Focal point position optimization with neural networks in CO 2 laser welding

1994 ◽  
Author(s):  
Claus B. Bagger ◽  
Hui Gong ◽  
Flemming O. Olsen
Keyword(s):  
Neural Networks ◽  
Laser Welding ◽  
Focal Point ◽  
Point Position

Optimal fusion of multi-focus image: Integrating WNMF and focal point analysis

2021 ◽  
pp. 2150156
Author(s):  
Shi-Hong Zhang ◽  
Qi-Yuan Zhan ◽  
Wen-Yu Li ◽  
Qiong-Ze Wang
Keyword(s):  
Image Fusion ◽  
Point Spread Function ◽  
Focal Point ◽  
Nonnegative Matrix ◽  
Fusion Algorithm ◽  
Point Position ◽  
Position Analysis ◽  
Point Spread ◽  
Spread Function ◽  
Focus Image

Image fusion can be used to improve the image utilization, spatial resolution and spectral resolution, which has been widely applied on medicine, remote sensing, computer vision, weather forecast and military target recognition. The goal of image fusion is to reduce the uncertainty and redundancy of the output and increase the reliability of the image on the basis of the maximum combination of relevant information. In this paper, a multi-focus image fusion algorithm based on WNMF and Focal point position analysis is proposed to improve the image fusion method based on nonnegative matrix factorization. In the imaging process, the Gaussian function is used to approximate the point spread function in the optical system. Then calculate the difference between the original image and the approximate point spread function and get the weighted matrix [Formula: see text]. Finally, we apply the weighted nonnegative matrix algorithm to image fusion, and the new fusion image with clear parts is obtained. Experimental results show that the multi-focus image fusion algorithm based on WNMF and Focal point position analysis (MFWF) is better.

Welding of Austenitic Stainless Steel AISI 304 by Fiber Laser

2017 ◽  
Vol 891 ◽  
pp. 190-194
Author(s):  
Katarína Bártová ◽  
Mária Dománková ◽  
Jozef Bárta
Keyword(s):  
Fiber Laser ◽  
Welding Speed ◽  
Focal Point ◽  
Weld Bead ◽  
Bead Width ◽  
Statistical Software ◽  
Aisi 304 ◽  
Depth Measurement ◽  
Point Position ◽  
The Difference

Paper deals with the welding of AISI 304 thin sheets with the thickness of 1 mm by fiber laser. Statistical software MiniTab was used for planning the experiment. The influence of laser power, welding speed and focal point position on width and depth of weld bead was examined. Output power, welding speed and focus point position were used as variable factors for DOE. Samples were prepared by standard metallography. Weld bead width and depth were evaluated. Statistical results were afterward verified by welding reference samples with material the thickness of 0.25 mm. The difference between real width of weld bead and predicted width obtained from statistical software was 8.26 %. In case of weld depth measurement, the difference was 23 %.

scholarly journals Disk Laser Welding of Armor Steel/ Spawanie Laserem Dyskowym Stali Pancernej

2014 ◽  
Vol 59 (4) ◽  
pp. 1641-1646 ◽  
Author(s):  
D. Janicki
Keyword(s):  
Laser Welding ◽  
Focal Point ◽  
Base Material ◽  
Steel Plates ◽  
Welding Parameters ◽  
Maximum Output ◽  
Butt Welding ◽  
Disk Laser ◽  
Armor Steel ◽  
Charpy Absorbed Energy

Abstract The paper describes the application of an Yb:YAG disk laser with a maximum output of 3.3 kW for the butt welding of armor steel plates ARMOX 500T 3.6 mm thick. The influence of laser welding parameters such as laser power beam, welding speed, focal point position on weld quality and mechanical properties of joints was studied. A proper selection of disk laser welding parameters provides non-porous and cracks free fully-penetrated welds with the aspect ratio up to 6.4. There was approx. 40% reduction in the hardness of heat affected zone (HAZ) in comparison to hardness of the base material (BM). The hardness values at the weld metal and the BM were similar. The joints exhibited about 15% lower ultimate tensile strength when compared with that of the BM. Charpy absorbed energy of the joints was approx. 30% lower than that of the BM.

scholarly journals PALS laser energy transfer into solid targets and its dependence on the lens focal point position with respect to the target surface

2008 ◽  
Vol 26 (2) ◽  
pp. 189-196 ◽  
Author(s):  
A. Kasperczuk ◽  
T. Pisarczyk ◽  
M. Kalal ◽  
M. Martinkova ◽  
J. Ullschmied ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Laser Energy ◽  
Focal Point ◽  
Target Surface ◽  
Plasma Jets ◽  
Point Position ◽  
Laser Plasma Interactions ◽  
Opposite Case ◽  
Laser Facility ◽  
Focusing Lens

AbstractThis paper is devoted to investigations of laser energy transfer into solid targets with respect to the focusing lens focal point position relative to the solid target surface as obtained at the PALS laser facility. The third harmonic of the PALS laser beam with energy ~90 J and pulse duration ~250 ps (FWHM) was used for irradiation of two kinds of targets made of Cu: a slab and a 3.6 µm thick foil. The focal point of the beam was located either inside or in front of the target surface, and care was taken to ensure the same laser spot radii in both cases (250 µm). It was demonstrated that these two opposite focal point positions give rise to significantly different laser-plasma interactions: with either depression or maximum of the laser intensity distribution in the center of the beam, respectively. It was also verified that the focal point position inside of the target is favorable for plasma jets creation, whereas the opposite case is more effective for acceleration of flyers.

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