The proposed research investigates the unique structure of the rostrum of the paddlefish (Polyodon spathula) for use in bio-inspiration. The rostrum comprises three different materials: midline cartilage, a network cartilage structure, and matrix tissue. The structure-property relationships of these materials were studied with various mechanical testing and imaging techniques. The mechanical properties and stress-strain behavior were applied to a material model that characterizes each material. A three-dimensional model was constructed from computed tomography images, and a mesh was exported for use in finite element simulations. Different boundary conditions were applied to show how the rostrum responds under deformation giving a stress distribution arising from different loadings. Finally, a new robust design paradigm is introduced with bio-inspiration introducing constraints and is explained through using the paddlefish rostrum as an example of a cell tower or antenna.

The biosonar system of bats has many unique adaptations which allow for navigation in extremely cluttered environments. One such adaptation is the rapid motion of the pinna and noseleaf observed in certain families of old-world bats (Rhinolophidae and Hipposiderae). Little is known about the physical properties about this adaptation affects emitted pulses or incoming echoes. To explore the physical properties of biosonar systems utilizing dynamic peripheries, biomimetic sonar systems have been devised, which can be used to simulate the structural characteristics of the pinna and noseleaf geometry as well as the motor characteristics. Using this method, it was determined that the changing conformations of the biomimetic baffles were responsible for time-variant signatures in echoes. These signatures could be seen in echoes from a variety of both simple and complex target shapes. Then to further the capabilities of the device, an improved actuation system was devised using pneumatic actuation. This allowed for the baffles to make several unique motions as opposed to being restricted to one previously. It was also shown that the distinct motion profiles of the system led to distinct differences in the received acoustic signal. The features encoded by this system could lead to improvements in the development of improved sensing of smaller autonomous systems. GRANT INFORMATION: This work was supported by grants from the Office of Naval Research (ONR) and the Naval Engineering Education Consortium (NEEC). Additional support was provided by an East Asia and Pacific Summer Institutes (EAPSI) fellowship from the National Science Foundation (NSF). / Doctor of Philosophy / 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.

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. / Ph. D. / In this dissertation, the movement of millipedes utilize to traverse effectively within an environment that provides significant resistance is studied. Through various experimental observations and mathematical modeling, we are able to develop an understanding of the techniques millipedes use to be effective burrowers. To validate our model and understanding the millipede movement techniques, a robot was designed to emulate a millipede’s body structure and movement behavior. The performance of the millipede robot was found to be consistent with that of the biological creatures, indicating that we are able to emulate their behavior to achieve desirable tasks. With this developed understanding of the fundamental concepts that allow millipedes to effectively move against large resistances, we introduce the ability to design robots or devices that can achieve similar performance for various applications ranging from search and rescue to health inspection. One such application is a device that traverse within the stomach (rumen) of dairy cows to investigate its biological features and characteristics for improvement in animal agricultural efficiency. The fundamental concepts of millipede motion are translated to a rumen monitoring vehicle design, which would operate in a wet-soil-like environment, similar to millipedes. The device motion techniques are demonstrated, an indication of successfully transferring the fundamental mechanism used by millipedes for an engineering application.

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.

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 to follow a target with precision. A step forward has been made toward bio-inspired target localization and pursuit.

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 kind.

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.

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 imitating the honeybee. This bio-inspired visual strategy not only provides an elegant navigation solution in an unknown environment aimed to equip fully-actuated miniature vehicles but also to explain how a 100mg honeybee can navigate with few computational ressources, i.e., without any SONAR, RADAR, LIDAR or GPS.

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.

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 second time, the O2 reduction using two electrons to produce H2O2 (a soft oxidant) or four electron to produce H2O (useful in fuel cells) are of interest. It has been shown that all these new complexes are capable of catalytically reducing O2 in acetone and that only the one without exchangeable position can do it in acetonitrile. The latter has also demonstrate its ability to change its selectivity to produce H2O2 or H2O by changing the sacrificial reductant concentration. These results bring interesting insights for O2 activation with bio-inspired copper complexes.