270.
Blowing snow causes disturbances that affect both tourism and transportation. Moreover, snowdrifts and accelerated snow metamorphosis dramatically increase the risk of avalanches. These observations call for more scientific and technical researches like those realized in Cemagref, Grenoble, France, where this Ph-D was achieved. Past works contributed to the development of physical and numerical models about blowing snow but the difficulties encountered to match the results get in the field and the general complexity involved in Aeolian particle transport required more studies. That’s why new experimental measurements were recorded either in a wind-tunnel or in the field. On one hand, image processing and spectral analysis were used to investigate the fluctuations of particle concentration blown in a stationary turbulent flow. On the other hand, the variability of concentration profiles during natural events of blowing snow was studied thanks to flux measurements. These latter required some dedicated sensors with specific calibration
Magnis, Lionel. "Estimation de vitesse de rotation par mesures de direction." Thesis, Paris, ENMP, 2015. http://www.theses.fr/2015ENMP0039/document.
This thesis addresses the general question of estimating the angular rate of a rigid body from on-board direction sensors (e.g. magnetometers, Sun sensors). The objective is to replace rate gyros which are very expensive compared to direction sensors, prone to saturation during high rate rotations and subject to failure. In a first part of the thesis, we address the specific cases of single-axis and slightly perturbed axis rotations.In a second part, we address the general case by an asymptotic non-linear observer. We build the observer from two non-collinear vector measurements or from a single vector measurements. The knowledge of the inertial coordinates of the reference vectors is not necessary. We then extend the observer to further estimate unknown torques and inertia parameters. The Euler’s equations play a central role in all the works developed in this thesis. It appears that, at least for the illustrative cases considered, rate gyros could be replaced with an estimation algorithm employing direction sensors which are much cheaper,more rugged and more resilient sensors
Durán, Medina Olmo. "Etude expérimentale et modélisation stochastique des fluctuations de la vitesse (vent et courant) et de la puissance électrique." Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10214/document.
The renewable energy output from wind and tidal turbines generates large fluctuations. Such large power variability are inherent to the turbulent wind and currents nature. This phenomenon is also called intermittency and it is a major obstacle for the development of this kind of energy. This thesis presents the analysis and characterization of stochastic fluctuations through a statistical approach. The theoretical framework is the multifractal energy cascades. The tools and methods aim to study the influence of the fully developed turbulence on a three-blade horizontal axis turbine. This approach provides a method for multiscale turbulence analysis, regardless the size of the considered system. The spectral analysis of wind and current velocity allows the characterization of flow scaling properties from a dissipation estimate. The Empirical Mode Decomposition offers on the other hand, an observation of the multiscale interaction between the input and output of such energy production systems. The study of the power intermittency allows in particular the conception of forecasting tools based on physical principles related to intermittency and to scaling. These tools are able to provide a solution for grid adaptation facing the wind and tidal energy fluctuations
Billette, Frédéric. "Estimation de macro-modèles de vitesse en sismique réflexion par stéréotomographie." Paris 7, 1998. http://www.theses.fr/1998PA077183.
Iooss, Bertrand. "Tomographie statistique en sismique réflexion : estimation d'un modèle de vitesse stochastique." ENSMP, 1998. http://www.theses.fr/1998ENMP0827.
Jobin, Jules. "La mesure de la vitesse du vent dans un écoulement atmosphérique turbulent ayant de fortes variations saisonnières de température." Mémoire, École de technologie supérieure, 2008. http://espace.etsmtl.ca/157/1/JOBIN_Jules.pdf.
Chalard, Emanuel. "Estimation de macro-modèles de vitesse en sismique réflexion par stéréotomographie 3D." Paris, ENMP, 2002. http://www.theses.fr/2002ENMP1094.
Perbal-Hatif, Séverine. "Estimation du temps, vitesse de traitement de l'information et mémoire : approche neuropsychologique." Paris 6, 2002. http://www.theses.fr/2002PA066291.
Mousset, Stéphane. "Estimation de la vitesse axiale à partir d'une séquence réelle d'images stéréoscopiques." Rouen, 1997. http://www.theses.fr/1997ROUES048.
Ailliot, Pierre. "Modèles autorégressifs à changements de régimes markoviens. Applications aux séries temporelles de vent." Rennes 1, 2004. https://tel.archives-ouvertes.fr/tel-00007602.
Beyou, Sébastien. "Estimation de la vitesse des courants marins à partir de séquences d'images satellitaires." Phd thesis, Université Rennes 1, 2013. http://tel.archives-ouvertes.fr/tel-00870722.
Quost, Xavier. "Modélisation de l'effet du vent sur les trains à grande vitesse. : Une étude dynamique et stochastiqe appliquée au risque de renversement." Ecully, Ecole centrale de Lyon, 2005. http://bibli.ec-lyon.fr/exl-doc/xquost.pdf.
The aim of this thesis is the study of the rollover of the high-speed trains subjected to strong lateral winds. To simulate this phenomenon research was carried out following two axes. The first axis deals with wheel-rail contact mechanics, solids mechanic and suspension models featuring large displacements. The STRIPES wheel-rail contact model was incorporated into specailly developed software, which was assessed against existing classical railway multi-body software. As a conclusion of this mechanical study, the lift kinematics of a wheelset was computed and an innovating criteria for evaluating both unloading and wheel uplift is submitted. The second research axis deals with modeling of the turbulence as seen by a moving vehicle. From Von Karman turbulence modeling and thanks to Cooper works a formulation of turbulence as seen by the train was proposed. This formulation is suitable for the study of vehicle sensitivity to strong wind by Monte-Carlo simulations. With an appropriate method of wind field generation, vehicle safety curve is computed. Differences with standard mehods are analyzed and discussed
Quost, Xavier Thouverez Fabrice. "Modélisation de l'effet du vent sur les trains à grande vitesse. Une étude dynamique et stochastiqe appliquée au risque de renversement /." [S.l.] : [s.n.], 2005. http://bibli.ec-lyon.fr/exl-doc/xquost.pdf.
Oliveira, José Carlos Rodrigues de. "Contrôle d'un variateur asynchrone sans capteur de vitesse : estimation du flux, du couple et de la vitesse : réalisation de la commande numérique." Toulouse, INPT, 1991. http://www.theses.fr/1992INPT105H.
Ferreyre, Frédéric. "Conception de commandes sécurisées de volet roulant sans capteur de vitesse." Phd thesis, Université Claude Bernard - Lyon I, 2010. http://tel.archives-ouvertes.fr/tel-00838016.
Ndao, Mamadou. "Estimation de la vitesse de retour à l'équilibre dans les équations de Fokker-Planck." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLV036/document.
This thesis is devoted to the Fokker-Planck équation partial_t f =∆f + div(E f).It is divided into two parts. The rst part deals with the linear problem. In this part we consider a vector E(x) depending only on x. It is composed of chapters 3, 4 and 5. In chapter 3 we prove that the linear operator Lf :=∆f + div(Ef ) is an in nitesimal generator of a strong continuous semigroup (SL(t))_{t≥0}. We establish also that (SL(t))_{t≥0} is positive and ultracontractive. In chapter 4 we show how an adequate decomposition of the linear operator L allows us to deduce interesting properties for the semigroup (SL(t))_{t≥0}. Indeed using this decomposition we prove that (SL(t))_{t≥0} is a bounded semigroup. In the last chapter of this part we establish that the linear Fokker-Planck admits a unique steady state. Moreover this stationary solution is asymptotically stable.In the nonlinear part we consider a vector eld of the form E(x, f ) := x +nabla (a *f ), where a and f are regular functions. It is composed of two chapters. In chapter 6 we establish that fora in W^{2,infini}_locthe nonlinear problem has a unique local solution in L^2_{K_alpha}(R^d); . To end this part we prove in chapter 7 that the nonlinear problem has a unique global solution in L^2_k(R^d). This solution depends continuously on the data
Hauet, Alexandre. "Estimation de débit et mesure de vitesse en rivière par Large-Scale Particle Image Velocimetry." Phd thesis, Grenoble INPG, 2006. http://tel.archives-ouvertes.fr/tel-00116889.
Une station LSPIV de mesure en continu et temps réel a été mise en place sur la rivière Iowa à Iowa City (USA). Les premières années de fonctionnement ont montré des estimations LSPIV de débit en bonne concordance avec la courbe de tarage du site et avec des mesures classiques réalisées au moulinet. L'établissement d'une importante base de données a permis une étude de sensibilité de la technique. Les sources d'erreur affectant la mesure ont été identifiées et quantifiées. L'étude de sensibilité a été affinée grâce à un simulateur numérique de la mesure LSPIV en rivière, outils capitalisant notre connaissance de la mesure et permettant d'évaluer l'importance relative de différentes sources d'erreur pour une situation donnée.
Une unité LSPIV motorisée (camionnette équipée d'un bras télescopique et d'une caméra) a été développée pour permettre l'application de la méthode en sites difficiles d'accès. Cette unité s'est montrée efficace, donnant des résultats d'excellentes qualités sur les différents sites testés. Des mesures LSPIV de champ de vitesse de surface ont été utilisées par ailleurs pour la validation de la modélisation hydraulique d'une zone d'écoulement complexe (la lône de Port-Galand sur l'Ain) et pour une étude de reconstitution de formes de fond de chenal en laboratoire.
Ghouili, Jamel. "Commande sans capteur d'une machine asynchrone avec estimation de la vitesse par réseaux de neurones /." Trois-Rivières : Université du Québec à Trois-Rivières, 2005. http://www.uqtr.ca/biblio/notice/resume/24101164R.pdf.
Ghouili, Jamel. "Commande sans capteur d'une machine asynchrone avec estimation de la vitesse par réseaux de neurones." Thèse, Université du Québec à Trois-Rivières, 2005. http://depot-e.uqtr.ca/1252/1/000123352.pdf.
Plessix, René-Edouard. "Détermination de la vitesse pour l'interprétation de données sismiques très haute résolution à l'échelle géotechnique." Paris 9, 1996. https://portail.bu.dauphine.fr/fileviewer/index.php?doc=1996PA090067.
Zhou, Tianyou. "Analyse de vitesse par migration : choix des paramètres utilisateurs et introduction des ondes transmises." Electronic Thesis or Diss., Université Paris sciences et lettres, 2020. http://www.theses.fr/2020UPSLM046.
Seismic imaging is the technique used to determine the structures of the subsurface from seismic signals. One of the most important parameters is the velocity model, that can be split into the macromodel controlling the kinematics of wave propagation and velocity perturbations. Migration builds the image of velocity perturbation for a given macromodel. Migration Velocity Analysis estimates the quality of the macromodel with an objective function measuring the focusing in the image domain. The gradient of this objective function with respect to the macromodel allows to find the optimal macromodel in an iterative way. The method has been improved recently by replacing the migration operator by the asymptotic inverse in the subsurface offset domain. In this thesis, we show that the quality of the gradient is sensitive to the user parameters. We provide practical guidelines to ensure proper gradient. These guidelines are applied to the synthetic Marmousi model. Recent developments propose to take into account the transmitted waves. We compare different strategies for combining the two different kinds of waves and recommend to apply a separate workflow. We apply the method to a marine real data set provided by Total. We propose a two-step workflow: after a first try of several iterations, we adjust the parameters and restart the iterations
Le, Méhauté Simon. "Étude et réalisation d'un lidar dial cohérent fibré à 1.65 µm pour la mesure simultanée de la vitesse du vent et de la concentration de méthane." Thesis, Littoral, 2020. http://www.theses.fr/2020DUNK0555.
Especially in the oil and gas industry, methane leaks threaten both safety and environment. The real-time monitoring of such plumes could prevent potential human or ecological disasters. In this context, one part of NAOMI project, involving TOTAL and ONERA, aims to develop remote sensing tools capable of locating (with a spatial resolution of 100 m) and characterize major methane leaks from a safety distance (1 km) on the field. To meet these specifications, the present work describes the study, design and performances assessments of a fiber lidar emitting in the near infrared (1.65 µm) : VEGA ("VEnt et GAz", French for "wind and gaz"). The choice of a coherent detection scheme allows to consider a dual-function system, able to simultaneously measure wind speed with Doppler shift (useful to assess plume dynamic) and methane concentration with the DIAL technique. In the lab, integrated-path measurements (target at 2.2 km) have shown, a first to our knowledge with a coherent lidar, VEGA's sensibility to methane. The accuracy of ambient level measurements (1.95 ± 0.26 ppm for 1 s averaging) is seen to be satisfying for the target application (involving much higher concentration). During a field campaign in 2018 (Lacq, France), the lidar has shown a good thermo-mechanical behaviour, justifying the choice of an all-fibered architecture. The use of several measurement procedures (simple, several laser lines of sight, several wavelengths) allowed VAGA to identify controlled methane leaks at 200 m (30 m resolution) in a wide range of flow rates (from 0.1 to 300 g.s-¹. During the campaign, the observed statistical errors, in the ±10 to 100ppm range for 1 s averaging, are in good agreement with theoretical models. Assessing these errors at greater distances shows, nonetheless, a need to improve the lidar (through mentioned improvement tracks) to reach an adequate precision at 1 km. Eventually, the basis for autonomous flow rate estimation, combining both wind and gas data, had been presented
Ortiz, Cayón Rodrigo. "Amélioration de la vitesse et de la qualité d'image du rendu basé image." Thesis, Université Côte d'Azur (ComUE), 2017. http://www.theses.fr/2017AZUR4004/document.
Traditional photo-realistic rendering requires intensive manual and computational effort to create scenes and render realistic images. Thus, creation of content for high quality digital imagery has been limited to experts and highly realistic rendering still requires significant computational time. Image-Based Rendering (IBR) is an alternative which has the potential of making high-quality content creation and rendering applications accessible to casual users, since they can generate high quality photo-realistic imagery without the limitations mentioned above. We identified three important shortcomings of current IBR methods: First, each algorithm has different strengths and weaknesses, depending on 3D reconstruction quality and scene content and often no single algorithm offers the best image quality everywhere in the image. Second, such algorithms present strong artifacts when rendering partially reconstructed objects or missing objects. Third, most methods still result in significant visual artifacts in image regions where reconstruction is poor. Overall, this thesis addresses significant shortcomings of IBR for both speed and image quality, offering novel and effective solutions based on selective rendering, learning-based model substitution and depth error prediction and correction
Mamfoumbi-Ocloo, Jean-Marcel. "Estimation de canaux de transmission respectant un modèle d'évolution temps/fréquence." Paris 11, 2006. http://www.theses.fr/2006PA112072.
The aim of this work is to propose channel estimation methods in the context of wireless transmission for the IEEE802. 11a standard. Multicareers technics (OFDM) have already been accepted in such standards. Our approach is in the framework of multicareers systems and takes advatange of these techniques. We propose, in a first time, a new channel model which is piecewise constant. This model permits to increase the observations being used to estimate a given parameter and also to reduce the number of channel coefficients which must be estimated. The introduction of this model in the EM (Expectation-Maximization) algorithm procedure provides an algorithm which maximizes the likelihood and the arithmetical complexity is turned from exponential to linear. The performances of this new algorithm are satisfactory. Then, we propose a Maximum a posteriori (MAP) version which takes into account the output of an autoregressive filter as a channel evolution model. The resulting algorithm improves performances significantly but its complexity becomes important. The last part of this work consists in proposing a method maximizing the a posteriori probability with a linear arithmetical complexity. The proposed method has the same fixed points than the original MAP algorithm and the convergence of these algorithms is established
Baïle, Rachel. "Analyse et modélisation multifractales de vitesses de vent. Application à la prévision de la ressource éolienne." Phd thesis, Université Pascal Paoli, 2010. http://tel.archives-ouvertes.fr/tel-00604139.
Martini, Adnan. "Modélisation et commande de vol d'un hélicoptère drone soumis à une rafale de vent." Phd thesis, Université de Metz, 2008. http://tel.archives-ouvertes.fr/tel-00340584.
Gabsi, Younès. "Détermination de la vitesse des vents terrestres par inversion de la mesure des décalages Doppler sur la lumière solaire diffusée et mesure de la rotation de l'atmosphère de Vénus." Paris 6, 2008. http://www.theses.fr/2008PA066152.
Godin, Olivier. "Information visuelle multirésolution pour l'estimation de la vitesse du trafic routier." Mémoire, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6583.
Amorino, Chiara. "Bias correction for drift and volatility estimation of jump diffusion processes and non - parametric adaptive estimation of the invariant measure." Thesis, université Paris-Saclay, 2020. https://www.biblio.univ-evry.fr/theses/2020/2020UPASE006.pdf.
The thesis deal with the parametric and non-parametric inference in jump process models.It consists of 3 parts which gather 4 chapters.The first part, which contains 2 chapters, focuses on the estimation of the drift and volatility parameters via some contrast function methods starting from a discretely observed process.The main goal is to minimise the conditions on the discretization step so that it can go to $0$ arbitrarily slowly.The second part of the thesis regards some asymptotic developments, and bias correction, for the estimation of the integrated volatility.The third part of the thesis is about the adaptive estimation of the invariant measure for jump processes
Benyoucef, Rayane. "Contribution à la cinématique à partir du mouvement : approches basées sur des observateurs non linéaires." Electronic Thesis or Diss., université Paris-Saclay, 2021. http://www.theses.fr/2021UPASG091.
This manuscript outlines the various scientific contributions during this thesis, with the objective of solving the problem of the 3D reconstructure Structure from Motion (SfM) through the synthesis of dynamic models and observation algorithms for thereconstruction of unmeasured variables. Undoubtedly, vision sensors are the most important source providing rich information about the environment and that's where the scene structure estimation begins to find professional uses. There has been significant interest in recovering the 3D structure of a scene from 2D pixels considering a sequence of images. Several solutions have been proposed in the literature for this issue. The objective of the classic “structure from motion (SfM)” problem is to estimate the Euclidean coordinates of tracked feature points attached to an object (i.e., 3-D structure) provided the relative motion between the camera and the object is known. It isthoroughly addressed in literature that the camera translational motion has a strong effect on the performance of 3D structure estimation. For eye-in-hand cameras carried by robot manipulators fixed to the ground, it is straightforward to measure linear velocity. However when dealing with cameras riding on mobile robots, some practical issues may occur. In this context, particular attention has been devoted to estimating the camera linear velocities. Hence another objective of this thesis is to find strategies to develop deterministic nonlinear observers to address the SfM problem and obtain a reliable estimation of the unknown time-varying linear velocities used as input of the estimator scheme which is an implicit requirement for most of active vision. The techniques used are based on Takagi-Sugeno models and Lyapunov-based analysis. In the first part, a solution for the SfM problem is presented, where the main purpose is to identify the 3D structure of a tracked feature point observed by a moving calibrated camera assuming a precise knowledge of the camera linear and angular velocities. Then this work is extended to investigate the depth reconstruction considering a partially calibratedcamera. In the second part, the thesis focuses on identifying the 3D structure of a tracked feature point and the camera linear velocity. At first, the strategy presented aims to recover the 3D information and partial estimate of the camera linear velocity. Then, the thesis introduces the structure estimation and full estimation of the camera linear velocity, where the proposed observer only requires the camera angular velocity and the corresponding linear and angular accelerations. The performance of eachobserver is highlighted using a series of simulations with several scenarios and experimental tests
Le, Rille Olivier. "Étude et validation d'un lidar hétérodyne émettant à 2 micron pour l'application à la météorologie et à l'environnement." Paris 6, 2002. http://www.theses.fr/2002PA066227.
Calif, Rudy. "Mesure et analyse de la vitesse du vent sur un site de production d'énergie éolienne en Guadeloupe : Modèles pour la prévision sur les échelles de temps inférieures à l'heure." Antilles-Guyane, 2005. http://www.theses.fr/2005AGUY0138.
Large scale wind power productions are usually sent to the utility networks, without any storage. However,the fluctuating nature of wind power need specific management of the utility grid, in particular when wind power variations on short times scales are considered. The amplitude of theses power variations can reach the wind farm power output. From wind velocity and electrical power measurements, we proceed toward three objectives:i) the characterization of the wind measurement signal from both the statistical and dynamical point of view : the developed analysis reveal two main catégories of times series for the wind velocity fluctuations. Ii) the set up of a model for real time wind power production forecast:we developop the tools needed for a mean wind speed persistent model thatc uses the distributions associated with the two categories defined above. Furthermore, we propose a wind speed time series generator based on stochastic differential equations that could be used to test the impact of wind power on utility grids. Iii) the characterization of the wind velocy-electrical power probabilistic transfer function for a wind farm, that includes the effect of the wind turbines scattering: we build such a transfer funtion for the measurement period studied. This transfer function gives access to probability for a wind farm to achieve a given power level at a given wind speed
Leclerc-Carlhian, Joséphine. "Comportement limité fort (vitesse de convergence presque sure et loi du logarithme itéré) d'estimateurs non paramétriques du mode." Paris 6, 2000. http://www.theses.fr/2000PA066276.
Perozzi, Gabriele. "Exploration sécurisée d’un champ aérodynamique par un mini drone." Thesis, Ecole centrale de Lille, 2018. http://www.theses.fr/2018ECLI0007/document.
This thesis is part of the project "Small drones in the wind" carried by the ONERA center of Lille. This project aims to use the drone as a "wind sensor" to manage a UAV quadrotor in disturbed wind conditions using wind field prediction. In this context, the goal of the thesis is to make the quadrotor a wind sensor to provide local information to update the navigation system. With real-time on-board wind estimation, the quadrotor can compute a trajectory planning avoiding dangerous areas and the corresponding trajectory control, based on anexisting cartography and information on the aerodynamic behavior of airflow close to obstacles. Thus, the results of this thesis, whose main objectives are to estimate instant wind and position control, will be merged with another study dealing with trajectory planning. An important problem is that pressure sensors, such as the aeroclinometer and the Pitot tube, are not usable in rotary-wing vehicles because rotors air inflow interferes with the atmospheric flow and lightweight LIDAR sensors generally are not available. Another approach to estimate the wind is to implement an estimation software (or an intelligent sensor). In this thesis, three estimators are developed using the sliding mode approach, based on an adequate drone model, available measurements on the quadrotor and inertial tracking position systems. We are then interested in the control of the trajectory also by sliding mode considering the nonlinear model of the quadrotor. In addition, we are still studying quite an early alternative solution based on the H control, considering the linearized model for different equilibrium points as a function of the wind speed. The control and estimation algorithms are strictly based on the detailed model of the quadrotor, which highlights the influence of the wind
Villette, Sylvain. "Estimation de vitesse par analyse d'images acquises en filé : Application à la caractérisation de la distribution centrifuge de granules d'engrais." Phd thesis, Université de Bourgogne, 2006. http://tel.archives-ouvertes.fr/tel-00496311.
Villette, Sylvain. "Estimation de vitesse par analyse d'images acquises en file : application à la caractérisation de la distribution centrifuge de granules d'engrais." Dijon, 2006. http://www.theses.fr/2006DIJOS042.
This dissertation demonstrates that motion blurred images acquired in the vicinity of the spinning disc of a fertiliser centrifugal spreader can be used to estimate the outlet velocity components of the granules. First, a recursive linear filter is applied to the image to detect the streak axes corresponding to the granule trajectories. This filter was specifically developed for our research by means of the Canny method and an edge model based on an experimental approach. Secondly, the trajectories are identified and characterised using the Hough Transform. Its computation is based on mechanical knowledge derived from spreading analysis. Next, the outlet velocities are deduced from the outlet angle measurements using kinematic relationships. The fertiliser angular distribution is also estimated using the frequency of trajectory identifications in the image. Finally, the spread pattern is computed by means of a ballistic flight model using the above parameters
Valeau, Vincent. "Mesure de la vitesse particulaire acoustique par anémométrie laser Doppler : estimation de fréquence instantanée à variation sinusoi͏̈dale, validation de la mesure." Le Mans, 1999. http://www.theses.fr/1999LEMAA006.
RAOUFFI, NOUR-EDDINE. "Mesure et interpretation de la polarisation lineaire de la raie coronale o vi 1031. 92 a mesure du champ magnetique et de la vitesse du vent solaire dans la basse couronne." Paris 11, 2000. http://www.theses.fr/2000PA112348.
Baral-Baron, Grégory. "Traitements avancés pour l’augmentation de la disponibilité et de l’intégrité de la mesure de vitesse 3D par LiDAR, dans le domaine aéronautique." Thesis, Supélec, 2014. http://www.theses.fr/2014SUPL0016/document.
The method use to respect security requirements in civil aviation consists in multiplying measuring chains for the same information. Now, it is recommended to add a dissimilar measuring chain, based on a different physical principle, in order to improve security level. Thus, Thales works on the development of a laser Doppler anemometer embedded on aircraft. This sensor is composed by four LiDAR (Light Detection And Ranging) axis distributed around the aircraft and air speed is estimated by the analysis of the reflection of the emitted laser wave on particles.This thesis objective is to design a LiDAR signal processing chain adapted to an aircraft sensor. The process is based on a time-frequency representation and it includes methods for signal detection in low concentrated air mass, useful particles selection in clouds and robust estimation to control measure reliability. The process has been evaluated during a test campaign realized at the Pic du Midi observatory. Its performances are greatly improved, especially in critical situations.The system architecture has also been studied. An estimation method designed from estimations performed on different LiDAR axis and an aerodynamic model of an aircraft is proposed in order to compensate for air mass perturbations close to the aircraft. Then, an optimization process is presented to improve sensor performances.The signal processing chain will have to be evaluated by flight tests, to explore a large atmospheric conditions variety and to quantify its strengths and weaknesses depending on conditions
Thiam, Baba. "Estimation récursive de fonctionnelles." Phd thesis, Université de Versailles-Saint Quentin en Yvelines, 2006. http://tel.archives-ouvertes.fr/tel-00131199.
Hamon, Abdellatif. "Estimation d'une densité de probabilité multidimensionnelle par dualité." Rouen, 2000. http://www.theses.fr/2000ROUES055.
Limido, Jérôme. "Étude de l'effet de l'usinage grande vitesse sur la tenue en fatigue de pièces aéronautiques." Toulouse 3, 2008. http://thesesups.ups-tlse.fr/753/.
The aim of this study is to describe the influence of the high speed machining conditions on the fatigue life of aeronautical alloy parts (AA-7010 aluminium). The approach suggested comprises three principal parts. In the first part, a 3D numerical model was developed to predict the 3D geometry of milled surface. This model takes into account the defects of the tool, the defects of assembly as well as the deflection of the tool due to the cutting forces. The 3D cutting forces are obtained thanks to a 2D SPH model. This method based on a particulate representation (therefore without grid) allows a new approach of the chip separation. The second part attempts to determine the life spans associated with the numerical surfaces obtained with the first part. The dominating influence of the surface texture on the fatigue life span is represented by the local stress concentration which it generates. The third part attempts to develop the articulation of the two preceding parts to obtain a life span prediction model starting from the machining parameters and the intrinsic properties of part material. The predicted life spans were compared with measurements resulting from milling tests representative of current machining conditions. The maximum error is approximately 15% compared to the tests. The model thus validated was used in trial cases to optimize the machining parameters compared to fatigue life. We show that it is possible to soften the machining constraints while preserving the desired fatigue life
Therrien, Charles. "Établissement d'une courbe de correction des précipitations solides en fonction de l'intensité du vent et validation par l'utilisation de modèles de simulation de la couverture de neige." Thesis, Université Laval, 2005. http://www.theses.ulaval.ca/2005/22934/22934.pdf.
Bertin, Karine. "Estimation asymptotiquement exacte en norme sup de fonctions multidimensionnelles." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2004. http://tel.archives-ouvertes.fr/tel-00008028.
Rivoirard, Vincent. "Estimation bayésienne non paramétrique." Phd thesis, Université Paris-Diderot - Paris VII, 2002. http://tel.archives-ouvertes.fr/tel-00002149.
GIAT, PASCAL. "Caracterisation ultrasonore de l'os par imagerie parametrique d'attenuation, de vitesse de propagation et par estimation de la retro diffusion : application a l'osteoporose." Paris 6, 1995. http://www.theses.fr/1995PA066093.
Autin, Florent. "Point de vue maxiset en estimation non paramétrique." Phd thesis, Université Paris-Diderot - Paris VII, 2004. http://tel.archives-ouvertes.fr/tel-00008542.