基于频率-波数的频域合成孔径导波成像研究  

Research on frequency domain synthetic aperture guided wave imaging based on frequency-wavenumber

作　　者：龙盛蓉 邓文武[2] 陈炫宇 韩壮禄 李志农 Long Shengrong;Deng Wenwu;Chen Xuanyu;Han Zhuanglu;Li Zhinong(Key Laboratory of Jiangxi Province for Image Processing&Pattern Recognition,Nanchang Hangkong University,Nanchang 330063,China;Key Laboratory of Nondestructive Testing of the Ministry of Education,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学江西省图像处理与模式识别重点实验室,南昌330063 [2]南昌航空大学无损检测教育部重点实验室,南昌330063

出　　处：《仪器仪表学报》2021年第10期230-238,共9页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(52075236);装备预研基金(6142003190210);江西省教育厅项目(GJJ180525);江西省图像处理与模式识别重点实验室开放基金(ET202008414)项目资助。

摘　　要：为实现管道中缺陷位置与尺寸的准确预测,在爆炸反射成像原理的基础上,提出了一种基于频率-波数的频域合成孔径导波成像算法。通过磁致伸缩方式在管道中激励出T(0,1)模态导波,对采集到的回波信号做二维傅里叶变换并进行角谱运算对频域内声场进行重构。最后,对其进行反傅里叶变换后实现目标区域内的聚焦成像。通过实验验证成像结果,同时与原始B扫结果进行了对比。结果表明,所提算法有效抑制了旁瓣效应产生,使成像分辨率提高了约30%,定量误差缩减了26.1%;同时研究表明在缺陷轴向位置、深度及倾斜角度发生改变时,利用该算法实现缺陷图像重构后,其检测准确度只受缺陷周向范围的绝对尺寸影响,对周向表面缺陷检测具体较高的灵敏度。To accurately predict the location and size of defects in the pipeline,a synthetic aperture guided wave imaging algorithm based on frequency wavenumber domain is proposed.And the principle of explosive reflection imaging is also utilized.The T(0,1)mode guided wave is excited in the pipeline by magnetostriction.The collected echo signal is subjected to two-dimensional Fourier transform and angular spectrum operation to reconstruct the sound field in the frequency domain.Finally,the focus imaging in the target area is realized by using the inverse Fourier transform.The imaging results are verified by experiments and compared with the original B-scan results.Results show that the side lobe effect is effectively controlled by the proposed algorithm.The imaging resolution is improved about 30%and the quantitative error is reduced by 26.1%.The affection of the axial position,the depth and the inclination angle of defects are also studied.By using the algorithm to reconstruct the defect image,the detection accuracy is only affected by the absolute size of the circumferential defects and the detection of circumferential surface defects has a high sensitivity.

关 键 词：管道 超声导波 频率-波数 频域合成孔径 成像算法 

分 类 号：TG115.28[金属学及工艺—物理冶金] TH878[金属学及工艺—金属学]