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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.
111

Evaluierung des Einsparpotentials durch Energierückgewinnung aus dem hybraulischen Kreislauf eines Hafenmobilkrans

Tempelhahn, Conny 11 January 2011 (has links)
Im Zuge strenger werdender Emissionsrichtlinien und steigender Kraftstoffpreise spielt die Energieeffizienz mobiler Arbeitsmaschinen eine zunehmend wichtigere Rolle. Die Firma Gottwald Port Technology GmbH hat in diesem Zusammenhang einen hybriden Antriebsstrang für einen Hafenmobilkran (HMK) in Zusammenarbeit mit der Technischen Universität Dresden erforscht und umgesetzt. Bei diesem Hybridsystem wird die kinetische und potentielle Energie aus dem elektrischen Hub- und Drehwerk des Krans, welche zuvor im Bremswiderstand in Wärme umgewandelt wurde, durch einen elektrischen Energiespeicher zurückgewonnen. Im Gegensatz dazu ist das hydraulisch betriebene Wippwerk noch nicht rückspeisefähig. Ziel dieser Arbeit ist die Identifikation einer technischen Lösung zur Energierückgewinnung aus der hydraulischen Anlage eines HMK und die Bewertung des erreichbaren Kraftstoffeinsparpotentials. Zunächst wird das bestehende hydraulische System untersucht, um die Anforderungen an das rückspeisefähige Konzept zu ermitteln. Dazu werden Modelle der Kinematik und Kinetik des Wippwerks abgeleitet. Anhand einer Entscheidungsanalyse wird ein hydraulisches Konzept aus einem Katalog verfügbarer Alternativen ausgewählt. Im Anschluss daran wird ein energieflussbasiertes Modell des Konzepts in Matlab/Simulink erstellt und in das bestehende Simulationsmodell integriert. Die Simulationsergebnisse zeigen ein großes Einsparpotential an Dieselkraftstoff durch den Einsatz des rückspeisefähigen Hydrauliksystems. / Due to stricter emission restrictions and rising fuel costs energy efficiency of mobile work machines is getting more important. In cooperation with Dresden University of Technology, Gottwald Port Technology GmbH has developed a mobile harbour crane with a hybrid drive train. This system can recuperate the kinetic and potential energy from the electrical slewing and hoisting gear, which was formerly dissipated to heat. This paper deals with the identification of a technical solution to recuperate energy form the hydraulic luffing gear to determine the potential reduction of fuel consumption. At first, the actual hydraulic system is analyzed to estimate the requirements of the new recuperation system. For that purpose, models of the kinematics and kinetics of the luffing gear are created. With the help of weighted criteria, a hydraulic concept is chosen of several alternatives. Afterwards, an energy flow based model in Simulink/Matlab is created and integrated in the existing simulation model of the crane. The simulation results confirm a considerable reduction of diesel fuel due to the application of hydraulic recuperation system.
112

Creating a Well-Situated Human-Autonomy Team: The Effects of Team Structure

Frost, Elizabeth Marie January 2019 (has links)
No description available.
113

Μελέτη συστήματος παροχής ηλεκτρικών τάσεων σε εργαστηριακό χώρο : παρεμβάσεις σε σύστημα ελέγχου PLC μέσω του προγράμματος SCADA / Study of a laboratory voltage supply system and construction with a PLC via SCADA application

Παπαδόπουλος, Βασίλειος 28 August 2009 (has links)
Το έτος 1987 στο Τμήμα Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών του Πανεπιστήμιου Πατρών και συγκεκριμένα στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του Τμήματος Ηλεκτρολόγων Μηχανικών, στα πλαίσια εκπαιδευτικών και ερευνητικών σκοπών, εγκαταστάθηκε ένα πλήρες αυτοματοποιημένο σύστημα παράγωγης και παροχής ηλεκτρικών τάσεων. Σκοπός του συστήματος ήταν η παροχή 10 διαφορετικών τύπων τάσεων σε 15 συγκεκριμένες θέσεις εργασίας στο χώρου του Εργαστηρίου. Το σύστημα ήταν πλήρως αυτοματοποιημένο, καθώς χρησιμοποιήθηκε προγραμματιζόμενος λογικός ελεγκτής (PLC) που ήταν επιφορτισμένος με τον έλεγχο, την εποπτεία και τη διαχείριση του Συστήματος. Επίσης υπήρχε προσωπικός Η/Υ άμεσα συνδεδεμένος στο σύστημα, μέσω του όποιου ο διαχειριστής του μπορούσε να παρακολουθεί, να διαχειρίζεται και να διανέμει τον κάθε τύπο από τις προσφερόμενες παροχές. Το σύστημα με την πάροδο του χρόνου εμφάνισε βασικά λειτουργικά προβλήματα, με αποτέλεσμα να μειωθεί δραστικά ο αριθμός των παρεχόμενων τύπων τάσεων, αλλά και η ικανότητα διαχείρισης και διανομής αυτών που παρέχονταν. Πιο συγκεκριμένα, το τμήμα τoυ προγραμματιζόμενoυ λογικού ελεγκτή (PLC) και του συνδεδεμένου Η/Υ του συστήματος ουσιαστικά και πρακτικά είχε τεθεί πλέον πλήρως εκτός λειτουργίας. Στόχος και σκοπός της παρούσας εργασίας ήταν η λύση των προβλημάτων του προαναφερθέντος συστήματος με τελικό αποτέλεσμα την κανονική και ομαλή λειτουργία του. Η λύση που προτείνεται είναι η υλοποίηση και η ενσωμάτωση ενός σύγχρονου δικτύου αυτοματισμού με τη χρήση σύγχρονων PLC (επιλέχθηκε η εταιρεία OMRON) καθώς και η ενσωμάτωση ενός συστήματος εποπτικού και διαχειριστικού ελέγχου, λογισμικό τύπου SCADΑ της ίδιας εταιρείας. Αναλύονται διεξοδικά τόσο ο τρόπος παραγωγής των τάσεων με τα αντίστοιχα κυκλώματα ισχύος όσο και ο τρόπος διανομής και διαχείρισης αυτών με τα αντίστοιχα κυκλώματα αυτοματισμού. Εμπεριέχονται εκτενείς αναφορές στα σύγχρονα PLC, στον τρόπο λειτουργίας και προγραμματισμού τους καθώς και ο τρόπος με τον οποίο είναι δυνατό να ενσωματωθούν και να λειτουργήσουν πλήρως στο υπάρχον σύστημα. Γίνεται μια εισαγωγή στα σύγχρονα συστήματα διαχείρισης και εποπτικού ελέγχου (SCADA) ώστε να μπορεί ο κάθε αναγνώστης, χωρίς να χρειάζονται υψηλού επιπέδου γνώσεις, να κατανοήσει τη χρησιμότητα και τη λειτουργία τους και μελετείται ο τρόπος με τον οποίο θα υλοποιηθεί το παραπάνω δίκτυο αυτοματισμού με τη χρήση των PLC και με την παρουσία του εποπτικού συστήματος SCADA. Γίνεται πλήρης αναφορά σε έναν πολύ βασικό τομέα του Ηλεκτρολόγου Μηχανικού στη σύγχρονη εποχή: τον υπολογισμό κόστους προμήθειας, εγκατάστασης και κατασκευής όλων των στοιχείων του εγχειρήματος και μελετούνται όλες οι παράλληλες επιλογές για την καλύτερη δυνατή λειτουργία του και την περαιτέρω ανάπτυξη και βελτίωση του. / The year 1987 in the Department of Electrical and Computer Engineering University of Patras and specifically in Electromechanical Energy Conversion Laboratory Department of Electrical Engineering, in educational and research purposes, installed a complete automated system for producing and providing electrical voltages. This system was able to provide 10 different types of voltages in 15 stations in the area of Laboratory. The system was fully automated, used a Programmable Logic Controller (PLC), which was responsible for monitoring, supervision and management system. Also there was a PC directly connected to the system, through which the administrator can monitor, manage and distribute each type of voltage. The system through the walking time showed major operational problems. As a result, the number of the types of voltages and the ability to manage and distribute those provided reduced drastically. Specifically, the part of programmable logic controller (PLC) and the connected computer system effectively and practically has run out of order. The purpose of this work was the solution of problems of the system and ultimately with final result the normal and smooth operation. The solution proposed is the implementation and integration of a modern network automation using modern PLC (the company chosen is OMRON) and the incorporation of a supervisory control and data acquisition application and (SCADA) software of the same company. Analyzed in detail both the production voltages with the respective power circuits and the method of distribution and management of the automation circuits. Contained extensive references to contemporary PLC, in operations and programming, and how it is possible to integrate and operate fully in the existing system. There is an introduction to SCADA to enable each reader without the need for high-level knowledge to understand the utility and operation, and considering how we implement the above automation network using a PLC and SCADA application. We mention a very important area of Electrical Engineering in the modern era: counting the cost of supply, installation and construction of all elements of the project and consider all parallel options for optimal operation and further development and improvement.
114

Implementação de controle supervisório em CLPs usando linguagem de alto nível / Implementation of supervisory control in PLCs using high-level language

Almeida, Suzana Ribas de 15 February 2012 (has links)
Made available in DSpace on 2016-12-12T17:38:31Z (GMT). No. of bitstreams: 1 SUZANA RIBAS DE ALMEIDA.pdf: 2655112 bytes, checksum: 346dca905796b24136deb70b7263fb5b (MD5) Previous issue date: 2012-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nowadays the competition between companies is increasing. In a production system, efficiency, speed and flexibility are important means for cost reductions. The complexity of automation systems has been increasing, which makes necessary the implementation of more efficient control programs, free of errors and easy to maintain. However, in most practical applications the solution of these problems is dependent on designer's experience and doesn t follow a formal methodology, which results in programs with errors and difficulties to understand and maintain, since only the designer understands the adopted solutions. The Supervisory Control Theory (SCT) is a method extensively researched in academic circles for the synthesis of control logic of automated systems. It allows control problems to be solved in a formal way, ensuring a minimally restrictive and no blocking solution that meets the control specifications. However, this theory is not widely used in industrial environments yet, once the methods for implementation of supervisors obtained by TCS are still deficient. Thus, the intention of this Dissertation consists of showing a methodology for implementation of supervisory control in Programmable Logic Controllers (PLCs). In this work, the synthesis of supervisors is made in accordance to local modular approach, which brings the benefits of a formal methodology and allows exploring the modularity of the plant and the control specifications. The implementation is based on an architecture structured in three levels: supervisor, interface and system to be controlled. For the implementation in CLP three different programming languages are applied: the high-level languages Sequential Function Charts (SFC) and Structured Text and the low-level Ladder Diagram language in some parts. The development of the methodology was based on two works: a doctoral thesis by Vieira (2007) and master thesis by Cruz (2011) and brought together the advantages presented in each one of these. To compare the proposed methodology and the two mentioned methods, several tests were made on a manufacturing cell available at PUCPR and simulations on a PLC and computer as well. The results show that the use of the methodology proposed in this work makes possible to implement PLC programs that are able to treat all non-controllable events occurred in the system to be controlled and treat one controllable event by each control cell in the same scan cycle. Furthermore, the use of high-level languages results in a program of easier interpretation and maintenance, also enabling reutilization of codes. In this work some problems related to CLPs implementations are also showed and proposals for solving them are presented, as properties as well that, if accepted, ensure that the problem does not occur. / Hoje em dia a competitividade entre as empresas está cada vez maior. Em um sistema de produção, a eficácia, a velocidade e a flexibilidade são importantes, pois significam redução de custos. Os sistemas de automação atuais estão cada vez mais complexos, justificando a necessidade de programas de controle mais eficientes, sem erros e de fácil manutenção. Entretanto, na maioria das aplicações práticas a solução destes problemas é feita com base na experiência do projetista, não seguindo uma metodologia formal, o que resulta em programas com erros e de difícil entendimento e manutenção, uma vez que só o projetista entende perfeitamente as soluções adotadas. A Teoria de Controle Supervisório (TCS) é um método para a síntese da lógica de controle de sistemas automatizados. Ela permite que problemas de controle sejam solucionados de modo formal, garantindo uma solução minimamente restritiva e não bloqueante e que atenda às especificações de controle. Entretanto, esta teoria ainda não é amplamente adotada em ambientes industriais, sendo a carência de métodos de implementação dos supervisores obtidos via TCS um elemento que contribui para que isso aconteça. Assim, esta dissertação se propõe a apresentar uma metodologia de implementação de controle supervisório em Controladores Lógicos Programáveis (CLPs). Neste trabalho, a síntese de supervisores é feita de acordo com a abordagem modular local, que traz os benefícios de uma metodologia formal e ainda permite explorar a modularidade da planta e das especificações de controle. A implementação é baseada numa arquitetura estruturada em três níveis: supervisor, interface e sistema a ser controlado. Para a implementação em CLP são empregadas três linguagens distintas de programação, as linguagens de alto nível Sequential Function Charts (SFC) e Structured Text, bem como a linguagem Ladder Diagram em algumas partes. O desenvolvimento da metodologia foi baseado em dois trabalhos: a tese de doutorado de Vieira (2007) e a dissertação de mestrado de Cruz (2011) e permitiu reunir as vantagens apresentadas em cada um destes. Para comparação entre a metodologia proposta e as duas metodologias citadas, foram feitos diversos testes em uma célula de manufatura existente na PUCPR, bem como simulações em CLP e em computador. Os resultados mostram que a metodologia proposta neste trabalho permite a implementação de programas em CLP que, num mesmo ciclo de varredura, são capazes de tratar todos os eventos não controláveis ocorridos na planta e ainda um evento controlável por célula de controle. Além disso, o uso de linguagens de alto nível resulta em um programa de mais fácil interpretação e manutenção, possibilitando ainda o reaproveitamento de códigos. Nesta dissertação também são abordados alguns problemas de implementação da estrutura de controle supervisório em CLPs, apresentando-se propostas para solucioná-los, bem como propriedades que, se atendidas, garantem que o problema não ocorra.
115

Um método para projeto de sistemas embarcados baseado no controle supervisório modular local / Embedded system design Method based on local modular supervisory control

Pinotti, Alexandre Junkes 11 December 2012 (has links)
Made available in DSpace on 2016-12-12T17:38:32Z (GMT). No. of bitstreams: 1 Alexandre Pinotti.pdf: 2613359 bytes, checksum: 2102dc273398a9bfa8e51bb28b5fded1 (MD5) Previous issue date: 2012-12-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents a method for embedded systems design based on the Supervisory Control Theory for Discrete-Event Systems. The method is composed of steps comprising the specification phase until the approval of the control system. The conception phase is based on the local modular approach for the synthesis of minimally restrictive supervisors that constrains the plant behavior by disabling controllable events and are nonblocking with respect to the set of marked states. The method also includes an implementation architecture for the supervisory control applied to microcontrollers to solve problems such as causality, choice and inexact synchronization. An interface concentrates all controllable and uncontrollable events generation. It deals with the choice problem when reduced supervisors are implemented, randomly choosing one controllable event among the possible ones. This dissertation also presents a tool developed for the automatic code generation of the proposed implementation structure. The main module code is generated to be independent of the number of supervisors and plant models, that is, is the same for any control application. The tool is used to obtain the control applied to a case study and also for the temperature control of a commercial refrigerator. The control system has been validated using the same tools applied for the validation of household appliances at Whirlpool Corporation / Neste trabalho é proposto um método de projeto para sistemas embarcados concebido com base na Teoria de Controle Supervisório de Sistemas a Eventos Discretos. O método é composto por etapas que vão desde a especificação até a aprovação do sistema de controle. A etapa de concepção do método utiliza da abordagem modular local para síntese de supervisores minimamente restritivos que limitam o comportamento da planta através da desabilitação de eventos controláveis e são não bloqueantes em relação ao conjunto de estados marcados. O método ainda inclui uma arquitetura de implementação do controle supervisório direcionada para microcontroladores, visando solucionar os problemas da causalidade, escolha e sincronização inexata. Uma interface é concebida para concentrar a geração de eventos controláveis e não controláveis. Apresenta-se uma solução para o problema da escolha quando são implementados supervisores reduzidos sendo tal escolha realizada de modo online definindo um evento controlável, entre os possíveis, de forma aleatória. Apresenta-se uma ferramenta desenvolvida para a geração de código baseada na estrutura de implementação proposta. O código do módulo principal é gerado de forma a ser independente do número de supervisores e modelos de planta envolvidos, sendo o mesmo para qualquer aplicação de controle. Utiliza-se a ferramenta para obtenção do código da lógica de controle em um estudo de caso e para a regulação de temperatura em um refrigerador comercial. A validação do controle é realizada utilizando-se de ferramentas aplicadas à validação de eletrodomésticos da linha branca na Whirlpool Eletrodomésticos.
116

Informační a komunikační technologie v energetice / Information and communication technologies in energetics

Stavinoha, Jakub January 2008 (has links)
The thesis is focused on the information and communication technologies used in the energetic. Problematic areas in energetic which are regulation, metering, control of waste minimalizations, expense and maximalization of earnings. These aspects lead to implementing expert systems, which have to process this bulk of information necessary for increasing efficiency and economization of single processes. Systems used in practice have their own hierarchical structure, where every application requires specific access of selection of used components that suit to the application. First of all it is about acceptable device selection in single level of the system: metering and regulation, data acquisition out of the process and informative layer. Suitable choice flowing from previous, already settled up application is possible to reach maximum efficiency of the whole system. In the thesis there are introduced systems used in practice and possibilities of increase the effectiveness of generation, transmission and distribution with ICT usage in distributed power generation. We are mainly talking about upgrade processes joined with power generation of energy, diagnostics, isolation states on the power line and usage of expert systems for distribution.

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