基于VMD的去噪算法在套管引线检测中的应用

Application of VMD-based De-noising Algorithm to Casing Lead Detection

超声检测套管引线的信号数据中存在大量的噪声干扰,使得回波时间提取精度产生较大误差。针对上述问题提出了一种基于变分模态分解(VMD)与小波阈值的去噪新方法。采用VMD对含噪信号进行分解,通过计算相关系数筛选出固有模态函数(IMF)中的高频分量进行小波阈值降噪,保留高频分量中的回波信息,最后与低频IMF进行信号重构。实测数据的去噪结果表明,去噪效果良好,有效地保留了高频分量中的真实信息,提高了超声回波信号的信噪比,从而增加了超声检测套管引线的测量精度。

A lot of noise interference in the signal data of ultrasonic detection casing leads causes many errors in the accuracy of echo time extraction.A new de-noising method based on variational mode decomposition(VMD)and wavelet threshold was proposed to solve the above problem.VMD was adopted to decompose the noised signal.Correlation coefficient was calculated to screen out the high-frequency component of the intrinsic mode function(IMF)for wavelet threshold noise reduction,while the echo information of the high-frequency component was retained.Finally,signal reconstruction was realized with the low-frequency IMF.The results of de-noising of the measured data showed that the proposed method could produce good de-noising effect,retain real information in the high-frequency component,and improve the signal-to-noise ratio of the echo signal,thus improving the measurement accuracy of the ultrasonic detection casing lead.