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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.
21

Zpracování zázněje z Dopplerovského radarového senzoru / Doppler's sensor beat freqeuncy proccessing

Dušek, Martin January 2010 (has links)
This work is engaged in ways of objects speed measuring mainly helped by Doppler Effect. The sensor HB410 is described in this work and its possible elaboration output heterodyne analog signal. The calculation of objects speed is deduced from frequency of heterodyne signal. In this work is projected circuit solution for elaboration of analog signal and its digitalization. Available types and nature of microcontrollers which are elaborating digital signal and communicating with PC are summarized in this work. In the last chapter is described microcontroller's driving software and PC software for speed measure.
22

Analýza dopravy z videa / Traffic Analysis from Video

Sochor, Jakub January 2014 (has links)
V rámci této práce byl navržen a implementován systém pro analýzu dopravy z videa. Tento system umožňuje detekovat, sledovat a klasifikovat automobily. Systém je schopný detekovat pruhy z pohybu projíždějících automobilů a také je možné určit, zdali daný automobil jede v protisměru. Rychlost projíždějících automobilů je také měřena. Pro funkčnost systému není vyžadován žadný manuální vstup nebo kalibrace kamery, jelikož kamera je plně automacky zkalibrována pomocí úběžníků. Navržený systém pracuje s velkou přesností detekce, sledování a klasifikace automobilů a také rychlost automobilů je měřena s~malou chybou. Systém je schopný pracovat v reálném čase a je aktuálně využíván pro nepřetržité online sledování dopravy. Největším přínosem této práce je plně automatické měření rychlostí projíždějích vozidel.
23

Implementace metod pro měření rychlosti otáčení rotačních strojů na platformě cRIO / Implementation of methods for measurement of rotational speed using cRIO platform

Fábry, Tomáš January 2016 (has links)
This diploma thesis implements methods for a measurement of rotational speed. It is implemented on the Compact RIO platform from National Instruments. Corresponding SW is implemented using the graphical programming language G in LabView environment. Developed system uses two different sensors – incremental encoder and tacho sensor for measurements of rotational speed. Thesis further analysis and implements a method for an encoder nonlinearity determination and for its on-line correction. For used methods, effects adding errors into the measurements are evaluated and quantified.
24

Cloudová aplikace pro analýzu dopravy / Cloud Application for Traffic Analysis

Valchář, Vít January 2016 (has links)
The aim of this thesis is to create a cloud application for traffic analysis without knowing anything about the system. The only input is address of the web camera pointing at traffic. This application is build on existing solution which is further enhanced. New modules for removing obstacles (such as lamppost covering part of the road) and splitting overlapping cars were added. The whole cloud solution consists of multiple components which communicates by HTTP messages and are controlled by web interface.
25

Porovnání měření rychlosti vodoměrnou vrtulí a laserovým anemometrem / Comparison of speed measurement by hydrometric propeller and laser anemometer

Kosík, Ondřej January 2022 (has links)
This final thesis deals primarily with the comparison of two calibration approaches. It determines the degree of mutual agreement and tries to answer the reasons of their deviations. This agreement was measured by the LDA method. It was found that the calibration approach based on the reference framework of values of the previous bachelor thesis differs systematically from the calibration using calibration equations obtained from certified laboratories by -2 %. The causes of this deviation were investigated using LDA and PIV. Although a significant number of measurements were performed, all tested hypotheses were refuted and therefore it was not possible to determine their cause.
26

K-distribution fading models for Bayesian estimation of an underwater acoustic channel

Laferriere, Alison Beth January 2011 (has links)
Thesis (S.M. in Electrical Engineering and Computer Science)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science; and the Woods Hole Oceanographic Institution), 2011. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 113-114). / Current underwater acoustic channel estimation techniques generally apply linear MMSE estimation. This approach is optimal in a mean square error sense under the assumption that the impulse response fluctuations are well characterized by Gaussian statistics, leading to a Rayleigh distributed envelope. However, the envelope statistics of the underwater acoustic communication channel are often better modeled by the K-distribution. In this thesis, by presenting and analyzing field data to support this claim, I demonstrate the need to investigate channel estimation algorithms that exploit K-distributed fading statistics. The impact that environmental conditions and system parameters have on the resulting distribution are analyzed. In doing so, the shape parameter of the K-distribution is found to be correlated with the source-to-receiver distance, bandwidth, and wave height. Next, simulations of the scattering behavior are carried out in order to gain insight into the physical mechanism that cause these statistics to arise. Finally, MAP and MMSE based algorithms are derived assuming K-distributed fading models. The implementation of these estimation algorithms on simulated data demonstrates an improvement in performance over linear MMSE estimation. / by Alison Beth Laferriere. / S.M.in Electrical Engineering and Computer Science
27

ESPECIFICAÇÕES DE PROJETO PARA MEDIÇÃO DE VELOCIDADE DE VENTO UTILIZANDO ANEMÔMETRO ULTRASÔNICO COM O MÉTODO DE DIFERENÇA DE FASE / SPECIFICATIONS OF PROJECT FOR MEASUREMENT WIND SPEED USING ULTRASONIC TRANSDUCERS WITH THE METHOD OF DIFFERENCE IN STAGE

Pinto, Mauro Sérgio Silva 27 October 2006 (has links)
Made available in DSpace on 2016-08-17T14:53:14Z (GMT). No. of bitstreams: 1 Mauro Sergio Silva Pinto.pdf: 649420 bytes, checksum: 2659c3409645c14d4672fc5713698782 (MD5) Previous issue date: 2006-10-27 / The time of flight method for determining the wind speed using ultrasonic transducers is presented in this work. The techniques of phase difference and threshold detection for determining the time of flight are presented. A more detailed study of the phase difference technique is carried out in order to determine the design specifications using this method with respect to the noise sensitivity, dependence of the measurement range with the medium temperature and measurement resolution. A design specification example is presented in order to illustrate the proposed procedures. / Apresenta-se neste trabalho o método do tempo de trânsito para determinação da velocidade do vento utilizando transdutores ultra-sônicos. Apresentam-se as técnicas da diferença de fase e detecção de limiar para determinação do tempo de trânsito deste método. Um estudo mais aprofundado é realizado para o método da diferença de fase de forma a determinar as especificações de projeto usando esse método, com relação à sensibilidade ao ruído, dependência da faixa de medição com temperatura do meio e resolução de medição. Um exemplo de especificação de projeto é apresentado de forma a ilustrar os procedimentos desenvolvidos.
28

Contrôle actif du rayonnement acoustique des plaques: une approche à faible autorité / Active control of sound radiation from plates: a low authority approach

De Man, Pierre 04 June 2004 (has links)
L'objectif de cette thèse consiste en l'étude d'une stratégie de contrôle actif à faible autorité avec comme application le contrôle actif du rayonnement acoustique d'une plaque. Depuis l'essor du contrôle actif, son application aux problèmes acoustiques et vibracoustiques a été investiguée par de nombreux chercheurs, exploitant soit la théorie du contrôle optimal, soit des approches originales basées plus particulièrement sur la physique. Des notions spécifiques au contrôle vibroacoustique ont été développées comme, par exemple, les modes radiatifs pouvant caractériser le rayonnement acoustique d'une plaque d'une manière adaptée au contrôle. <p>Le contrôle actif à faible autorité, pour lequel le Laboratoire de Structures Actives a développé une expertise dans le domaine de l'amortissement et du contrôle actif des vibrations, est une solution attractive par sa simplicité de mise en oeuvre. Le plus souvent implémenté sous la forme d'un contrôle décentralisé constitué de boucles indépendantes, le contrôle à faible autorité bénéficie de certaines garanties de stabilité et de robustesse. <p>Bien que notre stratégie de contrôle puisse s'appliquer à n'importe quel type de plaque, l'application considérée dans ce travail a été motivée par le contexte socio-économique actuel en rapport avec les nuisances acoustiques. Il était en effet intéressant d'évaluer la stratégie de contrôle pour le problème de la transmission acoustique d'un vitrage. La stratégie de contrôle se divise en deux étapes. Tout d'abord le développement d'un capteur unique destiné à fournir une mesure représentative du bruit rayonné par une plaque en basse fréquence. Deux capteurs de vitesse volumétrique (l'un discret, l'autre distribué) ont ainsi été développés et évalués expérimentalement. <p>Ensuite, une procédure d'optimisation de l'emplacement d'un ensemble d'actionneurs pilotés en parallèle est proposée. L'objectif de cette phase d'optimisation est de forcer la réponse fréquentielle du système à posséder les propriétés d'un système colocalisé. La stratégie de contrôle est ensuite évaluée sur deux structures expérimentales. <p><p>/ This thesis is concerned with a low authority active control strategy applied to the sound radiation control of a baffled plate. Since the development of active control ,numerous researchers have studied its application to acoustical or vibroacoustical problems using either the modern control theory or other methods based rather on the understanding of the physics of the problem. Vibroacoustical active control has lead to the definition of radiation modes allowing to describe the radiated sound of a plate in an appropriate manner for active control purposes. <p>Low autorithy control (LAC), for which the Active Structures Laboratory has gained an expertise for active vibration control applications is an interesting solution for its implementation simplicity. Most of the time it consists of several decentralized control loops, and benefits from guaranteed stability and robustness properties. Although our control strategy can be applied to any kind of plates, the application considered here has been motivated by the present socio-economical context related to noise annoyances. The active control strategy has been applied the problem of the sound transmission loss of glass plates (windows). This strategy is in two steps :first a volume velocity sensor is developed as to give a measure representative of the radiated sound at low frequencies. <p>Two sensors have been developed (one discrete and one distributed) and experimentally tested. Next, an optimisation strategy is proposed which allow to locate on the plate a set of several actuators driven in parallel. The goal of this optimisation task is to obtain an open-loop frequency response which behave like a collocated system. The control strategy is finally evaluated on two plate structures. / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished
29

Měření rychlosti vozidel pomocí stereo kamery / Vehicle Speed Measurement Using Stereo Camera Pair

Najman, Pavel January 2021 (has links)
Tato práce se snaží najít odpověď na otázku, zda je v současnosti možné autonomně měřit rychlost vozidel pomocí stereoskopické měřící metody s průměrnou chybou v rozmezí 1 km/h, maximální chybou v rozmezí 3 km/h a směrodatnou odchylkou v rozmezí 1 km/h. Tyto rozsahy chyb jsou založené na požadavcích organizace OIML, jejichž doporučení jsou základem metrologických legislativ mnoha zemí. Pro zodpovězení této otázky je zformulována hypotéza, která je následně testována. Metoda, která využívá stereo kameru pro měření rychlosti vozidel je navržena a experimentálně vyhodnocena. Výsledky pokusů ukazují, že navržená metoda překonává výsledky dosavadních metod. Průměrná chyba měření je přibližně 0.05 km/h, směrodatná odchylka chyby je menší než 0.20 km/h a maximální absolutní hodnota chyby je menší než 0.75 km/h. Tyto výsledky jsou v požadovaném rozmezí a potvrzují tedy testovanou hypotézu.
30

Měření rychlosti automobilů z dohledové kamery / Speed Measurement of Vehicles from Surveillance Camera

Jaklovský, Samuel January 2018 (has links)
This master's thesis is focused on fully automatic calibration of traffic surveillance camera, which is used for speed measurement of passing vehicles. Thesis contains and describes theoretical information and algorithms related to this issue. Based on this information and algorithms, a comprehensive system design for automatic calibration and speed measurement was built. The proposed system has been successfully implemented. The implemented system is optimized to process the smallest portion of the video input for the automatic calibration of the camera. Calibration parameters are obtained after processing only two and half minutes of input video. The accuracy of the implemented system was evaluated on the dataset BrnoCompSpeed. The speed measurement error using the automatic calibration system is 8.15 km/h. The error is mainly caused by inaccurate scale acquisition, and when it is replaced by manually obtained scale, the error is reduced to 2.45 km/h. The speed measuring system itself has an error of only 1.62 km/h (evaluated using manual calibration parameters).

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