应用小波变换剔除超声多重反射的研究  

Research on Appling of Wavelet Transform to Suppress Ultrasonic Multiple Reflections

作　　者：杨克己[1] 李功燕[1] 

机构地区：[1]浙江大学现代制造工程研究所,浙江杭州310027

出　　处：《计量学报》2005年第2期185-188,共4页Acta Metrologica Sinica

基　　金：国家自然科学基金(50375144);国家"863"发展计划基金(2002AA421110);浙江省自然科学基金(501129)

摘　　要：利用小波变换具有空间局部化的特性和表征信号奇异性的能力,在适当尺度下刻画待检对象表面第1次超声回波信号的极大值点,从中选择最大值点作为脉冲重复频率(PRF)技术"与操作"的基准点,以满足PRF技术在消除超声多重反射时对"与操作"基准点需高精度定位的要求,从而解决传统方法对检测设备和操作条件严格一致的弊端。计算机仿真与实验研究表明提出的方法是可行的,并具有较强的鲁棒性和适用性。Based on the characteristic of spatial localization and signal singularity detection ability of wavelet transform,the local peak points of the first ultrasonic echo from the checked object surface are accurately detected on appropriate scales. Then the maximum point is selected as the datum mark for the 'AND Operation' of pulse repetition frequency (PRF) technology, which in order to satisfy the high locating precision of the datum mark when using the PRF technology to suppress the ultrasonic multiple reflections, thus can avoid the old method limitation which need rigid coherence of the testing facility and operating condition. The results of computer simulation and experiment indicate that the method presented is feasible and perform strong robust.

关 键 词：计量学 小波变换 奇异性 多重反射 PRF技术 超声检测 

分 类 号：TB95[一般工业技术—计量学]