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Consideração do esmagamento do concreto através do modelo de trincas sobrepostas / Consideration of the concrete crushing through the overlapping crack modelEvangelho, Tiago Becker January 2013 (has links)
Neste trabalho é apresentada uma teoria para a consideração do esmagamento do concreto aplicada ao método elementos finitos, o Modelo de Trincas Sobrepostas. Neste caso, o esmagamento é considerado através da interpenetração dos elementos finitos. Em conjunto com o já conhecido Modelo de Trincas Coesivas, a abordagem é utilizada para simular o comportamento de vigas de concreto armado com alta taxa de armadura (concreto superarmado). Os experimentos empregados são vigas em flexão a três pontos (dois apoios e uma carga aplicada no centro do vão), onde as barras de aço são substituídas por uma camada de elementos finitos de altura equivalente. Aloca-se uma linha de elementos de interface coesiva verticalmente no centro das vigas no intuito de permitir o processo de dano, tanto em tração quanto em compressão. Na zona de interface entre os elementos de concreto e os de aço são colocados elementos de aderência. É verificada a influência nos modelos numéricos de diversos parâmetros, tais como altura da viga, armadura de compressão, armadura de cisalhamento e escala. / In this work is presented a theory to the consideration of the concrete crushing applied to the finite element method, the Overlapping Crack Model. In this case the crushing is considered through the interpenetration of finite elements. Together with the well-known Cohesive Crack Model, the approach is used to simulate the behavior of reinforced concrete beams with high volume fraction of reinforcement (under reinforced concrete). The used experiments are beams subjects to three-point bending, where the steel bars are replaced by an equivalent layer of finite elements. A central vertical line of interfaces is used in order to take into account the damage due to crushing and fracture. At the concrete-steel interface, friction elements are considered. The influence of some parameters, such as depth of the beam, compression and shear reinforcement, etc., is investigated.
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Détection de communautés recouvrantes dans des réseaux de terrain dynamiques / Overlapping community detection in dynamic networksWang, Qinna 12 April 2012 (has links)
Dans le contexte des réseaux complexes, la structure communautaire du réseau devient un sujet important pour plusieurs domaines de recherche. Les communautés sont en général vues comme des groupes intérieurement denses. La détection de tels groupes offre un éclairage intéressant sur la structure du réseau. Par exemple, une communauté de pages web regroupe des pages traitant du même sujet. La définition de communautés est en général limitée à une partition de l’ensemble des nœds. Cela exclut par définition qu’un nœd puisse appartenir à plusieurs communautés, ce qui pourtant est naturel dans de nombreux (cas des réseaux sociaux par exemple). Une autre question importante et sans réponse est l’étude des réseaux et de leur structure communautaire en tenant compte de leur dynamique. Cette thèse porte sur l’étude de réseaux dynamiques et la détection de communautés recouvrantes. Nous proposons deux méthodes différentes pour la détection de communautés recouvrantes. La première méthode est appelée optimisation de clique. L'optimisation de clique vise à détecter les nœds recouvrants granulaires. La méthode de l'optimisation de clique est une approche à grain fin. La seconde méthode est nommée détection floue (fuzzy detection). Cette méthode est à grain plus grossier et vise à identifier les groupes recouvrants. Nous appliquons ces deux méthodes à des réseaux synthétiques et réels. Les résultats obtenus indiquent que les deux méthodes peuvent être utilisées pour caractériser les nœds recouvrants. Les deux approches apportent des points de vue distincts et complémentaires. Dans le cas des graphes dynamiques, nous donnons une définition sur la relation entre les communautés à deux pas de temps consécutif. Cette technique permet de représenter le changement de la structure en fonction du temps. Pour mettre en évidence cette relation, nous proposons des diagrammes de lignage pour la visualisation de la dynamique des communautés. Ces diagrammes qui connectent des communautés à des pas de temps successifs montrent l’évolution de la structure et l'évolution des groupes recouvrantes., Nous avons également appliquer ces outils à des cas concrets. / In complex networks, the notion of community structure refers to the presence of groups of nodes in a network. These groups are more densely connected internally than with the rest of the network. The presence of communities inside a network gives an insight on network structural properties. For example, in social networks, communities are based on common interests, location, hobbies.... Generally, a community structure is described by a partition of the network nodes, where each node belongs to a unique community. A more reasonable description seems to be overlapping community structure, where nodes are allowed to be shared by several communities. Moreover, when considering dynamic networks whose interactions between nodes evolve in time, it appears crucial to consider also the evolution of the intrinsic community structure. This thesis focus on mining dynamic community evolution and overlapping community detection. We have proposed two distinct methods for overlapping community detection. The first one named clique optimization and the second one called fuzzy detection. Our clique optimization aims to identify granular overlaps and it is a fine grain scale approach. Our fuzzy detection is at a coarser grain scale with the strategy of identifying modular overlaps. Their applications in synthetic and real networks indicate that both methods can be used for characterizing overlapping nodes but in distinct and complementary views. We also propose the definition of predecessor and successor in mining community evolution. Such definition describes the relationship between communities at different time steps. We use it to detect community evolution in dynamic networks and show how modular overlaps evolve over time. A visualization tool called lineage diagrams is used to show community evolution by connecting communities in relationship of predecessor and successor. Several cases are studied.
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Consideração do esmagamento do concreto através do modelo de trincas sobrepostas / Consideration of the concrete crushing through the overlapping crack modelEvangelho, Tiago Becker January 2013 (has links)
Neste trabalho é apresentada uma teoria para a consideração do esmagamento do concreto aplicada ao método elementos finitos, o Modelo de Trincas Sobrepostas. Neste caso, o esmagamento é considerado através da interpenetração dos elementos finitos. Em conjunto com o já conhecido Modelo de Trincas Coesivas, a abordagem é utilizada para simular o comportamento de vigas de concreto armado com alta taxa de armadura (concreto superarmado). Os experimentos empregados são vigas em flexão a três pontos (dois apoios e uma carga aplicada no centro do vão), onde as barras de aço são substituídas por uma camada de elementos finitos de altura equivalente. Aloca-se uma linha de elementos de interface coesiva verticalmente no centro das vigas no intuito de permitir o processo de dano, tanto em tração quanto em compressão. Na zona de interface entre os elementos de concreto e os de aço são colocados elementos de aderência. É verificada a influência nos modelos numéricos de diversos parâmetros, tais como altura da viga, armadura de compressão, armadura de cisalhamento e escala. / In this work is presented a theory to the consideration of the concrete crushing applied to the finite element method, the Overlapping Crack Model. In this case the crushing is considered through the interpenetration of finite elements. Together with the well-known Cohesive Crack Model, the approach is used to simulate the behavior of reinforced concrete beams with high volume fraction of reinforcement (under reinforced concrete). The used experiments are beams subjects to three-point bending, where the steel bars are replaced by an equivalent layer of finite elements. A central vertical line of interfaces is used in order to take into account the damage due to crushing and fracture. At the concrete-steel interface, friction elements are considered. The influence of some parameters, such as depth of the beam, compression and shear reinforcement, etc., is investigated.
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Acontecimentos pictóricos: narrativas de um processo por sobreposição de camadasCoutinho, Roger Fraga, Coutinho, Roger Fraga 23 May 2014 (has links)
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Previous issue date: 2014-05-23 / Sem bolsa / Na presente pesquisa, que se desdobrou a partir de minha produção pictórica, reflito sobre questões advindas de meu processo de criação, este que acontece por sobreposições de camadas de tinta, pelas quais a cor atinge, lentamente, diferentes níveis de intensidade. Utilizo a narrativa como gênero textual, buscando uma maior aproximação com o processo para evidenciar o olhar imersivo situado entre ações e
gestos. As pinturas não obedecem a projetos definidos a priori, suas configurações surgem pelo diálogo entre a intencionalidade e os acontecimentos pictóricos, portanto uma dialética entre acaso e intenção. As relações cromáticas e espaciais são transformadas constantemente até que sejam suspensas as ações elaborais. Este fazer solicita um exercício da atenção capaz de potencializar percepções sempre renovadas
acerca dos acontecimentos pictóricos. Como referências artísticas investigo alguns aspectos das produções pictóricas de Henri Matisse, Mark Rothko, Barnett Newman, Günther Förg e, da artista brasileira, Gabriela Machado. Além de pensamentos sobre arte e processo de criação de Paulo Pasta e Hélio Oiticica. Os teóricos mais abordados são Maurice Merleau-Ponty e Simone Weil. / In the present study, which unfolds from my pictorial production, I reflect upon issues arising from my creation process, the one in question, happens by overlapping layers of paint, in which the color slowly reaches different levels of intensity. I use narrative as a genre, seeking a closer relationship with the process to highlight the immersive look set between actions and gestures. The paintings do not follow projects defined a priori, their configurations arise through the dialogue between intentionality and pictorial events,
therefore, a dialectics between chance and intention. Chromatic and spatial relationships are transformed constantly until the elaboration actis suspended. This making calls attention to potentiate ever new perceptions about pictorial events. As artistic references, investigate some aspects of pictorial production of Henri Matisse, Mark Rothko, Barnett Newman, Günther Förg and the Brazilian artist Gabriela Machado, in addition to thoughts on art and creation process of Paul Binder and Hélio Oiticica. More theorists addressed
are Maurice Merleau-Ponty and Simone Weil.
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Packing curved objects with interval methods / Méthodes intervalles pour le placement d’objets courbesSalas Donoso, Ignacio Antonio 29 April 2016 (has links)
Un problème courant en logistique, gestion d’entrepôt, industrie manufacturière ou gestion d’énergie dans les centres de données est de placer des objets dans un espace limité, ou conteneur. Ce problème est appelé problème de placement. De nombreux travaux dans la littérature gèrent le problème de placement en considérant des objets de formes particulières ou en effectuant des approximations polygonales. L’objectif de cette thèse est d’autoriser toute forme qui admet une définition mathématique (que ce soit avec des inégalités algébriques ou des fonctions paramétrées). Les objets peuvent notamment être courbes et non-convexes. C’est ce que nous appelons le problème de placement générique. Nous proposons un cadre de résolution pour résoudre ce problème de placement générique, basé sur les techniques d’intervalles. Ce cadre possède trois ingrédients essentiels : un algorithme évolutionnaire plaçant les objets, une fonction de chevauchement minimisée par cet algorithme évolutionnaire (coût de violation), et une région de chevauchement qui représente un ensemble pré-calculé des configurations relatives d’un objet (par rapport à un autre) qui créent un chevauchement. Cette région de chevauchement est calculée de façon numérique et distinctement pour chaque paire d’objets. L’algorithme sous-jacent dépend également du fait qu’un objet soit représenté par des inégalités ou des fonctions paramétrées. Des expérimentations préliminaires permettent de valider l’approche et d’en montrer le potentiel. / A common problem in logistic, warehousing, industrial manufacture, newspaper paging or energy management in data centers is to allocate items in a given enclosing space or container. This is called a packing problem. Many works in the literature handle the packing problem by considering specific shapes or using polygonal approximations. The goal of this thesis is to allow arbitrary shapes, as long as they can be described mathematically (by an algebraic equation or a parametric function). In particular, the shapes can be curved and non-convex. This is what we call the generic packing problem. We propose a framework for solving this generic packing problem, based on interval techniques. The main ingredients of this framework are: An evolutionary algorithm to place the objects, an over lapping function to be minimized by the evolutionary algorithm (violation cost), and an overlapping region that represents a pre-calculated set of all the relative configurations of one object (with respect to the other one) that creates an overlapping. This overlapping region is calculated numerically and distinctly for each pair of objects. The underlying algorithm also depends whether objects are described by inequalities or parametric curves. Preliminary experiments validate the approach and show the potential of this framework.
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Infrared welding of continuous fibre-reinforced thermoplastics – Investigations on overlapping jointsConstantinou, Marios, Gehde, Michael 07 July 2017 (has links) (PDF)
Continuous fibre-reinforced thermoplastics often are offered as impregnated and consolidated semi-finished products which are known as organic sheets. The thermoplastic matrix leads to several advantages including the thermoformability and weldability.
Parts made of organic sheets are frequently produced by forming the semi-finished product into half-shells and stiffening those shells in the course of the process e.g. by the injection moulding of ribs. Larger and more complex parts with hollow body structures can be manufactured e.g. by forming the semi-finished products into half-shells and joining the half-shells. However, the currently available manufacturing technologies for parts made of organic sheets have cap profile shaped joints which prevent the use of the reinforcing fibres across the joint plane.
Investigations have proven that overlapping weld joints in organic sheets show much higher strengths than cap profile shaped joints which can be explained by the fibre use across the joint plane. Furthermore, the infrared welding technology was verified as an appropriate process for the welding of organic sheets since no need for additional welding material is given, short heating times can be realized and no contact of the infrared emitters to the joining parts is required. Therefore, the present study shall reveal the high potential of the overlapping welding of organic sheets. Influences on the weld strengths of infrared welded organic sheets are described and potential improvements concerning the materials to be welded as well as the welding process are shown.
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The COMESA, EAC and SADC Tri-partite Free Trade Agreement: Prospects and Challenges for the Regions and AfricaMathys, Reagan January 2012 (has links)
Masters administration (M. Admin) / The tri-partite initiative in and for Africa has been accompanied by high levels of optimism since its political endorsement in 2008. It provides for an opportunity to resolve a host of problems with regards to regional integration in Eastern and Southern Africa. The overall aim of this study is to explore the prospects and challenges towards realising the Tri-partite Free Trade Area (T-FTA) in and for Africa. This study is pragmatic and implicitly seeks to uncover how the T-FTA could contribute to the African Regional Integration Project (ARIP), given the challenges that regional integration face in Africa. Regional integration has a long and rich history in Africa, which started at thehave been weak since the start and persist in its superficial nature with littledevelopmental impact. The reasons for the lack of meaningful integration in Africa are wide-ranging and span national, regional and system level analytical viewpoints. They encompass areas such as developmental levels, political will, respect for regional architecture, overlapping membership and the Economic Partnership Agreements (EPAs). These factors impact on the integration process in Africa and explain in varied ways why there has been little comprehensive economic integration. The starting point was to define the complex concept of regional integration. The dominant factors that define and affect regional integration in this study are that it is a state-based exercise, driven by economic integration, and influenced by the global political economy of the day. It was determined that Africa has adapted its regional integration strategies according to the shifts and influences in the global political economy on states, emanating from the post WWII period to the present day. The mpact of the global economy on Africa since independence was great and is viewed impact on the integration process. Regional integration is essentially a state to state pursuit for integration. Essentially, regional integration is being pursued by states that are still struggling to consolidate statehood, and this leaves little space to move towards a regional approach. However, given the dynamics of a globalised world, regional integration as a strategy is no longer questioned in Africa and is an important component of its developmental agenda. Clarifying the T-FTA was important, and this was done in order to highlight what the tri-partite initiative is and is not. This provided for an opportunity to investigate what the dominant areas are that have informed the emergence of the tri-partite process. The former was found to be largely economic in nature, focusing on harmonising the trade regimes of COMESA, EAC and SADC as a primary motivation. The tri-partite initiative will facilitate and encourage the harmonisation of trade regimes by stressing market integration, infrastructure development and industrialisation, coupled by a developmental approach. This is promising, as the tri-partite initiative seeks to simultaneously deal with many issues that have been commonly associated with the problems that regional integration face in Africa. When viewing the negotiating context, as well as the principles upon which it is to be based, indicate though, that Africa still favours individual state interest that will be hard to reconcile given that the tri-partite region currently has 26 participant states. In terms of economic integration, the T-FTA seeks to put new generation trade issues on the agenda by including services, movement of persons as well as trade facilitation, all of which have been found to be important in realising a trade in goods agenda that is the focus of regional integration in Africa. Analysing the grassroots realities of the market integration pillar offered some valuable insights towards the purposes of this study. The market integration pillar is inundated with challenges, with Rules of Origin (RoO) being the primary challenge towards consolidating the trade in goods agenda on a tri-partite level. New generation trade issues are going to be equally difficult to realise, given that they have no implementation record in the individual Regional Economic Communities (RECs). Promising though is that trade facilitation has already seen positive results by resolving non tariff barriers in the regions.Infrastructure development is equally challenging, although it provides a significant opportunity to create better connectivity (physical integration) between states. In lot of pan-African goals that directly feed into initiatives of the African Union (AU) pillar has not as yet created any concrete tri-partite plans, so it remains to be seen what can be achieved. Ideally, industrialisation is viewed as the pillar that will solve the supply-side constraints of African economies hence, strengthening the trade in goods agenda in the regions. Even though the T-FTA has practical challenges to implementation, there are at least two underlying factors that indirectly affect the prospects of realising the tripartite initiative. The EPAs are an emergent threat in that they run parallel to tripartite negotiations; and respect for a rules based integration process, are issues that warrant consideration. Fundamentally, in order to achieve a successful T-FTA will require a shift in the way business is done in African integration. African states need to realise that their national interests are best served through cooperation, in meaningful ways. Inevitably this requires good faith as well as ceding some sovereignty towards regional goals. Thus, there is a risk that the T-FTA not realised. The fundamentals of political will, economic polarisation and instability have to be resolved. This will lay an appropriate foundation for the tripartite initiative to be sustainable, with developmental impact. / South Africa
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Überlappendes Infrarotschweißen von Organoblechen zur Herstellung von Hohlkörperbauteilen – Verbindungseigenschaften und mögliche VerfahrensvariantenConstantinou, Marios, Gehde, Michael 07 December 2017 (has links) (PDF)
Endlosfaserverstärkte Thermoplaste werden oftmals als imprägnierte und konsolidierte Halbzeuge angeboten. Solche thermoplastischen Prepregs werden üblicherweise als Organobleche bezeichnet. Die thermoplastische Matrix ermöglicht unter anderem die Warmformbarkeit und Schweißbarkeit von Organoblechen.
Organobleche sind, durch die ausschließliche Möglichkeit sie mittels Thermoformen umzuformen, in ihrer Formgebung auf halbschalige Strukturen beschränkt, welche begrenzte Torsions-, Verwindungs- und Beulsteifigkeiten aufweisen. Um die Steifigkeiten dieser schalenförmigen, offenen Bauteile zu erhöhen, können z. B. versteifende Rippen oder Verstärkungssegmente eingebracht werden. Aufgrund des Thermoformprozesses sind mit Organoblechen, verglichen mit duroplastischen Systemen, jedoch nur kleine und einfache Bauteilgeometrien realisierbar. Um neben der Steifigkeitserhöhung auch größere und komplexere Bauteile herzustellen, können die schalenförmigen Organobleche während des Umformvorgangs gefügt werden. Auf diese Weise werden Hohlkörper in Doppelhutprofilform gefertigt. So werden, auch ohne Einbringung von Rippen o. ä., hohe Bauteilsteifigkeiten erreicht. Die Doppelhutprofilform hat jedoch eine nicht optimale Nutzung der Faserverstärkung über die Fügeebene hinweg zur Folge, da die Fasern von der Belastungsrichtung abweichend umgelenkt werden.
Im vorliegenden Beitrag wird daher das überlappende Infrarotschweißen von Organoblechen behandelt, was eine Faserverstärkung über die Fügeebene hinweg ermöglicht. Die Prozess- und Werkstoffeinflüsse auf die Verbindungseigenschaften werden beschrieben und Möglichkeiten zur Optimierung der Schweißnahteigenschaften dargestellt. Des Weiteren werden Optimierungskriterien für überlappende Infrarotschweißungen an den untersuchten Organoblechen festgelegt. Die im Verlauf der Forschungsarbeiten umzusetzenden Verfahrensvarianten zur Herstellung von Hohlkörperbauteilen aus Organblechen werden zudem vorgestellt.
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Environnement et croissance : Essais sur des implications des choix altruistes des ménages / Environment and growth : Essays on some implications of households' altruistic choicesConstant, Karine 15 July 2015 (has links)
Cette thèse est consacrée à l‘étude de la relation entre la croissance économique et l’environnement, en tenant compte des décisions altruistes des ménages envers leurs enfants en termes de legs économique, éducatif et environnemental. Ce travail s’articule autour de trois chapitres. Le premier se focalise sur les premiers stades de développement, marquant un tournant majeur de cette relation, et met en exergue le rôle des interactions des sphères économique, démographique et environnementale dans l’émergence d’un processus d’industrialisation polluante. Il illustre également les grandes disparités observées historiquement avec des économies piégées dans une trappe à pauvreté et d’autres se développant au prix d’une pollution élevée. Les chapitres suivants s’intéressent à des économies développées. Le deuxième chapitre prend en compte l’endogénéité des préférences environnementales pour analyser une politique environnementale composée d’outils usuels (taxe sur la pollution et dépenses de dépollution) et d’un outil éducatif visant à sensibiliser les ménages à l'environnement. Nous montrons qu’un tel "policy mix" peut permettre à la fois d’éviter des inégalités intergénérationnelles, provenant de fluctuations des préférences, et de favoriser la croissance économique. Le troisième chapitre traite des effets de la pollution sur l’espérance de vie et de l’aspect inégalitaire de leur répartition au sein de la population. Nous trouvons qu’il existe une trappe à inégalités, où les disparités empirent constamment mais qu’une politique environnementale peut permettre d’échapper à cette trappe et d’augmenter la croissance de l’économie, par ses effets sur la santé et l’éducation. / This thesis is devoted to the analysis of the relationship between economic growth and the environment, when considering the altruistic choices of parents toward their children, through environmental, economic and educative bequests. This work is organized around three chapters. The first focuses on the first stages of economic development, corresponding to a major turning point of this relationship. It highlights the role of interactions between economic, demographic and environmental spheres in the emergence of a polluting industrialization. Moreover, it illustrates the great disparities, historically observed, with economies stuck in a poverty trap and others developing at expense of their environment. The others chapter deals with developed economies. The second chapter takes into account the endogeneity of environmental preferences in order to analyze the implications of an environmental policy composed of usual tools (pollution tax and abatement activities) and an educative tool aiming to raise households’ environmental awareness. We show that such a policy mix may allow to avoid intergenerational inequalities, coming from fluctuations in preferences, and to enhance economic growth. The third chapter considers the effects of pollution on longevity and their unequal repartition across population. We highlight that there exists an inequality trap, where disparities are persistently widening, but also that an environmental policy may allow an economy to escape from this trap and to improve economic growth, through its positive effects on health and on the returns to education.
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Etalonnage de caméras à champs disjoints et reconstruction 3D : Application à un robot mobile / Non-overlapping camera calibration and 3D reconstruction : Application to Vision-Based RoboticsLébraly, Pierre 18 January 2012 (has links)
Ces travaux s’inscrivent dans le cadre du projet VIPA « Véhicule Individuel Public Autonome », au cours duquel le LASMEA et ses partenaires ont mis au point des véhicules capables de naviguer automatiquement, sans aucune infrastructure extérieure dédiée, dans des zones urbaines (parkings, zones piétonnes, aéroports). Il est doté de deux caméras, l’une à l’avant, et l’autre à l’arrière. Avant son déploiement, le véhicule doit tout d’abord être étalonné et conduit manuellement afin de reconstruire la carte d’amers visuels dans laquelle il naviguera ensuite automatiquement. Les travaux de cette thèse ont pour but de développer et de mettre en oeuvre des méthodes souples permettant d’étalonner cet ensemble de caméras dont les champs de vue sont totalement disjoints. Après une étape préalable d’étalonnage intrinsèque et un état de l’art sur les systèmes multi-caméra, nous développons et mettons en oeuvre différentes méthodes d’étalonnage extrinsèque (déterminant les poses relatives des caméras à champs de vue disjoints). La première méthode présentée utilise un miroir plan pour créer un champ de vision commun aux différentes caméras. La seconde approche consiste à manoeuvrer le véhicule pendant que chaque caméra observe une scène statique composée de cibles (dont la détection est sous-pixellique). Dans la troisième approche, nous montrons que l’étalonnage extrinsèque peut être obtenu simultanément à la reconstruction 3D (par exemple lors de la phase d’apprentissage), en utilisant des points d’intérêt comme amers visuels. Pour cela un algorithme d’ajustement de faisceaux multi-caméra a été développé avec une implémentation creuse. Enfin, nous terminons par un étalonnage déterminant l’orientation du système multi-caméra par rapport au véhicule. / My research was involved in the VIPA « Automatic Electric Vehicle for Passenger Transportation » project. During which, the LASMEA and its partnerships have developed vehicles able to navigate autonomously, without any outside dedicated infrastructure in an urban environment (parking lots, pedestrian areas, airports). Two cameras are rigidly embedded on a vehicle : one at the front, another at the back. Before being available for autonomous navigation tasks, the vehicle have to be calibrated and driven manually in order to build a visual 3D map (calibration and learning steps). Then, the vehicle will use this map to localize itself and drive autonomously. The goals of this thesis are to develop and apply user friendly methods, which calibrate this set of nonoverlapping cameras. After a first step of intrinsic calibration and a state of the art on multi-camera rigs, we develop and test several methods to extrinsically calibrate non-overlapping cameras (i.e. estimate the camera relative poses). The first method uses a planar mirror to create an overlap between views of the different cameras. The second procedure consists in manoeuvring the vehicle while each camera observes a static scene (composed of a set of targets, which are detected accurately). In a third procedure, we solve the 3D reconstruction and the extrinsic calibration problems simultaneously (the learning step can be used for that purpose) relying on visual features such as interest points. To achieve this goal a multi-camera bundle adjustment is proposed and implemented with a sparse data structures. Lastly, we present a calibration of the orientation of a multi-camera rig relative to the vehicle.
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