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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.
11

Έλεγχος και εκτίμηση κατάστασης ενός συστήματος μαγνητικής ταινίας

Παππάς, Μιχάλης 09 January 2012 (has links)
Συστήματα μαγνητικών ταινιών χρησιμοποιούνται ευρέως ως μέσα αποθήκευσης και αποκατάστασης δεδομένων. Λόγω του χαμηλού τους κόστους αναλογικά των σκληρών δίσκων συνεχίζουν να προτιμούνται σε μεγάλο πλήθος εφαρμογών όπως δευτερεύουσες συσκευές αποθήκευσης, εγγραφής και επεξεργασίας ηχητικών δεδομένων,βιντεοκάμερες κ.ά. Σε περιπτώσεις όπου θέλουμε να επεξεργαστούμε μια μαγνητοταινία για γρήγορη μεταφορά ή εγγραφή δεδομένων θα πρέπει -η ταινία- να μεταφέρεται σε υψηλή ταχύτητα από το μηχανισμό του συστήματος. Η ταχύτητα αυτή να διατηρείται σταθερή και να βρίσκεται σε συγχρονισμό ε την κεφαλή ανάγνωσης/εγγραφής προς αποφυγή σφαλμάτων μεταφοράς και αναγνώρισης δεδομένων, αναπηδήσεων και χρονικών σφαλμάτων. Σε πιθανά σφάλματα η επαναφορά της ταινίας στο επιθυμητό σημείο αποτελεί τη λύση για την αποκατάσταση του σφάλματος. Η επιτάχυνση και επιβράδυνση που δέχεται η ταινία σε κάθε γρήγορη αναζήτηση δεδομένων προκαλούν τη μεγαλύτερη επιβάρυνση σε αυτή. Ειδικά η συχνή επανατοποθέτηση της ταινίας στο ίδιο ση είο λόγω της βαθμιαίας εξασθένισης του σήματος ανάγνωσης. Σκοπός είναι ο σχεδιασμός ενός μηχανισμού εταφοράς της ταινίας ο οποίος προσφέρει μια ικανοποιητική τάση στην ταινία όπως και ταχύτητα μεταφοράς αυτής. / Optimal control and estimation of a magnetic tape-drive system.
12

Bewegungstechnik & Bewegungsdesign für Verarbeitungsmaschinen - Teil 1 -

Tietze, Sven, Majschak, Jens-Peter 12 March 2018 (has links) (PDF)
In der Lehrveranstaltung Bewegungstechnik & Bewegungsdesign für Verarbeitungsmaschinen werden die Studenten in die Lage versetzt, Systeme zur Bewegung von Arbeitsorganen in Verarbeitungs- und Textilmaschinen konstruktiv zu entwerfen und zu dimensionieren. Im Blickpunkt stehen zyklische Bewegungen, zu deren Realisierung auch der Einsatz von Mechanismen sinnvoll ist. Die interdisziplinäre Betrachtung der Bewegungstechnik dient als Einführung in die Problematik und als Grundlage für nachfolgende Optimierungen. Diese sind Gegenstand des Teils 2.
13

Bewegungstechnik & Bewegungsdesign für Verarbeitungsmaschinen - Teil 1 -

Tietze, Sven, Majschak, Jens-Peter 12 March 2018 (has links)
In der Lehrveranstaltung Bewegungstechnik & Bewegungsdesign für Verarbeitungsmaschinen werden die Studenten in die Lage versetzt, Systeme zur Bewegung von Arbeitsorganen in Verarbeitungs- und Textilmaschinen konstruktiv zu entwerfen und zu dimensionieren. Im Blickpunkt stehen zyklische Bewegungen, zu deren Realisierung auch der Einsatz von Mechanismen sinnvoll ist. Die interdisziplinäre Betrachtung der Bewegungstechnik dient als Einführung in die Problematik und als Grundlage für nachfolgende Optimierungen. Diese sind Gegenstand des Teils 2.:1 Bewegungsaufgaben in Verarbeitungsmaschinen 2 Struktur des Antriebssystems 3 Bewegungsdesign Basics 4 Vorgaben für schnelle Bewegungen linearer Systeme 5 Motor-G-Getriebe-Konfiguration 6 Motor-U-Getriebe-Konfiguration
14

Development of Cleaning Robot for Trench Drains

Kaushik, Adithya January 2019 (has links)
No description available.
15

Design, Analysis and Implementation of a Drive System for Delsbo Electric Light Rail Vehicle

Marklund, Daniel, Lindh, Maria January 2022 (has links)
The aim of this project is to design and implement a drive system and a driving strategy for a lightweight, battery-driven rail vehicle partaking in the Delsbo Electric student competition. The goal of the competition is to create a vehicle which consumes as little energy as possible.  A simulation model of the vehicle is developed in Simulink, based on existing hybrid car models. Different drive cycles are written in MATLAB and tested in the vehicle simulation, which calculates energy consumption, power and torque usage and other important data. This data is used to select an optimal driving strategy and dimension the drive system components.  The final drive system design consists of a permanent-magnet synchronous motor powered by lead acid batteries and controlled by a microcontroller and motor driver through a user interface consisting of a control board with buttons and switches.  The chosen driving strategy combines slow acceleration and constant speed in slopes with the pulse and glide strategy on flat parts of the track. The simulation shows a total energy consumption of 0.67 Wh/person and km, which is in the same order of magnitude as results from previous years, which is promising for the competition. However, the actual energy consumption can not be known until the vehicle has been built and tested. There is a lot of uncertainty around its parameters at this stage, which affects the reliability of the simulations. / Syftet med det här projektet är att designa och implementera ett drivsystem och en körstrategi för ett lättviktigt, batteridrivet rälsfordon. Fordonet ska användas i studenttävlingen Delsbo Electric. Målet med tävlingen är att bygga ett fordon som förbrukar så lite energi som möjligt.  För att göra detta utvecklas en simuleringsmodell av fordonet i Simulink, baserat på redan existerande modeller av hybridbilar. Olika körprogram skrivs i MATLAB och testkörs i modellen, som beräknar energiåtgång, använd effekt och vridmoment och annan viktig data. Dessa värden används sedan för att optimera körstrategin och dimensionera drivsystemets komponenter.  Det färdigdesignade drivsystemet består av en permanentmagnetiserad synkronmotor som matas från blyackumulatorer och styrs av en mikrokontroller och en driver via en kontrollpanel med knappar och switchar. Den valda körstrategin kombinerar låg acceleration och konstant hastighet i backarna med pulse-and-glide-strategin på de platta delarna av banan. Enligt simuleringarna ger den en total energiåtgång på 0.67 Wh/person-km, vilket är i samma storleksordning som tävlingsresultat från tidigare år. Detta bådar gott inför tävlingen, men det går inte att veta hur stor den faktiska energiförbrukningen kommer bli förrän fordonet är byggt och testat. Än så länge är många av dess parametrar osäkra, vilket påverkar tillförlitligheten hos simuleringarna. / Kandidatexjobb i elektroteknik 2022, KTH, Stockholm
16

Thermal Simulation of Hybrid Drive System

B M, Shiva Kumar, Ramanujam, kathiravan January 2011 (has links)
Safety, performance and driving comforts are given high importance while developing modern day cars. All-Wheel Drive vehicles are exactly designed to fulfill such requirements. In modern times, human concern towards depleting fossil fuels and cognizance of ecological issues have led to new innovations in the field of Automotive engineering. One such outcome of the above process is the birth of electrical hybrid vehicles. The product under investigation is a combination of all wheel drive and hybrid system. A superior fuel economy can be achieved using hybrid system and optimized vehicle dynamic forces are accomplished by torque vectoring action which in turn provides All-Wheel Drive capabilities. Heat generation is inevitable whenever there is a conversion of energy from one form into another. In this master thesis investigation, a thermal simulation model for the product is built using 1D simulation tool AMESim and validation is done against the vehicle driving test data. AMESim tool was chosen for its proven track record related to vehicle thermal management. The vehicle CAN data are handled in MATLAB. In a nutshell, Simulation model accounts for heat generation sources, oil flow paths, power loss modeling and heat transfer phenomena. The final simulation model should be able to predict the transient temperature evolution in the rear drive when the speed and torque of motor is supplied as input. This simulation model can efficiently predict temperature patterns at various locations such as casing, motor inner parts as well as coolant at different places. Various driving cases were tried as input including harsh (high torque, low speed) ones. Simulation models like this helps Engineers in trying out new cooling strategies. Flow path optimization, flow rate, convection area, coolant pump controlling etc are the few variables worth mentioning in this regard.
17

Pohonný a brzdový systém motorového vozu železnice pro muzeum průmyslových železnic / The propulsion and braking system of a motor vehicle for a railroad museum of industrial railways

Gerec, Matúš January 2017 (has links)
This thesis deals with the design of the propulsion and braking system for narrow gauge railcar. It contains the design of hydrostatic drive system with closed-loop hydraulic circuit. Then thesis describes the concept of propulsion system placement in the frame of the railcar and design of the braking system.
18

[en] ANALYSIS OF AN INNOVATIVE POSITIVE DISPLACEMENT ROTARY COMPRESSOR / [pt] ANÁLISE DE UM COMPRESSOR INOVADOR ROTATIVO DE DESLOCAMENTO POSITIVO

WILLIAN FELIPE THEOBALD 26 February 2019 (has links)
[pt] A presente dissertação trata do projeto, construção e ensaio preliminar de um novo modelo do compressor Kopelrot. É uma máquina de deslocamento positivo baseada em seis patentes depositadas desde 1998. Esta tecnologia está em desenvolvimento há aproximadamente 8 anos, tendo gerado artigos e dissertações, assim como a construção de dois protótipos. É apresentada, inicialmente, uma revisão dos trabalhos publicados sobre a tecnologia Kopelrot. Foram construídos junto ao novo modelo de compressor Kopelrot um novo sistema de acionamento e uma base para a fixação de ambos a um motor elétrico. Durante a elaboração dos desenhos foram realizadas simulações preliminares da geometria para definir a fabricação de algumas peças importantes. A base permite regular a excentricidade entre os eixos de centro do compressor e do sistema de acionamento e, dessa forma, variar a vazão volumétrica do compressor. Simulou-se a variação de volume no interior da câmara com o conjunto compressor Kopelrot/Sistema de acionamento, ajustado para 5 excentricidades diferentes, a fim de mapear o comportamento do Kopelrot quando sua capacidade é variada, deslocando-se os eixos de centro do compressor e do sistema de acionamento. Para as excentricidades escolhidas, foram calculadas, a partir de modelo termodinâmico simplificado, as variações de pressão, temperatura e massa no interior da câmara do compressor. Valores globais de potência consumida e eficiência volumétrica também foram calculados. Durante o funcionamento do protótipo identificaram-se alguns problemas tipicamente encontrados em tecnologias inovadoras. Devido a esses problemas, não foi possível a realização dos testes do compressor operando em condições normais de pressão. / [en] The present dissertation addresses the design, construction, simulation and preliminary tests of an innovative positive displacement rotary compressor. A review is presented on the previous works, papers and dissertations, based on this new this new Kopelrot technology. A new prototype, employing a new driving system, was manufactured. The main feature of the machine is that, by adjusting the eccentricity between compressor cylinder and driving mechanisms axis, a variable capacity device is obtained. Design, manufacturing and assembly of components and subsystems of the compressor are presented in detail. Design data of the compressor allowed for a simple thermodynamic simulation model to be developed. Main conclusions of the simulation are that a full positive displacement compression cycle can be attained with the Kopelrot technology and that use of discharge and suction valves is required in order to have the compressor operating under different conditions.
19

Integrated Design of Servo Mechatronic Systems for Driving Performance Improvement

Chen, Chin-yin 05 February 2009 (has links)
The servo mechatronic system design process usually covers two different engineering domains: structure design and system control. The relationship between these two domains is much closed. In order to reduce the disturbance caused by parameters in either one, the domain knowledge from those two different fields needs to be integrated. Thus, in order to reduce the disturbance caused by parameters in either one, the mechanical and controller design domains need to be integrated. Therefore, the integrated design method Design For Control (DFC), will be employed in this thesis. In this connect, it is not only applied to achieve minimal power consumption but also enhance structural performance and system response at same time. To investigate for the integrated design method, there are two common servo mechatronic systems: feed drive system and legged servo mechatronic system are used as the design platform. 1. Mechatronic Feed Drive System To investigate the method for integrated optimization, a mechatronic feed drive system of the machine tools is used as a design platform. The 3D software, Pro/Engineer is first used to build the 3D model to analyze and design structure parameters such as elastic deformation, nature frequency and component size, based on their effects and sensitivities to the structure. Additionally, in order to achieve system robust, Quantitative Feedback Theory (QFT), will be applied to determine proper control parameters for the controller. Therefore, overall physical properties of the machine tool will be obtained in the initial stage. Following this Design Then Control process, the iterative design process is following to enhance some of system performance. Finally, the technology design for control will be carried out to modify the structural and control parameters to achieve overall system performance. Hence, the corresponding productivity is expected to be greatly improved. 2. Legged Servo Mechatronic System The goal of this study is to develop a one-degree-of-freedom (DOF) legged servo mechatronic system with DFC. For this system, the kinematics and control dynamic analysis of legged servo mechatronic system have been solved by using four bar linkage with symmetrical coupler point, pantograph, and common position and velocity controller. In addition, in order to improvement system dynamic performance and reduce the control cost, the counterweight, that base on mass redistribution is employed to integrate structure and control into one design step for reduce shaking moment. Additionally, in order to improvement the system performance, the complete force balance is not only to take advantage of control cost, but also easy to control.
20

Design and Construction Modifications of Switched Reluctance Machines / Entwurf und konstruktive Modifikationen von Geschalteten Reluktanzmaschinen

Wichert, Torsten 25 February 2009 (has links) (PDF)
Although the design principles of the Switched Reluctance Machines (SRMs) are available in different fragments in numerous bibliography positions, there no exists the complex design procedure of whole drive system taking into account the SR Machine, control system and supply device as well. The hybrid design method for SRM drives with application of new analytical calculation methods, finite element method and simulation models is proposed in this thesis. The calculation/design system is characterised by important effectivity and reliability. The new possibilities in analytical determination of saturation effects and core losses under various modes of control, including sensorless method, are also taken into account. The correctness of the proposed design algorithms are verified by laboratory tests made on three motor prototypes manufactured in industry for concrete application. This dissertation provides the elements indispensable for more accurate and complex analysis and design of drives with switch reluctance motors. The elements of electrical motor and control system design as well as the considerations on the choice of supply device and controller subsystems are jointed in the thesis for final receiving of the design tool for considered industrial drive system.

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