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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

3D modelling of a Laser Welding Cell for movie presentation : making of the movie

Hansson, Henri January 2008 (has links)
<p>This report describes a Bachelor thesis work in which a robotised laser welding cell has been modelled and simulated for the purpose of making a presentation movie. The report shows that the work has been concentrated on making the movie from the modelling phase through the recording of the movie and ending up with the editing of the final presentation movie. A pre-study was made prior the Bachelor thesis work. In the pre-study a literature study was conducted about measurement and calibration of a welding cell. Measurement of almost all equipment in the entire cell was also conducted in the pre-study. The main result of this pre-study is a thorough investigation of what objects and functions that needs to be modelled in order to explain the functions in the specific laser welding cell The purpose for this Bachelor thesis work is to give an efficient and alternative way to present a laser welding cell that resides in Production Technology Centre (PTC) at Innovatum, Trollhättan Sweden. The movie can be used outside PTC or if the laser welding cell is occupied with work, since it is not allowed to be inside the cell when in progress. The result of this work is a nearly 12 minute long presentation movie which shows all predefined elements of the cell together with a real welding sequence with metal deposition (MD).</p>
2

3D modelling of a Laser Welding Cell for movie presentation : making of the movie

Hansson, Henri January 2008 (has links)
This report describes a Bachelor thesis work in which a robotised laser welding cell has been modelled and simulated for the purpose of making a presentation movie. The report shows that the work has been concentrated on making the movie from the modelling phase through the recording of the movie and ending up with the editing of the final presentation movie. A pre-study was made prior the Bachelor thesis work. In the pre-study a literature study was conducted about measurement and calibration of a welding cell. Measurement of almost all equipment in the entire cell was also conducted in the pre-study. The main result of this pre-study is a thorough investigation of what objects and functions that needs to be modelled in order to explain the functions in the specific laser welding cell The purpose for this Bachelor thesis work is to give an efficient and alternative way to present a laser welding cell that resides in Production Technology Centre (PTC) at Innovatum, Trollhättan Sweden. The movie can be used outside PTC or if the laser welding cell is occupied with work, since it is not allowed to be inside the cell when in progress. The result of this work is a nearly 12 minute long presentation movie which shows all predefined elements of the cell together with a real welding sequence with metal deposition (MD).
3

Vinkelegenskapsklassificering av svetsglas : Angående utvecklingen av en conometerbaserad klassifikationsutrustning.

Sundell, Erik January 2016 (has links)
Denna rapport är skriven för optikgruppen på 3M Svenska ABs forsknings- och utvecklingsavdelning i Gagnef. Rapporten beskriver den driftsatta tekniken för vinkelegenskapsklassificeringar av ADFer samt den berörda fysiken. Rapporten avser att underlätta det ofullständiga arbetet av att ackreditera optikgruppens förmåga att genomföra dessa klassifikationer. Rapporten inleds med att beskriva fysiken relaterad till mätning av mänsklig ljusupplevelse. Därefter presenteras bland annat tekniken kring en speciell kamera vars sensor är placerat i ett fourierplan, och därmed med varje pixel mäter ljus av olika infallsvinklar. Rapporten avslutas med konkreta förslag angående en klassifikationsprocedur och mätosäkerhetsuppskattningar, samt några tankar kring potentiell vidareutveckling. / This report is written for the optics group at 3M Svenska AB's research and development section in Gagnef, Sweden. It describes the commissioning process of an angular properties classification apparatus for Auto-Darkening Filters, commonly used while welding. The report describes details and considerations about the used equipment as well as physics related to it. It then suggests future action to be taken, and indicates possible improvements. Appendix A contains a brief user guide to the custom software developed by the author.
4

Givare för mätning av spolarvätseknivån

Fredriksson, Jonas, Johansson, Fredrik January 2003 (has links)
No description available.
5

Givare för mätning av spolarvätseknivån

Fredriksson, Jonas, Johansson, Fredrik January 2003 (has links)
No description available.
6

Design och konstruktion av handhållet instrument för mätning av ljusintensitet

Gustafsson, Simon January 2015 (has links)
Projektets mål var att utforma och konstruera ett mätinstrument för att upptäcka variationer i ljusintensitet. Uppdraget gavs av avdelningen för fasta tillståndets elektronik på Ångströmlaboratoriet i Uppsala. Instrumentets tänkta användningsområde är att undersöka om avdelningens testuppställningar för belysning av solceller levererar en homogen ljusintensitet. Genom att placera instrumentet på olika positioner under ljuskällan ska eventuella avvikelser i intensiteten kunna avläsas. Kraven på instrumentet var batteridrift och att det skulle vara handhållet. Vidare var det önskvärt att mätvärdet representerades med en analog visare, där mätintervallet skulle gå mellan 800 och 1200 W/m2. Efter litteraturstudier och informationssökning utfördes simuleringar i programmet LTSpice parallellt med prototypframtagning i lab. Instrumentet utformades med en fotodiod, vars ström omvandlas till en proportionell spänning via en transimpedansförstärkare. Denna spänning skalas sedan upp av ett differentialförstärkarsteg för att uppnå önskat intervall och känslighet. En konstant spänning subtraheras i differentialsteget för att mätaren ska ge utslag först över 800 W/m2. Spänningen läggs till sist över en analog amperemeter. I och med fotodiodens förmåga att ge ström proportionell mot ljusintensiteten erhölls linjära samband genom hela kretsen. Projektet kunde inte slutföras inom tidsramen då varken kretskort eller hölje hann konstrueras. En fullt fungerande prototyp på kopplingsdäck blev dock klar. Vidare är alla beräkningar och komponentval gjorda och dokumenterade i rapporten. Med andra ord borde instrumentet utan problem kunna konstrueras utifrån denna rapport.
7

Kalibreringsstation : Kalibrering av pallgafflar

Johansson, Mattias, Bengtsson, Ander January 2020 (has links)
The work is about designing a calibration station as an integral component of a company's existing product. The product is a robotic cell that automates the production of pallets. The purpose of the calibration station is to rectify an angular error that occurs on the pallet forks, which is mounted on the robot's tool, whose task is to lift and stack the pallets the robot cell manufactures. The company has theories as to why the angular error occurs and believes that there are a number of factors that influence. The purpose of the calibration station is to be able to calibrate the pallet forks when an angular error occurs and to correct all rotations and translations within an approved tolerance. Methods used to carry out the work are to study the problem and investigate how others have solved similar problems and to gather knowledge in the area of ​​calibration. The calibration station design and sensors are evaluated and discussed to determine which sensor and design will solve the task. Algorithms are programmed to find, calculate and correct angular errors that have occurred. The result of the calibration station that has been designed shows that it works for angular errors less than ten degrees in rotation and for translation in millimeters. After a calibration has been performed on the pallet forks, the result of the calibration falls within the requirements of the tolerances specified in the work. The work concludes with an evaluation of how the calibration station can be developed to perform better. / Arbetet handlar om att konstruera en kalibreringsstation som en ingående komponent i ett företags befintliga produkt. Produkten är en robotcell som automatiserar tillverkningen av pallar. Kalibreringsstationens syfte är att åtgärda ett vinkelfel som uppstår på pallgafflarna, som sitter på robotens verktyg, vars uppgift är att lyfta och stapla de pallar robotcellen tillverkar. Företaget har teorier om varför vinkelfelet uppstår och menar att det är ett flertal faktorer som påverkar. Kalibreringsstationens mål är att kunna kalibrera pallgafflarna när ett vinkelfel uppstår och korrigera alla rotationer och translationer inom en godkänd tolerans. Metoder som används för att genomföra arbetet är att studera problemet och undersöka hur andra har löst liknande problem samt samla kunskap inom området kalibrering. Kalibreringsstationens design samt sensorer utvärderas och diskuteras, för att komma fram till vilken sensor och design som skall lösa uppgiften. Algoritmer programmeras för att hitta, beräkna och korrigera vinkelfel som har uppstått. Resultatet för kalibreringsstationen som har konstruerats visar att den fungerar för vinkelfel mindre än tiotal grader i rotation samt för translation i millimeter. Efter att en kalibrering har utförts på pallgafflarna hamnar resultatet av kalibreringen inom kraven på toleranserna som angivits i arbetet. Arbetet avslutas med en utvärdering hur kalibreringsstationen kan utvecklas för att prestera bättre.
8

A 3D Visualization of White Blood Cell Populations : A Program to Visualize Analyzed Data from a Blood Sample / En 3D visualisering av vita blodkroppspopulationer : Ett program för att visualisera analyserad data från blodprov

Lundkvist, Andrea, Norman, Gabriella January 2018 (has links)
The goal of this project was to write a program to plot populations of white blood cell types in three dimensions and reduce the information from four dimensions to three in order to make it possible to plot. The dimension reduction should be done with as little loss of information as possible. PCA, principal component analysis, was used to perform the dimension reduction. A program for this was written in MATLAB. The program that builds the plot of the populations was written in c# using Visual Studios. The visualization was made in Unity. It was possible to rotate and zoom into the plot to get a better view. The project was given by Boule Medical AB as a part of the development of a new product. Boule Medical AB only had 2D plots and requested a 3D plot in their new product. The program was handed over to Boule Medical AB for future development.
9

Electrical Bioimpedance Cerebral Monitoring : Effects of Hypoxia

Seoane, Fernando January 2005 (has links)
Electrical bioimpedance spectroscopy is one way to study the electrical properties of biological matter. Different applications of electrical bioimpedance measurements have already been used in both research and clinical scenarios i.e. impedance plethysmography, total body water contents, etc. The electrical properties of tissue reflect the electrical characteristics of the constituent elements of the tissue and depend on its structure. Thus study of the electrical properties not only makes it possible to differentiate among tissues but also to determine the tissue condition. During hypoxia/ischemia the cell activates a certain chain of mechanisms of cellular adaptation in response to the insult. A consequence of these response mechanisms is that the biochemical composition of the cellular environment is altered and the cells swell (cellular edema). These alterations affect the electrical properties of tissue and the changes can be observed through measurement of the electrical bioimpedance of the affected tissue. Based on these ideas, this research work studies the effects of hypoxia/ischemia on the brain electrical impedance. The aim is to obtain the fundamental knowledge that may lead to the development of useful clinical tools for cerebral monitoring based on electrical bioimpedance spectroscopy. / QC 20120217 / Brain damage, Detection and localization of cell swelling
10

Electromagnetic Shielding of Fine Wires for Electrophysiological Sensing / Elektromagnetisk skärmning av tunna trådar förelektrofysiologiska mätningar

Mogren, Simon January 2020 (has links)
Tests have been performed to determine whether electromagnetic shielding of fine wires for electrophysiological sensing is a possible way to reduce the external noise in recording of nervous signals. By shielding the wires with a layer of silver, forming a coaxial cable, a reduction of the received power on the lead of 11.8-33 dBm was shown over the 10 – 10 000 Hz range when the test wire was subject to an electromagnetic field from an injection cable.  When putting the performance on the interval 50-100 Hz aside the same performance was measured to 25-33 dBm lower received power, which can be explained by 50 Hz noise from the electrical grid interfering with the measurements. However, when the shield was not grounded or grounded through a resistor worse performance was shown. The difference in received power between the unshielded and shielded configuration without grounding the shield was close to 0 dBm. Following this, the type of shielding investigated in this project has the potential to substantially shield thin wires from external interference under the condition that sufficient grounding is provided.

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