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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.
141

USING LABVIEW TO DESIGN A FAULT-TOLERANT LINK ESTABLISHMENT PROTOCOL

Horan, Stephen, Deivasigamani, Giriprassad 10 1900 (has links)
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / The design of a protocol for a satellite cluster link establishment and management that accounts for link corruption, node failures, and node re-establishment is presented in this paper. This protocol will need to manage the traffic flow between nodes in the satellite cluster, adjust routing tables due to node motion, allow for sub-networks in the cluster, and similar activities. This protocol development is in its initial stages and we will describe how we use the LabVIEW Sate Diagram tool kit to generate the code to design a state machine representing the protocol for the establishment of inter-satellite communications links.
142

Mise au point d'un réacteur épitaxial CBE

Pelletier, Hubert January 2011 (has links)
Ce projet de maîtrise consiste à l'asservissement et la mise en marche d'un réacteur d'épitaxie par jets chimiques au Laboratoire d'Épitaxie Avancée de l'Université de Sherbrooke. Le réacteur sert à la croissance dans l'ultravide de matériaux semi-conducteurs tels que l'arséniure de gallium (GaAs) et le phosphure d'indium-gallium (GalnP). La programmation LabVIEW™ et du matériel informatique de National Instruments sont utilisés pour asservir le réacteur. Le contrôle de la température de l'échantillon et de la pression de contrôle des réactifs de croissance dans le réacteur est assuré par des boucles de rétroaction. Ainsi, la température de l'échantillon est stabilisée à ±0,4 °C, alors que les pressions de contrôle de gaz peuvent être modulées sur un ordre de grandeur en 2 à 4 secondes, et stabilisées à ±0,002 Torr. Le système de pompage du réacteur a été amélioré suite à des mesures de vitesse de pompage d'une pompe cryogénique. Ces mesures révèlent une dégradation sur plus d'un ordre de grandeur de son pompage d'hydrogène avec l'opération à long terme. Le remplacement de la pompe cryogénique par une pompe turbo-moléculaire comme pompe principale a permis d'améliorer la fiabilité du système de pompage du système sous vide. D'autre part, la conductance du système d'acheminement de gaz et d'injection a été augmentée afin de réduire un effet mémoire des sources le système et faciliter la croissance de matériaux ternaires. Ainsi, des croissances de GaAs (100) sur substrat de même nature ont été effectuées et ont révélé un matériau de bonne qualité. Sa rugosité moyenne de 0,17 nm, mesurée par microscopie à force atomique, est très faible selon la littérature. De plus, une mobilité élevée des porteurs est obtenue à fort dopage au silicium, au tellure et au carbone, notamment une mobilité de 42 ± 9 cm2V_1s_1 des porteurs majoritaires "(trous) lors du dopage au carbone à 1,5 • 1019 cm-3, en accord avec la courbe théorique. La croissance du matériau ternaire GalnP a aussi été réalisée en accord de maille avec le substrat de GaAs, et avec une rugosité de 0,96 nm. Ceci constitue un premier pas dans la croissance d'alliages ternaires au laboratoire. Finalement, la mise eh marche du réacteur d'épitaxie par jets chimiques permet maintenant à cinq étudiants gradués de faire progresser des projets reliés directement à la croissance épitaxiale au Laboratoire d'Épitaxie Avancée de l'Université de Sherbrooke. [symboles non conformes]
143

DATA ACQUISITION, ANALYSIS, AND SIMULATION SYSTEM (DAAS)

Baca, Dawnielle C. 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The Data Acquisition, Analysis, and Simulation System (DAAS) is a computer system designed to allow data sources on spacecraft in the Flight System Testbed (FST) to be monitored, analyzed, and simulated. This system will be used primarily by personnel in the Flight System Testbed, flight project designers, and test engineers to investigate new technology that may prove useful across many flight projects. Furthermore, it will be used to test various spacecraft design possibilities during prototyping. The basic capabilities of the DAAS involve unobtrusively monitoring various information sources on a developing spacecraft. This system also provides the capability to generate simulated data in appropriate formats at a given data rate, and to inject this data onto the communication line or bus, using the necessary communication protocol. The DAAS involves Serial RS232/RS422, Ethernet, and MIL-STD-1553 communication protocols, as well as LabVIEW software, VME hardware, and SunOS/UNIX operating systems.
144

DESIGN AND IMPLEMENTATION OF SMART WIRELESS SENSOR NETWORK/ CONCEPTION ET IMPLANTATION D'UN RESEAU DE CAPTEURS SANS-FIL

Abdelmalek, Omar 01 June 2009 (has links) (PDF)
This work is concerned with the design design full functional nodes and to evaluate an application in wireless sensor network. The resulting designed product could form a reliable support for transferring data between nodes and a computer. MaxStream XBee ZNet 2.5 modules are chosen as the radio platform and LabVIEW as the virtual instrument for user interface.
145

Integrating Visual Data Flow Programming with Data Stream Management

Melander, Lars January 2016 (has links)
Data stream management and data flow programming have many things in common. In both cases one wants to transfer possibly infinite sequences of data items from one place to another, while performing transformations to the data. This Thesis focuses on the integration of a visual programming language with a data stream management system (DSMS) to support the construction, configuration, and visualization of data stream applications. In the approach, analyses of data streams are expressed as continuous queries (CQs) that emit data in real-time. The LabVIEW visual programming platform has been adapted to support easy specification of continuous visualization of CQ results. LabVIEW has been integrated with the DSMS SVALI through a stream-oriented client-server API. Query programming is declarative, and it is desirable to make the stream visualization declarative as well, in order to raise the abstraction level and make programming more intuitive. This has been achieved by adding a set of visual data flow components (VDFCs) to LabVIEW, based on the LabVIEW actor framework. With actor-based data flows, visualization of data stream output becomes more manageable, avoiding the procedural control structures used in conventional LabVIEW programming while still utilizing the comprehensive, built-in LabVIEW visualization tools. The VDFCs are part of the Visual Data stream Monitor (VisDM), which is a client-server based platform for handling real-time data stream applications and visualizing stream output. VDFCs are based on a data flow framework that is constructed from the actor framework, and are divided into producers, operators, consumers, and controls. They allow a user to set up the interface environment, customize the visualization, and convert the streaming data to a format suitable for visualization. Furthermore, it is shown how LabVIEW can be used to graphically define interfaces to data streams and dynamically load them in SVALI through a general wrapper handler. As an illustration, an interface has been defined in LabVIEW for accessing data streams from a digital 3D antenna. VisDM has successfully been tested in two real-world applications, one at Sandvik Coromant and one at the Ångström Laboratory, Uppsala University. For the first case, VisDM was deployed as a portable system to provide direct visualization of machining data streams. The data streams can differ in many ways as do the various visualization tasks. For the second case, data streams are homogenous, high-rate, and query operations are much more computation-demanding. For both applications, data is visualized in real-time, and VisDM is capable of sufficiently high update frequencies for processing and visualizing the streaming data without obstructions. The uniqueness of VisDM is the combination of a powerful and versatile DSMS with visually programmed and completely customizable visualization, while maintaining the complete extensibility of both.
146

Development of a Software Application to Extract the Features of Normal Respiratory Sounds from the Lungs and the Trachea

Sabarinathan, Ranjani 01 January 2006 (has links)
Auscultation has been widely regarded as one of the most important noninvasive diagnostic tools for clinical diagnosis of the respiratory tract. The purpose of this thesis was to develop a software application capable of extracting the key features of respiratory sound signals from the lungs and trachea of healthy persons. The efficacy of the program was evaluated by the verification of the important features of the sound signals from the left and right lungs and the trachea such as 1) right and left lung symmetry and 2) dissimilarity between the trachea and both lungs. The program was developed in LabView and was designed to capture the respiratory sound signals from the lungs and the trachea in real-time and process them in the time and frequency domains for further analysis. The features compared were 1) signal amplitude in the time domain and 2) power spectra in the frequency domain. Results of the study had shown that the program had been able to verify that 1) the key features of the breath sound signals from the left and right lungs were similar and 2) the features of the signals from the trachea and both lungs were different.
147

A Wireless Surface Electromyography (WSEMG) System

Bell, Aleeta E. 01 January 2006 (has links)
Surface Electromyography (SEMG) systems are utilized throughout the medical industry to study abnormal electrical activity of the human muscle. Historically, SEMG systems employ surface (skin) mounted sensors that transmit electrical muscle data to a computer base via an umbilical cord. A typical SEMG analysis may exercise multiple sensors, each representing a unique data channel, positioned about the patient's body. Data transmission cables are linked between the surface mounted sensor nodes and a backpack worn by the patient. As the number of sensors increases, the patient's freedom of mobility decreases due to the lengthy data cables linked between the surface sensors and the backpack. An N-channel wireless SEMG system has been developed based on the ZigBee wireless standard. The system includes N-channels, each consisting of a wireless ZigBee transmitting modem, an 8-bit microcontroller, a low-pass filter and a pre-amplifier. All channels stream data to a central computer via a wireless receiving modem attached directly to the computer. The data is displayed to the user through graphical development software called LabView. The wireless surface electromyography(WSEMG) system successfully transmits reliable electrical muscle data fiom the patient to a computer base. The development of a WSEMG system offers an attractivealternative to implementing wired surface electromyography testing by facilitating thefreedom of patient mobility not bound by data transmission cables.
148

DEVELOPMENT OF A ROBUST CASCADE CONTROLLER FOR A RIDERLESS BICYCLE

Persson, Niklas, Andersson, Tom January 2019 (has links)
A controlled riderless bicycle is desired for the purpose of testing autonomous vehicles ability to detect and recognise cyclists. The bicycle, which is a highly unstable system with complex dynamics have been subject to research for over a century, and in the last decades, controllers have been developed for autonomous bicycles. The controllers are often only evaluated in simulation, but some complex controllers have been developed on real-life bicycles as well. The goal of this work is to validate sensors and subsystems of an instrumented bicycle and to develop a robust controller which can balance a bicycle by using actuation on the steering axis alone. Using an iterative design process, the sensor measuring the lean angle and the steering system are improved and validated. By sensing the lean angle, the handlebar is manipulated to make the bicycle stable. For this purpose, a P, PD, two different PID, an LQR and a fuzzy controller are developed, evaluated and compared. The results show that the bicycle can ride without human interaction on a bicycle roller in different velocities. Additionally, numerous experiments are conducted in an outdoor environment in several different terrains, where the proposed control structure manages to balance and steer the bicycle.
149

Implementation of an Automatic Voltage Regulator for Synchronous Machines on an FPGA

Fjärstedt, Eric January 2019 (has links)
Synchronous generators used for hydro power and nuclear power is a well known topology but there is a vast amount of intricate technologies and methods to making them function properly. This masters thesis covers the development, implementation and verification of a magnetisation system for a synchronous generator. The software implementation is made in the LabVIEW programming environment and uses a high performance CompactRIO with an FPGA for measurements, calculation and output control signals. Together with several peripheral devices, the CompactRIO forms an excitation system and most importantly, an automatic voltage regulator. This system keeps the output voltage of the generator stable and has a variety of safety features such as over excitation limits, under excitation limits and a V/Hz limiter. The resulting system successfully monitors and controls the generator characteristics and the controllers, based on PI controllers, have short rise times, low overshoot and no significant static error. This magnetisation system was verified on a 185 kW synchronous machine and all functions showed satisfying results with the exception of the implemented power system stabiliser which need to be re-tuned.
150

Diseño e implementación de un sistema de automatización de ensayos característicos de máquinas eléctricas asíncronas: diseño e implementación de un instrumento virtual para el análisis de los resultados de los ensayos característicos de un motor asíncrono trifásico en entorno LabVIEW

Rodríguez Reátegui, Julio Diego 20 May 2013 (has links)
En la actualidad, la utilización de los instrumentos virtuales ha venido incrementándose en aplicaciones enfocadas a las ciencias e ingeniería. Esto se debe a que, a diferencia de los instrumentos tradicionales de laboratorio, estas son herramientas basadas en software, las cuales utilizan el hardware de una computadora o estación de trabajo para realizar las tareas para las cuales han sido diseñadas, lo cual le da grandes ventajas como una mayor portabilidad, personalización, adaptabilidad e interconectividad con otros sistemas. El objetivo de la tesis es la utilización de un entorno de desarrollo creado por la empresa National Instruments, llamado LabVIEW. En dicho entorno, se diseñará e implementará un instrumento virtual, cuyo propósito es el de ser usado para el análisis de los resultados obtenidos en el proceso de ejecución de los ensayos característicos realizados a un motor asíncrono trifásico. Para ello, el instrumento virtual deberá ser capaz de establecer una comunicación con un hardware externo encargado de llevar a cabo dichos ensayos de forma automática. Dicha comunicación enlazará al instrumento virtual con una tarjeta de adquisición de datos, lo cual permitirá al usuario del instrumento, ingresar datos de placa y parámetros de ensayo pertinentes, para que estos sean enviados al resto del sistema para la correcta realización de los ensayos. Así mismo, el instrumento virtual debe ser capaz de usar esta comunicación para recibir valores correspondientes a los resultados de los ensayos realizados en dicha máquina eléctrica, provenientes de la tarjeta de adquisición de datos mencionada. Utilizando los valores obtenidos durante el desarrollo de los ensayos, el instrumento realizará cálculos matemáticos pre-programados con la finalidad de poder mostrar en pantalla los parámetros del circuito eléctrico equivalente y las gráficas características correspondientes para el análisis del motor asíncrono trifásico ensayado con el fin de describir, de forma gráfica, su comportamiento y eficiencia. / Tesis

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