Defect localization by orthogonally projected multiple signal classification approach for magnetic flux leakage fields
Defect localization by orthogonally projected multiple signal classification approach for magnetic flux leakage fields
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DOI：
10.1016/j.ndteint.2008.03.009
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发表时间：
2008-09-01
影响因子：
4.2
通讯作者：
Janawadkar, M. P.
中科院分区：
文献类型：
--
作者：
Baskaran, R.;Janawadkar, M. P.
漏磁技术通过测量导磁棒外部的漏磁场来检测导磁棒内部的缺陷。导磁棒中不同尺寸的缺陷已被建模为具有不同力矩的局部反偶极子。这些缺陷位置和力矩必须基于随机噪声存在下泄漏场的测量来确定。多信号分类（MUSIC）方法已用于识别缺陷位置和这些缺陷的时刻。在找到代表较大缺陷的第一个偶极子的位置后，使用测量的磁场数据远离第一个缺陷位置的正交投影，通过 MUSIC 识别下一个偶极子的位置。这个过程一直持续到所有缺陷都被排除为止。通过直接正演计算模拟了三个深埋缺陷的泄漏场，并利用所得数据进行反演。即使存在合理水平的附加噪声，也可以通过这种方法识别缺陷的数量及其位置。 (C) 2008 Elsevier Ltd. 保留所有权利。
Magnetic flux leakage technique is used for defect detection inside a magnetically permeable bar by measuring the leakage fields outside the bar. Defects of varying sizes in a magnetically permeable bar have been modelled as localized anti-dipoles with different moments. These defect locations and moments have to be determined based on the measurement of the leakage fields in the presence of random noise. Multiple Signal Classification (MUSIC) approach has been used to identify the defect locations and the moments of these defects. After finding the location of the first dipole representing the larger defect, using orthogonal projection of the measured magnetic field data away from the first defect location, location of the next dipole is identified by MUSIC. This process is continued until all the defects are exhausted. The leakage fields from three deeply buried defects were simulated by direct forward calculation and the resulting data were utilized for inversion using this approach. It has been possible to identify the number of defects and their locations by this approach even in the presence of reasonable levels of additive noise. (C) 2008 Elsevier Ltd. All rights reserved.