相关函数在涡流检测信号提取分析中的应用

Application of Correlation Function in Extraction and Analysis of Eddy Current Testing Signal

为降低涡流检测信号处理的硬件复杂程度及提升后续数据分析处理灵活度,在不借助复杂硬件自平衡技术电路前提下,在LABVIEW图形化软件平台中设计了相关函数算法程序,对示波器MDO4024C所采集的原始交流电桥信号及电桥激励信号分别进行自相关及互相关运算去噪,提取分析不锈钢管不同位置的涡流信号的幅值及相位,最后再将检测信号在极坐标图中分析显示。实验结果表明,这一方法可有效实现对不锈钢管缺陷涡流信号的去噪及特征信号提取。

In order to reduce the hardware complexity of the eddy current detection signal processing and improve the flexibility of subsequent data analysis and processing,the relevant function algorithm program is designed in the LABVIEW graphical software platform without resorting to complex hardware self-balancing technology circuits. The original AC bridge signal and bridge excitation signal collected by the oscilloscope MDO4024 C are denoised by auto-correlation and cross-correlation operations respectively,and the amplitude and phase of the eddy current signal at different positions of the stainless steel tube are extracted and analyzed,and finally the detection signal is analyzed and displayed in the polar coordinate graph. Experimental results show that this method can effectively achieve the denoising of eddy current signals of stainless steel tube defects and the extraction of characteristic signals.