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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Estudo e desenvolvimento de sistema baseado em sensores de pressão aplicados à ortodontia

Crivellaro, Fernando Sacilotto January 2016 (has links)
Este trabalho tem por objetivo o estudo e o desenvolvimento de uma solução de engenharia para o mapeamento e caracterização da oclusão dentária, não somente no âmbito de sua distribuição ao longo da arcada, mas também através da mensuração da intensidade de pressão nos pontos de contato oclusal interarco. Neste sentido, empregaram-se esforços no aprofundamento do conhecimento neste campo da Odontologia, assim como, na elaboração de um sistema experimental que, utilizando sensores de pressão/força resistivos (FSR) específicos para uso odontológico, viabilizou a análise do estado da oclusão, atuando como agente facilitador no diagnóstico de desequilíbrios oclusais. Inicialmente, são apresentados e esclarecidos os principais conceitos da esfera odontológica, os quais são tomados como base para todos os projetos deste trabalho, além da abordagem referente às formas de contato entre os dentes, aos diferentes tipos de oclusão e seus problemas. Em relação ao desenvolvimento do sistema, foram projetadas duas placas de circuito impresso para interface com os sensores e elaborados o firmware de acesso ao hardware, assim como o software de gerenciamento global do sistema. Todos os blocos do circuito de condicionamento foram avaliados e as suas funcionalidades validadas. Do mesmo modo, a caracterização da resposta dos sensores e a sua homogeneidade ao longo da extensão sensível foram analisadas, demonstrando que a resistência elétrica varia de forma análoga em todas as áreas do sensor. Através de ensaios realizados com sujeito envolvido no projeto, estabeleceu-se um comparativo entre a utilização do papel carbono e o sistema desenvolvido, mostrando as vantagens na utilização do segundo, principalmente atreladas à capacidade de avaliação da intensidade dos contatos oclusais. Por fim, ainda se valendo do uso paralelo do papel carbono, foram efetuados ensaios de análise da oclusão em sujeito envolvido no projeto utilizando placa miorrelaxante, possibilitando a utilização da capacidade do sistema desenvolvido para executar ajustes precisos na placa, com a finalidade de manter o balanço de pressões oclusais entre ambos os lados da arcada. / This essay has as objective the study and development of an engineer solution for the dental occlusion mapping and characterization, not only related to the interarch occlusal contact distribution, but also through the pressure magnitude measuring in each. In this sense, was employed effort in the Odontological knowledge increasing and also in the system elaboration allowing the occlusion state evaluation and acting as an easier agent in the occlusion disturbs diagnosing using a specific pressure/force sensing resistor (FSR) for dental use. Initially the main concepts of the Odontological sphere are presented, clarified and took as a base for all the projects in this essay. Besides this, different teeth contacts shapes are shown, as well as the occlusion’s types and its problems. In the system development, two printed circuit boards were designed for sensor interfacing. The hardware access through the firmware was elaborated, even as the global system managing software. All the conditioning circuit blocks and functionalities were evaluated and validated. In the same way, the sensor’s output and its homogeneity through all the sensible extension were evaluated, showing that the sensor’s electric resistance changes in the same form in all the sensor’s areas. In addition, it was showed the advantages of the developed system over the articulation paper through trials with a subject that is part of the project, showing the capacity of the system in the occlusion contacts magnitude evaluation. Ultimately, also in an articulation paper versus the developed system comparison, it was made occlusion analysis trials with subject using a night guard for teeth grinding (bruxism), showing the system capacity of precisely adjust the night guards for pressure balance between the both arch sides.
12

In Situ Optically Trapped Probing System for Molecular Recognition and Localization

WAN, JINGFANG 28 September 2009 (has links)
No description available.
13

Shape sensing of deformable objects for robot manipulation / Mesure et suivi de la forme d'objets déformables pour la manipulation robotisée

Sanchez Loza, Jose Manuel 24 May 2019 (has links)
Les objets déformables sont omniprésents dans notre vie quotidienne. Chaque jour, nous manipulons des vêtements dans des configurations innombrables pour nous habiller, nouons les lacets de nos chaussures, cueillons des fruits et des légumes sans les endommager pour notre consommation et plions les reçus dans nos portefeuilles. Toutes ces tâches impliquent de manipuler des objets déformables et peuvent être exécutées sans problème par une personne. Toutefois, les robots n'ont pas encore atteint le même niveau de dextérité. Contrairement aux objets rigides, que les robots sont maintenant capables de manipuler avec des performances proches de celles des humains; les objets déformables doivent être contrôlés non seulement pour les positionner, mais aussi pour définir leur forme. Cette contrainte supplémentaire, relative au contrôle de la forme d’un objet, rend les techniques utilisées pour les objets rigides inapplicables aux objets déformables. En outre, le comportement des objets déformables diffère largement entre eux, par exemple: la forme d’un câble et des vêtements est considérablement affectée par la gravité, alors que celle-ci n’affecte pas la configuration d’autres objets déformables tels que des produits alimentaires. Ainsi, différentes approches ont été proposées pour des classes spécifiques d’objets déformables.Dans cette thèse, nous cherchons à remédier à ces lacunes en proposant une approche modulaire pour détecter la forme d'un objet pendant qu'il est manipulé par un robot. La modularité de cette approche s’inspire d’un paradigme de programmation qui s’applique de plus en plus au développement de logiciels en robotique et vise à apporter des solutions plus générales en séparant les fonctionnalités en composants. Ces composants peuvent ensuite être interchangés en fonction de la tâche ou de l'objet concerné. Cette stratégie est un moyen modulaire de suivre la forme d'objets déformables.Pour valider la stratégie proposée, nous avons implémenté trois applications différentes. Deux applications portaient exclusivement sur l'estimation de la déformation de l'objet à l'aide de données tactiles ou de données issues d’un capteur d’effort. La troisième application consistait à contrôler la déformation d'un objet. Une évaluation de la stratégie proposée, réalisée sur un ensemble d'objets élastiques pour les trois applications, montre des résultats prometteurs pour une approche qui n'utilise pas d'informations visuelles et qui pourrait donc être améliorée de manière significative par l'ajout de cette modalité. / Deformable objects are ubiquitous in our daily lives. On a given day, we manipulate clothes into uncountable configurations to dress ourselves, tie the shoelaces on our shoes, pick up fruits and vegetables without damaging them for our consumption and fold receipts into our wallets. All these tasks involve manipulating deformable objects and can be performed by an able person without any trouble, however robots have yet to reach the same level of dexterity. Unlike rigid objects, where robots are now capable of handling objects with close to human performance in some tasks; deformable objects must be controlled not only to account for their pose but also their shape. This extra constraint, to control an object's shape, renders techniques used for rigid objects mainly inapplicable to deformable objects. Furthermore, the behavior of deformable objects widely differs among them, e.g. the shape of a cable and clothes are significantly affected by gravity while it might not affect the configuration of other deformable objects such as food products. Thus, different approaches have been designed for specific classes of deformable objects.In this thesis we seek to address these shortcomings by proposing a modular approach to sense the shape of an object while it is manipulated by a robot. The modularity of the approach is inspired by a programming paradigm that has been increasingly been applied to software development in robotics and aims to achieve more general solutions by separating functionalities into components. These components can then be interchanged based on the specific task or object at hand. This provides a modular way to sense the shape of deformable objects.To validate the proposed pipeline, we implemented three different applications. Two applications focused exclusively on estimating the object's deformation using either tactile or force data, and the third application consisted in controlling the deformation of an object. An evaluation of the pipeline, performed on a set of elastic objects for all three applications, shows promising results for an approach that makes no use of visual information and hence, it could greatly be improved by the addition of this modality.
14

On the use of generalized force data for kinematically controlled manipulators

Schroeder, Kyle Anthony 16 February 2011 (has links)
The Department of Energy national laboratories, like Los Alamos National Lab or Sandia National Lab, perform work on radioactive and chemically dangerous materials. Gloveboxes are often used to shield workers from these hazards, but they cannot completely eliminate the danger and often create new safety concerns due to reduced operator dexterity and ergonomic posture. When feasible, robots can be employed to remove the human from the radioactive hazard; allowing them to analyze the situation and make decisions remotely. Force sensor data from the manipulator can be used to simplify the control of these remote systems as well as make them more robust. Much research has been done to develop force and torque control algorithms to introduce compliance or detect collisions. Many of these algorithms are very complicated and currently only implemented in research institutions on torque-controlled manipulators. The literature review discusses many such controllers which have been developed and/or demonstrated. This thesis reviews, develops, and demonstrates several beneficial algorithms which can be implemented on commercially-available kinematically-controlled robots using commercially-available sensors with a reasonable investment of time. Force data is used to improve safety and manage contact forces while kinematically controlling the robot, as well as improve the world model. Safety is improved by detecting anomalous and/or excessive forces during operation. Environmental modeling data is inferred from position and/or force data. A six-axis sensor and joint torque sensors on 2 7DOF manipulators are used to demonstrate the proposed algorithms in two DOE relevant applications: remotely opening an incompletely modeled cabinet door and moving a robot in a confined space. / text
15

Využití biofeedback senzorů pro aktivaci dechové a posturální funkce bránice u pacientů s chronickou low-back pain / Utilization of biofeedback sensors for the activation of breathing and postural function of diaphragm in patients with chronic low-back pain

Macigová, Lucie January 2019 (has links)
This thesis is focusing on objectifying the postural function of diaphragm with a biofeedback sensor in patients with low back pain (LBP). The theoretical part provides an overview of known facts about the postural function of the abdominal muscles and diaphragm and the connection between their activation and the change in intra-abdominal pressure and the origin of LBP. The thesis gives specifics of LBP, its etiology and possible methods of classification of non-specific LBP, as well as the methods of evaluating subjective disability. Other methods of objectifying postural functions other than the one used in this thesis are mentioned briefly. Methodology: In the experimental part, we used a capacitive force sensor to test 31 patients with non-specific chronic LBP (aver. age 25.25, SD ± 4.66, aver. height 176.77 cm, SD ± 9.97, aver. weight 77.93 kg, SD ±18.40) in 3 posturally different seated scenarios - resting breathing, with added external load when the subjects held a dumbbell of 20 % of their body weight) and with maximum voluntary increase in intra-abdominal pressure (the diaphragm test). The sensor position was on lumbar triangle and in the groin area. Oswestry Questionaire v2.1a was used to evaluate subjective disability. Results: An independent t-test analysis showes increase in the...
16

Three-Dimensional Motion Control and Dynamic Force Sensing of a Magnetically Propelled Micro Particle Using a Hexapole Magnetic Actuator

Long, Fei 08 June 2016 (has links)
No description available.
17

Crowd Detection During IndoorEvents Using FSR Sensor WithMicrocontrollers : Crowd detection and monitoring

Hama, Mohamad January 2024 (has links)
Overcrowding during indoor events can be risky, in-case of any kind of a hazard such as fire.This solution address this by providing real-time crowd detection solution using Force-SensingResistor (FSR) sensors, referred sensor (IR) and microcontrollers. The solution needs to offer accurate data in real-time to the event managers including number of people and entrancerate to help when and if the event areas will be overcrowded, thereby enhancing event safetyand decision-making. This thesis indicate that the system offers essential real-time data forevent safety with an accuracy of 87.25%. These data will assists event managers in makinginformed decisions to avoid the risks of overcrowding. This thesis evaluates the effectivenessof our system in comparison to other systems, discussing what we’ve learned, suggest possibleimprovements, and talk about whether our system could be useful in real-world indoor events.
18

Surface-enhanced optomechanical disk resonators and force sensing / Résonateurs à disques optomécaniques améliore par leurs surfaces et capteurs de force

Guha, Biswarup 11 July 2017 (has links)
L'optomécanique est la science des interactions entre la lumière et les mouvements mécaniques. Ce rapport de thèse décrit des expériences réalisées avec des microdisques fabriqué dans différents résonateurs semi-conducteurs III-V: l'Arséniure de Gallium (GaAs), l'Arséniure d'Aluminium Gallium (AlGaAs) et l'Arséniure d'Indium Phosphide (InGaP). Ces matériaux sont compatibles avec les fonctionnalités de l’optoélectronique et procurent un couplage optomécanique géant. Pour améliorer les performances des résonateurs en GaAs, nous avons développé des méthodes de traitement de surface permettant de réduire la dissipation optique par un facteur dix et ainsi d'atteindre un facteur de qualité de six millions. En plus de ces études sur le GaAs, nous avons réalisés une étude comparative des interactions optomecaniques dans des microdisques d'InGaP et d'AlGaAs, et nous avons mis en évidences leurs résonances optomécaniques. Finalement, nous avons réalisé des mesures de force avec des résonateurs en GaAs, démontrant un nouveau principe de détection basé sur notre étude de leur la trajectoire dans l'espace de phase et leur bruit de phase / Optomechanics studies the interaction between light and mechanical motion. This PhD thesis reports on optomechanical experiments carried with miniature disk resonators fabricated out of distinct III-V semiconductors: Gallium Arsenide (GaAs), Aluminium Gallium Arsenide (AlGaAs) and Indium Gallium Phosphide (InGaP). These materials are compliant with optoelectronics functionalities and provide giant optomechanical coupling. In order to boost performances of GaAs resonators, we implemented surface control techniques and obtained a ten-fold reduction of optical dissipation, attaining a Q of six million. On top of GaAs, we performed a comparative investigation of optomechanical interactions in InGaP and AlGaAs disk resonators, and demonstrated their operation as optomechanical oscillators. Finally, we carried out optomechanical force sensing experiments with GaAs resonators, analyzing a new sensing principle in light of the phase space trajectory and phase noise of the corresponding oscillators

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