表面缺陷交流电磁场检测信号的小波消噪处理  

Application of Labview-based Wavelet De-noising Method in ACFM Detection Signal Processing

作　　者：何新霞[1] 赵艳丽[1] 

机构地区：[1]中国石油大学(华东)信息与控制工程学院,山东东营257061

出　　处：《计算机测量与控制》2011年第1期195-197,共3页Computer Measurement &Control

基　　金：山东省科技发展计划项目[2007GG10005004]

摘　　要：运用交流电磁场检测技术检测工件表面缺陷时,由检测线圈提取的反映缺陷信息的磁场扰动信号很小,通常只有微伏/毫伏级,与含有的噪声干扰属于同一数量级;小波分析能同时利用信号与噪声在时频域内的差别,实现有效地信噪分离;借助于数据采集卡及信号调理电路,完成了对交流电磁场信号的检测和预处理,以Labview为软件开发平台,结合使用Matlab软件,对交流电磁场检测信号进行小波消噪处理,检出有用信号,为后期的缺陷定量分析打下基础;应用结果表明小波分析具有良好的降噪效果。The magnetic field disturbance signal extracted by the detecting coil to reflect defects information is very small, usually only micro--V / mV level, which has the same order of magnitude as the noise contained, when the ACFM technique is used to detect workpieee surface defects. In the wavelet analysis the difference between signal and noise in time--frequency domain can be used to effectively realize the separation of the signal and noise. ACFM signal is detected and pre--processed by means of data acquisition card and signal processing circuit. By using Labview and MATLAB, the wavelet denosing on ACFM detecting signal is performed to obtain useful signal and to size flaws. Results show that the wavelet analysis has good effect of de--noising.

关 键 词：交流电磁场检测 LABVIEW 消噪 小波分析 

分 类 号：TE951[石油与天然气工程—石油机械设备] TH114[机械工程—机械设计及理论]