Determination of the bore hole diameter by analyzing process emissions

Publikationstyp
Conference Paper
Date Issued
2013-10
Sprache
English
Author(s)
Janssen, Stefan  
Uchtmann, Hermann  
Kelbassa, Ingomar  
TORE-URI
http://hdl.handle.net/11420/12386
Start Page
181
End Page
189
Citation
ICALEO 2013 - 32nd International Congress on Applications of Lasers and Electro-Optics: 181-189 (2013)
Contribution to Conference
32nd International Congress on Applications of Lasers and Electro-Optics, ICALEO 2013  
Publisher DOI
10.2351/1.5062872
Scopus ID
2-s2.0-84893097784
Publisher
LIA
This paper reports on the analysis of process emissions in order to determine the bore hole diameter during laser percussion drilling. The visible light emitted from the plasma during a laser percussion drilling process is recorded by a high-speed camera. Subsequently, the recorded pictures from each pulse are being analyzed and evaluated to determine the final bore hole diameter without destroying the work piece (NDT). The pictures from the high-speed camera are processed and evaluated in a Matlab-written image processing tool which transforms the grayscale pictures into a black and white image. By aid of a threshold and Otsu-method the diameter is being calculated by the accumulated pixel area (Area-method). The paper focuses on which pulse and which capture time point to pick in order to achieve the most accurate diameter of a through-hole. Additionally, a comparison between the results of a Nd:YAG flash-light pumped laser source and a fiber laser source are presented and discussed.
DDC Class
600: Technik