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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

Svařování součástí pantografu dle normy ISO15085 / Welding of pantograph parts according to standard ISO 15085

Ondříšek, Jan January 2015 (has links)
The aim of this project is to examine the welding of the upper arm of the current collector - the pantograph of the electric locomotive according the the CSN EN 15085 norm. The first part of this thesis dealt with the elaboration of all needed WPS and with the proposal of the current preparation that is going to be realized. The experimental part dealt with the practical execution of the welding as defined in the first part. The macrostructure of weldings and the process of hardening have been evaluated based on the welding samples.
2

Ändhållplatsladdning av elbussar : En fallstudie av två stadsbusslinjer i Uppsala

Törnqvist, Joacim January 2019 (has links)
This thesis investigates the charging power and battery capacity needed for fast charging of fully electrical busses at end stations in Uppsala, Sweden. The operator, UL, wants to implement electrical busses by 2020 and a new depot for the city buses is being built with possibility to slow-charge the busses overnight. However, due to restrictions in the transmission grid the requested grid connection was denied by Vattenfall Eldistribution. Simulations in this thesis is based on the existing bus schedules for city bus route 6 and route 8 in Uppsala. The routes were selected by UL as suitable candidates for fast charging at end stations. Simulations were made with varying charging power, battery capacity and energy usage by the buses. A worst case-scenario was simulated to ensure that the solution would work even in bad weather conditions. The results show that it is possible to dimension the battery to match the current time schedule. The battery capacity needed depends on charging power, length of route and time available for charging. With 300 kW charging power, the battery capacity needed to manage the bus schedule during weekends were higher than during weekdays. Furthermore, the needed battery capacity for weekends on route 8 were significantly higher than for route 6. If the whole bus fleet would be electrified, the choice of charging technique and battery size depends on the routes and passenger capacity needed. A combination of different charging techniques may be the most efficient solutions when the whole bus fleet is considered.
3

Pantograph-catenary wear modelling using dynamic simulation / Nötningsmodellering av strömtagare och kontaktledning

Holmström, Gaston January 2022 (has links)
Wear condition modelling is a research topic which lately has increased in popularitydue to its significance to the railway industry. Large sums are spent on maintenanceof the network every year, which has generated a demand for understanding and predictingwear mechanisms in a multitude of components within both railway vehiclesand infrastructure. To acquire this knowledge, using a simulation software to predictwear and maintenance needs, is a cheap and dependable option. This thesis sets outto create a wear modelling software for the catenary-pantograph interaction, which intheory could enlighten railway operators of the condition of their infrastructure. This research contains an extensive literature review on the subject of wear modelling,analysing different strategies and theories of the wear mechanism and desired modelproperties. Thereafter, an attempt to recreate a model for a representative Swedishcase was conducted; implementing parameters of a typical Swedish rail vehicle to awear rate formula, recreating a passage of a pantograph sliding along the catenary.The output was a wear rate as a function of time, a determination of life expectancyfor the infrastructure and a worn profile of the catenary wire after one year of operation. The model, named AWEAR, was deemed functional for determining wear mechanismtendencies and behaviour for a few cases of alternating parameters. However, sinceno validation could be performed due to a lack of resources, the validity of the outputvalues could not be confirmed - thus leaving calibration of the model to future work.In conclusion, AWEAR needs to be calibrated for future research but does contain amultitude of enhancement opportunities proposed in this thesis. While not completelyfunctional, the software was deemed a useful foundation for future projects and mightresult in a product that aids operators maintaining their infrastructure.Keywords: Wear modelling, catenary pantograph interaction, mechanism, / Slitagemodellering är ett forskningsområde som den senaste tiden har ökat i popularitetpå grund av dess betydelse till järnvägsindustrin. Stora summor spenderas på underhållav nätverket varje år, vilket har genererat en efterfågan på att förstå och förutspåslitage i en mängd olika komponenter inom både spårfordon och infrastruktur.För att uppnå vetskapen, är att använda simulering till att förutspå slitage och underhållsbehov, ett billigt och tillitsfullt alternativ. Detta arbete söker att skapa ett slitagemodelleringsprogram för interaktionen mellan pantograf och kontaktledning, vilket iteorin skulle kunna upplysa järnvägsoperatörer om skicket på deras infrastruktur. Denna forskning innehåller en genomgående litteraturstudie inom ämnet slitagemodellering, där det olika strategier och teorier analyseras om slitagemekanism och önskade modellegenskaper. Därefter görs ett försök på att återskapa en modell för ettrepresentativt svenskt fall; där parametrar för svenska järnvägsfordon och svensk infrastruktur implementeras i en ekvaktion för att simulera en passage av en pantografglidandes längst med en kontaktledning. Resultatet var en slitagenivå som funktionav tiden, ett fastställande av förväntad livslängd på infrastrukturen och en modelleradprofil av kontaktledningen efter ett år i tjänst. Modellen, döpt till AWEAR, ansågs funktionabel till att identifiera tendenser inomslitagemekanism och beteende för ett fåtal fall av alternerande parametrar. Då ingenjämförelse med resultat och data från riktiga scenarion genomfördes på grund utav enbrist på resurser, kunde resultaten från modellen inte bekräftas och därmed lämnadeskalibreringen åt framtida arbete. Sammanfattningsvis behöver AWEAR kalibrerasför framtida forskning men innehåller därtill en mängd olika förbättringsmöjligheterföreslagna i denna rapport. Även om modellen hitills inte är fullkomligt funktionabel,kan den skapade mjukvaran anses vara nyttigt grundmaterial för framtida projekt. Islutändan kan detta därmed
4

Návrh výsuvné manipulační platformy mobilního robotu / Design of an extensible platform for mobile robot

Šumšal, Zdeněk January 2017 (has links)
This thesis is about the design of the telescopic platform. which should be fasten on robot called Breach. Purpose of this platform is to carry another equipment like sensors, cameras or manipulator. The platform has to provide chiefly the high demands on load capacity. Another part of the thesis is design of mechanism placed on this telescopic platform, or just on the robot Breach. This mechanism has to load up small subject on the top part of the platform and then unload it on chosen place. Only thing defined for this subjekt is maximal weight of 2 kilograms, but other parameters aren´t specified. Construction is therefore focused on maximal versatility of this mechanism.

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