Window-scanning thermal imaging defect detecting and tomography method and system

Abstract

The invention discloses window-scanning thermal imaging defect detecting and tomography method and system. When the system works, a detected objected is scanned by a heat source and a thermal imager at fixed speed and is heated by the heat source, and temperature information varied along the time after the surface of the detected objected is heated is recorded by the thermal imager as original data; the original data is reconstructed to acquire a temperature variation sequence of each point of the detected objected as a detection signal; a specific signal is utilized or produced as a reference signal; the detection signal and the reference signal are processed by virtue of methods such as time domain, frequency domain and mutual correlation; a time domain feature value, a frequency domain feature value, a mutual correlation amplitude feature value and a mutual correlation phase feature value are extracted, and therefore, the defect detection and the tomography are achieved. The method and the system can be applied to the nondestructive testing of devices, the characterization assessment of materials and the quality control of products in the fields of aerospace, new materials, petrochemical engineering, nuclear power, railways, automobiles, special equipment, machinery, metallurgy and civil construction.

Description

technical field [0001] The invention belongs to the technical fields of equipment non-destructive testing, material characterization evaluation, structural health monitoring and product quality control, and in particular relates to a thermal imaging detection method and system. Background technique [0002] With the development of modern science and industrial technology, non-destructive testing technology has become a necessary means to ensure product quality and equipment operation safety. At present, representative non-destructive testing technologies mainly include radiographic testing, ultrasonic testing, penetrant testing, magnetic particle testing, eddy current testing, and thermal imaging testing. [0003] Thermal imaging detection technology uses a heat source to heat the object to be inspected, and uses a thermal imager to observe and record the temperature change information on the surface of the object to be inspected, so as to detect and evaluate the surface and...

AI Technical Summary

Problems solved by technology

The main disadvantages of the static detection method are: 1) It is necessary to configure the position of the thermal imager multiple times to detect large objects, the detection efficiency is low, and the detection time is long; 2) The heat source is heated unevenly, resulting in poor imaging and defect detection results

However, the existing thermal imaging motion detection methods have certain deficiencies: 1) Using the temperature value of a column of pixels for imaging can only display temperature information at a certain moment, and cannot perform tomographic imaging; 2) Using the temperature collected by a thermal imager 3) It is impossible to obtain the temperature change information of each point of the inspected object, and it is difficult to use thermal wave theory and advanced digital signal processing methods for in-depth analysis

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