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Les travaux présentés dans cette thèse portent sur l’imagerie computationnelle active et passive en micro-ondes. L’utilisation d’une cavité chaotique comme composants compressif est étudiée tant théoriquement (modèle mathématique, résolution algorithmique du problème inverse) et expérimentalement. L’idée sous-jacente est de remplacer un réseau d’antennes par une unique cavité réverbérante dont un réseau d’ouvertures sur la face avant permet de coder l’information spatiale d’une scène dans la réponse temporelle de la cavité. La réverbération des ondes électromagnétique à l’intérieur de la cavité fournit les degrés de liberté nécessaires à la reconstruction d’une image de la scène. Ainsi il est possible de réaliser en temps réel une image haute-résolution d’une scène à partir d’une unique réponse impulsionnelle. Les applications concernent la sécurité ou l’imagerie à travers les murs. Dans ce travail, la conception et la caractérisation d’une cavité chaotique ouverte sont effectuées. L’utilisation de ce dispositif pour réaliser en actif des images de cibles de diverses formes est démontrée. Le nombre de degrés de liberté est ensuite amélioré en modifiant les conditions aux limites grâce à l’ajout lampes fluorescentes. L’interaction des ondes avec ces éléments plasma permet de créer de nouvelles configurations de la cavité, améliorant ainsi la résolution des images. L’imagerie compressive est ensuite appliquée à la détection et localisation passive du rayonnement thermique naturel de sources de bruit, à partir de la corrélation des signaux reçus sur deux voies. Enfin, une méthode novatrice d’imagerie interférométrique de cibles est présentée. Elle est basée sur la reconstruction de la réponse impulsionnelle entre deux antennes à partir du bruit thermique micro-ondes émis par un réseau de néons. Ces travaux constituent une avancée vers les systèmes d’imagerie futurs. / The broad topic of the presented Ph.D focuses on active and passive microwave computational imaging. The use of a chaotic cavity as a compressive component is studied both theoretically (mathematical model, algorithmic resolution of the inverse problem) and experimentally. The underlying idea is to replace an array of antennas with a single reverberant cavity with an array of openings on the front panel that encodes the spatial information of a scene in the temporal response of the cavity. The reverberation of electromagnetic waves inside the cavity provides the degrees of freedom necessary to reconstruct an image of the scene. Thus it is possible to create a high-resolution image of a scene in real time from a single impulse response. Applications include security or imaging through walls. In this work, the design and characterization of an open chaotic cavity is performed. Using this device, active computational imaging is demonstrated to produce images of targets of various shapes. The number of degrees of freedom is further improved by changing the boundary conditions with the addition of commercial fluorescent lamps. The interaction of the waves with these plasma elements allows new cavity configurations to be created, thus improving image resolution. Compressive imaging is next applied to the passive detection and localization of natural thermal radiation from noise sources, based on the correlation of signals received over two channels. Finally, an innovative method of interferometric target imaging is presented. It is based on the reconstruction of the impulse response between two antennas from the microwave thermal noise emitted by a network of neon lamps. This work constitutes a step towards for future imaging systems.

The objective of this research is to verify the three degree of freedom capabilities of a bio-inspired quad flapping-wing micro aerial vehicle in simulation and in hardware. The simulation employs a nonlinear plant model and input-output feedback linearization controller to verify the three degree of freedom capabilities of the vehicle. The hardware is a carbon fiber test bench with four flapping wings and an embedded avionics system which is controlled via a PD linear controller. Verification of the three degree of freedom capabilities of the quad flapping-wing concept is achieved by analyzing the response of both the simulation and test bench to pitch, roll, and yaw attitude commands.

Deliberate and accidental explosions along with the heightened risk of loss of life and property damage during such events have highlighted the need for research in the behaviour of materials under high strain rates. Where an extensive body of research is available on steel and concrete structures, little to no details on how to address the design or retrofitting of wood structures subjected to a blast threat are available. Studies reported in the literature that focused on full scale light-frame wood structures did not quantify the increase in capacity due to the dynamic loading while the studies that did quantify the increase mostly stems from small clear specimens that are not representative of the behaviour of structural size members with defects. Tests on larger-scale specimens have mostly focused on the material properties and not the structural behaviour of subsystems. Advancements in design and construction techniques have greatly contributed to the emergence of taller and safer wood structures which increase potential for blast threat. This thesis presents results on the flexural behaviour of light-frame wood stud walls subjected to shock wave loading using the University of Ottawa shock tube. The emphasis is on the overall behaviour of the wall subsystem, especially the interaction between the sheathing and the studs through the nailed connection. The approach employed in this experimental program was holistic, where the specimens were investigated at the component and the subsystem levels. Twenty walls consisting of 38 mm x 140 mm machine stress-rated (MSR) studs spaced 406 mm on center and sheathed with two different types and sheathing thicknesses were tested to failure under static and dynamic loads. The experimental results were used to determine dynamic increase factors (DIFs) and a material predictive model was validated using experimental data. The implications of the code are also discussed and compared to the experimental data. Once validated, an equivalent single-degree-of-freedom (SDOF) model incorporating partial composite action was used to evaluate current analysis and design assumptions. The results showed that a shock tube can effectively be used to generate high strain-rate flexural response in wood members and that the material predictive model was found suitable to effectively predict the displacement resulting from shock wave loading. Furthermore, it was found that current analysis and design approaches overestimated the wall displacements.

No description available.

Deliberate and accidental explosions along with the heightened risk of loss of life and property damage during such events have highlighted the need for research in the behaviour of materials under high strain rates. Where an extensive body of research is available on steel and concrete structures, little to no details on how to address the design or retrofitting of wood structures subjected to a blast threat are available. Studies reported in the literature that focused on full scale light-frame wood structures did not quantify the increase in capacity due to the dynamic loading while the studies that did quantify the increase mostly stems from small clear specimens that are not representative of the behaviour of structural size members with defects. Tests on larger-scale specimens have mostly focused on the material properties and not the structural behaviour of subsystems. Advancements in design and construction techniques have greatly contributed to the emergence of taller and safer wood structures which increase potential for blast threat. This thesis presents results on the flexural behaviour of light-frame wood stud walls subjected to shock wave loading using the University of Ottawa shock tube. The emphasis is on the overall behaviour of the wall subsystem, especially the interaction between the sheathing and the studs through the nailed connection. The approach employed in this experimental program was holistic, where the specimens were investigated at the component and the subsystem levels. Twenty walls consisting of 38 mm x 140 mm machine stress-rated (MSR) studs spaced 406 mm on center and sheathed with two different types and sheathing thicknesses were tested to failure under static and dynamic loads. The experimental results were used to determine dynamic increase factors (DIFs) and a material predictive model was validated using experimental data. The implications of the code are also discussed and compared to the experimental data. Once validated, an equivalent single-degree-of-freedom (SDOF) model incorporating partial composite action was used to evaluate current analysis and design assumptions. The results showed that a shock tube can effectively be used to generate high strain-rate flexural response in wood members and that the material predictive model was found suitable to effectively predict the displacement resulting from shock wave loading. Furthermore, it was found that current analysis and design approaches overestimated the wall displacements.

This work addresses the deep-learning-based 6 Degree-of-Freedom (DoF) pose estimation utilizing 3D cameras on an iPhone 13 Pro. The task of pose estimation is to estimate the spatial rotation and translation of an object given its 2D or 3D images. During the pose estimation network training process, a common way to expand the training dataset is to generate synthetic images, which requires the 3D mesh of the target object. Although several famous datasets provide the 3D object files, it is still a problem when one wants to generate a customized real-world object. The typical 3D scanners are mainly designed for industrial usage and are usually expensive. We investigated in this project whether the 3D cameras on Apple devices can replace the industrial 3D scanners in the pose estimation pipeline and what might influence the results during scanning. During the data synthesis, we introduced a pose sampling method to equally sample on a sphere. Random transformation and background images from the SUN2012 dataset are applied, and the synthetic image is rendered through Blender. We picked five testing objects with different sizes and surfaces. Each object is scanned both by front TrueDepth camera and rear Light Detection and Ranging (LiDAR) camera with the ‘3d Scanner App’ on iOS. The network we used is based on PVNet, which uses a pixel-wise voting scheme to find 2D keypoints on RGB images and utilizes uncertainty-driven Perspective-n-Point (PnP) to compute the pose. We achieved both quantitative and qualitative results for each instance. i) TrueDepth camera outperforms Light Detection and Ranging (LiDAR) camera in most scenarios, ii) when an object has less reflective surface and high-contrast texture, the advantage of TrueDepth is more obvious. We also picked three baseline objects from Linemod dataset. Although the average accuracy is lower than the original paper, the performance of our baseline instances shows a similar trend to the original paper’s results. In conclusion, we proved that the 3D cameras on iPhone are capable of the pose estimation pipeline. / Detta arbete tar upp den djupinlärningsbaserade 6 Degree-of-Freedom (DoF) poseringsuppskattning med 3D-kameror på en iPhone 13 Pro. Uppgiften med poseuppskattning är att uppskatta den rumsliga rotationen och translationen av ett objekt givet dess 2D- eller 3D-bilder. Ett vanligt sätt att utöka träningsdataup- psättningen under träningsprocessen för positionsuppskattning är att generera syntetiska bilder, vilket kräver 3D-nätet för målobjektet. Även om flera kända datamängder tillhandahåller 3D-objektfilerna, är det fortfarande ett problem när man vill generera ett anpassat verkligt objekt. De typiska 3D-skannrarna är främst designade för industriell användning och är vanligtvis dyra. Vi undersökte i detta projekt om 3D-kamerorna på Apple-enheter kan ersätta de industriella 3D-skannrarna i poseskattningspipelinen och vad som kan påverka resultaten under skanning. Under datasyntesen introducerade vi en posesamplingsmetod för att sampla lika mycket på en sfär. Slumpmässig transformation och bakgrundsbilder från SUN2012-datauppsättningen tillämpas, och den syntetiska bilden renderas genom Blender. Vi valde ut fem testobjekt med olika storlekar och ytor. Varje objekt skannas både av den främre TrueDepth-kameran och den bakre ljusdetektions- och avståndskameran (LiDAR) med "3d-skannerappenpå iOS. Nätverket vi använde är baserat på PVNet, som använder ett pixelvis röstningsschema för att hitta 2D-nyckelpunkter på RGB-bilder och använder osäkerhetsdrivet Perspective-n-Point (PnP) för att beräkna poseringen. Vi uppnådde både kvantitativa och kvalitativa resultat för varje instans. i) TrueDepth-kameran överträffar Light Detection and Ranging-kameran (LiDAR) i de flesta scenarier, ii) när ett objekt har mindre reflekterande yta och högkontraststruktur är fördelen med TrueDepth högre. Vi valde också tre baslinjeobjekt från Linemod dataset. Även om den genomsnittliga noggrannheten är lägre än originalpapperet, visar prestandan för våra baslinjeinstanser en liknande trend som originalpapperets resultat. Sammanfattningsvis bevisade vi att 3D-kamerorna på iPhone är kapabla att göra positionsuppskattning.

Dans le cadre de la protection du bâti face au risque sismique, les techniques d’analyse simplifiées, basées sur des calculs quasi-statiques en poussée progressive, se sont fortement développées au cours des deux dernières décennies. Le travail de thèse a pour objectif d’optimiser une stratégie d’analyse simplifiée proposée par Chopra et al. (2001) et adoptée par les normes américaines FEMA 273. Il s’agit d’une analyse modale non linéaire découplée, dénommée par les auteurs UMRHA qui se caractérisent principalement par : des calculs de type pushover selon les modes de vibration dominants de la structure, la création de modèles à un degré de liberté non linéaire à partir des courbes de pushover, puis le calcul de la réponse temporelle de la structure en recombinant les réponses temporelles associées à chaque mode de vibration. Dans ce travail, la méthode UMRHA a été améliorée en investiguant les points suivants. Tout d’abord, plusieurs modèles à un degré de liberté non linéaire déduits des courbes de pushover modal sont proposés afin d’enrichir la méthode UMRHA originelle qui emploie un simple modèle élasto-plastique : autres modèles élasto-plastiques avec des courbes enveloppes différentes, le modèle de Takeda prenant en compte un comportement hystérétique propre aux structures sous séismes, et enfin, un modèle simplifié basé sur la dégradation de fréquence en fonction d’un indicateur de dommage. Ce dernier modèle à un degré de liberté privilégie la vision de la chute de fréquence au cours du processus d’endommagement de la structure par rapport à une description réaliste des boucles d’hystérésis. La réponse totale de la structure est obtenue en sommant les contributions non linéaires des modes dominants aux contributions linéaires des modes non dominants. Enfin, la dégradation des déformées modales, due à l’endommagement subi par la structure au cours de la sollicitation sismique, est prise en compte dans la méthode M-UMRHA proposée dans ce travail, en généralisant le concept précédent de dégradation des fréquences modales en fonction d’un indicateur de dommage : la déformée modale devient elle-aussi dépendante d’un indicateur de dommage, le déplacement maximum en tête de l’ouvrage ; l’évolution de la déformée modale en fonction de cet indicateur est directement identifiée à partir des calculs de pushover modal. La pertinence de la nouvelle méthode M-UMRHA est investiguée pour plusieurs types de structures, en adoptant des modélisations éprouvées dans le cadre de la simulation des structures sous séismes : portique en béton armé modélisé par des éléments multifibres pour le béton et les armatures, remplissage en maçonnerie avec des éléments barres diagonales résistant uniquement en compression, bâti existant contreventé (Hôtel de Ville de Grenoble) avec des approches coques multicouches. Les résultats obtenus par la méthode simplifiée proposée sont comparés aux résultats de référence issus de l'analyse temporelle non linéaire dynamique. / In the context of building’s protection against seismic risk, simplified analysis techniques, based on quasi-static analysis of pushover, have strongly developed over the past two decades. The thesis aims to optimize a simplified method proposed by Chopra and Goel in 2001 and adopted by American standards FEMA 273. This method is a nonlinear decoupled modal analysis, called by the authors UMRHA (Uncoupled Modal for Response History Analysis) which is mainly characterized by: pushover modal analysis according to the dominant modes of vibration of the structure, setting up nonlinear single degree of freedom systems drawn from modal pushover curves, then determining the history response of the structure by combining of the temporal responses associated with each mode of vibration. The decoupling of nonlinear history responses associated with each mode is the strong assumption of the method UMRHA. In this study, the UMRHA method has been improved by investigating the following points. First of all, several nonlinear single degree of freedom systems drawn from modal pushover curves are proposed to enrich the original UMRHA method, in which a simple elastic-plastic model is used, other elastic-plastic models with different envelope curves, Takeda model taking into account an hysteretic behavior characteristic of structures under earthquakes, and finally, a simplified model based on the frequency degradation as a function of a damage index. The latter nonlinear single degree of freedom model privileges the view of the frequency degradation during the structure damage process relative to a realistic description of hysteresis loops. The total response of the structure is obtained by summing the contributions of the non linear dominant modes to those of linear non dominant modes. Finally, the degradation of the modal shapes due to the structure damage during the seismic loading is taken into account in the new simplified method M-UMRHA (Modified UMRHA) proposed in this study. By generalizing the previous model of frequency degradation as a function of a damage index: the modal shape becomes itself also dependent on a damage index, the maximum displacement at the top of the structure; the evolution of the modal shape as a function of this index is directly obtained from the modal pushover analysis. The pertinence of the new method M-UMRHA is investigated for several types of structures, by adopting tested models of structures simulation under earthquakes: reinforced concrete frame modeled by multifibre elements with uniaxial laws under cyclic loading for concrete and steel, infill masonry wall with diagonal bars elements resistant only in compression, existing building (Grenoble City Hall) with multilayer shell elements and nonlinear biaxial laws based on the concept of smeared and fixed cracks. The obtained results by the proposed simplified method are compared to the reference results derived from the nonlinear response history analysis.

This work presents a research in the field of robotic visual telepresence. At the beginning explains the principle of teleprezence and it makes classification of robots according to their properties and concepts. Furthermore, there is a review of modern existing robots. The following chapter discusses the human visual system, the basic parameters and functions including parameters of head movements. Subsequently have been selected critical parameters for visual telepresence. At the conclusion of the theoretical part were designed some experiments to validation of human body biological parameters. In the practical part was conducted measuring the extent and speed of head movements, eye distinction depending on the lighting and measurement of visual field man. Also, a series of experiments was performed for practical technical embodiment of the telepresence system rescue robot for class Orpheus.

Nowadays, small autonomous underwater robots are strongly preferred for remote exploration of unknown and unstructured environments. Such robots allow the exploration and monitoring of underwater environments where a long term underwater presence is required to cover a large area. Furthermore, reducing the robot size, embedding electrical board inside and reducing cost are some of the challenges designers of autonomous underwater robots are facing. As a key device for reliable operation-decision process of autonomous underwater robots, a relatively fast and cost effective controller based on Fuzzy logic and proportional-integral-derivative method is proposed in this thesis. It efficiently models nonlinear system behaviors largely present in robot operation and for which mathematical models are difficult to obtain. To evaluate its response, the fault finding test approach was applied and the response of each task of the robot depicted under different operating conditions. The robot performance while combining all control programs and including sensors was also investigated while the number of program codes and inputs were increased.