基于改进Hilbert-Huang变换的超声回波信号去噪研究  

Studies of Ultrasonic Echo Signal De-noising Based on Improved Hilbert-Huang Transform

作　　者：张永宏[1] 郝培培[1] 许学明[1] 孙亚杰[1] 

机构地区：[1]南京信息工程大学信息与控制学院,南京210044

出　　处：《科学技术与工程》2013年第12期3481-3487,共7页Science Technology and Engineering

基　　金：江苏省"六大人才"高峰高层次人才项目(2010-JXQC-132);教育部留学回国人员科研启动基金(教外司留[2010]609);江苏省"青蓝工程"中青年学术带头人资助项目资助

摘　　要：超声回波信号中包含大量有关缺陷性质的信息,由于信号在检测和传输过程中不可避免地受到随机噪声干扰,给后续信号处理带来误差。针对该问题,提出改进的希尔伯特-黄变换(Hilbert-Huang Transform,HHT)应用于超声回波信号去噪,提取回波信号中反映缺陷本质特征的信号。改进算法引入小波包变换对超声回波信号作预处理,对处理后的信号进行经验模态分解,提出对数似然检验法,识别并去除噪声引起的虚假分量,重构出有用回波信号。通过对添加高斯白噪声的超声回波信号去噪,验证改进算法应用于超声回波信号去噪的可行性和有效性。The ultrasonic echo signal contains a large number of information reflects defect properties. Echo signal also has various noise in defecting and transmission that brings error. Improved Hilbert-Huang transform （HHT） is proposed and it is applied to the ultrasonic echo signal de-noising, extraction of echo signal reflects the essential characteristics of the defect. Improved algorithm put forward wavelet packet which doing pretreatment for signal firstly. The log-likelihood test is proposed which was with the log-likelihood value of each intrinsic mode func- tion component and the original signal as the judgment basis to identify and remove illusive components. Then use- ful defect echo signal was reconstructed. Finally, by de-noising the ultrasonic echo signal with Gaussian white noise, the results demonstrate feasibility and effectiveness of the improved HHT.

关 键 词：超声检测 希尔伯特-黄变换 小波包 对数似然检验法 信号去噪 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]