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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

Applied Real-Time Integrated Distributed Control Systems: An Industrial Overview and an Implemented Laboratory Case Study

Zaitouni, Wael K 08 1900 (has links)
This thesis dissertation mainly compares and investigates laboratory study of different implementation methodologies of applied control systems and how they can be adopted in industrial, as well as commercial, automation applications. Namely the research paper aims to assess or evaluate eventual feedback control loops' performance and robustness over multiple conventional or state-of-the-art technologies in the field of applied industrial automation and instrumentation by implementing a laboratory case study setup: the ball on beam system. Hence, the paper tries to close the gap between industry and academia by: first, conducting a historical study and background information of main evolutional and technological eras in the field of industrial process control automation and instrumentation. Then, some related basic theoretical as well as practical concepts are reviewed in Chapter 2 of the report before displaying the detailed design. After that, the next Chapter, analyses the ball on beam control system problem as the case studied in the context of this research through reviewing previous literature, modeling and simulation. The following Chapter details the proposed design and implementation of the ball on beam case study as if it is under the introduced distributed industrial automation architecture. Finally, Chapter 5 concludes this work by listing several points leaned, remarks, and observations, and stating possible development and the future vision of this research.
142

Aplicación de sensores de flujo óptico para el desarrollo de nuevos sistemas de medida de bajo coste

Tresánchez Ribes, Marcel 23 December 2011 (has links)
En aquesta memòria es presenten diversos treballs relacionats amb la utilització dels sensor de flux òptic de baix cost pel desenvolupament de nous sistemes de mesura compactes i de molt baix cost. Les aplicacions plantejades permeten aprofitar tot el potencial industrial d’aquest tipus de sensors. Els sensors de flux òptic tenen la peculiaritat d’incorporar dins d’un únic encapsulat un sistema d’adquisició d’imatges i un processador digital preprogramat per a realitzar el còmput de flux òptic (optical flow) de la imatge. D’aquesta manera, aquest tipus de sensors no requereixen cap sistema processador addicional i, en alguns casos, poden funcionar sense cap altre element addicional de control. Actualment, l’èxit dels sensors de flux òptic ha facilitat la seva producció industrial massiva amb costos de fabricació molt baixos el que ha incentivat el desenvolupament de noves aplicacions en camps tan diversos com la robòtica on el cost és un element fonamental en les aplicacions destinades a un mercat de consum. En aquesta memòria es presenta, per una banda, l’anàlisi de l’estat de l’art dels sensors de flux òptic i les seves aplicacions, i per l’altra, el treball de recerca realitzat sobre l’ús d’aquest sensor per a desenvolupar un codificador rotatiu incremental, un codificador absolut, un sistema de detecció de monedes falses de 2 euros, i per a realitzar el seguiment de la pupil•la de l’ull d’una persona amb discapacitat. Els resultats obtinguts a partir de les proves experimentals realitzades amb els diferents sensors de flux òptics utilitzats als dispositius proposats han permès validar les propostes realitzades i la versatilitat del disseny del sensor. / En esta memoria se presentan diversos trabajos de investigación relacionados con la utilización de sensores de flujo óptico de bajo coste para el desarrollo de nuevos sistemas de medida compactos y de muy bajo coste. Las aplicaciones planteadas permiten aprovechar todo el potencial industrial de este tipo de sensores. Los sensores de flujo óptico tienen la particularidad de incorporar dentro de un único encapsulado un sistema de adquisición de imágenes y un procesador digital preprogramado para realizar el cómputo de flujo óptico (optical flow) de la imagen. De esta manera, este tipo de sensores no requieren ningún sistema procesador adicional y, en algunos casos, pueden funcionar sin ningún otro elemento adicional de control. Actualmente, el éxito comercial de los sensores de flujo óptico ha facilitado su producción industrial masiva con costes de fabricación muy bajos lo que ha incentivado el desarrollo de nuevas aplicaciones en campos tan diversos como la robótica donde el coste es un elemento fundamental en las aplicaciones destinadas a un mercado de consumo. En esta memoria se presenta, por un lado, el análisis del estado del arte de los sensores de flujo óptico y sus aplicaciones, y por el otro, el trabajo de investigación realizado sobre la utilización del sensor para el desarrollo de un codificador rotativo incremental, un codificador absoluto, un sistema de detección de monedas falsas de 2 euros y para realizar el seguimiento de la pupila del ojo de una persona con el fin de desarrollar un dispositivo apuntador que pueda ser de utilidad para una persona con discapacidad. Los resultados obtenidos en las pruebas experimentales realizadas con los diferentes sensores de flujo óptico utilizados en los dispositivos propuestos han permitido validar las propuestas realizadas y la versatilidad del diseño del sensor. / This work presents the research performed with optical flow sensors and the proposal of several new compact and low cost applications developed to take full advantage of the industrial potential of these sensors. Optical flow sensors include into the same chip an image acquisition system and a digital signal processor programmed to compute the optical flow of the image acquired. These sensors do not require additional post-processing and can operate without any other additional external control or processing device. Currently, the commercial success of the optical flow sensors has fostered its massive industrial production and has reduced its final cost. This characteristic, combined with the versatility of the design of the sensor, has also fostered the development of a huge range of new applications in different areas, such as robotics, where the cost is a fundamental factor that prone the development and commercialization of new consumer applications. This works presents, in one hand, a review of the state of the art of the research and development related with optical flow sensors and, in the other hand, a set of new applications proposed to take full advantage of the characteristics of the sensor. The new applications proposed are: a relative encoder, an absolute encoder, a counterfeit system for the 2€ case, and an accessibility device that tracks the pupil of the user to control pointer displacement in a computer screen. This device has been designed specifically to help people with mobility impairments in the upper extremities that cannot use the computer mouse. In all cases, the experimental results achieved with the different optical flow sensors used in the new applications proposed have validated the utility and versatility of each proposal and the utility and versatility of the design of this optical sensor.
143

Desenvolvimento e implementação de um sistema de controle de posição e velocidade de uma esteira transportadora usando inversor de frequência e microcontrolador

Raniel, Thiago [UNESP] 24 May 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-05-24Bitstream added on 2014-06-13T19:27:59Z : No. of bitstreams: 1 raniel_t_me_ilha.pdf: 1815527 bytes, checksum: 2b9558bcbd56601c8cbb627feda891cf (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A automação de esteiras rolantes é algo comum e importante em sistemas industriais, mas problemas práticos ainda representam desafios. Um dos desses desafios é manter a precisão em sistemas que exigem paradas sistemáticas, pois folgas mecânicas tendem a provocar variações nas posições de paradas ao longo do tempo. A aplicação de motores de indução têm se tornado comum e soluções eficientes e de baixo custo têm sido pesquisadas. Neste trabalho foi desenvolvido e implementado um sistema de controle de posição e velocidade aplicado em esteiras transportadoras utilizando inversor de frequência, microcontrolador, encoder óptico incremental e sensor indutivo. O movimento da esteira transportadora é efetuado por um motor de indução trifásico, que é acionado pelo conjunto microcontrolador – inversor de frequência. Este conjunto impõe uma frequência no estator do motor através de uma troca de mensagens entre microcontrolador e inversor de frequência (Sistema Mestre-Escravo). Para o envio e recebimento das mensagens, utilizou-se o protocolo de comunicação serial USS® (Universal Serial Interface Protocol) através do padrão RS-485. Os controles de posição e velocidade de rotação do eixo do motor fundamentam-se no sinal gerado pelo encoder óptico incremental, responsável por informar a posição do eixo do motor ao longo da trajetória, e no sensor indutivo que determina uma referência externa importante para a esteira transportadora. Para o funcionamento automático da esteira, elaborou-se um software em linguagem de programação C. Como resultado obteve-se um sistema de controle de posição e velocidade do eixo do motor de indução trifásico que apresenta bons resultados / Automated conveyors system have been largely used in industrial applications. However, there are still practical issues to be overcome. One of them is due to the system mechanical limitation which can lead to low accuracy for applications based on “stop-and-go” movements. Induction motors have been largely used in such applications and low costs solutions have been searched. In this work it was developed and implemented a system of positioning and velocity control applied to conveyors which is based on frequency inverter, microcontroller, optical incremental encoder and inductive sensor. The conveyor’s movement is made by means of a three-phase induction motor, which is driven by the couple microcontroller–frequency inverter. There are messages exchange between the microcontroller and the frequency inverter (Master – Slave configuration) which is based on the communication serial protocol USS through the RS-485 standard. The position and velocity of the motor spindle are controlled using an optical incremental encoder, which is responsible to provide the position of the trajectory, and an inductive sensor which determines the initial reference to the conveyor. The software used to control the system was developed in C language. The results show a low cost system with good results
144

Turbokódy a jejich použití ve sdělovacích systémech / Turbocodes and their application in telecommunication systems

Trčka, Tomáš January 2008 (has links)
This Diploma thesis deals with Turbo code problems. The Turbo codes belong to the group of error correction codes, sometimes referred to as forward error correcting (FEC) codes or channel codes. This thesis can be thematically divided into two basic parts. The first part describes turbo code encoder and decoder block diagram with the illustration of two most frequently used iterative decoding algorithms (SOVA and MAP). The end of this part contains best known turbo codes, which are used in present communication systems. The second part pursues simulation results for the turbo codes using Binary Phase Shift Keying (BPSK) over Additive White Gaussian Noise (AWGN) channels. These simulations were created in the MATLAB/SIMULINK computer program. It will be shown here, that there exist many different parameters, greatly affecting turbo codes performance. Some of these parameters are: number of decoding iterations used, the input data frame length, generating polynoms and RSC encoders constraint lengths, properly designed interleaving block, decoding algorithm used, etc.
145

Zabezpečení přenosu dat BCH kódy / Error protection of data transmission using BCH Codes

Kašpar, Jaroslav January 2008 (has links)
The thesis Data transmission error-protection with BCH codes deals with a large class of random-error correcting cyclic codes which are able to protect binary data and can be used for example in data storages, high speed modems. Bose, Chaudhuri and Hocquenghem (BCH) codes operate over algebraic structures called Galois fields. The BCH encoding is the same as cyclic encoding and can be done with linear feedback shift register but decoding is more complex and can be done with different algorithms - in this thesis there are two algorithms for decoding Peterson and Berlekam-Massey mentioned. The aim of this thesis is to find BCH code which is able to correct t = 6 independent errors in up to data sequence n = 150 bits, then peruse possible realizations of the codecs and set criteria for the best realization, then design and test this realization. This thesis is split into three main parts. In the first part there are encoding and decoding methods of the BCH code generally described. The second part deals with selecting of the right code and realization. There was chosen BCH (63,30) code and realization with FPGA chip. In the last part is described design of BCH encoder and decoder and compilation in the Altera design software.
146

Řídicí mikroprocesorový systém s kmitočtovým syntezátorem pro KV radiostanici / Microprocessor control unit with frequency synthesizer for SW radiostation

Povalač, Aleš January 2009 (has links)
The thesis is focused on the development of a radioamateur short-wave transceiver. The basic functions, features and parameters are described in the introduction. The bandplan and appropriate types of emission are also included in the introductory part. The frequency synthesis module is discussed in the second part of the document. Emphasis is placed on the direct digital synthesis method (DDS) using modern Analog Devices circuits. The proposed DDS module includes a high-speed clock source. The description of an intermediate frequency module with a demodulator is also placed there. The final part in devoted to the design of a transceiver control panel with a graphical display, a keyboard and a rotary encoder. The firmware for an ATmega128 microcontroller is described in detail at the end of the thesis.
147

Vysokofrekvenční obvodový analyzátor s DDS / DDS Based High-frequency circuit analyzer

Priškin, Jiří January 2010 (has links)
At first this thesis is dealing with the basic principles of network analyzers and afterwards goes to propose conception of a polyscope, as a special type of the scalar network analyzer, designed for magnitude frequency response measurement of two-port devices. As a result of this part of the thesis is the polyscope's block circuit diagram and also selection of key integrated circuits for sweep generator, logarithmic detector and control circuits. As the following part of the thesis is a design of the all basic analyzer's circuits resulting in their schematics diagrams and printed circuit boards, do assembly of all modules and mechanical construction of the instrument and look of the front panel. Some of the tasks is implementation of the firmware and personal computer application able to download measured data from the circuit analyzer via USB and generate chart in Microsoft Office Excel book.
148

Porovnání možností komprese multimediálních signálů / Comparison of Multimedia Signal Compression Possibilities

Špaček, Milan January 2013 (has links)
Thesis deals with multimedia signal comparison of compression options focused on video and advanced codecs. Specifically it describes the encoding and decoding of video recordings according to the MPEG standard. The theoretical part of the thesis describes characteristic properties of the video signal and justification for the need to use recording and transmission compression. There are also described methods for elimination of encoded video signal redundancy and irrelevance. Further on are discussed ways of measuring the video signal quality. A separate chapter is focused on the characteristics of currently used and promising codecs. In the practical part of the thesis were created functions in Matlab environment. These functions were implemented into graphic user interface that simulates the activity of functional blocks of the encoder and decoder. Based on user-specified input parameters it performs encoding and decoding of any given picture, composed of images in RGB format, and displays the outputs of individual functional blocks. There are implemented algorithms for the initial processing of the input sequence including sub-sampling, as well as DCT, quantization, motion compensation and their inverse operations. Separate chapters are dedicated to the realisation of codec description in the Matlab environment and to the individual processing steps output. Further on are mentioned compress algorithm comparisons and the impact of parameter change onto the final signal. The findings are summarized in conclusion.
149

Zdroj vysokonapěťových pulzů pro elektroporaci buněk / High Voltage Pulse Generator for Electroporation of Cells

Puczok, Václav January 2016 (has links)
The main goal of this thesis is to design control board for the experimental electroporation device and to develop control firmware. The first chapter of this work focuses on the electroporation phenomenon itself. Behaviour of the cell model in external electrical field is described there as well as simulation and overview of how electroporation affects living tissue. It also explains the main requirements for parameters of the electroporation pulses as well as need for ECG synchronization. Furthermore, some remarks are given about novel high frequency electroporation method, which involves use of nanosecond bipolar high voltage pulse bursts. The second chapter briefly introduces commercial electroporation device called Nanoknife, including control part, power part, and it's limits. The third chapter consists of introduction of the novel experimental electroporation device developed at BUT. Power part of this device is discussed as well. Next chapter focuses on design of the control board for this device and also on description of the particular schematic parts. There is a control algorithm explanation in the fifth chapter of this thesis followed by the brief manual to machine operation.
150

Modul pro verifikaci rotačních pozičních senzorů / Module for verification of rotational position sensors

Krolák, David January 2016 (has links)
This master‘s thesis deals with design and realisation of a control module for automated measurements of the modern contactless inductive position sensors by a mechanical rotational system consisting of a DC motor and an incremental quadrature encoder. The thesis presents methods of driving DC motor and recording of measured data by a microcontroller. The thesis presents a communication protocol between the control module and personal computer via USB interface. A part of this thesis is also to develop a control software and firmware, including the measurement and evaluation of properties of the control module.

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