In January 2015 i finished my master thesis in Information and Computer Engineering at the Institute of Technical Informatics of the TU Graz. Unfortunately i am not allowed to show details of my work. This is why i put here only the abstract, so that anyone might get an imagination what my thesis and work [1] was about.

Abstract

The precise measurement of object surfaces and edges with sub-micrometer resolution plays an important role in many applications nowadays. These high-precision measuring devices are used in processes where an accurate and automatic handling of sensitive parts or components is necessary. This master thesis is about the improvement of an optical LED/Laser edge scanning device which is used for accurate measuring of object-edges and surfaces. The thesis objective is the evaluation of different light sources, such as e.g. LEDs or Laserdiodes, with respect to their optical image projection properties, so that a qualitative proposition regarding the degree of measurement accuracy can be made. Therefore different optical path models are developed and edge-detection algorithms with measured reference datasets in MatLab implemented and tested, such that these datasets can be subsequently integrated on a selected microcontroller system. The measuring principle relies on multiple-exposure and projection of the object onto a light sensitive detector, furthermore on analyzing the exposure data to find the position of the projection edges and on the fusion of the redundant measuring data information in order to infer an edge position (X/Y) in the measurement plane with triangulation methods. If sufficient light sources are used, there is a possibility that multiple edges of an object can be detected at once using redundant exposure information. This multiple projection data can contain additional information about the object´s edge condition. This includes e.g. measuring of the edge position, object thickness, edge fractions, etc.

[1] Christian Mentin,  Analysis and optimisation of an Laser measuring system with respect to the choice of light sources and consideration of physical effects in the optical path, Graz University of Technology, 2015.