A method for judging the depth of non-conductor defects based on multi-pair electrode capacitive imaging detection technology

Abstract

The invention discloses a method for judging the depth of a non-conductor defect based on a multi-pair electrode capacitive imaging detection technology, which relates to the field of non-destructive detection signal processing, including: receiving input multi-pair electrode capacitive imaging detection signals, wherein the detection signal includes defect detection Signal Y n and no defect detection signal YS n ; Find the defect signal change value △Y n =Y n -YS n , and at the same time judge the defect signal change value △Y n Whether it is greater than or equal to the preset threshold P n ; If not, it is judged that the defect does not exist; if it is, it is judged that the defect exists; for the defect signal Y n Corresponding abscissa X n Carry out coordinate transformation, the transformed abscissa HX n =X n -d n / 2; for defect signal Y n Transform, the transformed ordinate HY n =Y n . / YS n ; and according to the abscissa HX n with ordinate HY n Draw a graph; when the number of troughs in the graph corresponding to the defect is 1, determine the maximum electrode pair number C a ; When the number of troughs in the graph corresponding to the same defect is 2, determine the minimum electrode pair number C b ; Then it is judged that the depth of the defect lies in the electrode pair C a with C b between the effective detection depths.

Description

Technical field [0001] The present invention relates to the field of non-destructive detection signal processing, and more particularly to a method of determining a non-conductor defect depth based on multi-pair electrode capacitance imaging detection techniques. Background technique [0002] Multi-pair electrode capacitive imaging detection technology is a new type of detection technology based on the development of single-pair of electrode capacitance imaging detection techniques, and single-pair electrode capacitor imaging detection technology is a quasi-static edge generated between a pair of coplanar electrode plates. Electric field detecting the defects, when the defect is within an effective detection electric field between the coplanar electrode plate, the defect perters the distribution of the effective electric field, affects the measured charge on the detection plate, thereby achieving the purpose of detecting defects. [0003] Although single-pair electrode capacitor ...

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Problems solved by technology

[0003] Although single-pair electrode capacitive imaging detection technology can detect conductor surface defects and non-conductor internal defects, the detection results can only roughly reflect the length and width information of defects, and cannot reflect the depth information of non-conductor internal defects

With the rapid development of non-destructive testing technology toward refinement and visualization, single-pair electrode capacitance imaging detection, which lacks the important parameter of defect depth information, faces many disadvantages; To a certain extent, it can reflect the depth information of non-conductor internal defects. During the detection process, the conductor material needs to be placed under the non-conductor material, and the reflected defect depth information is only the upper or lower part of the non-conductor material; and for the same It takes a lot of time to scan the defect multiple times, and the efficiency is low; at the same time, when the single-pair electrode capacitive imaging detection technology detects defects under multiple lift-off heights, it is necessary to accurately grasp the variation range of the lift-off height. If the lift-off height If the grasp is not accurate, it will cause misjudgment of the depth information of the internal defects of non-conductor materials, resulting in inaccurate test results

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