Molten pool contour image extraction method for realizing closed connected domain

Abstract

The invention relates to a molten pool contour image extraction method for realizing a closed connected domain. The molten pool contour image extraction method comprises the following steps: 1, extracting a molten pool image; 2, preprocessing and calculating the molten pool image; 3, calculating based on a gradient graph convenient for matching a guide operator template; 4, performing image merging; and 5, extracting a contour line of the molten pool image. By utilizing the device and the method, the problem that the contour line of the molten pool is difficult to extract as the front end of the molten pool is influenced by arc light due to non-uniform brightness distribution of the front end and the rear end of the molten pool is solved; the problems of unobvious gray scale change and weak gradient of two end parts of the rear end of the molten pool after an image is converted into a grey-scale map due to dark area brightness and non-uniform distribution of the rear end of the moltenpool are solved; the indication effect is achieved on the welding seam forming and the welding quality improvement.

Description

technical field [0001] The invention relates to a molten pool outline image extraction method for realizing a closed connected domain, and belongs to the technical field of image analysis. Background technique [0002] The image features of molten pool play an important guiding role in the formation of weld seam and the detection of welding quality. In the image of the molten pool extracted by the traditional method, the brightness distribution of the front end and the rear end of the molten pool area is uneven, and the front end of the molten pool is more seriously affected by the arc light, and the details of this part are richer. The case where the edge information of the pool header is covered up. Compared with the front end, the brightness of the rear end of the molten pool is darker and unevenly distributed. After the image at both ends is converted into a grayscale image, the grayscale changes are not obvious and the gradient is weak. [0003] When the edge detecti...

AI Technical Summary

Problems solved by technology

[0003] When the edge detection operator is used to detect the area, the weak edge area will not be able to respond and the detected edge is not continuous and complete.

Directly use the Canny operator to detect the edge of the stainless steel molten pool image under the TIG welding process, and the detected contour edge line will be affected by three aspects: 1. The edge of the weak edge area at the back end of the molten pool cannot be accurately detected; 2. .The brightness saturation area formed by arc light reflection on the surface of the molten pool introduces interference edges; 3.The texture information of the formed weld area at the back end of the molten pool introduces interference edges

Compared with traditional image detection methods, the Canny edge detection operator is an optimized edge detection operator solution with high performance. If this algorithm cannot achieve satisfactory results on TIG welding stainless steel molten pool images, Then it will be very difficult to use the traditional image edge detection algorithm to obtain an accurate and complete outline of the melt pool area.

[0004] At present, there is an urgent need for an effective melting pool contour detection and extraction method to solve the problem of incomplete contour edges detected by edge detection operators.

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