Application scheme-quantitative analysis and detection of pipeline defects using infrared thermal imaging

Quantitative analysis and detection of pipeline defects using infrared thermal imaging

In the inspection process of the pipeline robot, it is usually necessary to check the defects on the inner wall of the pipeline and estimate the degree of danger of the defective part, so that the defects can be repaired in time and the service life of the pipeline is extended. The current method is mainly for the internal defect inspection technology of the robot carrying the detection device, but such equipment is still very scarce. With the development of non-destructive testing technology, not only qualitative analysis results but also quantitative analysis results of the size, depth and other information of pipeline defects are needed in practical engineering applications.

The picture shows the comparison between infrared image and grayscale image

Using infrared thermal imaging technology to detect defects is a rapidly developing method. However, it is difficult to quantitatively and accurately analyze the size and location of the defects in the image collected by the thermal imaging camera through manual observation. This can only determine whether there are defects and the approximate shape of the defects, which is not conducive to effectively assessing the risk level of the defects. Therefore, it is very necessary to perform image processing and analysis on the collected thermal images. At present, the quantitative analysis of defects mainly focuses on the analysis of defect areas. The previous method can obtain the defect area of pixel size, but it is still difficult to determine the actual size of the defect area in units of physical length.

The picture shows the defect position calibration

The researchers proposed an infrared thermal imager image processing pipeline defect detection method, which can be used to quantitatively analyze the type and area of surface defects and detect the position on the inner wall of the pipeline. In order to solve the problem of acquiring infrared thermal images, a special infrared thermal imager based on eddy current heating is designed, which can be used to obtain and calibrate thermal images of inner wall defects with small distortion from pixels to actual size. Experiments show that the method can be installed in a pipeline inspection robot in combination with the proposed infrared imaging device to achieve non-destructive detection of the surface defects of the pipeline inner wall.

Reference materials:

Yixuan Li, Yunwei Zhang, Yangyang Fan. A Quantitative Analysis Method for Pipeline Defect Inspection Based on Infrared Thermal Imaging [C]. 2018 2nd IEEE Advanced Information Management, Communicates, Electronic and Automation Control Conference(IMCEC 2018).