A microwave frequency modulation thermal wave imaging system and method

Abstract

The invention discloses a microwave frequency modulation thermal wave imaging system and method. The system uses microwaves modulated by the amplitude of the FM signal to heat the object to be inspected, and uses a thermal imager to record the surface temperature of the object to be inspected. Set the frequency modulation signal or the temperature signal of the non-defective area as the reference signal. Perform fast Fourier transform on the temperature signal and the reference signal, extract the amplitude, phase and peak frequency of a specific frequency as eigenvalues; perform cross-correlation on the temperature signal and the reference signal, and extract the correlation coefficient of the specific delay time and the peak delay time As an eigenvalue; perform frequency-domain cross-correlation on the temperature signal and a reference signal, and extract the cross-correlation amplitude and phase of a specific delay time and peak delay time as eigenvalues. Imaging is performed using the eigenvalues ​​of all pixels in the inspected area. The method and system have the advantages of strong anti-interference, rich depth information, short detection time, etc., and can be applied to the fields of non-destructive testing, medical imaging, target detection and the like.

Description

technical field [0001] The invention belongs to the technical fields of non-destructive testing, target detection and medical imaging, and in particular relates to a microwave thermal imaging detection, detection and imaging system and method. 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 inspection technology uses a heat source to heat the inspected object, and uses a thermal imager to observe and record the temperature change information on the surface of the inspected object, so as to detect and evaluate the surface and internal defects of the inspected object. Th...

AI Technical Summary

Problems solved by technology

The existing microwave thermal imaging defect detection technology has the following shortcomings: 1) The defect detection method relies on the original thermal image and transient temperature curve, which is susceptible to noise interference; 2) It is difficult to overcome the interference of uneven heating and surface emissivity; 3) The detection time required to obtain information of different depths is long

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