首页|基于激光超声的矩形缺陷合成孔径成像方法仿真研究

基于激光超声的矩形缺陷合成孔径成像方法仿真研究

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目前,激光超声合成孔径聚焦技术(SAFT)对内部缺陷的成像检测应用越来越多,对内部缺陷的成像质量要求也越来越高.基于合成孔径后处理成像方法,提出一种激光超声模式波在信号的多融合预处理技术下的成像优化方法,以实现对试件内部矩形缺陷的高质量检测.对采集的激光超声模式波依次进行差分计算、模式波包络提取、包络极大值线性插值、均值化去伪像的处理,再选取处理过的模式波进行SAFT成像.与未预处理的模式波成像结果的对比表明:后处理成像方法对缺陷的纵向深度探测误差平均降低了2.37%,横向宽度的检测误差平均降低了30.88%,使得缺陷的尺寸和位置判别更准确;成像质量显著提升,描述成像质量的能量梯度(EOG)函数平均值是预处理前的1.88倍.该后处理成像方法实现了对内部缺陷位置的定性精准判别、对尺寸的精准检测及高质量成像,为激光超声内部缺陷的检测方法提供了一种可能更优的后处理方案.
Simulation Study on Synthetic Aperture Imaging Method for Rectangular Defects Based on Laser Ultrasound
Currently,laser ultrasonic synthetic aperture focusing technology(SAFT)is being increasingly used for imaging and detecting internal defects.A method,based on the synthetic aperture postprocessing imaging methods,for achieving high-quality detection of rectangular defects inside a specimen is proposed using laser ultrasonic mode wave imaging optimization under multifusion preprocessing signal technology.Differential calculation,envelope extraction of signals,linear interpolation of maximum values,and removal of artifacts using the mean value are performed on the detected laser ultrasonic mode waves,and then we select the processed mode waves for SAFT imaging.The comparison with the imaging results from mode waves without prior processing indicates that the postprocessing imaging method can accurately and qualitatively identify defects.Furthermore,errors in longitudinal depth detection and transverse width detection of defects are reduced by 2.37%and 30.88%,respectively,improving the accuracy of defect size and their location determination.Thus,the imaging quality is considerably improved,as evidenced by a 1.88-fold increase in the average value of the energy gradient(EOG)function,which characterizes imaging quality.This postprocessing imaging method achieved qualitative and accurate identification of internal defect positions,precise size detection,and high-quality imaging,providing a promising postprocessing solution for laser ultrasound-based internal defect detection methods.

laser ultrasoundsynthetic aperture focusing imagingmulti-fusion preprocessingimaging optimizationdefect detection

何力、郭华玲

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中北大学电气与控制工程学院,山西 太原 030051

激光超声 合成孔径聚焦成像 多融合预处理 成像优化 缺陷检测

信息探测与处理重点实验室项目

ISPT2020-6

2024

激光与光电子学进展
中国科学院上海光学精密机械研究所

激光与光电子学进展

CSTPCD北大核心
影响因子:1.153
ISSN:1006-4125
年,卷(期):2024.61(10)
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