Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-06-08T11:17:37Z No. of bitstreams: 1 ricardosilvacampos.pdf: 8528381 bytes, checksum: 29e3f07b2a4b4215d4e42d012e0f5df3 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-13T13:24:53Z (GMT) No. of bitstreams: 1 ricardosilvacampos.pdf: 8528381 bytes, checksum: 29e3f07b2a4b4215d4e42d012e0f5df3 (MD5) / Made available in DSpace on 2016-07-13T13:24:53Z (GMT). No. of bitstreams: 1 ricardosilvacampos.pdf: 8528381 bytes, checksum: 29e3f07b2a4b4215d4e42d012e0f5df3 (MD5) Previous issue date: 2016-02-15 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Este trabalho apresenta o simulador FisioPacer, que é um simulador que reproduz a propagação do pulso elétrico pelo tecido cardíaco e a sua deformação mecânica. Foi utilizado um autômato celular acoplado a um sistema massa-mola para que as simulações sejam realizadas rapidamente. Foi também utilizado um algoritmo genético para automaticamente determinar parâmetros do modelo de forma a reproduzir outros experimentos in silico e o comportamento de um ventrículo real. Com intuito de validar o modelo foram feitos setenta e dois experimentos e os resultados foram comparados com outro simulador robusto, baseado em equações diferenciais. As comparações mostraram que o FisioPacer reproduziu satisfatoriamente o comportamento do tecido, sendo até quinze mil vezes mais rápido. Além disto, foram simuladas as funcionalidades eletromecânicas de um ventrículo esquerdo a partir de dados de um paciente, obtidos via ressonância magnética. / This work proposes a computational heart model named FisioPacer, which aims to reproduce the electrical pulse propagation over the cardiac tissue and its mechanical deformation. In order to perform fast simulations, it was used a cellular automaton coupled with a mass-spring system. A genetic algorithm was also used to automatically adjust model parameters, in order to reproduce in silico experiments and a real left ventricle behavior. For the model validation, seventy two experiments were performed and the results were compared to another robust simulator, based on partial differential equations. The comparisons showed that the FisioPacer simulator could reproduce cardiac tissue electromechanics, with up to 15000-fold improvement in computational time. Furthermore, a real patient left ventricle was simulated, with data obtained via MRI.

The diploma thesis describes localization of communications nodes in the Wireless Sensor Networks. This thesis contains basic algorithms for localization sensor's nodes as are Map-Growing and ABC (Assumption Based Coordinates). Then is chosen acceptable algorithm for simulation on random sensor networks. For research these problems is used software MATLAB. For a given the university's environment are researched appropriate algorithms with possible optimalization algorithms. The result of diploma thesis is a localization algorithm with initial multilateration system and this system is located in the center sensor's network. As algorithm IMap4-Growing (Improved Map4-Growing) with optimization, which uses optimization distance between sensors and radio range. In the diploma thesis is simulated optimalization algorithm Mass-Spring.

No description available.

Les travaux réalisés pendant mon doctorat répondent à la problématique de la simulation physique, en temps interactif, du comportement d'objets déformables soumis à des changements topologiques. Mes travaux ont abouti à la définition d'un nouveau modèle unifié couplant un modèle topologique complet et un modèle physique, pour la simulation physique d'objets déformables décomposés en éléments surfaciques comme volumiques, tout en réalisant pendant cette simulation des changements topologiques comme la découpe ou la subdivision locale d'un élément du maillage. Cette dernière opération a permis de proposer une méthode adaptative où les éléments du maillage sont raffinés selon un critère géométrique au cours de la simulation. Nous avons fait le choix des cartes combinatoires et plus particulièrement celui des complexes cellulaires linéaires, comme modèle topologique de notre modèle unifié. Ils ont l'avantage d'être génériques par rapport à la dimension de l'objet représenté mais également par rapport à la topologie des cellules en lesquelles l'objet est décomposé. Le système masses-ressort a, quant à lui, été choisi comme modèle physique de notre modèle unifié. L'avantage de ce dernier réside dans la simplicité de ses équations, son implémentation intuitive, son interactivité et sa facilité à gérer les changements topologiques. Enfin, la définition d'un modèle unifié nous a permis de proposer un modèle évitant la redondance d'informations et facilitant la mise à jour de ces dernières suite à des changements topologiques / The work made during my PhD, respond to the problematic of physical simulation of the behavior of deformable objects subject to topological changes in interactive time. My work resulted in the definition of a new unified model coupling a complete topological model and a physical model for physical simulation of deformable objects decomposed in surface as volume elements, while performing during this simulation topological changes such as cutting or subdivision local of a mesh element. This operation allowed us to propose an adaptive method where mesh elements are refined during the simulation according to a geometric criterion. For the topological model of our unified model, we made the choice of combinatorial maps and more particularly linear cellular complexes. Their main advantage of the latter is the simplicity of its equations, its intuitive implementation, its interactivity and its ease to handle topological changes. Finally, the definition of a unified model allowed us to propose a model avoiding duplication of information and facilitate the update after topological changes

Ces travaux de thèse s’intéressent aux outils de simulation rapide de la fabrication d’un pneumatique. L'objectif est de prédire le mouvement et la position des éléments constitutifs du pneumatique, lors de leur mise en conformation, en prenant en compte les déformations induites par les actions mécaniques associées. Ces travaux s’appuient sur la mise en place d’un algorithme visant à modéliser le gonflement d’un outillage et la mise en place d’un modèle de déformation d’un système de formes géométriques aux caractéristiques mécaniques différentes. L'algorithme de gonflement de l’outillage se base sur la théorie des membranes inextensibles et son industrialisation est validée pour des dimensions standards de pneumatiques. La méthode Masse-Ressort est retenue pour réaliser la déformation de formes géométriques afin d’obtenir des résultats de déformation en temps réel. Dans ces travaux, cette méthode est adaptée aux matériaux d’un pneumatique à partir de travaux de caractérisations géométrique et mécanique validés par comparaison aux Éléments Finis. En conclusion, la modélisation développée permet une description à chaque étape du procédé de fabrication. / This thesis deals with fast simulation tools used to manufacture of a tire. The goal is to predict the displacement and position of the components of a tire taking into account the deformations induced by the associated mechanical actions. This work is based on the implementation of an algorithm for modeling the inflation of a tool and the development of a deformation model in order to compute the deformation of geometric shapes taking into account different mechanical properties. The algorithm to model the inflation of the tool is based on the theory of inextensible membranes and its industrialization is validated for standard sizes of tires. Mass-Spring method is used to achieve the deformation of geometric shapes in order to compute deformation in real time. In this work, this method is suitable for materials of a tire from geometric and mechanical characterizations validated by comparison with FEM. To conclude, the developed modelization allows a description for each step of the manufacturing process.

The goal of this project was to evaluate the viability of a mass-spring-damper based model for modeling of biological tissue. A method for automatically generating such a model from data taken from 3D medical imaging equipment including both the generation of point masses and an algorithm for generating the spring-damper links between these points is presented. Furthermore, an implementation of a simulation of this model running in real-time by utilizing the parallel computational power of modern GPU hardware through OpenCL is described. This implementation uses the fourth order Runge-Kutta method to improve stability over similar implementations. The difficulty of maintaining stability while still providing rigidness to the simulated tissue is thoroughly discussed. Several observations on the influence of the structure of the model on the consistency of the simulated tissue are also presented. This implementation also includes two manipulation tools, a move tool and a cut tool for interaction with the simulation. From the results, it is clear that the mass-springdamper model is a viable model that is possible to simulate in real-time on modern but commoditized hardware. With further development, this can be of great benefit to areas such as medical visualization and surgical simulation. / Målet med detta projekt var att utvärdera huruvida en modell baserad på massa-fjäderdämpare är meningsfull för att modellera biologisk vävnad. En metod för att automatiskt generera en sådan modell utifrån data tagen från medicinsk 3D-skanningsutrustning presenteras. Denna metod inkluderar både generering av punktmassor samt en algoritm för generering av länkar mellan dessa. Vidare beskrivs en implementation av en simulering av denna modell som körs i realtid genom att utnyttja den parallella beräkningskraften hos modern GPU-hårdvara via OpenCL. Denna implementation använder sig av fjärde ordningens Runge-Kutta-metod för förbättrad stabilitet jämfört med liknande implementationer. Svårigheten att bibehålla stabiliteten samtidigt som den simulerade vävnaden ges tillräcklig styvhet diskuteras genomgående. Flera observationer om modellstrukturens inverkan på den simulerade vävnadens konsistens presenteras också. Denna implementation inkluderar två manipuleringsverktyg, ett flytta-verktyg och ett skärverktyg för att interagera med simuleringen. Resultaten visar tydligt att en modell baserad på massa-fjäder-dämpare är en rimlig modell som är möjlig att simulera i realtid på modern men lättillgänglig hårdvara. Med vidareutveckling kan detta bli betydelsefullt för områden så som medicinsk bildvetenskap och kirurgisk simulering.

Haptic feedback is a growing phenomenon that incorporates the sense of touch through tactile sensations such as vibrations, electrical signals, air pressure, and sound waves or through force feedback, which employs torques and/or forces to replicate the pressure and weight of a simulated object. Utilizing haptic technology establishes a communication bridge between the user and the technical component, enhancing the user's understanding of the technical component's surroundings. This thesis focuses on designing a force feedback haptic device with an impedance control strategy, enabling the imposition of dynamic behavior during simulated robot interactions. Impedance control is a commonly employed approach in haptic devices, utilizing a mass-spring-damper model to vary stiffness, damping, and inertia levels, thereby simulating realistic forces and torques in master-slave interactions.  Initially, a haptic device resembling the shape of a Delta robot was designed using Solidworks, with size and weight distribution serving as the primary design considerations. Subsequently, the device was further represented using a generic robot description format, incorporating the design's joints and links. This representation was then paired with kinematic connections delineating the robot's motion and dynamic matrices to simulate the robot's movement. Alongside the integration of an impedance control strategy, simulations were conducted to emulate robot interactions. These simulations tested the system under various conditions, including scenarios with and without introduced torque disturbances. Including torque disturbances was intended to enhance the simulation's realism and assess the impact of impedance control parameter choices on the system's behavior. In summary, the research concludes how a closed-chain robot, the Delta robot, can be modeled as a haptic device with an impedance control strategy, offering valuable guidance for future research. / Haptisk återkoppling är ett växande fenomen som integreras i allt fler användningsområden. Genom att återskapa känslan av att röra vid eller interagera med föremål, antingen genom att simulera taktila sensationer som vibrationer, elektriska signaler, lufttryck och ljudvågor eller genom att återge kraftåterkoppling till användaren, kan användarens förståelse för tekniska komponenter och deras omgivning öka. Kraftåterkoppling möjliggör imitation av tryck och vikt hos simulaterade objekt, vilket förbättrar realismen i användarupplevelsen. Detta examensarbete har inriktat sig på att designa en haptisk pryl med kraftåterkoppling och en styrmekanism baserad på impedanskontroll. Genom att implementera impedanskontroll kan dynamiska beteenden inkorporeras i systemet genom varierande styrka, dämpning och tröghet. Dessa impedansparametrar möjliggör realistiska simuleringar av kraft och vridmoment i samband med virtuella robotinteraktioner. Först utformades en haptisk pryl som efterliknar formen av en Delta-robot med hjälp av CAD-programmet Solidworks. Här var storlek och viktfördelning primära överväganden i designprocessen. Därefter representerades enheten genom en generisk robotbeskrivning som inkluderade dess leder och länkar. Denna representation kopplades sedan ihop med kinematiska samband som reglerade enhetens rörelse. Tillsammans med integreringen av impedanskontrollstrategin genomfördes simuleringar som efterliknade robotinteraktioner. Dessa simuleringar omfattade olika scenarier, inklusive de med vridmomentsstörningar och de utan. Syftet med att inkludera vridmomentsstörningar var att öka realismen i simuleringen och utvärdera påverkan av valda parametrar för impedanskontrollen på systemets beteende. Sammanfattningsvis har detta arbete resulterat i utformningen av en haptisk pryl med kraftåterkoppling, som efterliknar en Delta-robot. Prylen har modellerats som en trädstruktur, med kinematiska samband som sammanfogar dess ändnoder. Det här arbetet har bidragit till kunskapen om hur realistiska haptiska interaktioner kan skapas och öppnat möjligheter för framtida forskning och utveckling inom detta område.