Infrared lock-in thermal wave non-destructive detection method based on image sequence processing

Abstract

The invention discloses an infrared lock-in heat wave non-destructive detection method based on image sequence processing, which is a new method for realizing infrared lock-in heat wave non-destructive detection by using computer software to process the sequence of infrared images. The method comprises the following implementation steps: using a focal plane infrared heat imager to collect the image sequence of heat wave signals, using a halogen light source modulated by sine law to excite, carrying out digital lock-in processing on heat wave signals and analysis of feature images. When the method is used for non-destructive detection, the focal plane infrared heat imager 5 is fixed on a tripod 16 and connected with a data acquisition card of a computer 11, and infrared lock-in processing software 12 based on the image sequence is used for finishing initialization and image display of the infrared heat imager. The halogen light source 6 is fixed on a special support 7 to ensure that incident light is irradiated in an area to be detected of a sample piece 2 as far as possible, a function generator 14 is connected with a light source power amplifier 13 through a signal wire 15, and light intensity of the halogen light source 6 is controlled to change by the sine law. The incident light of the halogen light source 6 is irradiated to the surface of the sample piece 2 to generate excited heat waves 4. The infrared lock-in processing software 12 based on the image sequence records reflected heat waves 3 or transmitted heat waves 1 generated on the surface of the sample piece 2, a lock-in processing module is used for extracting feature information of the heat wave signals and forming the feature images, an image processing and analyzing module processes and analyzes the heat wave feature images, and inner defect features of the sample piece 2 are extracted, so as to realize fast and accurate non-destructive detection of inner defects and damages of the sample piece 2.

Description

technical field [0001] The invention relates to a method for nondestructive detection and analysis of internal defects and damages of materials or components by means of active infrared thermal wave detection, and in particular to a new method for nondestructive detection of infrared phase-locked thermal waves based on image sequence processing. Background technique [0002] With the development of modern science and industrial technology, non-destructive testing technology has also been continuously improved, and it has become a necessary means to ensure product quality and equipment operation safety. Currently representative non-destructive testing technologies mainly include radiographic testing (RT), ultrasonic testing (UT), magnetic particle testing (MT), penetrant testing (PT) and electromagnetic testing (ET). Radiographic testing (RT) is generally applicable to castings, weldments, non-metallic products and composite materials, etc., and is not limited by materials an...

AI Technical Summary

Problems solved by technology

The principle of penetrant testing is simple and easy to understand, the equipment is relatively simple, the operation is relatively simple, the sensitivity is high, and the defect display is intuitive, but the test solution used is volatile and can only detect surface opening defects, not porous materials.

Electromagnetic testing (ET) is only used for surface and near-surface defect detection of conductive materials. It is sensitive to edge effects caused by sudden changes in part geometry and is prone to false display

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