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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

Desarrollo de un sistema de control que hace el seguimiento del máximo punto de potencia en paneles solares aplicado a sistemas de generación fotovoltaica para entornos rurales / Development of a control system that monitors the maximum power point in solar panels applied to photovoltaic generation systems for rural environments

Peña La Torre, Walter José, Nevado Talledo, José Eduardo 16 July 2019 (has links)
El presente proyecto detalla el desarrollo de un sistema de control que tiene como objetivo mejorar el performance de aplicaciones solares para electrificación rural. La idea fundamental es que el sistema realiza el seguimiento del máximo punto de potencia en paneles solares estabilizando su funcionamiento en esta zona. Para poder diseñar y construir el sistema, se hará uso de técnicas de control, conocimientos de conversores DC-DC y además de programación de microcontroladores. Esta tesis consta de cinco capítulos. En el primer capítulo se presenta la problemática y justificación del desarrollo del proyecto, así como los objetivos buscados. En el segundo capítulo se trata el marco teórico de la tesis, una explicación de las técnicas de control utilizadas, conceptos aplicados a fuentes DC-DC y una descripción de los elementos que conforman Sistema Fotovoltaico. En el tercer capítulo se trata de la descripción del hardware, en el cual se describe el diseño del conversor DC-DC elegido. En el cuarto capítulo se presenta la descripción de la etapa de control, la cual muestra el algoritmo usado para el control, así como la simulación y los resultados. Por último, en el quinto capítulo, se muestra los resultados experimentales de la construcción del circuito y su operación, así como un informe de costos de la tesis. / The present project details the development of a control system that aims to improve the performance of solar applications for rural electrification. The designed system monitors the maximum power point in a solar panel stabilizing its operation in this area. In order to design and build the system, control techniques, knowledge of DC-DC converters and programming of microcontrollers were use. This thesis consists of five chapters. In the first chapter the problem and justification of the development of the project is presented, as well as the objectives sought. The second chapter deals with the theoretical framework of the thesis, an explanation of the control techniques used, concepts applied of DC-DC sources and a description of the elements that make up the Photovoltaic Autonomous System. The third chapter deals with the hardware description, in which the design of the chosen DC-DC converter is detail. In the fourth chapter the description of the control stage is presented, which shows the fuzzy algorithm used for the control, as well as the simulation and the results. Finally, in the fifth chapter, the experimental results of the developed prototyped are shown in a 100W photovoltaic panel control scenario then conclusion of the development process are presented as well. / Tesis
142

Configurable Hardware Support for Single Processor Real-Time Systems

Nordström, Susanna January 2008 (has links)
<p>This thesis describes a further development of a building block for programmable devices in embedded systems handling real-time functionality.</p><p>Embedded systems are included in a variety of products within different technical areas such as industrial automation, consumer electronics, automotive industry, and communication-, and multimedia systems. Products ranging from trains and airplanes to microwave ovens and washing machines are controlled by embedded systems.</p><p>Programmable devices constitute a part of these embedded systems. Today, a programmable device can include a complete system containing building blocks connected with each other via programs written using a hardware description language. The programmable devices can be programmed and changed over and over again and this flexibility makes it possible to explore how these building blocks can best be designed in relation to system requirements, before final implementation.</p><p>This thesis describes a further development of a building block for programmable devices implemented in a non-traditional way, i.e., the implementation is written using both hardware description language and traditional software languages. This new building block handles real-time functionality in a non-traditional way that enables certain benefits, such as increased performance, predictability and less memory consumption. Using a non-traditional implementation also has its drawbacks, and e.g., extensions and adjustments can be hard to handle since modifications are required in both hardware and software programming languages.</p><p>The new building block was investigated in order to see how it could be facilitated when used for real-time functionality. The configurability of the block was extended which enables further customization of the building block. This leads to the possibility to use the block within a wider spectrumof applications. It is also possible to reduce the size and cost of the final product since resource usage can be optimized.</p><p>Furthermore, a mathematicalmodel estimating resource usage for real-time functionality has been developed. The model enables distinctive trade-offs comparisons, and guidance for system designers, when considering what type of real-time operating system to use in a certain design.</p>
143

Driver Drowsiness Monitoring Based on Yawning Detection

Abtahi, Shabnam 20 September 2012 (has links)
Driving while drowsy is a major cause behind road accidents, and exposes the driver to a much higher crash risk compared to driving while alert. Therefore, the use of assistive systems that monitor a driver’s level of vigilance and alert the fatigue driver can be significant in the prevention of accidents. This thesis introduces three different methods towards the detection of drivers’ drowsiness based on yawning measurement. All three approaches involve several steps, including the real time detection of the driver’s face, mouth and yawning. The last approach, which is the most accurate, is based on the Viola-Jones theory for face and mouth detection and the back projection theory for measuring both the rate and the amount of changes in the mouth for yawning detection. Test results demonstrate that the proposed system can efficiently measure the aforementioned parameters and detect the yawning state as a sign of a driver’s drowsiness.
144

Implementering av ett inbyggt system för automatisk styrning av en robotbil.

Aldrin, Martin January 2007 (has links)
Denna rapport beskriver ett examensarbete för högskoleingenjörsexamen i elektroteknik vid Växjö Universitet. Syftet är att konstruera ett styrsystem till en robotbil, ett program som hindrar bilen från att krocka med omgivningen. Roboten ska även kunna styras från en dator via ett grafiskt gränssnitt implementerat i Labview. Nödvändig hårdvara för styrning och kommunikation har konstruerats. Det har behövts tre olika programmeringsspråk för att nå de krav som har ställts på uppgiften, C, Perl och Labview. Microprocessorn i robotbilen har programmerats i C och gör bilen helt autonom, endast beroende av signaler från avståndssensorer. Avlusningsprogrammet skrevs i Perl och styrningen från datorn har implementerats i Labview. Avlusningsprogrammet togs fram på grund av att det blev svårt att hålla koll på allt som skedde med värden och beräkningar i den automatiska styrningen av robotbilen. / This thesis describes a project for the bachelor degree in electrical engineering at Växjö University. The purpose with this project is to construct a guidance system for a robot car, a program that prevents the car from colliding with objects when moving without external control. The robot could also be controlled from the computer through a virtual instrument implemented in Labview. The necessary hardware for steering and communicating has been constructed. The software is implemented using three different programming languages, C, Perl and Labview.
145

Reducering av effektförbrukning i inbyggda system med Linux / Reduce power consumption in embedded Linux

Folkesson, Marcus January 2010 (has links)
Linux is a growing operating system in embedded systems. Today, Linux is not only in heavy servers but also in cell phones, PDAs, cameras and other devices running on battery power. While current technology is more energy efficient, more and more technologies are implemented into a single unit resulting in an overall increase of power consumption. Low power consumption is an increasingly important feature of a system today. Lower power consumption means lower costs, less environmental impact, and longer life for applications that runs on batteries. This work compiles methods to reduce power consumption of Linux systems. The work includes examining whether the available opportunities are platform-specific or of a more general nature. The evaluations of methods for efficacy, has been performed on three different platforms. Testing consists of different types of stress tests and turning the units on-and-off. The results show that many of the features for power management that are available in a Linux system are of a general nature and that the Linux kernel has good support for implementation of new power management functions. Through the power reduction tests it has been proven that reducing the frequency of the processor and bit rate of the Ethernet controller provides the highest efficiency gain at different load levels. This work also investigates whether implementation of dynamic frequency scaling on a new processor is a complex task or not. Implementations in the Linux kernel provide general code that means that only the processor-specific part needs to be implemented. The implementation was carried out without major complications. / Linux är ett växande operativsystem inom inbyggda system som finner allt fler tillämpningar i elektroniska produkter. Idag finns Linux inte enbart i tunga servrar utan även i mobiltelefoner, handdatorer, kameror och andra enheter som går på batteridrift. Samtidigt som dagens teknik är allt mer energieffektiv så implementeras allt fler tekniker i en och samma enhet vilket medför en total ökning av effektförbrukning. En låg effektförbrukning är en allt mer betydande egenskap hos ett system idag. En lägre effektförbrukning innebär lägre kostnader, mindre miljöpåverkan, och längre drifttid för applikationer som drivs på batteri. Arbetet sammanställer metoder för att reducera effektförbrukningen hos system med Linux. Arbetet innefattar även att undersöka huruvida de möjligheter som finns är plattformsspecifika eller av generell karaktär. Vid utvärdering av metoders effektpåverkan har tester utförts på tre olika plattformar. Testerna består av på- och avslag av enheter samt olika typer utav belastningstester. Resultatet visar att många utav de energisparfunktioner som finns tillgängliga i Linuxsystem är av generell karaktär och att Linuxkärnan har bra stöd för vidare implementering av energisparfunktioner. Vid försöken till effektreducering har det visat sig att minskning av hastigheten på processor och ethernet-controller ger störst vinst vid olika belastningsgrader. Arbetetet undersöker även huruvida implementationen utav dynamisk frekvensskalning på en ny processor är en komplicerad process eller inte. Resultatet visar att implementationen av funktionen för en ny processor inte är allt för komplicerad. Detta mycket på grund av att Linuxkärnans infrastruktur är uppbyggd i lager där många utav dessa lager är av generell karaktär och kan återanvändas. Detta medför att endast den hårdvaruspecifika delen behöver implementeras.
146

Embedded web server remote control and communication

Huo, Weikun, Liu, Lihua January 2012 (has links)
This is a embedded system that designed to achieve the goal of remote control andwireless communication with web page. The embedded web server using uIP whichis TCP/IP stack. Web page are designed using HTML5, JavaScript and CSS languageto format the layout. On the home page, you can see the index of different items.
147

Modular Embedded System Design / Implementation For Mechatronic Education And Research

Nursal, Ali Ozgu 01 September 2007 (has links) (PDF)
In this thesis a modular embedded system for Mechatronics education and research is designed and implemented. Four types of control boards are manufactured and related software is developed at board and PC level. A star like topology is used for boards architecture. One bridge board is responsible for handling communication between the PC and all the other boards that are connected independently to that bridge board. For PC communication Universal Seial Bus (USB), for inter peripheral communication serial peripheral interface (SPI) is used. By the use of USB and SPI, the system becomes scalable and hot pluggable. All these four boards can be used in stand alone and/or together in different applications. The system covers / general analog digital input output, several types of motor control and simple graphical display applications. The firmware and software is developed in a modular, flexible and transparent way allowing users all level accessibility. This way, the application fields and the content of the courses that will be using this system become very versatile. A simulation of hard disk reading experiment is designed and implemented to show the integral capabilities of the system. In this experiment all the boards are utilized and used together. As a result, a system is designed for Mechatronics experiments and research. A modular approach is adopted which is compsed of units that can also work in a stand-alone manner. A software library developed for the PC platform facilitates high-level usage of these cards whereas it is possible to implement custom codes on these boards. To sum up, an affordable, versitale, scalable and transparent system is developed which is specifically tailored for Mechatronics applications.
148

Implementering av ett inbyggt system för automatisk styrning av en robotbil.

Aldrin, Martin January 2007 (has links)
<p>Denna rapport beskriver ett examensarbete för högskoleingenjörsexamen i elektroteknik vid Växjö Universitet. Syftet är att konstruera ett styrsystem till en robotbil, ett program som hindrar bilen från att krocka med omgivningen. Roboten ska även kunna styras från en dator via ett grafiskt gränssnitt implementerat i Labview. Nödvändig hårdvara för styrning och kommunikation har konstruerats.</p><p>Det har behövts tre olika programmeringsspråk för att nå de krav som har ställts på uppgiften, C, Perl och Labview. Microprocessorn i robotbilen har programmerats i C och gör bilen helt autonom, endast beroende av signaler från avståndssensorer. Avlusningsprogrammet skrevs i Perl och styrningen från datorn har implementerats i Labview. Avlusningsprogrammet togs fram på grund av att det blev svårt att hålla koll på allt som skedde med värden och beräkningar i den automatiska styrningen av robotbilen.</p> / <p>This thesis describes a project for the bachelor degree in electrical engineering at Växjö University. The purpose with this project is to construct a guidance system for a robot car, a program that prevents the car from colliding with objects when moving without external control. The robot could also be controlled from the computer through a virtual instrument implemented in Labview. The necessary hardware for steering and communicating has been constructed. The software is implemented using three different programming languages, C, Perl and Labview.</p>
149

Linux auf eingebetteten Systemen / Linux on embedded systems

Rößler, Marko 01 April 2004 (has links) (PDF)
Presentation held on the 123. Unix-Stammtisch. It contains information about the usage of Linux on embedded systems. The boot process of Linux, the design of an embedded system environment and small libraries and tools are discussed in detail. / Vortrag zum 123. Unix Stammtisch der TU-Chemnitz. Befasst sich mit dem Entwurf und Betrieb von eingebetteten Systemen mit dem Betriebssystem Linux. Von der D-Box bis zur Linux-Armbanduhr, der Linux-Boot Prozess, Aufbau einer Linuxumgebung undminimalistisches Bibiotheken.
150

Porting DotGNU to Embedded Linux

Stein, Alexander 29 March 2011 (has links) (PDF)
Programming PLC systems is limited by the provided libraries. In contrary, hardware-near programming needs bigger efforts in e. g. initializing the hardware. This work others a foundation to combine advantages of both development sides. Therefore, Portable.NET from the DotGNU project has been used, which is an implementation of CLI, better known as “.NET”. The target system is the PLCcore-5484 microcontroller board, developed by SYS TEC electronic GmbH. Built upon the porting, two variants to use interrupt routines withing the Portabe.NET runtime environment have been analyzed. Finally, the reaction times to occuring interrupt events have been examined and compared. / Die Programmierung für SPS-Systeme ist durch die gegebenen Bibliotheken beschränkt, während hardwarenahe Programmierung einen größeren Aufwand durch z.B. Initialisierungen hat. Diese Arbeit bietet eine Grundlage, um die Vorteile beider Entwicklungsseiten zu kombinieren. Dafür wurde Portable.NET des DotGNU-Projekts, eine Implementierung des CLI, bekannter unter dem Namen “.NET”, benutzt. Das Zielsystem ist das PLCcore-5484 Mikrocontrollerboard der SYS TEC electronic GmbH. Aufbauend auf der Portierung wurden zwei Varianten zur Einbindung von Interrupt-Routinen in die Portable.NET Laufzeitumgebung untersucht. Abschließend wurden die Reaktionszeiten zu eintretenden Interrupts analysiert und verglichen.

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