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Robotics and more particularly humanoid robots are envisioned as a solution to support humans in dangerous, repetitive and demeaning tasks. Indeed, humanoid robots, with their human shape, are perfectly tailored to integrate our environment and use tools originally designed for humans. However, unstabilized vision of such robots severely degrades their perception, thus preventing them to autonomously operate in unknown environments. In this context, gaze stabilization emerged as a promising way to overcome this limitation. It consists in actively controlling the motors of the robot head and eyes in order to stabilize the perceived images. In this thesis, driven by bio-inspiration, we explore the potential use of the concept of internal model to support humanoid robot gaze stabilization. This concept from neuroscience, internally simulating the sensorimotor system, is indeed known to play a central role in human motor control and could also benefit to robot control. This doctoral dissertation starts by describing the tools developed to implement and test gaze stabilization controllers. More precisely, dynamic modelling of humanoid robots and middleware based software architecture are addressed. After that, two beneficial uses of internal model for robotic gaze stabilization are demonstrated. First, an anticipatory gaze stabilization based on the concept of virtual linkage is proposed. Then, a multimodal control scheme based on the reafference principle is presented. It complements the first controller with visual and inertial reflexes.

(FSA - Sciences de l'ingénieur)  – UCL, 2017

Advisors/Committee Members: UCL - SST/IMMC/MEED - Mechatronic, Electrical Energy, and Dynamics Systems, UCL - Ecole Polytechnique de Louvain, Delannay, Laurent, Ronsse, Renaud, De Vleeschouwer, Christophe, Fisette, Paul, Orban De Xivry, Jean-Jacques, Vanderborght, Bram, Asfour, Tamim.

▼ Bats are known for using echolocation in addition to sight for hunting and navigating at night. The capabilities of bats and their ``sonar'' systems vary widely, as each species has evolved to survive in its specific environment. Certain species of bats indigenous to Eurasia are observed to perform complex motions of the outer ear and noseleaf (a ridged structure which sits atop the nostrils and acts like a ``megaphone'' of sorts). These bats are noted to be able to live in particularly cluttered environments and could be a particularly useful model organism for improving sonar. This is because since they are able to acquire detailed information about its surroundings with only their nostrils and ears, are able to outperform complicated man-made devices with thousands more sensing elements. To be able to better understand how a fast-moving ear and noseleaf can improve the sonar capabilities of bats, robots which mimic these bats have been devised, with the main purpose being to replicate the sensing elements of the bat. There have been significant changes made to the robotic sonar head in order to allow for us to expand the capabilities of our research. Using CT-scans as reference, the design of the baffles was redesigned to become more realistic and to have more features observed in the bats. A new method was designed in order to move the ``ears'' and ``noseleaf'' of the robot, using pneumatic actuators, which allowed for better control of the system. Finally, prototype sensors were developed to aid in the development of a motion feedback system to ensure a stable system. The robotic sonar has been used in several experiments to study the effects of a fast-moving, flexible anatomy on the physical properties of echoes. This is first illustrated by studying the echoes from various targets with changes in ear and noseleaf shape. Additionally, with the use of the improved actuation system, it was shown that different motion profiles lead to different responses. The continued development of this system and the changes to the signals explored provide new opportunities for furthering the fields of adaptive sensing as they apply to robots and other platforms. Being able to use a few ``smart'' sensors will help reduce the size, power, and weight costs of traditional sensing designs and allow for more robust and efficient technology to be produced. Advisors/Committee Members: Mueller, Rolf (committeechair), Moore, Ignacio T. (committee member), Leonessa, Alexander (committee member), LaConte, Stephen Michael (committee member).

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N2O est le troisième plus important gaz à effet de serre ainsi qu’un des principaux gaz responsables de la dégradation de la couche d’ozone. Une approche bio-inspirée de la N2Oréductase (N2Or), enzyme réduisant N2O via un site actif comportant quatre ions cuivre pontés par un atome de soufre, aide au design de nouveaux systèmes. Six complexes à valences mixtes comportant un motif Cu2(µ-S) considéré comme minimum pour avoir une activité ont alors été synthétisés. Il a été démontré que la structure de ces centres métalliques est affectée par le solvant utilisé. Dans un solvant non coordinant comme l’acétone, tous les complexes possèdent une liaison intermétallique et une valence délocalisée à température ambiante. En revanche en solvant coordinant, la coordination de molécules d’acétonitrile rend impossible la formation de liaison intermétallique et localise la valence.Pour tester l’activité N2Or de ces complexes, un prototype permettant un bullage constant en cuve UV a été conçu. L’objectif est de mettre au point une réduction catalytique de N2O en utilisant un réducteur sacrificiel et une source de proton. Le gaz utilisé lors des tests semble cependant contenir une faible quantité de O2 empêchant la caractérisation des activités. Une optimisation visant à purifier N2O avant les tests est en cours.Par ailleurs, les réductions de O2 à deux électrons pour former H2O2 (un oxydant doux) et à quatre électrons pour former H2O (réaction utilisée dans les piles à combustibles) en font un domaine attractif. Il a été démontré que tous les complexes synthétisés lors de ces travaux sont capables de réduire catalytiquement O2 dans l’acétone et que seulement celui sans position échangeable est actif dans l’acétonitrile. Ce dernier a de plus montré une capacité à changer de sélectivité (H2O2 vs H2O) en fonction de la concentration en réducteur sacrificiel utilisé.

N2O is the third most important global warming gas and one of the most aggressive gas against ozone layer. A bio-inspired approach from N2Oreductase (N2Or), enzyme catalysing the two electron reduction of N2O with a four sulfur-bridged copper ions centre, helps for the design of new systems. Six mixed valent copper complexes containing the minimum Cu2(µ-S) core were then synthetized. It has been shown that these structures are affected by solvents in solution. Indeed, in a non-coordinating solvent like acetone, all these complexes have an intermetallic bond and a delocalized valence at room temperature. However in a coordinating solvent, the acetonitrile coordination makes it impossible to form a Cu-Cu bond and localize the valences.To test the N2Or activity, a prototype allowing a constant N2O bubbling in a UV cuve using a closed system was designed. The aim is to develop a catalytic reduction using sacrificial reductant and proton source. However, the gas bottle used for activity tests seems to contain a small amounts of O2 preventing results interpretation. The aim is now to optimize the prototype by adding a system that can purify N2O before activity tests.In a…

Advisors/Committee Members: Torelli, Stéphane (thesis director), Ménage, Stéphane (thesis director).

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Grâce aux progrès réalisés dans les domaines de la robotique et des systèmes de transport intelligents (ITS), les véhicules autonomes du futur sont en train de devenir une réalité. Comme les véhicules autonomes devront se comporter en toute sécurité en présence d’autres véhicules, de piétions et d’autres objets fixes ou en mouvement, une des choses les plus importantes qu’ils doivent faire est de percevoir efficacement à la fois leur mouvement et l’environnement autour d’eux. Dans cette thèse, nous avons d’abord étudié comment des capteurs visuels bio-inspirés, qui mesurent le flux optique en 1-D en utilisant seulement quelques pixels sur la base du système visuel de la mouche, pourraient être utilisés pour améliorer les manœuvres de stationnement automatiques. Nous avons ensuite travaillé sur une nouvelle rétine de silicium bio-inspirée, en montrant que le nouveau pixel, appelé M²APIX, est capable de s’auto-adapter dans une gamme de 7 décades et de répondre de manière appropriée à des changements de luminosité rapides jusqu’à ±3 décades, tout en conservant une sensibilité aux contrastes aussi bas que 2%. Nous avons enfin développé et testé un nouveau capteur de flux optique basé sur cette rétine auto-adaptative et sur une nouvelle méthode robuste pour le calcul du flux optique, qui est robuste aux variations de lumière, textures et vibrations que l’on retrouve en milieu routier. Nous avons également construit un robot de type voiture, appelé BioCarBot, qui estime sa vitesse et son angle de braquage au moyen d’un filtre de Kalman étendu (EKF), en utilisant uniquement les mesures de flux optique délivrées par deux capteurs de ce type regardant vers le sol.

Thanks to the advances in the fields of robotics and intelligent transportation systems (ITS), the autonomous vehicles of the future are gradually becoming a reality. As autonomous vehicles will have to behave safely in presence of other vehicles, pedestrians and other fixed and moving objects, one of the most important things they need to do is to effectively perceive both their motion and the environment around them. In this thesis, we first investigated how bio-inspired visual sensors, giving 1-D optic flow using a few pixels based on the findings on the fly’s visual system, could be used to improve automatic parking maneuvers. We subsequently tested a novel bio-inspired silicon retina, showing that the novel pixel, called M2APix, can auto-adapt in a 7-decade range and respond appropriately to step changes up to ±3 decades, while keeping sensitivity to contrasts as low as 2%. We lastly developed and tested a novel optic flow sensor based on this auto-adaptive retina and a new robust method for computing the optic flow, which is robust to the light levels, textures and vibrations that can be found while operating on the road. We also constructed a car-like robot, called BioCarBot, which estimates its velocity and steering angle by means of an extended Kalman filter (EKF) using only the optic flow measurements delivered by two downward-facing sensors of this…

Advisors/Committee Members: Ruffier, Franck (thesis director).

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La tendance marquée de ces dernières années au niveau des systèmes informatiques est à l'Ubiquitous Computing. Ces plateformes pervasives ont des contraintes (environnementales et architecturales) qui leurs sont propre et influence la manière de les programmer. En se basant sur l'étude des réseaux de capteurs une approche orientée agents et bio-inspirée est proposée pour programmer les plateformes pervasives en assurant leur adaptabilité dans un environnement non maitrisé. La question se pose de savoir comment améliorer les performances de ce type de plateforme construites à partir de modules possédant peu de ressources de calcul. L'emploi de coprocesseurs parallèles est envisagé. L'utilisation de matériel spécifique à l'un ou l'autre des modules de la plateforme pose des problèmes de facilité de programmation. Une solution de programmation adaptée est proposée tirant partie de la portabilité de Java et de la flexibilité de l'environnement proposé précédemment. L'ensemble de ces deux contributions qui forme un environnement de programmation pour plateformes pervasives, a été testé sur la plateforme PERPLEXUS.

Ubiquitous Computing is the emerging trend in computing systems. These pervasives platforms have characteristic constraints (environmental and architectural). Such characteristics clearly impact the way pervasive platforms should be programmed. Base on Sensor Network programming experience an agent oriented and bio-inspired approach is proposed as a reliable programming framework for pervasive platforms. Nevertheless, how to improve performance of such platforms made of modules with small computing resources. The use of parallel coprocessors is then considered. Such distributed and locally hardware dependent programming does not ease platform programming. Taking advantage of Java's portability and of the proposed framework flexibility a coprocessor programming solution is proposed. These contributions are basic blocks of a pervasive platform programming environment that has been tested on the PERPLEXUS platform.

Advisors/Committee Members: Robert, Michel (thesis director).

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Inspirés par les propriétés optiques des yeux composés de la mouche et par l’observation de micromouvements périodiques de sa rétine, différents capteurs visuels ont montré qu’il était possible de localiser un contraste très précisément. Ce fut les premières démonstrations d’hyperacuité visuelle de l’œil de la mouche.Dans cette thèse, un œil composé artificiel, doté d'un large champ de vision, est utilisé. Grâce à un nouvel algorithme de fusion des données visuelles, cet œil peut mesurer le déplacement d’un robot et lui permettre de se stabiliser au-dessus d’un environnement texturé. Localiser un contraste de manière linéaire sur l'ensemble du champ visuel demeure toutefois difficile. Un deuxième algorithme permet d’améliorer la localisation d’une barre grâce à un étalonnage, mais montre une certaine dépendance aux variations de contraste et de luminosité ambiante.Afin d'éviter ce processus d’étalonnage, un troisième algorithme qui s’appuie sur les travaux d'Heiligenberg et Baldi, a été proposé pour localiser deux contrastes. Ces auteurs ont montré que la somme pondérée de plusieurs capteurs ayant un champ récepteur gaussien pouvait fournir une estimation linéaire de la position d'un stimulus. Nous avons, pour la première fois, appliqué une variante de ce principe à un œil composé artificiel. Cet œil, une fois monté sur un robot permet de suivre une cible à une distance constante.Finalement, un œil composé artificiel dont la résolution intrinsèque est faible, peut être doté d’une hyperacuité visuelle et permettre de suivre une cible avec précision. Ces travaux ont ainsi conduit à proposer des stratégies bio-inspirées pour la localisation et la poursuite de cible.

Inspired by the optical properties of the fly compound eyes and the observation of its retinal periodic micro-movements, several visual sensors established that the localization of a contrast can be made very precisely. It was the first demonstration of the visual hyperacuity of the fly compound eye.In this thesis, an artificial compound eye with a wide field of view was used. Thanks to a novel algorithm fusing the visual signals, the sensor embedded onboard an aerial robot measures its displacement and enables the robot to hover above a textured environment.The localization of a contrast precisely over the whole field of view is still difficult. A second algorithm improved the localization of a bar thanks to a calibration. But it has a dependency to the contrast and the illuminance variations.In order to avoid a calibration process, a third algorithm was proposed to localize two contrasts. It is based on the work of Heiligenberg and Baldi, which showed that an array of Gaussian receptive field can provide a linear estimation of a stimulus position. For the first time, we applied a modified version of their estimation to an artificial compound eye. This sensor mounted on a rover allows following a target precisely at a constant distance.Finally, an artificial compound eye with a coarse spatial resolution can be endowed with hyperacuity and enables a robot…

Advisors/Committee Members: Viollet, Stéphane (thesis director), Ruffier, Franck (thesis director).

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Les matériaux naturels tels que l'os et la nacre d’ormeau sont constitués de blocs de construction relativement faibles et présentent pourtant souvent des combinaisons remarquables de rigidité, de résistance à la rupture et de ténacité. Ces performances sont dues en grande partie à leurs architectures de brique et de mortier. De nombreux efforts sont consacrés à la duplication de ces principes dans les matériaux synthétiques. Toutefois, les progrès sont en grande partie basés sur des approches empiriques, qui prennent beaucoup de temps et ne garantissent pas la réalisation optimale.La modélisation est une alternative attrayante pour guider la conception et les voies de traitement de ces matériaux. Dans ce travail, nous développons un modèle numérique basé sur la méthode des éléments discrets (DEM) pour comprendre les mécanismes de renforcement et optimiser les propriétés mécaniques des matériaux de type nacre en fonction de leurs paramètres microstructurales. Le modèle suit l’évolution de la fissure, prend en compte de différents mécanismes de renforcement et évalue quantitativement la rigidité, la résistance à la rupture et la ténacité. Une approche intéressante, basée sur l'imagerie EBSD, est présentée pour modéliser le matériau réel et ses différentes variations microstructurales. Les résultats sont ensuite combinés pour fournir des directives de conception pour les composites synthétiques de type brique et mortier comprenant uniquement des constituants fragiles.

Natural materials such as bone and the nacre of some seashells are made of relatively weak building blocks and yet often exhibit remarkable combinations of stiffness, strength, and toughness. Such performances are due in large part to their brick and mortar architectures. Many efforts are devoted to translate these design principles into synthetic materials. However, much of the progress is based on trial-and-error approaches, which are time consuming and do not guarantee that an optimum is achieved.Modeling is an appealing alternative to guide the design and processing routes of such materials. In this work, we develop a numerical model based on Discrete Element Method (DEM) to understand the reinforcement mechanisms and optimize the mechanical properties of nacre-like materials based on their microstructural parameters. The model follows the crack propagation, accounts for different reinforcement mechanisms, and quantitatively assess stiffness, strength, and toughness. An interesting approach, based on EBSD imaging, is presented to model the real material and its different microstructural variations. Results are then combined to provide design guidelines for synthetic brick-and-mortar composites comprising with only brittle constituents.

Advisors/Committee Members: Martin, Christophe (thesis director).

▼ Many highly-evolved bio-photonic structures, which tailor the propagation of light by coherent optical scattering, have been investigated. These natural designs, which have many diverse ecological functions, are becoming increasingly studied as sources of innovation and inspiration for a range of scientific, technological, and commercial applications. The brilliant blue colour reflected from the scales of the Morpho butterfly is just one example of nature’s ability to manipulate light and colour strongly. In this thesis, the photonic structure present in the scales of the Morpho butterfly is investigated as a source of bio-inspiration in the pursuit of high- performance photonic vapour sensors. The intention of this is to outperform classical sensor approaches which traditionally suffer from poor selectivity between chemical species. By measuring the change in reflectance from the iridescent scales of the Morpho butterfly, both a sensitive and, critically, a selective response to chemical vapours can be obtained. Here, the origin of this unique multivariable vapour-induced optical response is investigated, and this biological template is further explored as a source of innovation for the mature field of chemical sensing. By using synergy between experimental and theoretical techniques, a mechanism for the sensitive and selective response of the Morpho butterfly’s scales to different chemical vapour environments is elucidated. This mechanism arises from combined chemical and physical effects within the photonic nanostructure. Following this, demonstrations of this biological template’s vapour response attributes, which have large and desirable diversity in the optical responses, are made. These response attributes are visualised in the spectral changes associated with optical excitation conditions, such as from different angles and polarisation states, and also in the temporal response profiles. Finally, theoretical sensor designs that outperform the Morpho scales are described. Simple principles that might improve the currently unacceptable levels of selectivity in contemporary sensor implementations are outlined and the vapour response of a Morpho-inspired photonic structure is presented.

▼  As water makes up approximately 70% of the Earth's surface, humans have expanded operations into aquatic environments out of both necessity and a desire to gain potential innate benefits. This expansion into aquatic environments has consequently developed a need for cost-effective and safe underwater monitoring, surveillance, and inspection, which are missions that autonomous underwater vehicles are particularly well suited for. Current autonomous underwater vehicles vastly underperform when compared to biological swimmers, which has prompted researchers to develop robots inspired by natural swimmers. One such robot is designed, built, tested, and numerically simulated in this thesis to gain insight into the benefits of passive mechanisms and the development of reduced-order models. Using a bio-inspired robot with multiple passive tails I demonstrate herein the relationship between maneuverability and passive appendages. I found that the allowable rotation angle, relative to the main body, of the passive tails corresponds to an increase in maneuverability. Using panel method simulations I determined that the increase in maneuverability was directly related to the change in hydrodynamic moment caused by modulating the circulation sign and location of the shed vortex wake. The identification of this hydrodynamic benefit generalizes the results and applies to a wide range of robots that utilize vortex shedding through tail flapping or body undulations to produce locomotion. Passive appendages are a form of embodied control, which manipulates the fluid-robot interaction and analogously such interaction can be sensed from the dynamics of the body. Body manipulation is a direct result of pressure fluctuations inherent in the surrounding fluid flow. These pressure fluctuations are unique to specific flow conditions, which may produce distinguishable time series kinematics of the appendage. Using a bio-inspired foil tethered in a water tunnel I classified different vortex wakes with the foil's kinematic data. This form of embodied feedback could be used for the development of control algorithms dedicated to obstacle avoidance, tracking, and station holding. Mathematical models of autonomous vehicles are necessary to implement advanced control algorithms such as path planning. Models that accurately and efficiently simulate the coupled fluid-body interaction in freely swimming aquatic robots are difficult to determine due, in part, to the complex nature of fluids. My colleagues and I approach this problem by relating the swimming robot to a terrestrial vehicle known as the Chaplygin sleigh. Using our novel technique we determined an analogous Chaplygin sleigh model that accurately represents the steady-state dynamics of our swimming robot. We additionally used the subsequent model for heading and velocity control in panel method simulations. This work was inspired by the similarities in constraints and velocity space limit cycles of the swimmer and the Chaplygin sleigh, which makes this… Advisors/Committee Members: Phanindra Tallapragada, Ardalan Vahidi, Yue Wang, John Wagner.

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The feet of many insects contain both a ‘sticky’ pad and sharp claws that can be intelligently actuated to ‘switch’ (on/off) their adhesion to smooth and rough surfaces, respectively. In contrast, synthetic switchable adhesives designs are mechanistically simple and unable to adapt to real-world surfaces. This work proposes a bio-inspired hybrid (multi-mechanistic) and adaptive device that can control adhesion and friction on both smooth and rough surfaces. A novel pneumatic smart surface is designed that both actuates (rotates) multifunctional adhesive microtopography and provides sensory feedback at multiple independent areas on the surface. It will be shown that by rotating topography, the surface can switch between sticky and non-sticky states (99.3% reduction) and can also interlock with holes and protrusions (asperities) of rough surfaces. Through integrated and external sensory feedback combined local control, the device can sense adhesion loss, surface contact, and ultimately develop localized adhesive strategies that optimise global adhesion.

M.A.S.

2020-11-20 00:00:00

Advisors/Committee Members: Hatton, Benjamin D, Materials Science and Engineering.

▼ This study involves the development of novel methods to enhance structural efficiency in the development of high performance lightweight stiff metal mechanical components. Optimised designs are created from biologically-inspired templates, taking advantage of new additive manufacturing techniques which enable the realisation of more complex shapes.The study focuses on the numerical side of design development and evaluation. Two case studies of aerospace components are considered: first, of an aircraft engine nacelle and second, of turbine blisks. In the first study, rib stiffeners, based on fibre arrangement in plant stem cells, are introduced and their geometric features are optimised for mass minimisation with mechanical response constraints done via genetic algorithms coupled with finite element analysis. The displacements of the optimised nacelle are lower compared to the original. Mass has lower optimisation emphasis, thus final values approach the mass limit. Optimised designs from different loading cases and magnitudes thereof have similar physical features. In the second study, turbine blisks are redesigned with an internal foam structure based on cancellous bones. Optimised 3D foam blisks are developed evaluated against the original solid design and with a different foam type. A study undertaken on 2D foam discs under inertial load demonstrates that foam configuration and densification methods influence the mechanical responses. The thesis shows that viable biologically-inspired designs can be developed using optimisation techniques. In both cases remarkable mass reduction is achieved while remaining within mechanical constraints. The Pareto front is traced on the design space from optimisation results, representing the set of optimal designs rather than a single unique solution. In the nacelle the displacement contour heavily influences the rib layout, which prefers intersections at boundary condition sites. The weight-to-displacement ratios of bio-inspired designs are lower than in equivalent topologically-optimised ones. In the turbine blisk, foam stiffness under inertial load is found to increase with node connectivity. Increasing relative density increases stresses but decreases displacement, and the specific behaviour is influenced by the method in varying density. In 3D the resulting foam blisks have higher stresses and displacement than the solid one, but their weight-to-displacement ratio can be improved using high-connectivity foams. Advisors/Committee Members: Hoffman, Mark, Materials Science & Engineering, Faculty of Science, UNSW.

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Le but de cette thèse est de contribuer à la perception sous-marine pour des applications de robotique grâce à un champ électrique. Nous proposons de nouvelles méthodes pour l’inspection, la localisation et l’estimation de forme d’un objet ellipsoïdal en utilisant un capteur inspiré des poissons faiblement électriques. Premièrement, nous montrons que l’objet peut être détecté et que son matériau et sa position par rapport à l’axe du capteur peuvent être discriminés en utilisant de simples détections de seuils sur les courants mesurés. Ensuite, nous proposons l’implémentation successive de trois lois de contrôle réactives permettant au capteur de se diriger vers l’objet et d’effectuer une révolution autour de celui-ci en suivant ses frontières. Puis, nous utilisons l’algorithme MUSIC afin de localiser le centre de l’objet. Enfin, les paramètres géométriques de l’objet et son orientation sont estimés grâce à une méthode d’optimisation basée sur les moindres carrés et sur l’inversion du modèle analytique du tenseur de polarisation d’un objet ellipsoïdal. Nous montrons que ces algorithmes fonctionnent en conditions expérimentales. Pour les algorithmes de localisation et d’estimation de forme, des techniques impliquant des déplacements du capteur sont proposées, afin de réduire significativement les imprécisions dues aux écarts entre le modèle et les mesures de courant.

The aim of this thesis is to contribute to the underwater perception for robotics applications using an electric field. We propose new methods for the inspection, the localization and the shape estimation of an ellipsoidal object using a sensor inspired by the weakly electric fish. Firstly, we show that the object can be detected and its material and position relative to the sensor axis discriminated, using simple threshold detections on the measured currents. Then, we propose the successive implementations of three reactive control laws allowing the sensor to head for the object and revolve around it by following its boundaries. After that, we use the MUSIC algorithm in order to localize the object’s center. Finally, the geometrical parameters of the object and its orientation are estimated thanks to an optimization algorithm based on the least squares method and the inversion of the analytical model of the polarization tensor of an ellipsoidal object. We show that these algorithms can be experimentally implemented. For the localization and the shape estimation algorithms, some additional techniques involving sensor movements are proposed in order to significantly reduce the imprecisions due to the gap between the model and the actual currents’ measurements.

Advisors/Committee Members: Boyer, Frédéric (thesis director).

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Cette thèse présente l'implémentation d'une stratégie visuelle bio-inspirée sur un aéroglisseur miniature totalement actionné, qui lui permet de naviguer dans le plan horizontal d'un tunnel inconnu. L'élaboration de ce pilote automatique, nommé LORA, fait suite aux études éthologiques menées sur l'abeille depuis ces dernières décennies et nous ont amené à énoncer le principe de la régulation du flux optique pour le contrôle du vol de croisière. Ce pilote automatique est un double régulateur de flux optique latéral constitué de deux boucles visuo-motrices interdépendantes contrôlant conjointement la vitesse d'avance et la position du robot par rapport aux obstacles sans avoir à mesurer ou estimer aucun de ces paramètres. La clé de voûte de ce système de guidage est une troisième boucle destinée à maintenir le cap grâce à un micro-gyromètre et un micro-compas magnétique permettant au robot d'effectuer des mouvements de translation qui génèrent sur son œil composé artificiel du flux optique de translation, seul dépendant du ratio vitesse/distance aux obstacles. Cet œil estime le flux optique grâce à ses deux ou quatre Détecteurs élémentaires de mouvement (total de 4 ou 8 pixels). L'aéroglisseur est alors capable de franchir sans collision, à la manière d'une abeille, divers tunnels : droit, fuselé ou présentant une pente, un virage, une absence de texture sur un mur ou même une zone non-stationnaire. Cette stratégie visuelle bio-inspirée fournit non seulement une solution de navigation élégante à destination de robots totalement actionnés mais elle permet aussi d'expliquer comment une abeille de 100mg peut naviguer sans l'aide de SONAR, RADAR, LIDAR, ou GPS.

In this work, we present for the first time a bio-inspired motion vision-based navigation strategy embedded on a miniature fully-actuated hovercraft allowing it to navigate safely on the horizontal plane of an unknown corridor. The design of this autopilot, called LORA, follows the ethological findings made on honeybees these last decades, which led us to elaborate the principle of the optic flow regulation which might be used by insects to control their flight. The bee-inspired LORA autopilot is a dual optic flow regulator which consists in two intertwined visuomotor feedback loops which control jointly the forward speed of the robot and its clearance to the obstacles. The keystone of this bio-inspired guidance system is a heading-lock system enabling the robot to move in translations and therefore experience a purely translational optic flow which depends only on the ratio speed/clearance to obstacles thanks to a micro-gyrometer and a micro-magnetic compass. The estimation of optic flow is made by a minimalist compound eye, made of two or four Elementary Motion Detectors (only 4 or 8 pixels). The hovercraft is therefore able to cross without crashing a straight or a tapered corridor, presenting a frontal sloping terrain, a bend, a textureless wall, or even a non-stationary section by automatically adapting both its forward speed and its clearance to the walls…

Advisors/Committee Members: Viollet, Stéphane (thesis director).

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La conception de systèmes de perception autonomes, tels que des robots capables d’accomplir un ensemble de tâches de manière sûre et sans assistance humaine, est l’un des grands défis de notre siècle. Pour ce faire, la robotique développementale propose de concevoir des robots qui, comme des enfants, auraient la faculté d’apprendre directement par interaction avec leur environnement. Nous avons dans cette thèse exploré de telles possibilités en se limitant à l’apprentissage de la localisation des objets d’intérêt (ou objets saillants) dans l’environnement du robot.Pour ce faire, nous présentons dans ces travaux un mécanisme capable d’apprendre la saillance visuelle directement sur un robot, puis d’utiliser le modèle appris de la sorte pour localiser des objets saillants dans son environnement. Cette méthode a l’avantage de permettre la création de modèles spécialisés pour l’environnement du robot et les tâches qu’il doit accomplir, tout en restant flexible à d’éventuelles nouveautés ou modifications de l’environnement.De plus, afin de permettre un apprentissage efficace et de qualité, nous avons développé des stratégies d’explorations basées sur les motivations intrinsèques, très utilisées en robotique développementale. Nous avons notamment adapté l’algorithme IAC à l’apprentissage de la saillance visuelle, et en avons conçu une extension, RL-IAC, pour permettre une exploration efficace sur un robot mobile. Afin de vérifier et d’analyser les performances de nos algorithmes, nous avons réalisé des évaluations sur plusieurs plateformes robotiques dont une plateforme fovéale et un robot mobile, ainsi que sur des bases de données publiques.

Conceiving autonomous perceptual systems, such as robots able to accomplish a set of tasks in a safe way, without any human assistance, is one of the biggest challenge of the century. To this end, the developmental robotics suggests to conceive robots able to learn by interacting directly with their environment, just like children would. This thesis is exploring such possibility while restricting the problem to the one of localizing objects of interest (or salient objects) within the robot’s environment.For that, we present in this work a mechanism able to learn visual saliency directly on a robot, then to use the learned model so as to localize salient objects within their environment. The advantage of this method is the creation of models dedicated to the robot’s environment and tasks it should be asked to accomplish, while remaining flexible to any change or novelty in the environment.Furthermore, we have developed exploration strategies based on intrinsic motivations, widely used in developmental robotics, to enable efficient learning of good quality. In particular, we adapted the IAC algorithm to visual saliency leanring, and proposed an extension, RL-IAC to allow an efficient exploration on mobile robots.In order to verify and analyze the performance of our algorithms, we have carried out various experiments on several robotics platforms, including a foveated system and a mobile…

Advisors/Committee Members: Filliat, David (thesis director).

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De nos jours, l'engouement pour la robotique autonome ne cesse d'augmenter en particulier pour les microdrones. En effet, ces aéronefs de petite taille font l'objet de nombreuses recherches afin de les miniaturiser et de rendre leur navigation plus autonome. Ainsi, cette thèse explore un système de vision parcimonieux dédié à la navigation courte portée au moyen de capteurs visuels auto-adaptatifs innovants composés de seulement 12 pixels aux propriétés optiques inspirées de celles de l'abeille. Deux algorithmes de mesure de flux optique sont ensuite comparés en conditions idéales sur 5 décades d'irradiance et 3 décades de vitesses optiques, puis testés en conditions réelles de vol. L'algorithme le plus robuste et le plus efficace, de par ses très faibles besoins calculatoires, a été embarqué à bord d'un micro quadrirotor pesant environ 400 g et équipé d'un système visuel parcimonieux de 96 pixels stabilisé via une nacelle articulée en roulis et tangage pour compenser les rotations du quadrirotor. Les stratégies de navigation observées chez l'abeille ont ensuite été simulées dans des environnements virtuels (tunnel de longueur 6 m ou 12 m pour une section minimale de 25 ou 50 cm) et la preuve de faisabilité de la détection du flux optique à bord d'un microdrone a été démontrée en conditions réelles de vol en salle expérimentale (vol de 4 m de long à une distance minimale de 50 cm). Couplé à des stratégies de navigation inspirées de l’abeille, ce système visuel innovant dédié à la perception du mouvement permettra dans un futur proche de naviguer dans des environnements encombrés ou exigus.

The interest in autonomous robotics is continually expanding, especially in the domain of micro air vehicles. Indeed, much research focuses on these small-size aircraft in order to miniaturize them and to make their navigation more autonomous. This PhD thesis explores a parsimonious vision system dedicated to short range navigation using innovative self-adaptive visual sensors composed of only 12 pixels with optical properties inspired by those of honeybees. Two optic flow measurement algorithms are first compared under ideal conditions over 5 decades of irradiance and 3 decades of optical velocity, then tested under real flight conditions. The most robust and efficient algorithm, due to its very low computing requirements, was embedded on board a micro quadrotor weighing about 400 g and equipped with a parsimonious visual system of 96 pixels stabilized via an articulated gimbal in roll and pitch to compensate the quadrotor rotations. The navigation strategies observed in honeybees were simulated in virtual environments (6 m or 12 m long tunnel for a minimum section of 25 or 50 cm) and the feasibility of the detection of the optic flow on board a micro quadrotor was demonstrated in real flight conditions in experimental room (flight of 4 m long at a minimum distance of 50 cm). Coupled with navigation strategies inspired by the honeybee, this innovative visual system dedicated to the perception of movement will in the near future…

Advisors/Committee Members: Bootsma, Reinoud Jan (thesis director), Serres, Jean Joseph (thesis director).

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La bio-inspiration applique des principes et des stratégies issus de systèmes biologiques afin de faciliter la conception technologique. Doté d’un fort potentiel pour l’Innovation, la biomimétique, son pendant méthodologique, est en passe d’évoluer vers un processus clé pour les entreprises. Un certain nombre de freins demeurent cependant à lever afin que la conception bio-inspirée s’apparente à une démarche robuste et répétable. Les travaux réalisés abordent cette diffusion de la conception bio-inspirée selon deux axes distincts. Ils s’efforcent tout d’abord d’harmoniser champs conceptuels relatifs à la bio-inspiration et modèles de processus biomimétiques, en vue de rendre possible l’évaluation des outils supportant cette démarche de conception. Cette évaluation méthodologique, couverte selon l’angle objectif et subjectif, aboutit à la formalisation d’un modèle structurant, un arbre de classification, à même de guider les concepteurs biomimétiques à travers le processus biomimétique. En parallèle de l’établissement de ce cadre de référence méthodologique, les travaux s’évertuent à explorer un autre verrou inhérent à la démarche : l’interaction entre biologie et ingénierie. Les travaux tendent ainsi, par le développement d’un outil, à réduire l’une des barrières d’entrée de ce type d’approche, en proposant un modèle décrivant fonctionnellement les systèmes biologiques sans prérequis d’expertise biologique. La concaténation de ces réalisations aborde directement l’enjeu principal de ce champs disciplinaire : son essor par la dissémination de son application à l’innovation industrielle, en vue de favoriser l’émergence de « produits biomimétiques » au détriment des « accidents bio-inspirées ».

Biomimetics applies principles and strategies which stem from biological systems in order to facilitate technological design. Providing a high innovation potential, biomimetics could become a key process for various business. However, there are still a few challenges to overcome in order for the bioinspired design to become a sustainable approach. The work which has been carried out addresses this bioinspired design diffusion with two distinct focuses. First of all, they tend to standardize conceptual fields for bio-inspiration and biomimetic process models to enable the evaluation of tools supporting said design process. This methodological assessment, addressed from an objective and subjective point of view, results in the formalization of a structuring model, a classification tree which guides designers through the biomimetic process. Alongside the development of this methodological reference framework establishment, the work tends to overcome another obstacle of the bioinspired design implementation which is the interaction between biology and engineering. By developing a specific tool, the research studies offer a model which functionally describes biological systems without biological expertise prerequisites. The concatenation of these accomplishments addresses the main issue of these disciplinary fields: its development…

Advisors/Committee Members: Aoussat, Améziane (thesis director).

▼ Design inspired by nature has been known as biomimicry or biomimetic design that is believed to transform human technologies into a sustainable status through translation of biological models, systems, and processes. Considering energy efficiency as one of the aspects of sustainability in the concept of bio-inspired building design, the problem was how to access the solutions best matched to the design problem. Various tools for finding existing knowledge from a different domain are described but as yet there appears to be no tool for allowing building designers to access the efficient ways found in nature of producing energy, using energy, and recycling resources. What the research investigated was to find if it is possible to develop a generalised thermo-bio-architectural (ThBA) framework by use of which architects would be able to improve the energy performance of buildings in a wide range of climates, by following a systematic process that methodically connects design thermal challenges to thermal adaptation principles used in nature. The ThBA was developed by studying biology to find how thermal regulation strategies used by living organisms can be classified and generalised. The proposed ThBA was confirmed and evaluated before it was used for the rest of the research. The biological part of the ThBA was assessed by biological experts within a focus group session. Having the ThBA confirmed, the research also investigated how the heat transfer principles in buildings can be articulated to be linked to the generalised thermal adaptation strategies in nature. For this, a series of case studies were selected and for each an energy simulation was run to analyse its thermal performance and identify its thermal challenges. Then, the ThBA was used to introduce innovative solutions for improving the thermal performance of the case studies with big energy use to reveal unexpected techniques or technologies. This, however, necessitated its reconfiguration so as to be useful for architects. Testing the ThBA for two extreme climates in New Zealand, highlighted the fact that the simple translation of the majority of biological thermal adaptation principles are being used by architects, although for some, the architectural equivalents did not function in exactly in the same way as biological thermoregulation strategies. The differences were seen either in the central thermoregulatory principles or the broader properties within which the key principles fitted. Apart from that, for both architectural and biological thermoregulatory strategies the heat transfer parameter and methods were the same. Given that, in a context where biomimicry is understood as the imitation of complicated thermoregulatory solutions in nature for which innovation is evolutionary achieved, the term biomimetics seems to not have a place in the context of bio-inspired energy efficient design considering the current state of technology. The ThBA, however, suggested a few strategies that might address opportunities for designing a new generation of… Advisors/Committee Members: Donn, Michael, Vale, Brenda.

▼ Jellyfish have inhabited this planet for millions of years and are the oldest known metazoans that swim using muscles. They are found in freshwater sources and in oceans all over the world. Over millions of years of evolution, they have adapted to survive in a given environment. They are considered as one of the most energy efficient swimmers. Owing to these characteristics, jellyfish has attracted a lot of attention for developing energy efficient unmanned undersea vehicles (UUVs). The goal of this thesis is to provide understanding of the different physical mechanisms that jellyfish employs to achieve efficient swimming by using analytical and computational models. The models were validated by using the experimental data from literature. Based upon these models refinements and changes to engineering vehicles was proposed that could lead to significant enhancement in propulsion efficiency. In addition to the propulsion, the thesis addresses the practical aspects of deploying a jellyfish-inspired robotic vehicle by providing insights into buoyancy control and energy generation. The thesis is structured in a manner such that propulsive and structural models inspired from the natural animal were systematically combined with the practical aspects related to ionic diffusion driven buoyancy control system and thermal  – magnetic energy harvesting system. Jellyfish morphology, swimming mechanism and muscle architecture were critically reviewed to accurately describe the natural behavior and material properties. We provide full understanding of mesoglea, which plays most significant role towards swimming performance, in terms of composition, mechanical properties and nonlinear dynamics. Different jellyfish species exhibit different microstructure of mesoglea and thus there is a wide variety of soft materials. Mechanical properties of collagen fibers that form the main constituent toward imparting elasticity to mesoglea were reviewed and analyzed. The thesis discusses the theoretical models describing the role of structure of mesoglea towards its mechanical properties and explains the variation occurring in stiffness under given experimental environment. Muscle architecture found in jellyfish, nerve nets and its interconnection with the muscles were investigated to develop comprehensive understanding of jellyfish propulsion and its reaction to external stimuli. Different muscle arrangements were studied including radial, coronal muscle, and coronal-muscles-with-breaks in-between them as observed in Cyanea capillata. We modeled these muscle arrangements through finite element modeling (FEM) to determine their deformation and stroke characteristics and their overall role in bell contraction. We found that location and arrangement of coronal muscle rings plays an important role in determining their efficient utilization. Once the understanding of natural jellyfish was achieved, we translated the findings onto artificial jellyfish vehicle designed using Bio-inspired Shape Memory Alloy Composite (BISMAC)… Advisors/Committee Members: Priya, Shashank (committeechair), Tafti, Danesh K. (committee member), Costello, John Henry (committee member), West, Robert L. (committee member), O'Brien, Walter F. Jr. (committee member).

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Ce manuscrit traite de la conception d’un robot quadrirotor bio-inspiré. Ce robot, nommé QuadMorphing, s’inspire de l’oiseau et possède la capacité de se replier en vol afin de diminuer son envergure. Cette particularité est intéressante pour des problématiques d’évitement d’obstacles dans des milieux encombrés.Le travail présenté ici contient une présentation du robot où la plateforme mécatronique y est décrite en détails. Puis, des résultats expérimentaux sont présentés et commentés afin de quantifier les performances du prototype QuadMorphing durant des scénarios de franchissement d’obstacles.La deuxième partie de cette thèse traite de l’estimation de la taille d’obstacles en vol grâce à une perception visuelle monoculaire. Deux algorithmes d’estimation ont été simulés afin d’être validés pour être ensuite mis en place sur une nouvelle version du robot qui a été testée expérimentalement. Ces estimations permettent par la suite de rendre le robot plus autonome pour éviter les collisions avec son environnement et actionner son système de changement de forme si cela est nécessaire.

This paper describes a bio-inspired quadrotor design. This robot, called QuadMorphing, is inspired by birds and has the ability to fold its mechanical structure to reduce its wingspan during the flight. This feature could be useful for obstacle avoidance task in cluttered environments.The work presented here contains a full description of the mechatronic structure. Then, experimental results are presented and discussed in order to quantify the QuadMorphing performances during obstacle avoidance scenarios.The second part of this thesis deals with estimating obstacle size during flight using monocular visual perception. Two estimation algorithms were simulated in order to be validated and then implemented for experimental testing on a new version of the robot. In order to make the robot autonomous, the estimation of the size of the obstacle allows the robot to avoid collisions with its environment and to perform its morphological reduction if necessary.

Advisors/Committee Members: Viollet, Stéphane (thesis director).

▼ There has been a growing interest in development of nature-inspired miniature mobile robotics, for navigating complex ground scenarios, unknown terrains, and disaster-hit areas. One application is the development of a remotely operated vehicle (ROV) for rumen monitoring to improve our understanding of microbiology, and real-time physical changes and correlations with health. This interest is being driven from the desire to improve the safety and efficiency of food production by improving precision animal agriculture, which involves understanding the digestive system of ruminant animals and responding to the biochemical and physical changes. Most miniature robotic locomotion methods have taken inspiration from insects and have focused on adopting approaches that results in improved gait performance with respect to stability, velocity, cost-of-transport, and ability to navigate uneven surface terrains. In order to operate in the rumen environment, the locomotion mechanism should have the ability to handle large frictional and viscous forces in the direction of motion performing submerged burrowing-like action. The rumen environment consists of varying stiffness content with different fluidic concentration across the layers, reaching high viscosity and densities similar to wet soil or mud. Taking inspiration from millipedes for a locomotion mechanism to function in such an environment is attractive as these organisms have evolved to be proficient burrowers in similar substrates. In this dissertation, the bio-mechanics of millipedes were investigated in-depth and modeled using analytical approaches. Multiple experiments were conducted on real animals to gain fundamental understanding of their locomotive abilities under varying environmental conditions. From this understanding, their gait behavior was emulated on a robotic platform to confirm the predicted dynamics and practically demonstrate the phenomena of modulating thrust force. The robotic models were also utilized to validate the parametric analysis and gain insight of the burrowing ability in varying gait behavior and body morphology. The primary features that govern the millipede behavior for effective burrowing were analyzed and utilized to design a locomotion mechanism for a rumen ROV. The design of the locomotion mechanism was tested in rumen-like media consisting of a wet mud mixture, where both locomotion thrust and steering ability were demonstrated. Advisors/Committee Members: Priya, Shashank (committeechair), Behkam, Bahareh (committee member), Mueller, Rolf (committee member), Kurdila, Andrew J. (committee member), Marek, Paul E. (committee member).

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Cette thèse a visé à comprendre et à recréer artificiellement un mécanisme d'auto-assemblage présent dans la soie d'araignée. Les gouttes de glue microniques qui existent sur la soie d'araignée dîte de capture servent à fournir à la toile ses propriétés adhésives. Ces gouttes jouent pourtant un autre rôle : elles améliorent grandement les propriétés mécaniques de la soie, et permettent de préserver l'intégrité structurelle de la toile. La localisation de l'instabilité de flambage au sein des gouttes de glue, site de surcompression par les ménisques capillaire, implique que ce système de gouttes sur fibre se comporte sous compression comme un liquide, alors que sous tension il possède un régime solide. Les araignées ont donc trouvé un moyen de créer des hybrides mécaniques liquide-solide.La première partie de ma thèse fut dédiée à la caractérisation d'échantillons naturels, qui a permis dans la seconde partie de construire un système entièrement artificiel qui reproduit la soie d'araignée de capture, grâce à des microfibres flexibles longues de plusieurs centimètres. Une simple goutte de liquide mouillant permet la création efficace d'un système semblable aux échantillons naturels. La caractérisation fine de ces systèmes de gouttes sur fibre enroulables a mené à un très bon accord entre les résultats expérimentaux, les simulations numériques et une analogie avec les transitions de phase, notamment pour des propriétés telles que le seuil d'activation, l'existence d'une hystérésis ou encore la morphologie de l'enroulement. Ces résultats ont permis la conception de techniques non conventionnelles dans des domaines tels que les méta-matériaux et la micro-fabrication.

This PhD work aimed to understand and recreate artificially a self-assembling mechanism involving capillarity and elasticity present in spider silk. The primary function of the micronic glue droplets that exist on spider capture silk is to provide the spider web with adhesive properties. These droplets play yet another role: the dramatic enhancement of silk mechanical properties, as well as the preservation of the integrity of the web structure. The localization of the buckling instability within the glue droplets, site of over-compression due to the capillary meniscii implies that under compression this special drop-on-fibre system behaves like a liquid, whereas under tension it has a classical elastic spring regime. Spiders have thus found a way to create liquid-solid mechanical hybrids.The first part of my thesis aimed to the characterization of natural samples, which allowed in the second part to build a completely artificial system that mimics the natural samples, through fabrication of centimeter-long micronic soft fibres. The simple addition of a wetting liquid droplet made for an effective system with mechanical properties quantitatively close to that of spider capture silk.Fine characterization of the created drop-on-coilable-fibre systems yielded very good agreement between experimental results and predictions from numerical simulations and a…

Advisors/Committee Members: Antkowiak, Arnaud (thesis director), Neukirch, Sébastien (thesis director).

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Le développement de la navigation autonome est devenu l'un des enjeux technologiques majeurs du 21ème siècle. Aucune solution fiable ne saurait faire l'économie du GPS ni même des caméras, très répandues en robotique. Cette thèse vise à mettre en place une nouvelle stratégie de navigation parcimonieuse inspirée des fourmis du désert Cataglyphis afin de localiser un robot terrestre mobile hexapode. S'inspirant de l’œil composé des fourmis, un compas céleste minimaliste doté de deux photodiodes sensibles au rayonnement UV et surmontées de filtres linéaires polarisants, permet d'acquérir l'angle de polarisation de la lumière du ciel, lequel sert de cap en navigation terrestre. Le compas céleste a démontré d'excellentes performances, résilientes à l’égard des conditions météorologiques. Les tâches de navigation ont été réalisées par le robot hexapode AntBot, équipé du compas céleste et d'un capteur de flux optique constitué de 12 pixels auto-adaptatifs dont la réponse mime celle des cellules photoréceptrices des tortues. AntBot dispose d'un intégrateur de chemin inspiré des fourmis Cataglyphis. Ce système fusionne le cap donné par le compas céleste, la distance mesurée par le flux optique, et le nombre de pas pour déterminer la position du robot par rapport à son point de départ. Il en a résulté une erreur de navigation moyenne stable d'environ 6cm, indépendante de la forme ou de la distance des trajectoires accomplies (variant de 5 à 15m). Ces résultats montrent que cette stratégie de navigation peut être envisagée en parallèle d'un GPS, pour un coût calculatoire faible, afin de bénéficier d'un système de localisation précis, robuste et efficace.

Autonomous navigation is one of the leading technological challenges of the 21st century and is currently solved using GPS and camera-based strategies. This PhD thesis aims at setting up new navigation strategies inspired by desert ants Cataglyphis, requiring few resources and tested on board a hexapod walking robot. Taking inspiration from the ants' compound eye, a novel celestial compass - composed of just two ultraviolet-sensitive photodiodes topped with rotating linear polarizers - provides measurements of the angle of polarization of the skylight with high angular precision. This angle is used as the vehicle's heading while navigating. This compass provided excellent performances regardless of the meteorological condition. Navigation tasks were performed with our hexapod robot AntBot equipped with both the celestial compass and an optic flow sensor, which includes 12 auto-adaptive pixels mimicking photoreceptors in turtles. AntBot has a path integrator navigation system inspired by behavioral studies in desert ants Cataglyphis. This strategy uses the heading given by the celestial compass, the distance measured with the optic flow sensor, and the stride integrator to determine the vehicle's position with respect to its departure location. Experiments resulted in a navigation error of approximately 6cm regardless of the shape and the length of the trajectory (varying…

Advisors/Committee Members: Viollet, Stéphane (thesis director), Serres, Julien (thesis director).

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Les systèmes autonomes sont récemment devenus une solution efficace pour des applications telles que l'exploration et la surveillance d'environnements. Dans ces situations, l'utilisation de plusieurs robots pourrait améliorer l'efficacité des solutions proposées, bien que cela nécessite des stratégies d'organisation qui soient à la fois robuste, flexible et adaptables à la taille de la flotte de robots. En robotique en essaim, ces qualités sont assurées par la décentralisation, la redondance (plusieurs/tous les robots effectuent la même tâche), des interactions locales et des règles simples. Les interactions et communications locales sont une composante clef de la robotique en essaim. Jusqu'ici, la communication n'a été utilisée que pour des tâches relativement simples, tels que signaler les préférences ou l'état d'un robot. Cependant, la communication peut être bien plus riche et similaire aux langages humains. Dans ces conditions, elle permettrait aux essaims de robots de gérer de nouvelles situations qui ne seraient pas prévues par leurs concepteurs. De riches communications sont donc nécessaires pour obtenir des essaims entièrement autonomes, en particulier dans des environnements inconnus. Dans cette thèse, nous proposons une approche pour faire émerger des communications riches dans des essaims de robots en utilisant les jeux de langages comme protocole de communication et l'agrégation probabiliste comme cas d'étude. L'agrégation probabiliste est un prérequis pour de nombreuses tâches en robotique en essaim mais elle est aussi extrêmement sensible aux conditions expérimentales. Elle requiert donc un réglage spécifique de ses paramètres pour chaque nouvelle condition, y compris les changements d'échelle ou de densité. Avec notre approche, nous avons observé que l'exécution simultanée du jeu de nommage et de l'agrégation mène, dans certaines conditions, à un nouveau comportement d'agglomération en plusieurs groupes, chacun avec son propre nom, qui est contrôlable via les paramètres de l'agrégation. En poussant ces interactions plus loin, nous démontrons que les dynamiques sociales du jeu de nommage peuvent sélectionner des paramètres d'agrégation efficaces. Cette sélection culturelle crée donc des contrôleurs résilients, qui évoluent en-ligne en fonction du contexte courant.

Automatically-controlled artificial systems have recently been used in numerous settings including environmental monitoring and explorations, with great success. In such cases, the use of multiple robots could increase efficiency, although we should ensure that their communication and organisation strategies are robust, exible, and scalable. These qualities can be ensured through decentralisation, redundancy (many/all robots perform the same task), local interaction, and simplistic rules, as is the case in swarm robotics. One of the key components of swarm robotics is local interaction or communication. The later has, so far, only been used for relatively simple tasks such as signalling a robot's preference or state. However, communication…

Advisors/Committee Members: Frémont, Vincent (thesis director).

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Conception, modélisation et contrôle des actionneurs intrinsèquement conformes avec une considération particulière sur la configuration anthropomorphe agoniste-antagoniste "La recherche vise à la conception, la modélisation et le contrôle des actionneurs intrinsèquement conformes pour les systèmes anthropomorphes.La première partie du travail se concentre sur l'étude de divers Existants et rechercher la possibilité d'autres actionneurs autres que les moteurs électriques conventionnels.Une attention particulière est accordée aux actionneurs souples à base de polymères élctroactifs qui ont un bon potentiel dans les futures applications robotiques. Parallèlement, on a synthétisé un modèle de la dynamique de l'actionneur et du contrôleur basé sur le modèle (MPC et contrôle optimal) pour un bras anthropomorphe 7 Dofs actionné par une paire antagoniste-agoniste de Muscles Artificiels Pneumatiques (PAM) à chaque articulation. Ce modèle et contrôleur est alors intégré dans l'environnement logiciel développé par l'équipe. En utilisant le bras manipulateur anthropomorphe basé sur PAM et le simulateur numérique, des tests sont effectués afin d'évaluer le potentiel de cet actionneur et de comparer avec les capacités du corps humain.

Design, modeling and control of inherently compliant actuators with a special consideration on agonist- antagonist anthropomorphic configuration" The research aims at the design, modeling and control of inherently compliant actuators for anthropomorphic systems. The first part of the work focuses on the study of various existing designs and look for the possibility of alternative actuators other than the conventional electric motors. Special attention is given to elctroactive polymer based soft actuators which have good potential in future robotic applications. In parallel, a model of the actuator dynamics and the model-based controller (MPC and optimal control) have been synthesized for an anthropomorphic 7 Dofs arm actuated by antagonist-agonist pair of Pneumatic Artificial Muscles (PAMs) at each joint. Such model and controller is then integrated within the software environment developed by the team. Using the PAMs based anthropomorphic manipulator arm and the numerical simulator, tests are done in order to evaluate the potential of this actuator and compare with the human body capabilities.

Advisors/Committee Members: Tondu, Bertrand (thesis director), Souères, Philippe (thesis director).

▼ The work presented in this dissertation was aimed at understanding biology's application of soft materials to enhance sensing abilities and initiate innovative bio-inspired material-based approaches for flow (fluidic and air) sensors and photo-thermal sensors. A key aim is to help strengthen this niche of functional materials science referred to, here, as bio-inspired materials in sensing roles. The work aspires to traverse the boundaries of the subject in order to provide a strong foundation for future scientific explorations of the subject. The studies presented here, include studies of flow sensing in fish and implementing a bio-mimetic approach to microfabricated flow sensors. The work also includes studies of material based signal filtering in spiders, as well as, bio-inspired photo-thermal transduction mechanisms. The capabilities of the methodology are demonstrated with successful engineering studies. Advisors/Committee Members: Tsukruk, Vladimir (Committee Chair), Shofner, Meisha (Committee Member), Srinivasarao, Mohan (Committee Member), Thio, Yonathan (Committee Member), Weissburg, Marc (Committee Member).

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Les insectes sont capables de prouesses remarquables lorsqu’il s’agit d’éviter des obstacles,voler en environnement perturbé ou poursuivre une cible. Cela laisse penser que leurs capacités de traitement, aussi minimalistes soient-elles, sont parfaitement optimisées pour le vol. A cela s’ajoute des mécanismes raffinés, comme la stabilisation de la vision par rapport au corps, permettant d’améliorer encore plus leurs capacités de vol.Ces travaux de thèse présentent l’élaboration d’un micro drone de type quadrirotor, qui ressemble fortement à un insecte sur le plan perceptif (vibration rétinienne) et reprend des points structurels clés, tels que le découplage mécanique entre le corps et le système visuel. La conception du quadrirotor (de type open-source), son pilotage automatique et son système occulo-moteur sont minutieusement détaillés.Des traitements adaptés permettent, malgré un très faible nombre de pixels (24 pixels seulement), de poursuivre finement du regard une cible en mouvement. A partir de là, nous avons élaboré des stratégies basées sur le pilotage par le regard, pour stabiliser le robot en vol stationnaire, à l’aplomb d’une cible et asservir sa position ; et ce, en se passant d’une partie des capteurs habituellement utilisés en aéronautique tels que les magnétomètres et les accéléromètres. Le quadrirotor décolle, se déplace et atterrit de façon autonome en utilisant seulement ses gyromètres, son système visuel original mimant l’oeil d’un insecte et une mesure de son altitude. Toutes les expérimentations ont été validées dans une arène de vol, équipée de caméras VICON.Enfin, nous décrivons une nouvelle toolbox qui permet d’exécuter en temps réel des modèles Matlab/Simulink sur des calculateurs Linux embarqués de façon complètement automatisée (http://www.gipsalab.fr/projet/RT-MaG/). Cette solution permet d’écrire les modèles, de les simuler, d’élaborer des lois de contrôle pour enfin, piloter en temps réel, le robot sous l’environnement Simulink. Cela réduit considérablement le "time-to-flight" et offre une grande flexibilité (possibilité de superviser l’ensemble des données de vol, de modifier en temps réel les paramètres des contrôleurs, etc.).

Insects, like hoverflies are able of outstanding performances to avoid obstacles, reject disturbances and hover or track a target with great accuracy. These means that fast sensory motor reflexes are at work, even if they are minimalist, they are perfectly optimized for the flapping flight at insect scale. Additional refined mechanisms, like gaze stabilization relative to the body, allow to increase their flight capacity.In this PhD thesis, we present the design of a quadrotor, which is highly similar to an insect in terms of perception (visual system) and implements a bio-inspired gaze control system through the mechanical decoupling between the body and the visual system. The design of the quadrotor (open-source), itspilot and its decoupled eye are thoroughly detailed. New visual processing algorithms make it possible to faithfully track a moving target, in…

Advisors/Committee Members: Marchand, Nicolas (thesis director), Viollet, Stéphane (thesis director).

▼ Rapid terrestrial locomotion is a fascinating but difficult problem that roboticists face. Considerations must be made towards dynamics, controls, estimation, the environment, electronics, and mechanical design. Wheeled and legged robots have been heavily researched and have gained much success, however they still have their limitations, especially when ground contact is lost.Inspired by the high performance of lizards actively using their tails to stabilize perturbations and rapidly reorient their body, we propose to add an active inertial appendage to terrestrial robots that will greatly improve their stability and maneuverability.In this dissertation we present three main focus areas. We first develop the capabilities of a novel tailed robot with an active single degree-of-freedom (DOF) tail. We then discuss the single degree of freedom orientation sensing developed for this robot. Finally, we construct a nonlinear controller to enable reorientation of the body of a 2-link robot in three-dimensions while being constrained to a tail that only has two DOF of actuation.The first 177 (g) active tailed robot, Tailbot, has a single DOF of actuation and contains attitude inertial sensors. By utilizing both contact forces and zero net angular momentum maneuvering, this tailed robot can rapidly right itself in a fall, avoid flipping over after a large perturbation, and smoothly transition between surfaces of different slopes. We used a modeling approach to show that a tail-like design offers significant advantages to other alternatives, including reaction wheels, when the speed of response is important.In order to provide the reliable orientation sensing for the single DOF robot we design a novel time varying complementary filter. Complementary filtering (CF) is a signal processing methodthat is commonly used for the fusion of gyroscope and accelerometer measurements in order to robustly estimate the attitude of a rigid body. The traditional CF uses linear time invariant filters to combine the two different measurements of the same physical quantity. Here we present an extension to the CF method with time-varying filters. A fuzzy logic method is developed to adjust the parameters. Stability analysis as well as experimental results are presented to verify the proposedmethod.Finally, we propose a nonlinear control scheme for attitude control of a falling, two link active tailed robot with only two DOF of actuation. We derive a simplified expression for the robot's angular momentum and invert this expression to solve for the shape velocities that drive the body'sangular momentum to a desired value. By choosing a body angular velocity vector parallel to the axis of error rotation, the controller steers the robot towards its desired orientation. The proposed scheme is accomplished through feedback laws as opposed to feedforward trajectory generation, is fairly robust to model uncertainties, and is simple enough to implement on a low power microcontroller.We verify our approach by implementing the controller on a small 175 (g)…

▼ Cities occupy 2% of the earth's surface, and yet consume 75% of the world's resources. As a major contributor to rapidly growing global energy expenditures, urban buildings are often designed and operated inefficiently despite their significant contributions to carbon emissions, triggering environmental deterioration locally and worldwide. Moreover, ongoing industrialization and urbanization pose challenges for achieving a more sustained and resilient built environment. The goal of this PhD research is to advance our understanding of urban building networks' thermal-energy dynamics in order to achieve sustainable energy conservation in the built environment. Considering buildings as networks rather than as stand-alone entities highlights the inextricably linked and interwoven relationship between urban micro-climates and buildings. With this approach, I strive to explore, mitigate, and optimize the mutual influences of the Inter-Building Effect (IBE) in dense urban settings through numerical and empirical analyses. My research also draws inspiration for investigating solutions to complex engineering problems from nature, as I seek to understand synergies between building and biological systems to discover innovative connections and integrate biology to transform buildings through sustainable building network designs. This dissertation contains three interdependent projects to explore, mitigate and optimize the IBE, respectively. I first developed a systematic approach to separately assess the complex interactions that constitute the IBE in dense urban settings and conducted cross-regional analyses in a dynamic simulation environment. Having disaggregated, quantified and understood the effects of mutual shading and mutual reflection within a network of buildings, I then, in the second project, examined different measures to mitigate the negative IBE impact under certain circumstances (e.g. directional reflective optical properties of building facades and thermal storage technologies). These two projects extended prior work that examined the potential for a biological system retroreflective surface to reduce IBE in urban building networks. Therefore, in my third project, I introduced a broad framework that draws parallels between natural and built environment systems through a levels-of-organization perspective leading to the search for an optimal status of the IBE. Inspired from a self-regulating phenomenon of plant density, I presented and discussed an approach to determine optimal urban building network density as an example for how this framework can support cross-level assessment. The findings expand and deepen our understanding of the IBE and provide insights on the strategies to mitigate the negative mutual impact within dense urban building networks. This research contributes a unique and holistic perspective on the interdependencies in the urban building network system. To design density-optimal building networks will become increasingly important to sustainable urban development and smart growth as clusters… Advisors/Committee Members: Taylor, John E. (committeechair), Garvin, Michael J. (committee member), Moore, Ignacio T. (committee member), Pisello, Anna Laura (committee member).