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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.
1

Wireless power and data transmission to high-performance implantable medical devices

Kiani, Mehdi 08 June 2015 (has links)
Novel techniques for high-performance wireless power transmission and data interfacing with implantable medical devices (IMDs) were proposed. Several system- and circuit-level techniques were developed towards the design of a novel wireless data and power transmission link for a multi-channel inductively-powered wireless implantable neural-recording and stimulation system. Such wireless data and power transmission techniques have promising prospects for use in IMDs such as biosensors and neural recording/stimulation devices, neural interfacing experiments in enriched environments, radio-frequency identification (RFID), smartcards, near-field communication (NFC), wireless sensors, and charging mobile devices and electric vehicles. The contributions in wireless power transfer are the development of an RFID-based closed-loop power transmission system, a high-performance 3-coil link with optimal design procedure, circuit-based theoretical foundation for magnetic-resonance-based power transmission using multiple coils, a figure-of-merit for designing high-performance inductive links, a low-power and adaptive power management and data transceiver ASIC to be used as a general-purpose power module for wireless electrophysiology experiments, and a Q-modulated inductive link for automatic load matching. In wireless data transfer, the contributions are the development of a new modulation technique called pulse-delay modulation for low-power and wideband near-field data communication and a pulse-width-modulation impulse-radio ultra-wideband transceiver for low-power and wideband far-field data transmission.
2

Élaboration d'un système de suivi de l'endommagement de composants mécaniques fonctionnant en régime variable et à très basse vitesse : Application au diagnostic sur roulements / Development of a surveillance system for very low and variable speed machines’ mechanical components : An application for bearing diagnosis

Moustafa, Wael 09 June 2016 (has links)
Dans la majorité des secteurs industriels, les coûts de maintenance des systèmes de production représentent une partie non négligeable de l’ensemble de ces coûts. Pour améliorer les performances et la fiabilité des systèmes, différentes stratégies de maintenance sont utilisées. L’objectif est d’être capable de détecter toutes défaillances potentielles susceptibles d’affecter la production. L’analyse vibratoire est aujourd’hui un des outils les plus performants en termes de détection et de suivi de ces défaillances. Cependant, l’application de cette technique reste difficile dans le cas de machines fonctionnant avec des vitesses de rotation faibles et variables. Dans la présente thèse, nous proposons une technique alternative à l’analyse vibratoire pour surveiller l’état de fonctionnement de ces machines. Nous nous intéresserons plus particulièrement au suivi des roulements. Cette technique alternative se base sur l’analyse des variations de la vitesse angulaire instantanée qui sont générées par un défaut de roulement. Cette technique sera testée sur un banc d’essai et comparée avec d’autres techniques telles que l’analyse des signaux vibratoires et ultrasonores pour différentes conditions de chargement et pour différents types de défauts de roulement. Cette étude montre une grande efficacité de cette méthode dans le cas de très basses vitesses de rotation, constantes ou variables. L’ensemble de cette méthodologie a ensuite été implémentée sur un four de diffusion d’une unité de production sucrière. Les mesures réalisées montrent que cette technique est une technique prometteuse pour le suivi de systèmes fonctionnant avec des vitesses de rotation faibles et variables. / In the majority of industrial sectors, production systems’ maintenance costs represent an important part of the whole process’s cost. In order to improve systems’ reliability and performance, different maintenance strategies are used. The goal is to be able to detect all potential malfunction that may affect the production. Nowadays, vibration analysis is one of the best tools in term of detection and defect monitoring. However, the application of these vibration based techniques remain difficult in the case of machines functioning at low speeds. In this thesis, we propose an alternative technique of vibration analysis for the surveillance of these machines that operate on very low speeds and variable speeds. We are specifically interested in bearings’ monitoring. This alternative technique is based on instantaneous angular speed’s variations analysis that are induced by a bearing defect. This technique is tested on a test bench and compared with other techniques such as vibration and ultrasound analysis for different loading conditions and for different bearing fault types. This study shows a high efficiency of this method in the case of very low speeds, constant and variable. This methodology has then been implemented on sugar diffusion oven in a sugar production factory. The measurements shows that this technique is a promising technique for machines’ surveillance in very low and variable speeds working conditions.
3

Optimization of Remote ServiceSolution for large installations : Wireless LAN and WAN for ABB Robotics

Stenbom, Håkan January 2011 (has links)
This report describes a thesis work carried out at ABB Robotics in Västerås. The objective of this thesis is to find technologies  and equipments  for wireless data transfer  suitable for the present and future needs of ABB Robotics Remote Service for large installations in industrial environments. ABB Robotics has a Remote Service solution to securely gather information from robots, manage alarms and potentially execute remote commands by ABB Robotics. This solution consists of an intelligent Service  Box plugged to the robot. This  Service Box is also connected through GPRS or directly through Internet to create a secure VPN connection to a central Remote Service  server. The Remote Service Box is well  suited  for small customers with  1-10 robots with plug  and play installation, but show limitations at a larger scale of deployment  due to equipment costs,  network and installation complexity. A new Service Box is planned that will accommodate future added functionality to Remote Service. This Service Box will require new network solutions as the added functionality  is depending on a higher bandwidth than the GPRS networks can deliver. I have surveyed most existing  wireless  networking technologies  and  analyzed  them  withrespect  to function, cost and availability which provide a knowledge base that makes it possible to find  suitable  solutions. When the most suitable technologies are identified a survey was performed to find equipments that meet the requirements at the lowest cost. A new hierarchical network topology is proposed  that will lead to cost savings by replacing multiple WAN connections in the present solution with  a network switch and  single WAN connection to Internet. As manufacturers of network equipments for industrial environments are relatively few, alternative solutions were also investigated in order to find the most cost effective solutions. The  proposed  network topology together with the data from the surveys lead to recommendations on using Wi-Fi  in the wireless LAN and  a  3G mobile  network for the WAN connection to Internet, as well as recommendations on alternative network equipments that  potentially  can  lead to substantial savings when the new network solutions are implemented.
4

Bezdrátová čidla pro měření hladiny vody / Wireless water level sensors

Pospíšil, Jakub January 2010 (has links)
The thesis deals with both scheme and its implementation of water-level metering apparatus. This data are send wireless into 500 m distant station. Potential ways of solution are gradually studied and final design suggested. Detailed implementation methods are described in the following section. Ultrasonic sensors are employed for level measurement and controlling element is processor ATmega162, data are transmitted by transceiver RC1280HP. Apparatus is suggested with a view to the lowest power consumption considering it will be supplied only with a accumulator. Solving of accepting station is not a part of the thesis. Functional tested sample is understated in the execution section.
5

Popularizing implants : Exploring conditions for eliciting user adoption of digital implants through developers, enthusiasts and users

Ericsson Duffy, Mikael January 2020 (has links)
Digital implants have become a new frontier for body hackers, technology enthusiasts and disruptive innovation developers, who seek to service this technology for themselves and to new users. This thesis has explored conditions for future user adoption of human body augmentation with digital implants. The conditions explored were mainly self-beneficial health optimization through technology, self-quantification or convenience scenarios. Applying Diffusion Of Innovation theory, Value-based Acceptance Model and research through design methods were used. The process consisted of quantitative and qualitative data gathering and analysis, using interviews, surveys and iterative prototyping with evaluation. The results show mixed user attitude towards implant usage, mainly depending on users' need for added benefits, whether the user is a technology enthusiast actively using technology for self-beneficial gain or a casual everyday consumer of technology. Certain conditions could affect adoption of implants into mainstream usage, mainly data privacy, regulation, convenience, self-quantification or health management. In order for implants to succeed as a mainstream technology, there needs to be proper secure infrastructure, easy installation and coordinated services that offer individual benefits of health or convenience, with a high consumer confidence in supported services, installation / removal and devices. Several companies are working on offering such a service, in order to evaluate such a proposition, iterative prototypes were created to evaluate a health management scenario as a streamlined consumer service, using a service design blueprint and a related interactive smartphone application prototype.

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