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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

Automated procedures for orientation of digital images

Morgado, Ana M. de O. January 1996 (has links)
No description available.
2

Programmable Logic Controllers and Supervisory Control and Data Acquisition: A System Design for Increased Availability

Shultz, James Edward, Jr. January 1991 (has links)
No description available.
3

Otimização de um sistema de controle e aquisição de dados para calibração de medidores de radiação X com utilização de ferramentas computacionais / Optimization of a data acquisition and control system for calibration of X rays detectors with usage of computational tools

RODRIGUES, YKLYS S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:41:32Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:24Z (GMT). No. of bitstreams: 1 19119.pdf: 508301 bytes, checksum: 3422d21714bb4a632dc695da92788ff5 (MD5) / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
4

Towards Safer Rides: Measuring Motorcycle Dynamics with Smartphones

Stanglmayr, Maximilian, Bäumler, Maximilian 26 October 2020 (has links)
Motorradfahrer gehören zu den am meisten gefährdeten Verkehrsteilnehmern im Straßenverkehr. Häufig ist die Unfallursache ein Kontrollverlust auf Landstraßen, der durch Ausnutzung des physikalischen Potenzials in Form von größeren Schräglagenwinkeln vermieden werden könnte. Gleichzeitig sind in der Realität gefahrene Schräglagen über eine größere Gruppe von Fahrern und eine längere Strecke unbekannt, was vor allem auf die erforderliche spezielle Messtechnik zurückzuführen ist. Der Schwerpunkt liegt daher auf der Entwicklung eines kostengünstigen Messverfahrens zur Messung der Schräglagenwinkel von Motorrädern. Smartphones zeichnen sich in der Regel durch integrierte Inertialsensoren aus, die für die Erfassung der Fahrdynamik von Motorrädern geeignet sind. Mit Hilfe einer auf die Anforderungen zugeschnittenen Smartphone-App zur Erfassung von Messdaten auf dem Motorrad werden die Daten der Sensoren aufgezeichnet. Anschließend werden mittels einer Offline-Auswertung die Drehwinkel zwischen dem Smartphone und dem Motorrad-Koordinatensystem bestimmt, die inertialen Messdaten transformiert und der Schräglagenwinkel berechnet. Ein wesentlicher Bestandteil ist die Validierung der entwickelten Messkette durch einen Vergleich der Ergebnisse mit einem hochpräzisen Messsystem. Dieser wurde auf verschiedenen Strecken zur Bestimmung der Datenqualität durchgeführt. Als Machbarkeitsstudie diente eine Probandenstudie, die die Praxistauglichkeit der Messkette bestätigte. Die Studienergebnisse werden zusätzlich auszugsweise dargestellt und diskutiert. Die erfolgreiche Validierung auf verschiedenen Strecken, die Praxistauglichkeit der Datenerfassung und die Genauigkeit des Messsystems ermutigen dazu, die Smartphone-App auf ein größeres Panel von Testpersonen auszurollen und damit Daten über ein größeres Fahrerkollektiv zu erheben.:Introduction, State of Research, Methods, Measurement Chain Verification, Results and Discussion, Conclusion / Motorcyclists are among the most vulnerable road users in road traffic. Often, the cause of accidents is a loss of control on rural roads which could be averted by making use of the physical potential in terms of larger lean angles. At the same time, in reality driven lean angles over a larger group of riders and a longer route are unknown which is mainly due to the special measuring technology required. The focus is therefore on the development of a low-cost measurement method for measuring the lean angles of motorcycles. Smartphones are usually characterized by integrated inertial sensors, which are suitable for the acquisition of motorcycle driving dynamics. Employing a smartphone app tailored to the requirements for collecting measurement data on the motorcycle, the data of the sensors are recorded. During the offline evaluation, the rotation angles between the smartphone and the motorcycle coordinate system are determined, the inertial measurement data are transformed and the roll angle is calculated. An essential part is the alignment of the developed measurement chain with a high-precision measurement system. This was carried out on different routes and thus the data quality was determined. As a feasibility study, a test person study with several participants was carried out, which confirmed the practical suitability of the measurement chain. Hence, the study outcomes are briefly shown and discussed. The successful validation on different routes, the practical suitability of the data acquisition and the accuracy of the measurement system encourage to roll out the smartphone app to a larger panel of test persons and thus to collect data on a larger driver collective.:Introduction, State of Research, Methods, Measurement Chain Verification, Results and Discussion, Conclusion
5

Development of a Rotordynamic Signal Processing MATLAB Interface and a Two-Disk Rotor Model

Baker, David L 01 December 2017 (has links) (PDF)
Using MATLAB and a National Instruments data acquisition card, a signal processing program meant to monitor the behavior of rotordynamic systems in real-time was developed and tested. By using traditional analysis methods in this field of engineering, commonly desired data representations such as bode, polar, orbit, full spectrum plots were able to be produced to a very high accuracy. Additional capabilities offered by this application are slow roll compensation, synchronous and sub-synchronous filtering, and true three dimensional plotting. The verification of this program was done by comparing the results to the ones acquired with Bently Nevada’s “Automated Diagnostics for Rotating Equipment” (ADRE) system. In addition to a data acquisition program, theoretical models of the two-disk rotor were created to estimate the unknown physical parameters of the system. By simulating the rotor with and without gyroscopic effects included, estimates for the stiffness, damping, eccentricity, initial phase, and initial skew values present in the system were determined.
6

Sistema georeferenciado de aquisição de dados para caracterização de motos eletricas / Data acquisition system georeferencity for eletrics motorcycles characterization

Oliveira, Nestor Ezequiel de 14 August 2018 (has links)
Orientador: Elnatan Chagas Ferreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-14T08:58:45Z (GMT). No. of bitstreams: 1 Oliveira_NestorEzequielde_M.pdf: 11297935 bytes, checksum: f508b0e6ae1a58f18ecbebc7879ff5fb (MD5) Previous issue date: 2009 / Resumo: Aproximadamente 40% da energia total produzida no mundo é consumida no setor de transporte, tendo criado uma grande demanda para estudos de fontes alternativas de energia para os veículos. Este trabalho acadêmico tem como por objetivo apresentar um estudo desenvolvido com veículos elétricos (VEs), com o desenvolvimento de projeto de circuitos eletrônicos de aquisição de dados e condicionamento de sinais das grandezas elétricas e mecânicas, tais como tensão da bateria, corrente elétrica consumida, carga da bateria, temperatura, RPM do motor, velocidade da moto elétrica, sendo que todos os dados são georeferenciados. Estes dados fornecem informações importantes sobre as características e o desempenho das motos elétricas estudadas, além de revelar informações que podem demonstrar a viabilidade de se utilizar este veículo em aplicações comerciais. São apresentados os resultados obtidos com o monitoramento destes VEs durante 12 meses. / Abstract: Approximately 40% of the total energy produced in the world is consumed in the transport sector, having created a great demand for studies of alternative sources of energy for the vehicles. This academic work has as for objective to present a study developed with electric motorcycles (VEs), with the development of project of electronic circuits of acquisition of data and conditioning of signs of the electric and mechanical greatness, such as tension of the battery, consumed electric current, load of the battery, temperature, RPM of the motor, speed of the electric moto, and everybody the data are georeferencing. These data supply important information on the characteristics and the acting of the studied electric motorcycles, besides revealing information that can demonstrate the viability of using this vehicle in commercial applications. The results obtained with the monitoration of these (VEs) for 12 months are presented. / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica
7

The Design and Development of a Perceptual-Based Haptic Display Device

Akhter, Sohaib 07 August 2013 (has links)
Graphical information presented as pictures, graphs, maps, and the like are an important media for relaying knowledge and are a fundamental means of education rarely experienced by people who are blind or have a severe visual impairment. This thesis presents the design, development and testing of a multiple finger, haptic matrix dynamic display device capable of relaying graphical information through simulated textures. The design is based on user perception studies that determined which hand constraints provided the best tradeoff between simplicity of design, accuracy and time to answer. The best design was one that incorporated multiple fingers in close proximity to each other and restricted wrist rotation. Upon further testing after the development of the device, evidence was gathered to show its effectiveness. Although subjects could determine key information from the simulated textures, there is a clear mismatch between the simulated representations of the objects and their tactile or embossed counterparts. There is some evidence that shows that the spatial resolution of the actuators may be a source of this error and also some evidence to state that it is the inability to track the edges that causes the difference between determining the physical diagrams and the simulated. On the other hand, results on determining locations using simulated maps were far closer to the control texture maps used than the results for object diagrams. Further studies could be done to determine the effect of higher actuator spatial resolution on object identification and edge tracking.
8

Ανάπτυξη ενός "συστήματος τεχνητής νοημοσύνης" ενεργού ελέγχου δονήσεων και θορύβου με τη χρήση ενός τεχνητού νευρωνικού δικτύου και ενός γενετικού αλγορίθμου / Development of an "expert system" for active vibration and noise control by means of an artificial neural network and a genetic algorithm

Ευθήμερος, Γεώργιος 11 August 2011 (has links)
Είναι ευρύτατα γνωστό ότι ο θόρυβος δημιουργείται από δονούμενες επιφάνειες. Για την αντιμετώπιση του θορύβου στην πηγή του, δηλαδή τη δονούμενη επιφάνεια, δύο κυρίως τρόποι έχουν αναπτυχθεί. Ο πρώτος τρόπος αφορά τη χρησιμοποίηση παθητικών μέσων, δηλαδή ηχομονωτικών υλικών που αποσβένουν συγκεκριμένες συχνότητες. Ο δεύτερος τρόπος αφορά τη χρήση ενεργητικών μέσων. Τα ενεργητικά μέσα είναι διατάξεις που αποτελούνται από ένα σύστημα ελέγχου και ένα σύνολο αισθητήρων και ενεργοποιητών. Η λειτουργία ενός τέτοιου Συστήματος Ενεργού Ελέγχου Δονήσεων (ΣΕΕΔ) βασίζεται στην καταγραφή μέσω των αισθητήρων του τρόπου δόνησης της επιφάνειας (πρωτεύον πεδίο δόνησης), την δημιουργία σημάτων ελέγχου από τον ελεγκτή (ίδιου πλάτους αλλά με διαφορά φάσης 180o) και την αποστολή τους στους ενεργοποιητές που θα δημιουργήσουν ένα δευτερεύον πεδίο δόνησης. Η υπέρθεση των δύο πεδίων έχει σαν αποτέλεσμα την δημιουργία ενός εναπομείναντος πεδίου με πλάτη δόνησης αισθητά χαμηλότερα από αυτά του πρωτεύοντος. Το αντικείμενο της παρούσας διατριβής είναι η ανάπτυξη ενός γενικευμένου ΣΕΕΔ, ο έλεγχος του οποίου βασίζεται σε εργαλεία Τεχνητής Νοημοσύνης όπως τα Τεχνητά Νευρωνικά Δίκτυα και οι Γενετικοί Αλγόριθμοι για την αναγνώριση του τρόπου δόνησης οποιασδήποτε επιφάνειας και το βέλτιστο έλεγχο της δόνησής της, χωρίς να απαιτείται καμία πρότερη γνώση της δυναμικής συμπεριφοράς της επιφάνειας. Επιπλέον, το υπό μελέτη ΣΕΕΔ είναι ικανό να ελέγχει τέσσερις συχνότητες αντί μιας που απαντάται συνήθως στην πλειονότητα των εφαρμογών. Ο σκοπός της διατριβής αυτής είναι η απόδειξη της αρχής λειτουργίας ενός τέτοιου συστήματος. Η προσέγγιση για την επίτευξη αυτού του στόχου περιλαμβάνει πειραματικές μετρήσεις ενός πρωτότυπου ΣΕΕΔ σε μία απλοποιημένη πειραματική διάταξη. Τα αποτελέσματα από την εφαρμογή του εν λόγω ΣΕΕΔ δείχνουν ότι παρά τους περιορισμούς που υπεισέρχονται λόγω των δυνατοτήτων του υλικού (hardware) του χρησιμοποιούμενου εξοπλισμού, το υπό μελέτη ΣΕΕΔ λειτουργεί επιτυχώς στη βασική αρχή του, ενώ έχει τις προϋποθέσεις και τη δυναμική για περαιτέρω βελτιστοποίηση και εξέλιξη σε ένα ευρύ φάσμα εφαρμογών. / It is generally approved that noise is created by vibrating surfaces. In order to tackle this phenomenon at its source, mainly two approaches have been followed. The first approach involves passive means, that is sound insulation materials that dampen certain frequencies. The second approach involves the use of active means. The active means are arrangements that consist of a control system and a set of sensors and actuators. The application of such an arrangement for vibration control is called Active Vibration Control (AVC) and is based on the sampling (by means of sensors) of the primary field of vibration of the surface, the creation of control signals by the controller (secondary field - of the same amplitude but with phase difference of 180o) and finally applying these control signals on the vibrating surface, by means of the actuators. The superimposing of the two vibration signals (primary and secondary) results to a residual field where the amplitudes of vibration are significantly lower than in the primary. The objective of the thesis at hand is to develop a Generic AVC with the controller developed using Artificial Intelligence tools such as the Artificial Neural Networks (ANNs) and Genetic Algorithms (GAs), in order to identify the vibration patterns of any surface and the optimal control of its vibration, without any prior knowledge of the dynamic behavior of the surface. Moreover, the developed AVC system will be able to identify and control four dominating frequencies instead of one that is usually the choice in the majority of similar applications. The scope of this work is the ‘Proof of Concept’ of the successful operation of such a generic AVC system. The approach to this end includes experimental testing of a prototype AVC system on a simplified experimental set-up. The results of the application of the developed AVC system, performed also by independent parties in the framework of a EC-funded Basic Research project, prove the successful operation of the developed AVCS, even within the limitation of the contemporary data acquisition platform (hardware and software) used, imposes limitations in the efficiency of the AVCS, and provide the basis for its further development and application in a multitude of problems.
9

Konzept und beispielhafte Implementierung einer nichtinvasiven Identifikationsroutine an Werkzeugmaschinen

Schöberlein, Chris 29 November 2016 (has links) (PDF)
Im Bereich der Werkzeugmaschinen können Identifikationsmethoden zur Realisierung einer ressourceneffizienten Produktion durch Überwachung prozessrelevanter Parameter beitragen. Aufgrund der hierarchischen Trennung moderner Steuerungssysteme bildet deren konzeptionelle Gestaltung und Implementierung am Beispiel einer nichtinvasiven Identifikationsroutine an einer Werkzeugmaschine den Kern der vorliegenden Arbeit. Das Ziel besteht darin, eine autonome Anwendung zur Integration unterschiedlicher Überwachungsmechanismen zu entwickeln und durch exemplarische Integration einer Parameteridentifikation zu validieren. Im Anschluss an die theoretischen Vorbetrachtungen werden deshalb zunächst verschiedene konzeptionelle Entwürfe zur Integration des Identifikationsverfahrens an einer Werkzeugmaschine diskutiert und anhand definierter Bewertungskriterien klassifiziert. Die Auswahl eines geeigneten Konzeptes unter Berücksichtigung eines Bewertungsindex sowie eine beispielhafte Implementierung bilden die Grundlage für den experimentellen Funktionsnachweis. / In the field of machine tools, identification methods can contribute to the realization of a resource-efficient production by monitoring of process-relevant parameters. Due to the hierarchical separation of modern control systems, their conceptual design and implementation using the example of a non-invasive identification routine on a machine tool forms the main aspect of the master thesis. The goal is to develop an autonomous application for different monitoring mechanisms and its validation through an exemplary parameter identification. Following the theoretical previews different conceptual designs are discussed and classified according to defined evaluation criteria. The selection of an appropriate concept under consideration of an evaluation index and its exemplary implementation are the basis for the experimental functional verification.
10

Approximations and Applications of Nonlinear Filters / Approximation und Anwendung nichtlinearer Filter

Bröcker, Jochen 30 January 2003 (has links)
No description available.

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