Dissertations / Theses on the topic 'Robotic Structure'
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Hudeček, Vít. "Návrh univerzálního robotického systému." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231725.
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Clift, Louis G. "Robotic 3D reconstruction utilising structure from motion." Thesis, University of Essex, 2017. http://repository.essex.ac.uk/20734/.
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Sensing the real-world is a well-established and continual problem in the field of robotics. Investigations into autonomous aerial and underwater vehicles have extended this challenge into sensing, mapping and localising in three dimensions. This thesis seeks to understand and tackle the challenges of recovering 3D information from an environment using vision alone. There is a well-established literature on the principles of doing this, and some impressive demonstrations; but this thesis explores the practicality of doing vision-based 3D reconstruction using multiple, mobile robotic platforms, the emphasis being on producing accurate 3D models. Typically, robotic platforms such as UAVs have a single on-board camera, restricting which method of visual 3D recovery can be employed. This thesis specifically explores Structure from Motion, a monocular 3D reconstruction technique which produces detailed and accurate, although slow to calculate, 3D reconstructions. It examines how well proof-of-concept demonstrations translate onto the kinds of robotic systems that are commonly deployed in the real world, where local processing is limited and network links have restricted capacity. In order to produce accurate 3D models, it is necessary to use high-resolution imagery, and the difficulties of working with this on remote robotic platforms is explored in some detail.
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Enyedy, Albert J. "Robotic Construction Using Intelligent Scaffolding." Digital WPI, 2020. https://digitalcommons.wpi.edu/etd-theses/1356.
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Construction is a complex activity that requires the cooperation of multiple workers. Every year, construction activities cause injuries and casualties. To make construction safer, new solutions could be provided by robotics. Robots could be employed not only to replace human workers, but also to make construction in harsh environments safe and cost-effective, paving the way for enhanced underwater infrastructure, deeper underground mining, and planetary colonization. In this thesis, we focus on the topic of collective construction, which involves the cooperation of multiple robots, by presenting a collective robot construction method of our own. Collective construction can be a more viable option than employing individual, complex robots, by potentially allowing the effective realization of large structures, while offering resilience through redundancy, analogous to insect colonies. Our approach offers a novel solution in the design trade-off between choosing the number of robots involved vs. the complexity of the robots involved. On the one hand, capable and complex robots are expensive, limiting the cost effectiveness of realizing large swarms which provide redundancy and increase the system’s resilience to faults. On the other hand, simple and inexpensive robots can be manufactured in large numbers and offer high redundancy, at the cost of limited individual capa bilities and lower performance. We use two types of robots: intelligent scaffolding and worker robots. The intelligent scaffolding acts as regular scaffolding, allowing the worker robots to navigate the structure they assemble, while also guiding and monitoring the construction of the structure. The worker robots move and connect scaffolding and building material while only knowing the local commands necessary to complete their task. This approach is loosely inspired by termite mounds, in which termites use the process of stigmergy in which they mark construction pellets with pheromones to affect the progress of construction, while navigating the struc ture that they build. Thanks to intelligent scaffolding, construction robots have a simple design that allows minimalist onboard computation and communication equipment. In this thesis, we produced a minimum viable prototype demonstrating this concept. Intelligent scaffolding is realized through smart blocks that can be laid and connected to each other. The smart blocks are capable of simple computation and communication once laid. The construction robot uses local navigation methods by line-following across the scaffolding and building blocks of the system. The blocks and construction robot both have a modular design, simplifying the process of manufacturing and repairs while maintaining a low cost. The robot and blocks use magnets to increase the margin of error during block manipulation and allow for the assembly and removal of scaffolding as well as its reuse between build sites. To communicate with the robot, the intelligent scaffolding blocks send local IR signals, similar to TV remote signals, when the robot is on top of them, minimizing the risk of global interference and keeping the system portable. To monitor the connectivity of the system throughout the life cycle of the structure, electrical connections run through each of the blocks, which indicate the status of the structure and can be used to diagnose the location of breaks in the structure for maintenance.
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Stoyanov, Danail Valentinov. "Recovering 3D structure and motion in robotic laparoscopic surgery." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430137.
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Jayaweera, Nirosh Dilruk. "Adaptive robotic assembly of large compliant aero-structure components." Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434085.
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Kloss, Alina [Verfasser]. "Combining Learning and Structure for Robotic Manipulation / Alina Kloss." Tübingen : Universitätsbibliothek Tübingen, 2021. http://d-nb.info/1226756719/34.
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Viggh, Herbert E. M. "Artificial intelligence applications in teleoperated robotic assembly of the EASE space structure." Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/39358.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, and Dept. of Electrical Engineering and Computer Science, 1988.Bibliography: leaf 197.
by Herbert E. M. Viggh.
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, and Dept. of Electrical Engineering and Computer Science, 1988.
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Bayar, Gokhan. "Configurable Robot Base Design For Mixed Terrain Applications." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606530/index.pdf.
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Mobile robotics has become a rapidly developing field of interdisciplinary research within robotics. This promising field has attracted the attention of academicy, industry, several government agencies. Currently from security to personal service mobile robots are being used in a variety of tasks. The use of such robots is expected to only increase in the near future.
In this study, it is aimed to design and manufacture a versatile robot base. This base is aimed to be the main driving unit for various applications performed both indoors and outdoors ranging from personal service and assistance to military applications. The study does not attempt to individually address any specific application, indeed it is aimed to shape up a robotic module that can be used in a wide range of application on different terrain with proper modification. The robot base is specifically designed for mixed terrain applications, yet this study attempts to provide some guidelines to help robot designers. The manufactured robot base is tested with tracks, wheels, and with both tracks and wheels, results are provided as guidelines to robot designers. Last but no the least, this study aims to obtain the know-how of building functional and flexible robots in Turkey by facilitating local resources as much as possible.
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He, Hu. "Joint 2D and 3D cues for image segmentation towards robotic applications." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/71760/1/Hu_He_Thesis.pdf.
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This thesis investigates the fusion of 3D visual information with 2D image cues to provide 3D semantic maps of large-scale environments in which a robot traverses for robotic applications. A major theme of this thesis was to exploit the availability of 3D information acquired from robot sensors to improve upon 2D object classification alone. The proposed methods have been evaluated on several indoor and outdoor datasets collected from mobile robotic platforms including a quadcopter and ground vehicle covering several kilometres of urban roads.
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Almeshal, Abdullah. "Development and control of a novel-structure two-wheeled robotic vehicle manoeuvrable in different terrains." Thesis, University of Sheffield, 2013. http://etheses.whiterose.ac.uk/4885/.
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This thesis presents the development of a novel two-wheeled robotic vehicle with a movable payload and able to manoeuvre in different environments and terrains. The vehicle structure is based on the double inverted pendulum on cart mechanism. The system has five degrees of freedom that allow the vehicle to serve as a basis for new mobility solution applications. In this study, the vehicle model is derived mathematically using the Euler-Lagrange approach to describe the system dynamics. A hybrid fuzzy logic control approach is designed to stabilise and drive the vehicle on different terrains with different inclination angles. The Matlab Simulink environment is used to simulate the vehicle system. A hybrid spiral dynamic bacteria chemotaxis optimisation algorithm is used to optimise the control parameters to achieve the least mean square error of system response and to reduce the amount of exerted control effort. Various simulation scenarios are considered to demonstrate the vehicle’s ability to work on smooth and frictional surfaces. Disturbances are applied to the vehicle to evaluate the performance of the developed control system in coping with disturbances of variable amplitudes and durations. It is shown that the vehicle exhibits a stable response and a high degree of control robustness. A steering mechanism is implemented to drive the vehicle in different environments and terrains encountered in real life. Environment modelling has been incorporated into the vehicle system to simulate various ground types and levels of frictional forces. It is demonstrated that the vehicle is able to successfully manoeuvre in indoor and outdoor environments and on flat and sloped surfaces fulfilling the aims and objectives of the research.
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Cousturier, Richard. "Amélioration par la gestion de redondance du comportement des robots à structure hybride sous sollicitations d’usinage." Thesis, Université Clermont Auvergne (2017-2020), 2017. http://www.theses.fr/2017CLFAC090/document.
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Les robots industriels ont évolué fondamentalement ces dernières années pour répondre aux exigences industrielles de machines et mécanismes toujours plus performants. Ceci se traduit aujourd’hui par de nouveaux robots anthropomorphes plus adaptés laissant entrevoir la réalisation de tâches plus complexes et soumis à de fortes sollicitations comme durant l’usinage. L’étude du comportement des robots anthropomorphes, à structures parallèles ou hybrides montre une anisotropie aussi bien cinématique, que dynamique, impactant la précision attendue. Ces travaux de thèse étudient l’intégration des redondances cinématiques qui permettent de pallier en partie ce problème en positionnant au mieux la tâche à réaliser dans un espace de travail compatible avec les capacités attendues. Ces travaux ont permis d’améliorer notre outil d’optimisation et de le tester à la fois sur un modèle Eléments Finis du robot et sur le robot réel. Ainsi, ces travaux de thèse apportent des contributions à : - la définition de critères adaptés à la réalisation de tâches complexes et sollicitantes pour la gestion des redondances cinématiques ; - l’identification du comportement des structures sous sollicitations par moyen métrologique (Laser tracker) ; - l’optimisation du comportement permettant l’amélioration de la qualité de réalisation des opérations d’usinage ; - la modélisation Eléments Finis des robots prenant en compte l’identification des rigidités des corps et articulairesIndustrial robots have evolved fundamentally in recent years to reach the industrial requirements. We now find more suitable anthropomorphic robots leading to the realization of more complex tasks like deformable objects cutting such as meat cutting or constrained to high loading like during machining. The behavior study of anthropomorphic robots, parallel or hybrid one highlights a kinematic and dynamic anisotropy, which impacts the expected accuracy.This thesis studied the integration of the kinematic redundancy that can partially overcome this problem by well setting the task to achieve it in a space compatible with the expected capacity.This work helped us to improve our optimization tool and to try it on both FE model of the robot and real robot.Thus, the thesis makes contributions to: - the definition of criteria adapted to the realization of complex and under high loading task for the management of the kinematic redundancy; - the structural behavior identification, under loading, by metrology tools (Laser tracker) ; - the behavior optimization to improve the cutting process quality during machining ; - robots finite elements modeling using stiffness identification for both bodies and joints
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Debnath, Jayanta Kumar. "Development of Scheduling, Path Planning and Resource Management Algorithms for Robotic Fully-automated and Multi-story Parking Structure." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1470399189.
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Majer, Tomáš. "Návrh pracoviště s průmyslovým robotem." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-382109.
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This diploma thesis deals with design of a robotized workplace for welding truss structures. First, the target construction that the work focuses on is shown. Then the functions of the entire workplace are designed, including the procedures for activities and the gross displacement of the used components and their layout. The next chapter itemize specific robots and components. This, along with the solution of safety and ergonomics, makes the layout of the entire workplace more precise. Everything is completed by creating a simulation model in Siemens Tecnomatix Process Simulate, where all the welding operations are simulated.
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Merrell, Paul Clark. "Structure from Motion Using Optical Flow Probability Distributions." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd764.pdf.
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Vakilinejad, Mohammad. "Amélioration de la précision des robots industriels pour la découpe de matériaux composites." Thesis, Paris, ENSAM, 2019. http://www.theses.fr/2019ENAM0071.
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La participation des bras robotiques industriels à différentes applications de fabrication est en constante évolution. Ces dispositifs, qui n'étaient autrefois utilisés que dans des applications fondées sur leur répétabilité acceptable, prennent maintenant la place d'opérateurs humains dextérités ou de dispositifs d'usinage rigides dans les tâches de fabrication de haute précision. Toutefois, les défauts hérités de ces structures nécessitent des études plus approfondies pour garantir des performances acceptables. Dans cette thèse, les efforts ont été consacrés en premier lieu à observer la contribution des différentes sources d'erreur dans la fabrication robotisée impliquée. Les principaux contributeurs à l'imprécision du robot ont été étudiés pour les processus d'identification et de compensation. Un modèle élastostatique d'un robot industriel est généré. Une nouvelle méthode d'identification des erreurs de transmission des articulations est abordée, capable de réduire massivement le temps d'identification. Pour améliorer la qualité des pièces dans le processus d'usinage par ultrasons de nid d'abeille robotisé, une nouvelle approche est proposée pour intégrer le comportement de conformité de l'outil à celui de la structure du robot. Une procédure détaillée de développement du modèle de force d'usinage et de mesure des erreurs géométriques est également présentée pour ce processus d'usinage. Pour réduire l'effet des sources d'erreurs non-géométriques, un processus d'optimisation est exécuté pour le placement optimal de la pièce dans l'espace de travail du robotThe involvement of industrial robotic arms in different manufacturing applications is going through an ever-changing era. These devices which were once only used in applications based on their acceptable repeatability are now taking place of dexterous human operators or rigid machining devices in high precision manufacturing tasks. However, the inherited shortcomings of these structures require further investigations to ensure acceptable performance. In this thesis, efforts were dedicated firstly to observe the contribution of different error sources in robotic involved manufacturing. The main contributors to the robot inaccuracy were investigated for identification and compensation processes. An elastostatic model of an industrial robot is generated. A novel method in identifying joint transmission errors is addressed capable of massively reducing the identification time. To enhance the workpiece quality in robotic-based honeycomb ultrasonic machining process, a new approach to integrate tool compliance behaviour with the one of robot structure is proposed. A detailed procedure of developing the machining force model and geometrical error measurement is also presented for this machining process. To reduce the effect of non-geometrical error sources, an optimization process is executed for optimal placement of workpiece in robot workspace
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Meyer, Julien. "Proposition d’un modèle numérique pour la conception architecturale d’enveloppes structurales plissées : application à l’architecture en panneaux de bois." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0099/document.
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L’objectif de notre recherche consiste à caractériser le concept de plissage afin de proposer un modèle numérique permettant de concevoir des structures architecturales plissées en panneaux de bois. Dans ce contexte, nous ouvrons une perspective originale sur l’intégration de la dimension morpho-structurale comme facteur de modulation de l’architecture. Nous abordons également le plissage dans sa dimension numérique par une approche paramétrique. Cette dernière permet une modélisation adaptative dans le continuum conception-fabrication. Notre méthode, implémentée dans l’outil CARA(s)PACE (Conception of Architectural Research Algorithm for Structural Pleated Approaches and Creative Envelopes), permet de générer une géométrie de plissage à partir d’une surface de référence. Cet outil est composé d’un modeleur géométrique paramétrique couplé à des moteurs d’évaluation. Il guide le concepteur dans la recherche de formes fondées sur le plissage, sécurise les propositions et fournit les données numériques nécessaires pour une fabrication robotiséeThe purpose of this research is to characterise the concept of pleating in order to give a numerical model allowing the design of wooden pleated architectural structures. In this context, we are bringing a singular perspective to the integration of the morpho-structural dimension as a modulating factor of architecture. We also deal with creasing in its digital dimension by adopting a parametric approach which allows an adaptive modelling within the ‘design-manufacturing’ continuum. Our method, implemented in the CARA(s)PACE (Conception of Architectural Research Algorithm for Structural Pleated Approaches and Creative Envelopes) tool, generates a geometry of pleating from a reference surface. This tool is composed of a parametric and geometric modeller coupled with evaluation engines. It guides the designer in the research of forms based on creasing, secures the suggestions and provides the numerical data needed for a robotic manufacturing
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Marmol, Velez Andres Felipe. "Robust and dense visual slam for robot-assisted minimally invasive orthopaedic procedures." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/132169/1/Andres_Marmol%20Velez_Thesis.pdf.
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Orthopaedic surgeons are currently overburdened by physical and mental challenges that significantly increase the risk of injury to more than 2 million patients every year. This thesis proposes a robotic surgical-assistant for minimally-invasive orthopaedic surgeries that can alleviate surgeon workload and reduce the risk of unintended patient injury. A robotic prototype, along with a set of state-of-the-art robotic vision algorithms, was designed and validated in knee arthroscopy, the most common orthopaedic procedure worldwide. The proposed system can reliably inform surgeons of the location of an instrument within a detailed 3D map of the anatomy. Extensive experimentation, including cadaveric trials, demonstrated the system's unparalleled performance in real operative conditions.
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Gomes, Samuel da Silva. "Modelagem e controle de atuadores robóticos e veículos subaquáticos não tripulados." reponame:Repositório Institucional da FURG, 2011. http://repositorio.furg.br/handle/1/3434.
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Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Engenharia Oceânica, Escola de Engenharia, 2011.Submitted by Lilian M. Silva (lilianmadeirasilva@hotmail.com) on 2013-04-22T19:33:16Z No. of bitstreams: 1 Modelagem e controle de atuadores robóticos e veículos subaquáticos não tripulados.pdf: 2108153 bytes, checksum: 01646a2e791884ffca750c5291ce8bd1 (MD5)
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Esta dissertação trata da modelagem e do controle de um atuador robótico e de veículos subaquáticos não tripulados. Primeiramente o trabalho compara e valida experimentalmente dois modelos de atrito existentes na literatura (LuGre e Gomes). Desenvolve-se um controle de posição baseado em estrutura variável para o atuador robótico do tipo harmonic-drive. Simulações são realizadas a fim de verificar a robustez do controlador perante a variação paramétrica em comparação com o controle proporcional, integral e derivativo (PID). Resultados experimentais das aplicações dos controles são obtidos mostrando desempenhos muito próximos aos de simulação. Posteriormente é feito um estudo sobre veículos subaquáticos não tripulados (Tatuí e Nerov). A modelagem cinemática é descrita por ângulos de Euler e a modelagem dinâmica inclui a interação da estrutura mecânica do veículo com o meio aquático e a ação dos propulsores. Desenvolve-se um sistema de controle de posição e orientação utilizando estrutura variável. Resultados de simulação ilustram as características do controlador com incertezas paramétricas e correntes oceânicas em comparação com o PID usando a estratégia de linearização por realimentação.
The subject of this dissertation is the modeling and control of a robotic actuator and also of unmanned underwater vehicles. Firstly, it compares and experimentally validates two friction models (LuGre and Gomes). A position control based on a variable structure is developed for the harmonic-drive type of robotic actuator. Simulations are performed to verify the robustness of the controller against the parametric variation and to compare to the proportional, integral and derivative control (PID). Experiments then show results similar to those from simulations. Later, we a study about unmanned underwater vehicles (Tatuí and Nerov) is presented. The kinematics modeling is described by Euler’s angles. The dynamics modeling includes the interaction of the vehicle’s mechanical structure with the aquatic environment and the actuation of the propellers. By using a variable structure, a position and orientation control system is developed. The simulation results then show the characteristics of the controler with parametric uncertainties and ocean streams, and compares them with those from a PID controler with feedback linearization.
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Trevor, Alexander J. B. "Semantic mapping for service robots: building and using maps for mobile manipulators in semi-structured environments." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53583.
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Although much progress has been made in the field of robotic mapping, many challenges remain including: efficient semantic segmentation using RGB-D sensors, map representations that include complex features (structures and objects), and interfaces for interactive annotation of maps. This thesis addresses how prior knowledge of semi-structured human environments can be leveraged to improve segmentation, mapping, and semantic annotation of maps. We present an organized connected component approach for segmenting RGB-D data into planes and clusters. These segments serve as input to our mapping approach that utilizes them as planar landmarks and object landmarks for Simultaneous Localization and Mapping (SLAM), providing necessary information for service robot tasks and improving data association and loop closure. These features are meaningful to humans, enabling annotation of mapped features to establish common ground and simplifying tasking. A modular, open-source software framework, the OmniMapper, is also presented that allows a number of different sensors and features to be combined to generate a combined map representation, and enabling easy addition of new feature types.
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Loing, Vianney. "Stéréotomie et vision artificielle pour la construction robotisée de structures maçonnées complexes." Thesis, Paris Est, 2019. http://www.theses.fr/2019PESC1015/document.
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Ce travail de thèse s'inscrit dans le contexte du développement de la robotique dans la construction. On s’intéresse ici à la construction robotisée de structures maçonnées complexes en ayant recours à de la vision artificielle. La construction sans cintre étant un enjeu important en ce qui concerne la productivité sur un chantier et la quantité de déchets produits, nous explorons, à cet effet, les possibilités qu'offre la rigidité en flexion inhérente aux maçonneries topologiquement autobloquantes. La génération de ces dernières, classique dans le cas plan, est généralisée ici à la conception de structures courbes, à partir de maillages de quadrangles plans et de manière paramétrique, grâce aux logiciels Rhinoceros 3D / Grasshopper. Pour cela, nous proposons un ensemble d'inégalités à respecter afin que la structure obtenue soit effectivement topologiquement autobloquante. Ces inégalités permettent, par ailleurs, d'introduire un résultat nouveau ; à savoir qu'il est possible d'avoir un assemblage de blocs dans lequel chacun des blocs est topologiquement bloqué en translation, mais un sous-ensemble — constitué de plusieurs de ces blocs — ne l'est pas. Un prototype de maçonnerie à topologie autobloquante est finalement conçu. Sa conception repose sur une découpe des joints d'inclinaison variable qui permet de le construire sans cintre. En parallèle, nous abordons des aspects de vision artificielle robuste pour un environnement chantier, environnement complexe dans lequel les capteurs peuvent subir des chocs, être salis ou déplacés accidentellement. Le problème est d'estimer la position relative d'un bloc de maçonnerie par rapport à un bras robot, à partir de simples caméras 2D ne nécessitant pas d'étape de calibration. Notre approche repose sur l'utilisation de réseaux de neurones convolutifs de classification, entraînés à partir de centaines de milliers d'images synthétiques de l’ensemble bras robot + bloc, présentant des variations aléatoires en terme de dimensions et positions du bloc, textures, éclairage, etc, et ce afin que le robot puisse apprendre à repérer le bloc sans trop de biais d’environnement. La génération de ces images est réalisée grâce à Unreal Engine 4. Cette méthode permet la localisation du bloc par rapport au robot avec une précision millimétrique, sans utiliser une seule image réelle pour la phase d'apprentissage ; ce qui constitue un avantage certain puisque l'acquisition de données représentatives pour l'apprentissage est un processus long et fastidieux. Nous avons également construit une base de données riche, constituée d’environ 12000 images réelles contenant un robot et un bloc précisément localisés, permettant d’évaluer quantitativement notre approche et de la rendre comparable aux approches alternatives. Un démonstrateur réel intégrant un bras ABB IRB 120, des blocs parallélépipédiques et trois webcams a été mis en place pour démontrer la faisabilité de la méthodeThe context of this thesis work is the development of robotics in the construction industry. We explore the robotic construction of complex masonry structures with the help of computer vision. Construction without the use of formwork is an important issue in relation to both productivity on a construction site and the amount of waste generated. To this end, we study topological interlocking masonries and the possibilities they present. The design of this kind of masonry is standard for planar structures. We generalize it to the design of curved structures in a parametrical way, using PQ meshes and the softwares Rhinoceros 3D and Grasshopper. To achieve this, we introduce a set of inequalities to respect in order to have a topological interlocked structure. These inequalities allow us to present a new result. Namely, it is possible to have an assembly of blocks in which each block is interlocked in translation, while having a subset — composed of several of these blocks — that is not interlocked. We also present a prototype of topological interlocking masonry. Its design is based on variable inclination joints, allowing construction without formwork. In parallel, we are studying robust computer vision for unstructured environments like construction sites, in which sensors are vulnerable to dust or could be accidentally jostled. The goal is to estimate the relative pose (position + orientation) of a masonry block with respect to a robot, using only cheap cameras without the need for calibration. Our approach relies on a classification Convolutional Neural Network trained using hundreds of thousands of synthetically rendered scenes with a robot and a block, and randomized parameters such as block dimensions and poses, light, textures, etc, so that the robot can learn to locate the block without being influenced by the environment. The generation of these images is performed with Unreal Engine 4. This method allows us to estimate a block pose very accurately, with only millimetric errors, without using a single real image for training. This is a strong advantage since acquiring representative training data is a long and expensive process. We also built a new rich dataset of real robot images (about 12,000 images) with accurately localized blocks so that we can evaluate our approach and compare it to alternative approaches. A real demonstrator, including a ABB IRB 120 robot, cuboid blocks and three webcams was set up to prove the feasibility of the method
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Svensson, Fredrik. "Structure from Forward Motion." Thesis, Linköpings universitet, Bildbehandling, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-60136.
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This master thesis investigates the difficulties of constructing a depth map using one low resolution grayscale camera mounted in the front of a car. The goal is to produce a depth map in real-time to assist other algorithms in the safety system of a car. This has been shown to be difficult using the evaluated combination of camera position and choice of algorithms. The main problem is to estimate an accurate optical flow. Another problem is to handle moving objects. The conclusion is that the implementations, mainly triangulation of corresponding points tracked using a Lucas Kanade tracker, provide information of too poor quality to be useful for the safety system of a car.I detta examensarbete undersöks svårigheterna kring att skapa en djupbild från att endast använda en lågupplöst gråskalekamera monterad framtill i en bil. Målet är att producera en djupbild i realtid som kan nyttjas i andra delar av bilens säkerhetssystem. Detta har visat sig vara svårt att lösa med den undersökta kombinationen av kameraplacering och val av algoritmer. Det huvudsakliga problemet är att räkna ut ett noggrant optiskt flöde. Andra problem härrör från objekt som rör på sig. Slutsatsen är att implementationerna, mestadels triangulering av korresponderande punktpar som följts med hjälp av en Lucas Kanade-följare, ger resultat av för dålig kvalitet för att vara till nytta för bilens säkerhetssystem.
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Chao, Hung-Hsiang Jonathan. "Parallel/pipeline VLSI computing structures for robotic applications /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487260135357358.
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Orthey, Andreas. "Exploiting structure in humanoid motion planning." Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/14685/1/orthey.pdf.
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If humanoid robots should work along with humans and should be able to solve repetitive tasks, we need to enable them with a skill to autonomously plan motions. Motion planning is a longstanding core problem in robotics, and while its algorithmic foundation has been studied in depth, motion planning is still an NP-hard problem lacking efficient solutions. We want to open up a new perspective on the problem by highlighting its structure: the behavior of the robot, the mechanical system of the robot, and the environment of the robot. We will investigate the hypothesis that each structural component can be exploited to create more efficient motion planning algorithms. We present three algorithms exploiting structure, based on geometrical and topological arguments: first, we exploit the behavior of a walking robot by studying the feasibility of footstep transitions. The resulting algorithm is able to plan footsteps avoiding up to 60 objects on a 6 square meters planar surface. Second, we exploit the mechanical system of a humanoid robot by studying the linear linkage structures of its arms and legs. We introduce the concept of an irreducible motion, which is a completeness-preserving dimensionality reduction technique. The resulting algorithm is able to find motions in narrow environments, where previous sampling-based methods could not be applied. Third, we exploit the environment by reasoning about the topological structure of contact transitions. We show that analyzing the environment is an efficient method to precompute relevant information for efficient motion planning. Based on those results, we come to the conclusion that exploiting structure is an essential component of efficient motion planning. It follows that any humanoid robot, who wants to act efficiently in the real world, needs to be able to understand and to exploit structure.
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Ma, Mo. "Navigation using one camera in structured environment /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?ECED%202007%20MA.
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Mangalgiri, Vickram S. (Vickram Suresh) 1979. "Analysis for robotic assembly of large flexible space structures." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/27038.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (leaves 79-83).
Space solar power is a renewable, environment-friendly alternative to satisfy future terrestrial power needs. Space solar power stations will need to have large dimensions (on the order of hundreds of meters) to be able to collect enough power to make them cost effective. It will be infeasible to transport these large structures, fully assembled, from earth to space, or use human astronauts for their construction in space, leaving robotic assembly as the only viable option. The focus of the current work is to identify potential challenges to the large structure assembly process in space and develop methods to address them. One of the major causes of failure in the assembly process would be dimensional mismatch between the two structures to be joined. The first part of this thesis analyses the static and dynamic effects on a typical large space structure using finite element models and predicts the deformation that the structure will undergo due to thermal and vibration effects in space. Forced assembly methods using cooperative robots are developed to compensate for these dimensional errors. The second part of the thesis deals with the application of forced assembly methods to representative assembly scenarios. The scenarios are categorized based on the nature of the deformation involved. The differences between the use of thrusters and manipulators by robots are discussed and assembly plans are developed for each scenario using either or both types of actuators. A genetic algorithm based planner is developed and implemented to optimize the assembly process within the limits of the assumptions made.
by Vikram S. Mangalgiri.
S.M.
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Ruffatto, Donald F. III. "Hybrid electrostatic and micro-structured adhesives for robotic applications." Thesis, Illinois Institute of Technology, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3733995.
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Current adhesives and gripping mechanisms used in many robotics applications function on very specific surface types or at defined attachment locations. A controllable, i.e. ON-OFF, adhesive mechanism that can operate on a wide range of surfaces would be very advantageous. Such a device would have applications ranging from robotic gripping and climbing to satellite docking and inspection/service missions. The main goal of the research presented here was to create such an attachment mechanism through the use of a new hybrid adhesive technology. The newly developed adhesive technology is a hybridization of electrostatic and micro-structured dry adhesion. The result provides enhanced robustness and utility, particularly on rough surfaces. There were challenges not only in the integration of these two adhesive elements but also with its application in a complete gripping mechanism.
Electrostatic and directional dry adhesives were both individually investigated. The electrode geometry for an electrostatic adhesive was optimized for maximum adhesion force using finite element analysis software. Optimization results were then verified through experimental testing. New manufacturing techniques were also developed for electrostatic adhesives that utilized a metalized mesh embedded in a silicone polymer and Kapton film based construction, greatly improving adhesion. The micro-structured dry adhesive used was provided by Dr. Aaron Parness, from the NASA Jet Propulsion Lab (JPL), and consists of an array of vertical stalks with an angled front face, referred to as micro-wedges. The hybrid electrostatic dry adhesive (EDA) was created by fabricating the electrostatic adhesive directly on top of a dry adhesive mold. This process created an array of dry adhesive micro-wedges directly on the surface of the electrostatic adhesive. In operation the electrostatic adhesive provides a normal force which serves to pull the dry adhesive into the surface substrate. With greater surface contact more of the dry adhesive is able to engage, bring the electrostatic adhesive even closer to the surface and increasing its effectiveness. Therefore, the combination of these two technologies creates a positive feedback cycle whose whole is often greater than the sum of its parts.
An interface mechanism is needed to transmit applied loads from a rigid structure to the flexible adhesive while still maintaining its conformability. This is especially important for strong adhesion on rough surfaces, such as tile and drywall. Different concepts such as a structured fibrillar hierarchy and a fluid-filled backing pouch have been explored. Additionally, finite element analysis was used to evaluate different fribrillar shapes and geometries for the structured hierarchy. The goal was to equalize the load distribution across the adhesive while still maintaining surface compliance. A gripper mechanism was also created which used a servo for actuation and three rigid tiles with a directional dry adhesive. It was tested on a perching Micro Air Vehicle (MAV) as well as in the RoboDome facility at NASA's Jet Propulsion lab to simulate a satellite docking/capture maneuver.
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Bebek, Ozkan. "ROBOTIC-ASSISTED BEATING HEART SURGERY." Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1201289393.
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Eranki, Venkata Krishna Prashanth, and Gurudu Rishank Reddy. "Design and Structural Analysis of a Robotic Arm." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-13834.
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Automation is creating revolution in the present industrial sector, as it reduces manpower and time of production. Our project mainly deals around the shearing operation, were the sheet is picked manually and placed on the belt for shearing which involves risk factor. Our challenge is designing of pick and place operator to carry the sheet from the stack and place it in the shearing machine for the feeding. We have gone through different research papers, articles and had observed the advanced technologies used in other industries for the similar operation. After related study we have achieved the design of a 3-jointed robotic arm were the base is fixed and the remaining joints move in vertical and horizontal directions. The end effector is also designed such that to lift the sheet we use suction cups were the sheet is uplifted with a certain pressure. Here we used Creo-Parametric for design and Autodesk-Inventor 2017 to simulate the designed model.
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Dixon, Theresa S. B. Massachusetts Institute of Technology. "Development of manufacturing technique for composite structures for robotic applications." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59906.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 23-25).
An experimental study was performed with the aim of developing a technique for manufacturing composite parts for use in dynamic robotic applications in lieu of heavy and expensive metal parts used in conventional robotic systems. There is already a wide usage of sandwich board materials in load bearing applications, but these do not provide equal strength in all directions, particularly compressive strength. Additionally, these materials are only available in two-dimensional shapes. The process developed over the course of this project seeks to make a fully covered composite of any desired geometries. The specific robotics project addressed was the hyper dynamic quadruped robotic platform, which ultimately seeks to design and construct a robot capable of a high speed gallop. This thesis began exploring methods of fabricating parts for one of the legs of the platform, specifically a radius part. Manufactured components needed to be both light in weight to facilitate ease of movement for the robot and strong enough to withstand the forces from the shifting weight during running. Proposed design parameters called for a foam core with a hard plastic shell to meet these needs. This technique can lead to a cheaper manufacturing method with a potential impact on the future robotics industry. After an investigation into the properties of different liquid polyurethane foams and plastics, the manufacturing techniques explored began with machining molds for both the inner core and outer shell of composite parts into wax blocks. The project aims were to develop a prototyping process, but this can lead to mass-production. Two versions of a manufacturing process with these blocks were developed, one which uses an open mold and one which uses a closed mold. Either method is viable for fabrication, with a preference for the open mold in parts with simple geometry and small thickness, and for the closed mold in larger parts or ones with complicated or interrupted outer perimeters.
by Theresa Dixon.
S.B.
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Huang, Yijiang S. M. Massachusetts Institute of Technology. "Automated motion planning for robotic assembly of discrete architectural structures." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/118487.
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Thesis: S.M. in Building Technology, Massachusetts Institute of Technology, Department of Architecture, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 71-80).
Architectural robotics has proven a promising technique for assembling non-standard configurations of building components at the scale of the built environment, complementing the earlier revolution in generative digital design. However, despite the advantages of dexterity and precision, the time investment in solving the construction sequence and associated robotic motion grows increasingly with the topological complexity of the target design. This gap between parametric design and robotic fabrication congests the overall digital design/production process and often confines designers to geometries with standard topology. In the goal of filling this gap, this research presents a new robotic assembly planning framework called Choreo, which eliminates human-intervention for parts that are typically arduous and tedious in architectural robotics projects. Specifically, Choreo takes discrete spatial structure as input, and then assembly sequence, end effector pose, joint configuration, and transition trajectory are all generated automatically. Choreo embodies novelties in both algorithm design and software implementation. Algorithm-wise, a three-layer hierarchical assembly planning framework is proposed, to gradually narrow down the computational complexity along the deep and branched search tree emerging in this combined task and motion planning problem. Implementation-wise, Choreo's system architecture is designed to be modularized and adaptable, with the emphasis on being hardware-agnostic and forging a smooth integration into existing digital design-build workflow. Case studies on fabrication results of robotic extrusion (also called spatial 3D printing) are presented to demonstrate Choreo's power on efficiently generating feasible robotic instructions for assembling shapes with non-standard topology and across the scales.
by Yijiang Huang.
S.M. in Building Technology
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Han, Kyung Min. "Collision free path planning algorithms for robot navigation problem." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5021.
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Thesis (M.S.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 29, 2008) Includes bibliographical references.
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Mealier, Anne-Laure. "Comment le langage impose-t-il la structure du sens : construal et narration." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1333.
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Cette thèse a été effectuée dans le cadre du projet européen WYSIWYD (What You Say is What You Did). Ce projet a pour but de rendre, plus naturelles, les interactions Humain-robot, notamment par le biais du langage. Le déploiement de robots compagnon et de robots de service requière que les humains et les robots puissent se comprendre mutuellement et communiquer. Les humains ont développé une codification avancée de leur comportement qui fournit la base de la transparence de la plupart de leurs actions et de leur communication. Jusqu'à présent, les robots ne partagent pas ce code de comportement et ne sont donc pas capables d'expliquer leurs propres actions aux humains. Nous savons que dans le langage parlé, il existe un lien direct entre le langage et le sens permettant à une personne qui écoute d'orienter son attention sur un aspect précis d'un événement. Ceci est particulièrement vrai en production de langage. On sait que la perception visuelle permet l'extraction des aspects de «qui a fait quoi à qui» dans la compréhension des événements sociaux. Mais dans le cadre d'interactions humaines, il existe d'autres aspects importants qui ne peuvent être déterminés uniquement à partir de l'image visuelle. L'échange d'un objet peut être interprété suivant différents points de vue, par exemple du point de vue du donateur ou de celui du preneur. Nous introduisons ainsi la notion de construal. Le construal est la manière dont une personne interprète le monde ou comprend une situation particulière. De plus, les événements sont reliés dans le temps, mais il y a des liens de causalité ainsi que des liens intentionnels qui ne peuvent pas être vus d'un point de vue uniquement visuel. Un agent exécute une action, car il sait que cette action satisfait le désir d'un autre agent. Cela peut ne pas être visible directement dans la scène visuelle. Le langage permet ainsi de préciser cette particularité : "Il vous a donné le livre parce que vous le vouliez". La première problématique que nous mettons en évidence dans ce travail est la manière dont le langage peut être utilisé pour représenter ces construals. Autrement dit, la manière dont un orateur choisit une construction grammaticale plutôt qu'une autre en fonction de son centre d'intérêt. Pour y répondre, nous avons développé un système dans lequel un modèle mental représente un événement d'action. Ce modèle est déterminé par la correspondance entre deux vecteurs abstraits : le vecteur de force exercée par l'action et le vecteur de résultat correspondant à l'effet de la force exercée. La deuxième problématique que nous étudions est comment des constructions de discours narratif peuvent être apprises grâce à un modèle de discours narratifs. Ce modèle se base sur des réseaux neuronaux de production et de compréhension de phrases existants que nous enrichissons avec des structures additionnelles permettant de représenter un contexte de discours. Nous présentons également la manière dont ce modèle peut s'intégrer dans un système cognitif global permettant de comprendre et de générer de nouvelles constructions de discours narratifs ayant une structure similaire, mais des arguments différents. Pour chacun des travaux cités précédemment, nous montrons comment ces modèles théoriques sont intégrés dans la plateforme de développement du robot humanoïde iCub. Cette thèse étudiera donc principalement deux mécanismes qui permettent d'enrichir le sens des évènements par le langage. Le travail se situe entre les neurosciences computationnelles, l'élaboration de modèles de réseaux neuronaux de compréhension et de production de discours narratifs, et la linguistique cognitive où comprendre et expliquer un sens en fonction de l'attention est crucialThis thesis takes place in the context of the European project WYSIWYD (What You Say is What You Did). The goal of this project is to provide transparency in Human-robot interactions, including by mean of language. The deployment of companion and service robots requires that humans and robots can understand each other and communicate. Humans have developed an advanced coding of their behavior that provides the basis of transparency of most of their actions and their communication. Until now, the robots do not share this code of behavior and are not able to explain their own actions to humans. We know that in spoken language, there is a direct mapping between languages and meaning allowing a listener to focus attention on a specific aspect of an event. This is particularly true in language production. Moreover, visual perception allows the extraction of the aspects of "who did what to whom" in the understanding of social events. However, in the context of human interaction, other important aspects cannot be determined only from the visual image. The exchange of an object can be interpreted from the perspective of the giver or taker. This introduces the notion of construal that is how a person interprets the world and perceive a particular situation. The events are related in time, but there are causal and intentional connexion that cannot be seen only from a visual standpoint. An agent performs an action because he knows that this action satisfies the need for another person. This may not be directly visible in the visual scene. The language allows specifying this characteristic: "He gave you the book because you like it." The first point that we demonstrate in this work is how the language can be used to represent these construals. In response, we have developed a system in which a mental model represents an action event. This model is determined by the correspondence between two abstract vectors: the force vector exerted by the action and the result vector corresponding to the effect of the applied force. The application of an attentional process selects one of the two vectors, thus generating the construal of the event. The second point that we consider in this work is how the construction of narrative discourse can be learned with a narrative discourse model. This model is based on both existing neural networks of production and comprehension of sentences that we enrich with additional structures to represent a context of discourse. We present also how this model can be integrated into an overall cognitive system for understanding and generate new constructions of narrative discourse based on similar structure, but different arguments. For each of the works mentioned above, we show how these theoretical models are integrated into the development platform of the iCub humanoid robot. This thesis will explore two main mechanisms to enrich the meaning of events through language. The work is situated between computational neuroscience, with development of neural network models of comprehension and production of narrative discourse, and cognitive linguistics where to understand and explain the meaning according to joint attention is crucial
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Schmalz, Andrew Peter. "Classification, analysis, and control of planar tensegrity structures for robotic applications." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 127 p, 2007. http://proquest.umi.com/pqdweb?did=1313919761&sid=12&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Preston, Edward. "Collaborative robotic plasma arc welding of fabricated titanium aero-engine structures." Thesis, University of Nottingham, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.546461.
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Kernbach, Serge. "Structural self-organization in multi-agents and multi-robotic systems." Berlin Logos-Verl, 2007. http://d-nb.info/990756041/04.
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Kernbach, Serge. "Structural self-organization in multi-agents and multi-robotic systems /." Berlin : Logos Verl, 2008. http://deposit.d-nb.de/cgi-bin/dokserv?id=3164655&prov=M&dok_var=1&dok_ext=htm.
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Aydemir, Alper. "Exploiting structure in man-made environments." Doctoral thesis, KTH, Datorseende och robotik, CVAP, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-104410.
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Robots are envisioned to take on jobs that are dirty, dangerous and dull, the three D's of robotics. With this mission, robotic technology today is ubiquitous on the factory floor. However, the same level of success has not occurred when it comes to robots that operate in everyday living spaces, such as homes and offices. A big part of this is attributed to domestic environments being complex and unstructured as opposed to factory settings which can be set up and precisely known in advance. In this thesis we challenge the point of view which regards man-made environments as unstructured and that robots should operate without prior assumptions about the world. Instead, we argue that robots should make use of the inherent structure of everyday living spaces across various scales and applications, in the form of contextual and prior information, and that doing so can improve the performance of robotic tasks. To investigate this premise, we start by attempting to solve a hard and realistic problem, active visual search. The particular scenario considered is that of a mobile robot tasked with finding an object on an entire unexplored building floor. We show that a search strategy which exploits the structure of indoor environments offers significant improvements on state of the art and is comparable to humans in terms of search performance. Based on the work on active visual search, we present two specific ways of making use of the structure of space. First, we propose to use the local 3D geometry as a strong indicator of objects in indoor scenes. By learning a 3D context model for various object categories, we demonstrate a method that can reliably predict the location of objects. Second, we turn our attention to predicting what lies in the unexplored part of the environment at the scale of rooms and building floors. By analyzing a large dataset, we propose that indoor environments can be thought of as being composed out of frequently occurring functional subparts. Utilizing these, we present a method that can make informed predictions about the unknown part of a given indoor environment. The ideas presented in this thesis explore various sides of the same idea: modeling and exploiting the structure inherent in indoor environments for the sake of improving robot's performance on various applications. We believe that in addition to contributing some answers, the work presented in this thesis will generate additional, fruitful questions.QC 20121105
CogX
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Moon, Suk-Min. "Active damping control of a compliant base manipulator." Ohio : Ohio University, 1999. http://www.ohiolink.edu/etd/view.cgi?ohiou1175797025.
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Herrod, Nicholas John. "Three-dimensional robot vision using structured illumination." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257308.
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Mazumdar, Anirban. "Mag Feet : a robotic device for the inspection of steel bridge structures." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/50569.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.Includes bibliographical references (p. 83-84).
The aging of America's steel bridges presents many challenges. Undetected cracks and corrosion can eventually lead to catastrophic failure. Due to the difficulties with inspecting existing bridges the use of mobile robots for steel bridge inspection has become an important area of research. This thesis describes the analysis, design, and implementation of a new approach to steel bridge inspection robots using tilting feet equipped with permanent magnets. This robot, titled "Mag-Feet", is capable of adhering to steel surfaces and can move along steel surfaces using a combination of three distinct gait modes. These three gait modes allow the robot to "Moonwalk" along horizontal surfaces, "Shuffle" up inclined surfaces, and "Swing" over small obstacles. The "Swing" motions present their own set of interesting challenges. Since the robot can only adhere to the surface using finite (and relatively small) magnetic forces, it may fall due to the reaction forces caused by the swing- up motion. To prevent failure modes, an optimal swing-up trajectory was designed so that the maximum reaction force during the trajectory was minimized. The trajectories were parameterized using sigmoids and were determined by solving the dynamic equations as a 2 point boundary value problem. Finally, a proof of concept prototype was constructed and was used to experimentally evaluate the design. These experiments illustrate the promise of the design and control approaches that were formulated.
by Anirban Mazumdar.
S.M.
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Aldrich, Jack B. "Control synthesis for a class of light and agile robotic tensegrity structures /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3153685.
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Martell, Angel Alfredo. "Benchmarking structure from motion algorithms with video footage taken from a drone against laser-scanner generated 3D models." Thesis, Luleå tekniska universitet, Rymdteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-66280.
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Structure from motion is a novel approach to generate 3D models of objects and structures. The dataset simply consists of a series of images of an object taken from different positions. The ease of the data acquisition and the wide array of available algorithms makes the technique easily accessible. The structure from motion method identifies features in all the images from the dataset, like edges with gradients in multiple directions, and tries to match these features between all the images and then computing the relative motion that the camera was subject to between any pair of images. It builds a 3D model with the correlated features. It then creates a 3D point cloud with colour information of the scanned object. There are different implementations of the structure from motion method that use different approaches to solve the feature-correlation problem between the images from the data set, different methods for detecting the features and different alternatives for sparse reconstruction and dense reconstruction as well. These differences influence variations in the final output across distinct algorithms. This thesis benchmarked these different algorithms in accuracy and processing time. For this purpose, a terrestrial 3D laser scanner was used to scan structures and buildings to generate a ground truth reference to which the structure from motion algorithms were compared. Then a video feed from a drone with a built-in camera was captured when flying around the structure or building to generate the input for the structure from motion algorithms. Different structures are considered taking into account how rich or poor in features they are, since this impacts the result of the structure from motion algorithms. The structure from motion algorithms generated 3D point clouds, which then are analysed with a tool like CloudCompare to benchmark how similar it is to the laser scanner generated data, and the runtime was recorded for comparing it across all algorithms. Subjective analysis has also been made, such as how easy to use the algorithm is and how complete the produced model looks in comparison to the others. In the comparison it was found that there is no absolute best algorithm, since every algorithm highlights in different aspects. There are algorithms that are able to generate a model very fast, managing to scale the execution time linearly in function of the size of their input, but at the expense of accuracy. There are also algorithms that take a long time for dense reconstruction, but generate almost complete models even in the presence of featureless surfaces, like COLMAP modified PatchMacht algorithm. The structure from motion methods are able to generate models with an accuracy of up to \unit[3]{cm} when scanning a simple building, where Visual Structure from Motion and Open Multi-View Environment ranked among the most accurate. It is worth highlighting that the error in accuracy grows as the complexity of the scene increases. Finally, it was found that the structure from motion method cannot reconstruct correctly structures with reflective surfaces, as well as repetitive patterns when the images are taken from mid to close range, as the produced errors can be as high as \unit[1]{m} on a large structure.
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Hedborg, Johan. "Pose Estimation and Structure Analysisof Image Sequences." Licentiate thesis, Linköpings universitet, Bildbehandling, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-58706.
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Autonomous navigation for ground vehicles has many challenges. Autonomous systems must be able to self-localise, avoid obstacles and determine navigable surfaces. This thesis studies several aspects of autonomous navigation with a particular emphasis on vision, motivated by it being a primary component for navigation in many high-level biological organisms. The key problem of self-localisation or pose estimation can be solved through analysis of the changes in appearance of rigid objects observed from different view points. We therefore describe a system for structure and motion estimation for real-time navigation and obstacle avoidance. With the explicit assumption of a calibrated camera, we have studied several schemes for increasing accuracy and speed of the estimation.The basis of most structure and motion pose estimation algorithms is a good point tracker. However point tracking is computationally expensive and can occupy a large portion of the CPU resources. In thisthesis we show how a point tracker can be implemented efficiently on the graphics processor, which results in faster tracking of points and the CPU being available to carry out additional processing tasks.In addition we propose a novel view interpolation approach, that can be used effectively for pose estimation given previously seen views. In this way, a vehicle will be able to estimate its location by interpolating previously seen data.Navigation and obstacle avoidance may be carried out efficiently using structure and motion, but only whitin a limited range from the camera. In order to increase this effective range, additional information needs to be incorporated, more specifically the location of objects in the image. For this, we propose a real-time object recognition method, which uses P-channel matching, which may be used for improving navigation accuracy at distances where structure estimation is unreliable.Diplecs
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Wang, Xuerui, and Li Zhao. "Navigation and Automatic Ground Mapping by Rover Robot." Thesis, Högskolan i Halmstad, Halmstad Embedded and Intelligent Systems Research (EIS), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-6185.
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This project is mainly based on mosaicing of images and similarity measurements with different methods. The map of a floor is created from a database of small-images that have been captured by a camera-mounted robot scanning the wooden floor of a living room. We call this ground mapping. After the ground mapping, the robot can achieve self-positioning on the map by using novel small images it captures as it displaces on the ground. Similarity measurements based on the Schwartz inequality have been used to achieve the ground mapping, as well as to position the robot once the ground map is available. Because the natural light affects the gray value of images, this effect must be accounted for in the envisaged similarity measurements. A new approach to mosaicing is suggested. It uses the local texture orientation, instead of the original gray values, in ground mapping as well as in positioning. Additionally, we report on ground mapping results using other features, gray-values as features. The robot can find its position with few pixel errors by using the novel approach and similarity measurements based on the Schwartz inequality.
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Erdogan, Can. "Planning in constraint space for multi-body manipulation tasks." Diss., Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/54978.
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Robots are inherently limited by physical constraints on their link lengths, motor torques, battery
power and structural rigidity. To thrive in circumstances that push these limits, such as in search
and rescue scenarios, intelligent agents can use the available objects in their environment as
tools. Reasoning about arbitrary objects and how they can be placed together to create useful
structures such as ramps, bridges or simple machines is critical to push beyond one's physical
limitations. Unfortunately, the solution space is combinatorial in the number of available objects
and the configuration space of the chosen objects and the robot that uses the structure is high
dimensional.
To address these challenges, we propose using constraint satisfaction as a means to test the
feasibility of candidate structures and adopt search algorithms in the classical planning literature
to find sufficient designs. The key idea is that the interactions between the components of a
structure can be encoded as equality and inequality constraints on the configuration spaces of the
respective objects. Furthermore, constraints that are induced by a broadly defined action, such as
placing an object on another, can be grouped together using logical representations such as Planning
Domain Definition Language (PDDL). Then, a classical planning search algorithm can reason about
which set of constraints to impose on the available objects, iteratively creating a structure that
satisfies the task goals and the robot constraints. To demonstrate the effectiveness of this
framework, we present both simulation and real robot results with static structures such as ramps,
bridges and stairs, and quasi-static structures such as lever-fulcrum simple machines.
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Ginige, A. "A vision system for a robot working in a semi-structured environment." Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382244.
Full text
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Ono, Masahiro S. M. Massachusetts Institute of Technology. "Experimental validation of the efficient robotic transportation algorithm for large-scale flexible space structures." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42199.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2007.Includes bibliographical references (p. 77-79).
A new large space structure transportation method proposed recently is modified and experimentally validated. The proposed method is to use space robots' manipulators to control the vibration, instead of their reaction jets. It requires less fuel than the reaction jet-based vibration control methods, and enables quick damping of the vibration. The key idea of this work is to use the decoupled controller, which controls the vibration mode and rigid body mode independently. The performance of the proposed method and the control algorithm is demonstrated and quantitatively evaluated by both simulation and experiments.
by Masahiro Ono.
S.M.
48
Devaurs, Didier. "Extensions of sampling-based approaches to path planning in complex cost spaces : applications to robotics and structural biology." Phd thesis, Toulouse, INPT, 2014. http://oatao.univ-toulouse.fr/12252/1/devaurs.pdf.
Full textAbstract:
Planning a path for a robot in a complex environment is a crucial issue in robotics. So-called probabilistic algorithms for path planning are very successful at solving difficult problems and are applied in various domains, such as aerospace, computer animation, and structural biology. However, these methods have traditionally focused on finding paths avoiding collisions, without considering the quality of these paths. In recent years, new approaches have been developed to generate high-quality paths: in robotics, this can mean finding paths maximizing safety or control; in biology, this means finding motions minimizing the energy variation of a molecule. In this thesis, we propose several extensions of these methods to improve their performance and allow them to solve ever more difficult problems. The applications we present stem from robotics (industrial inspection and aerial manipulation) and structural biology (simulation of molecular motions and exploration of energy landscapes).
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Tyrell, Nathan S. "Attitude control via structural vibration : an application of compliant robotics." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111922.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 109-113).
We review and present techniques for effecting and controlling the reorientation of structures "floating" in angular-momentum-conserving environments, applicable to both space robotics and small satellite attitude control. Conventional orientation control methods require either the usage of continuously rotating structures (e.g. momentum wheels) or the jettisoning of system mass (e.g. hydrazine thrusters). However, the systems proposed herein require neither rotating structures nor mass ejection; instead, orientation is controlled by the imposition of a bounded cyclic shape change-the canonical example of such a system is a cat righting herself while falling, thereby always landing on her feet-coupled with the conservation of angular momentum, which acts analogously to a nonholonomic constraint on the system dynamics. Further, by considering the reduced system dynamics, we extend the concept to consider the class of structures where the requisite cyclic shape change is attainable via dynamical effects, such as the normal modes of structural vibration for structures with finite stiffness. This is the central novel result of this thesis and has implications for the design of space structures where the attitude control hardware is integrated directly into the preexisting structure, the development of orientation control techniques for soft robots in space and underwater, and the design of MEMS attitude control actuators for very tiny satellites. We apply mathematical tools drawn from differential geometry and geometric mechanics, which can be intimidating but which provide a comprehensive and powerful framework for understanding a wide range of locomotion problems fundamental to robotics and control theory. These tools allow us to make succinct statements regarding gait design, controllability, and optimality that would be otherwise inaccessible.
by Nathan S. Tyrell.
S.M.
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Law, Po-lun. "Model-based variable-structure control of robot manipulators in joint space and in Cartesian space /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B18973097.
Full textAbstract:
Thesis (M. Phil.)--University of Hong Kong, 1995.Cover title: Model-based variable-structure control of robot maniqulators in joint space and in Cartesian space. Includes bibliographical references (leaf 161-175).