A sub-pixel detection method for structural cracks

A detection method and structure technology, applied in image analysis, graphic image conversion, image data processing and other directions, can solve the problems of unable to identify cracks, unable to realize sub-pixel crack image recognition, etc., to reduce the number of captured images, improve Crack detection accuracy and the effect of improving detection efficiency

Active Publication Date: 2022-01-04
北京雷图科技有限公司
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AI Technical Summary

Problems solved by technology

The traditional edge detection algorithm can only realize the whole pixel detection, that is, it can only detect the edge of the unit pixel level.
The traditional method can only identify crack images whose crack width is equal to or greater than 2 pixels. If the crack width is less than 2 pixels, this method cannot identify cracks, nor can it realize the recognition of sub-pixel crack images.

Method used

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  • A sub-pixel detection method for structural cracks
  • A sub-pixel detection method for structural cracks
  • A sub-pixel detection method for structural cracks

Examples

Experimental program
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Effect test

Embodiment 1

[0150] For the known width of the structural crack, which is 0.1mm to 1mm, adjust the position of the shooting camera to the case where the calibration coefficient is g(d)=1(mm / pixel), and adjust the distance between the shooting camera and the shooting plane (that is, the structural crack) Distance, to adjust the pixel value of the captured structural crack on the image, so that the width of the structural crack corresponds to the pixel value, that is, the pixel value corresponding to a crack with a width of 0.1 is 0.1, and the pixel value corresponding to a crack with a width of 0.2 is 0.2...and so on.

[0151] By adopting the structure crack sub-pixel detection method of the present invention, the comparison chart between the actual measured width value and the known width is obtained as follows. Wherein, the crack width unit: mm. Table 1 is the comparison chart between the actual measured width value and the known width of standard sample 1~standard sample 15, and table 2...

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Abstract

The invention relates to a sub-pixel detection method for cracks in a structure, comprising the following steps: 1. Obtain multiple surface images of the structure, and record the position and attitude information of the camera when each image is taken; 2. According to the lens parameters of the camera when shooting Image correction and image calibration are performed on the captured images with the position and attitude information to obtain the calibration coefficient of the distance from the camera to the shooting plane; 3. Stitching multiple images taken to obtain the surface expansion diagram of the structure; 4. Based on training A good crack image training model, which divides the surface expansion diagram of the structure into regions, and extracts cracks in different regions; 5. Thinning the extracted crack binary image, obtaining the crack skeleton map, and calculating the starting point position of the crack Information, end point position information, bifurcation point position information, and calculate the sub-pixel width and length of the crack. The invention takes both efficiency and precision into account, and can detect crack parameters of 0.1 pixel.

Description

technical field [0001] The present invention relates to the technical field of crack sub-pixel detection in structures, in particular to a sub-pixel detection method for cracks in structures. Background technique [0002] Any architectural structure will be affected by the natural environment and human activities, resulting in varying degrees of degradation and decay. Over time, these visible or subtle changes may affect the safety and durability of the structure. In some special fields, such as water conservancy projects, cracks can endanger the safety of dams; in nuclear power plants, defects in the concrete casing of reactors can cause radiation leakage, and defects in air cooling towers can affect production. For some large modern architectural structures such as stadiums, terminal buildings and grand theaters, the decline of the structure is directly related to personal safety. [0003] At present, in China, external methods are mainly used for surface inspection of st...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G06K9/00G06K9/62G06T3/40G06T7/70G06T7/80
CPCG06T3/4038G06T7/70G06T7/80G06F18/22
Inventor 石晶欣赵岩钟正凯吕伟朱文宇
Owner 北京雷图科技有限公司
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