小波分析用于钢板孔洞的涡流检测研究

小波的时频局部化和多尺度特性,使其特别适用于信号的奇异性探测和瞬态信号的检测以及强周期性噪声干扰下非平稳信息的提取。将小波分析用于钢板孔洞测量的数据处理过程中,通过以最大信噪比为依据的自定义信息代价函数来获取小波包最优基函数,使重构信号的信噪比大幅度提高,从而确保了钢板孔洞的测量精度与分辨率。实验分析表明,小波分析不仅可用于单孔信号的高效定位提取,而且通过一定的逻辑分析与判断,同样适用于连孔和多孔信号以及存在管道焊缝信号的高效分辨。

Study on eddy current detection of hole defects in steel plate by a wavelet analysis method

Wavelet analysis is useful and effective in the singularity detection and transient analysis of signal and acquiring of non-steady information under a seriously periodic interfering noise because of its characteristics of time-frequency localization and multi-resolution.A wavelet analysis method was used in the data processing for detection of hole defects in steel plate.The signal-to-noise ratio(SNR) of reconstructed signal was increased by the prior wavelet packet basis acquired with a self-defined cost function based on the maximum SNR.So the measurement precision and discernibility of hole defects in steel plate were ensured.The experimental analysis shows that the wavelet analysis can be used to identify not only a single hole signal but also the link hole or multi-hole and existing welding line signal by some logical analysis and judgment.