超声声场激光层析成像及其扫描参数优化研究  

Laser Tomography Imaging and Optimization of Scanning Parameters for Ultrasound Field

作　　者：张小丽 何程昊 冯秀娟[1] 张慧[2] 牛锋[1] 何龙标[1] Zhang Xiaoli;He Chenghao;Feng Xiujuan;Zhang Hui;Niu Feng;He Longbiao(Institute of Mechanics and Acoustic Metrology,National Institute of Metrology,Beijing 100029,China;School of Precision Instrument and Opto-Electronics Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]中国计量科学研究院力学与声学计量科学研究所,北京100029 [2]天津大学精密仪器与光电子工程学院,天津300072

出　　处：《中国激光》2024年第5期36-47,共12页Chinese Journal of Lasers

基　　金：中国计量科学研究院基本科研业务费(AKYZZ2210);国家自然科学基金(51575502);天津市自然科学基金(22JCZDJC00140)。

摘　　要：空气耦合(简称“空耦”)超声换能器具有非接触检测、适合复杂工况和原位检测等独特优势,已被广泛应用于超声无损检测等领域。声场重建对于开展空耦超声换能器声束宽度、扩散角等声场特性参数的表征,进而保障超声检测系统的横向分辨率及定位精度具有重要意义。笔者基于声光效应和层析成像技术对50~200 kHz空耦超声换能器的声场重建开展研究。超声声场的重建质量与空间分辨率密切相关,但高空间分辨率会导致扫描时间呈几何倍数增长。笔者从仿真和实验的角度对声场空间分辨率(即声场扫描参数)进行优化,在保证声场重建图像质量的前提下将扫描效率提高了2~4倍。同时,将优化后的声场重建结果与传声器在相同位置处的声场直接测量结果进行比较,验证了声光效应层析成像进行超声声场重建的可靠性。Objective Air-coupled ultrasonic transducers offer unique advantages such as non-contact testing,adaptability to complex working conditions,and in situ testing.They are widely used in areas such as ultrasonic ranging,radar,flow meters,and nondestructive testing.Sound field reconstruction holds importance for characterizing the sound field parameters of air-coupled ultrasonic transducers,including beam width and diffusion angle,ensuring the transverse resolution and positioning accuracy of the ultrasonic testing system.The laser method,drawing on the acousto-optic effect,exhibits advantages such as a narrow laser beam,high spatial resolution,extensive frequency range,high sensitivity,and a non-invasive sound field.This makes it an ideal approach for sound field reconstruction.Achieving optimal spatial resolution and superior imaging quality remains pivotal when using laser tomography for sound field reconstruction.Typically,improving the imaging quality involves reducing the translation and rotation step spacing(often to less than half the sound wavelength)to secure more comprehensive sound pressure path data.Given the short wavelength of ultrasonic transducers,the scanning efficiency of ultrasound field reconstruction decreases considerably.This study,therefore,centers on the sound field reconstruction of air-coupled ultrasonic transducers within the 50-200 kHz frequency range and seeks to optimize the scanning parameters.The goal is to enhance scanning efficiency while maintaining the quality of the reconstructed sound field image.We aim for our fundamental strategy and insights to aid in the realization of ultrasound field reconstruction and the enhancement of scanning efficiency via laser tomography.Methods This study investigated the sound field reconstruction of air-coupled ultrasonic transducers at frequencies of 50-200 kHz based on acousto-optic effects and tomography technology.The spatial resolution of the sound field was optimized through simulations and experiments.Initially,a model was established to

关 键 词：测量 层析成像处理 声光效应 激光测振仪 声场表征 扫描效率 

分 类 号：O426.3[理学—声学]