Este trabalho propõe um sistema de manipulação robótica para interação física segura com objetos ou humanos em ambientes não estruturados. A proposta considera a execução de tarefas de manipulação e a prevenção e tratamento de colisões utilizando apenas uma lei de controle, o controle de impedância. A inovação científica consiste em um sistema multifuncional implementado com uma única lei de controle em contraste com os sistemas já existem que utilizam chaveamento entre controladores para cada diferente funcionalidade do sistema, e que apresentam diversas desvantagens como instabilidade e oscilações, aumento da complexidade de programação, entre outras. Inicialmente é proposto um planejador de manipulação e regrasping baseado na combinação de trajetórias suaves e na adaptação dos parâmetros de um controle de impedância em tempo de execução. A mudança da impedância para cada etapa é obtida pela modificação dos parâmetros de inércia, rigidez e amortecimento do controlador. A estabilidade desta mudança dinâmica é possível pela utilização de trajetórias suaves obtidas com planejador Squeezed Screw modificado, cujas trajetórias geradas são livres de descontinuidades na posição e na velocidade. Adicionalmente, a prevenção de colisões é realizada com o auxílio de campos potenciais de forças de repulsão formados pela análise de dados de um sistema de visão também proposto. Estes mesmos dados são utilizados para a construção de um mapa de impedâncias ao redor do objeto cuja finalidade é suavizar efeitos de colisões indesejadas. Experimentos com um robô de arquitetura aberta e com um sistema de visão de baixo custo foram realizados na execução tarefa de manipulação de referência para se avaliar o desempenho da metodologia proposta em diferentes condições de operação encontradas em ambientes não estruturados, como por exemplo: erros de medida de posição, de calibração, ocorrência de colisões, etc. A tarefa de manipulação eleita foi a reorientação em 60° de um objeto circular no plano. Os resultados obtidos nos experimentos mostram a capacidade do controle de impedância associado a trajetórias suaves de realizar a tarefa eleita segundo avaliação utilizando como métricas de desempenho a porcentagem de reorientação, que apresentou uma média de 80% mesmo na presença de erros de medida do sensor de visão e erros de determinação da posição do objeto. / Recent applications in various robotics areas consider interaction between robots and objects or humans in non-structured environments. Under these conditions, in addition to the desire of robots to be able to perform their main tasks, handling, navigation, rehabilitation, etc, it is also desired to prevent and properly handle possible unwanted collisions, whether with objects, with other robots, animals or humans. There are several proposed methods for avoidance, handling and reaction for collisions, however, a widely used strategy is the controller switching between different robot states. There are several drawbacks within this strategy: instability and oscillation, increased programming complexity and consequent increased failure risk, need for different sensors and consequent increase in cost, among others. This work proposes a system applied to the robotic manipulation which is based on only one control law, the impedance control, whose expected capacity is, further performing manipulation tasks, avoidance and handling of potential undesired collisions. It is initially proposed a manipulation planner based the combination of smooth trajectories and the adjustment of parameters an impedance control at runtime. The change of impedance for each phase is achieved by modifying the parameters: mass, spring and damping controller. The stability of this dynamic change is possible by using smooth trajectories obtained with a modified Squeezed Screw trajectory planner, whose paths are discontinuities free in the position and speed. Additionally, collision avoidance is achieved through potential fields the repulsive forces of formed by analysis of data vision. The same data is used to construct an impedance map surrounding the object which objective is collision handling. Experiments with an open architecture robot and a low cost vision system are carried out in the execution of a benchmark manipulation task to evaluate the proposal performance under different operating conditions found in unstructured environments, for example, position measurement errors, calibration problems, occurrence of collisions, among others.

Le but des tokamaks est de produire de l'énergie à partir des réactions de fusion Deutérium-Tritium. Les impuretés dégradant les performances du plasma, par dilution et rayonnement, sont produites par: réactions D-T (Hélium), injection de gaz et interaction plasma-paroi. Dans ITER le divertor sera en Tungstène (W). Les expériences sur JET et ASDEX-Upgrade montrent que W peut pénétrer jusqu'au cœur du plasma et conduire à un effondrement radiatif. La compréhension, la prédiction et le contrôle du transport du W est de fait obligatoire. Collisions et turbulence contribuent au transport d'impuretés. Dans la topologie magnétique du tokamak, les collisions mènent au transport néoclassique. Jusqu'à présent, ces deux canaux de transport sont modélisés séparément, en supposant les flux additifs. Nous avons abordé cette question critique au moyen de simulations gyrocinétiques (GK) 5D avec le code GYSELA. Nous avons construit un nouvel opérateur de collision GK multi-espèces, valable pour toute impureté trace thermique. La version réduite implémentée vérifie les propriétés de conservation des collisions élastiques et la théorie néoclassique. Le coefficient de diffusion et la vitesse de pincement sont en accord avec les prédictions pour tous les régimes de collisionnalité. L'écrantage thermique du W est également retrouvé, mais pas à l'amplitude attendue. Des simulations auto-cohérentes révèlent les synergies entre les transports néoclassiques et turbulents: le flux total de W diffère jusqu'à un facteur 2 de la somme des deux flux obtenu à partir de simulations distinctes. Ceci est partiellement dû à la modification par la turbulence du mode poloïdal m = 1 du potentiel électrique. / Tokamaks aim at producing energy out of Deuterium-Tritium fusion reactions. Impurity degrade performance by diluting the D-T fuel and radiating. They originate from D-T reactions (Helium), or from edge seeding and plasma-wall interaction. In ITER the divertor will be in Tungsten (W). JET and ASDEX-Upgrade experiments have shown that W can penetrate up to the core and lead to radiative collapses. Understanding, predicting and possibly controlling its transport is therefore mandatory. Both collisions and turbulence contribute to impurity transport. In the tokamak magnetic topology, collisions lead to neoclassical transport. So far, these two transport channels are modelled separately, assuming additivity of the fluxes. We have addressed this critical issue by means of 5D gyrokinetic (GK) simulations with the GYSELA code. We have derived a new multi-species GK collision operator, valid for any trace and thermal impurity. The implemented reduced version, adapted to the high performance computing constraints of GYSELA, verifies the conservation properties of elastic collisions and the neoclassical theory. The diffusion coefficient and pinch velocity agree with the predictions in all collisionality regimes. Thermal screening is also recovered for W, although not at the expected magnitude - in link to isotropy and stationarity assumptions. Self-consistent simulations reveal synergies between neoclassical and turbulent transports: the total flux of W differs by up to a factor 2 from the sum of the two, obtained from separate simulations. This is partly due to the modification – magnitude and radial structure – by turbulence of the m=1 poloidal mode of the electric potential.

Dans cette thèse, nous étudions deux sous-familles d'attaques par canaux cachés sur l'exponentiation modulaire appelées respectivement attaques par collision et attaques horizontales. Cette étude est faite selon deux axes : leurs mises en pratique et les possibles contremesures.Dans un premier temps, nous étudions les attaques par canaux cachés sur un simulateur développé durant cette thèse. Ce simulateur permet de vérifier la bonne implémentation d'une attaque par canaux cachés avant sa mise en pratique dans un environnement réel. Dans un deuxième temps, nous étudions les attaques par collision dans un environnement réel. Pour cela, nous nous sommes intéressés à l'automatisation de la détection effective de collision. Ainsi, nous proposons un nouveau critère de détection de collision.Dans un troisième temps, nous étudions l'estimation du rapport signal à bruit d'un jeu de traces dans le contexte des attaques par canaux cachés. Ainsi, nous proposons une nouvelle façon d'estimer le rapport signal à bruit lors d'une attaque par canaux cachés. En outre, nous montrons que cette estimation du rapport signal à bruit peut être exploitéepour l'analyse des fuites d'un canal caché mais aussi pour effectuer un filtrage adaptatif ne nécessitant pas la connaissance de certains paramètres du composant analysé.Dans un quatrième temps, au travers d'une étude détaillée des principales étapes d'une attaque horizontale, nous montrons les problèmes pouvant intervenir dans la pratique et comment les résoudre. Ainsi des solutions génériques sont proposées. Nous proposons finalement de possibles contremesures aux attaques horizontales sur l'exponentiation modulaire / This thesis is focused on the study of two sub-families of side channel attacks applied on modular exponentiation called respectively, collision based attacks and horizontal (or single shot) attacks. This study is made according to two axes: their applications and the possible countermeasures.Firstly, we study side channel attacks on a simulator developed during this thesis. This simulator allows to validate the good implementation of a any side channel attack before its application in a real environment.Secondly, we study collision based attacks in a real environment. For this purpose, we study the automation of collision detection in practice. Then, we introduce a new collision detection criterion and show its practical interest. Afterwards, we study the estimation of the signal to noise ratio in the context of side channel attacks. So, we introduce a fast and accurate method for its estimation during a side channel analysis. From our method we derive pragmatic and efficient methods for the daily tasks of evaluators. Among them the analysis of the electrical activity of integrated circuit or the identification of the frequencies carrying usable information or information leakage.Finally, through a detailed description of the main stages of an horizontal attack, we propose effective and practical solutions to improve secret information extraction in real environment and on the other hand possible countermeasures against the horizontal attacks applied on modular exponentiation.

Les systèmes d’aide à la conduite, en général, et plus particulièrement les systèmes d’aide à l’évitement de collision sont de plus en plus en présents dans les véhicules car ils ont un très fort potentiel de réduction du nombre d’accidents de la circulation.En effet, ces systèmes ont pour rôle d’assister le conducteur, voire de se substituer à lui lorsque la situation de conduite indique un risque de collision important. Cette thèse traite du développement de ces systèmes en abordant quelques problématiques rencontrées.Afin de réagir convenablement, le système a d’abord besoin d’une représentation aussi fidèle que possible de l’environnement du véhicule. La perception est faite au moyen de capteurs extéroceptifs qui permettent de détecter les objets et d’en mesurer divers paramètres selon leur principe de mesure. La fusion des données individuelles des capteurs permet d’obtenir une information globale plus juste, plus certaine et plus variée. Ce travail traite en profondeur des méthodes de suivi d’objets par fusion de données multi-capteur, multimodale au niveau piste. Les approches proposées ont été évaluées puis approuvées grâce à des données de roulage réel et sur des données de conduite simulées.Il est ensuite nécessaire de faire une analyse de la scène perçue au cours du temps afin d’évaluer le risque de collision encouru par le véhicule porteur du système. Cette thèse propose des méthodes de prédiction de trajectoire et de calcul de probabilité de collision, à divers horizons temporels afin de quantifier le risque de collision et d’établir ainsi divers niveaux d’alerte au conducteur. Un simulateur de scénarios automobiles a été utilisé pour valider la cohérence des méthodes d’analyse de scène.Enfin, lorsque le risque de collision atteint un seuil jugé critique, le système doit calculer une trajectoire d’évitement de collision qui sera ensuite automatiquement exécutée. Les principales approches de planification de trajectoires ont été revues et un choix a été fait et motivé en accord avec le contexte de système d’aide à la conduite. / Driver assistant systems in general, and specially collision avoidance systems are more and more installed in recent vehicles because of their high potential in reducing the number road accidents. Indeed, those systems are designed to assist the driver or even to take its place when the risk of collision is very important. This thesis deals with the main challenges in the development of collision avoidance systems. In order to react in a convenient way, the system must, first, build a faithful representation of the environment of the ego-vehicle. Perception is made by means of exteroceptive sensors that detect objects and measure different parameters, depending on their measurement principle. The fusion of individual sensor data allows obtaining a global knowledge that is more accurate, more certain and more varied. This research work makes a deep exploration of high level multisensor, multimodal, multitarget tracking methods. The proposed approaches are evaluated and validated on real driving data and also on simulated scenarios. Then, the observed scene is continuously analyzed in order to evaluate the risk of collision on the ego-vehicle. The thesis proposes methods of vehicle trajectory prediction and methods to calculate the probability of collision at different prediction times. This allows defining different levels of alert to the driver. an automotive scenarion simulator is used to test and validate the proposed scene analysis approaches. Finally, when the risk of collision reaches a defined critical value, the system must compute a collision avoidance trajectory that will be automatically followed. The main approaches of trajectory planning have been revisited et one has chosen according to the context of driver assistant system.

The aim of this diploma thesis is determination of speed during sideswipe collisions of two vehicles involved. In theoretical part, available knowledge base and the preparation of experiments made for this thesis are described. Practical part describes individual experiments, and processes and evaluates the results of said experiments. This thesis aims to improve current knowledge base about sideswipe collisions.

Master's thesis deals with vehicles collisions within an environment of logistic distribution storehous. The aim is to avoid potential collisions that can occur between these vehicles. In the first chapter are detailed collisions of particles and elements impact for the law of conservation of energy and momentum. In further sections is carried out detailed research of elastic and inelastic collisions in an ideal environment, which are the theoretical basis for the simulation of the real environment. Collisions are supported by detailed calculations and added pictures. The second chapter deals with the development of double-layer application simulating elastic collisions in an ideal environment. In subchapters are descriptions of the classes and methods for computing prediction of collisions with examples of source code. The last section describes the software platform JavaFX and used animation classes that are required for visualization issues. The last chapter, which is the main goal of the work is done by the expansion of the existing design environment of storehouse and vehicles. Particular chapters then describe the cases of various types of collisions their detection and avoidance. There is an application designed to address this issue, with a description of the classes and methods. Used methods are supported with flowcharts for easier understanding.

Thesis deals with problems of forensic technical analysis of traffic accidents, concretely with creation of complex methodology for analysis of traffic accidents of vehicles on the crossroad. There are defined terms of "complex system and complex analysis of traffic accident", technically acceptable range of important input values, systematization of accidents on the crossroad with methodologies in the thesis. Thesis shows problematical expert procedures, suggests scheme of expert evidence and includes methodology of measurement of common movement of vehicles on the crossroad and recommendation for expert procedures.

Les systèmes moléculaires sous irradiation sont présents dans le monde vivant et la matière inerte. D’un point de vue macroscopique, ils sont constitués d’un très grand nombre de molécules mais l’action d’un rayonnement agit à travers les électrons localisés sur une molécule, créant ainsi, localement et sur des échelles de temps courts, une situation manifestement très éloignée de l’équilibre thermodynamique. Etudier les nanosystèmes moléculaires sous irradiation permet d’accéder à la manière dont l’énergie déposée dans une molécule va être redistribuée dans le système, via les interactions entre molécules. Les distributions de vitesses d’une molécule évaporée mesurées pour les nanogouttes de méthanol protonées présentent un comportement bimodal avec, comme observé pour l’eau, l’évaporation de molécules avec des vitesses nettement supérieures à celles attendues après redistribution complète de l’énergie. De plus, une réaction dans l’agrégat, conduisant à la formation du diméthyléther protoné avec élimination d’une molécule d’eau, a été observée. La possibilité d’étudier la compétition suite à l’irradiation entre l’évaporation moléculaire et une réaction d’élimination pourra contribuer à contraindre les hypothèses quant à la formation de molécules prébiotiques en conditions interstellaires.Les résultats sur les nanogouttes mixtes eau-méthanol ont été comparés à ceux obtenus avec celles dopées en pyridine et celles d’eau pure. L’analyse de la partie basse vitesse des distributions de vitesses des molécules d’eau évaporées montrent que l’évaporation intervient avant la redistribution complète de l’énergie dans l’ensemble de l’agrégat. Il apparaît qu’il y a moins d’énergie disponible pour l’évaporation d’une molécule d’eau quand l’excitation initiale est déposée sur le méthanol protoné ou sur l’ion pyrimidium. Ainsi, à la différence de l’ion hydronium qui est parfaitement solvaté, les impuretés favorisent la croissance de ces petits agrégats d’eau dont la présence dans l’atmosphère facilite les premières étapes de la formation des aérosols / Molecular systems under irradiation are present in the living as well as in inert matter. From a macroscopic point of view, the matter is made up of a very large number of molecules but the action of radiation acts through the electrons located on a molecule and thus, creating locally and on short time scales a situation clearly far from the thermodynamic equilibrium. Studying molecular nanosystems under irradiation provides access to understanding of how the energy deposited in a molecule will be redistributed into the system through interactions between surrounding molecules.The velocity distributions of evaporated molecules measured for irradiated protonated methanol nanodroplets have a bimodal behaviour, as observed for water, including evaporation of molecules with much higher velocities than expected after complete redistribution of energy. In addition, a reaction in the cluster leading to the formation of protonated dimethyl-ether with elimination of a water molecule was observed. The possibility of studying the competition between molecular evaporation and an elimination reaction following irradiation of a nanodroplet will contribute to constrain the hypothesis on the formation of prebiotic molecules under interstellar conditions. The results for the water-methanol mixed nanodroplets were compared with those obtained with pyridine doped water nanodroplets and protonated water nanodroplets. Analysis of the low velocity part of the velocity distributions of the evaporated water molecules shows that evaporation occurs before the complete redistribution of energy in the cluster. It appears that there is less energy available for evaporation of a water molecule when the initial excitation is located on the protonated methanol ion or on the pyrimidium. Thus, unlike the hydronium ion which is fully solvated, impurities promote the growth of these small water clusters, whose presence in the atmosphere facilitates the early stages of aerosol formation

With the increasing interest in Virtual/Augmented Reality, the next generation of application platforms is emerging in the form of immersive and engaging experiences. The company Dewire Knightec is exploring an application platform based on the web technology WebXR where users can interact with multiple applications simultaneously. However, numerous independent applications rendering content in the same 3D environment can lead to objects intersecting and occluding, leading to visual conflicts. In this thesis work, we discuss the concept of visual conflicts and avoidance strategies. We present a fully working prototype of a conflict mitigation framework for concurrent WebXR applications. The framework mitigates conflicts using two main collision avoidance strategies in the form of multiple render options and position offsetting. The proposed framework is demonstrated in a scenario where applications render contents on top of buildings in the user’s surroundings. By running multiple applications, a user can for example read a restaurant menu, see mall opening hours, and get travel directions simultaneously. The feasibility and efficiency of the proposed avoidance strategy in developed framework has been evaluated using a focus group of developers and software architects. After the evaluation, the framework can be summarized as a good foundation for future multi-application XR platforms.

The utilization of driverless forklifts necessitates stringent safety measures to prevent any harm to human or material involved in their operation. This thesis addresses the critical need for collision detection algorithms for driverless forklifts, particularly in scenarios where traditional sensors are obstructed during loading and unloading processes. Instead of relying on external sensors, this research focuses on utilizing the internal sensors already present in the forklift. Signals from the forklift were collected during various driving scenarios in a controlled lab environment. Five different algorithms were developed and evaluated, providing detailed insights into their strengths and limitations. These algorithms employ a range of techniques, including physical modeling, regression modeling, residual analysis, and machine learning classification. All five algorithms demonstrate notable accuracy and reliability in collision detection. The research contributes to the advancement of collision detection technology in industrial environments, offering practical insights for safer and more productive material handling operations.