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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

Automatisk nivåreglering av strålkastare / Automatic headlight level control

Elmelid, Axel January 2012 (has links)
To be allowed to sell Z-suspended vehicles with dipped beam Xenon or LED lighting, Scania have to develop automatic headlight level control. This master’s thesis aims to be the foundation to that development. The thesis consists of several parts; a market analysis of how competitors to Scania and the general vehicle industry solve this problem; several available principles for detecting the amount of control needed; the construction of a test station for sensors, a control unit and components connected controlled by the control unit; a further theoretical and practical development of one principle – one rotational sensor connected between the chassis and the back drive axis; a state flow model programmed in Simulink that produces the control signal for the headlight leveling from the sensor input. Lastly the thesis gives some recommendations to the further development and implementation of automatic headlight level control on Scania vehicles.
2

Heat transfer analysis on LED-board in closed environment / Värmeledningsanalys av LED-kort i stängd miljö

Eneberg, Victor, Linby, Johannes January 2022 (has links)
Motorcyclists are more often involved in accidents with severe harm or even fatal outcome compared to other road users. An experienced motorcycle driver is well familiar with the problem when the day light is reduced. The visibility is of course highly decreased. Allight International develops a light bulb that through a gyroscopic feature allows the light image to always be projected in the same axi-symmetric plane. The low beam head light usually accompanies the drivers movement when cornering, creating a black void ahead that leads to decreased vision. The light bulb has not yet been tested in a headlight and the LED is assumed to have high working temperature, which can lead to a shortened service life and technical errors due to the heat. By comparing empirical tests such as infrared camera and thermocouples on the prototype with theoretical tests such as computer aided design, finite element method, and computational fluid dynamics, a better understanding of how the model can be adapted to counteract the high temperature has achieved. Empirical analysis show that at a lower current of where the light bulb produces a brightness around the lower region of an automotive low beam headlight, the existing solution seems to work with the help of the fan creating forced convection. The improved and evaluated prototype, makes it possible to increase the current for the light bulb when more of the generated heat dissipates from the heat source. / Motorcyklister är mer involverade i olyckor med allvarlig eller dödlig utgång jämfört med generella trafikanter. En erfaren motorcykelförare är väl bekant med problemen som uppstår vid mörkerkörning. Givetvis blir sikten kraftigt försämrad. Allight International utvecklar en typ av lampa som med hjälp av ett gyroskop tillåter ljusbilden att alltid projiceras i samma axialsymmetriska plan. Vanligtvis följer lampan med förarens rörelse när denne svänger vilket skapar ett svart tomrum frammåt som leder till skymd sikt. Lampan har inte testas än i strålkastare och värmen antas ge en för hög arbetstemperatur, vilket kan leda till en forkortad livslängd samt tekniska fel på grund av värmen. Genom att utföra empiriska tester på prototypen som infraröd kamera och thermoelement tillsammans med teoretiska verktyg som computer aided design, finita elementmetoden och computational fluid dynamics fås en bättre förståelse för hur modellen kan anpassas för att motverka den höga temperaturen. Empiriska analyser visar att vid en lägre strömstyrka som motsvarar den ljusstyrka som är kravet för fordonsändamålsenliga halvljus, fungerar den nuvarande prototypen tillsammans med en fläkt som ger forcerad konvektion. Den förbättrade och utvärderade geometrin gör det möjligt att öka strömstyrkan då mer värme kan föras bort från värmekällan.

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