基于InSb磁敏电阻器的脉冲涡流信号处理方法研究

脉冲涡流检测方法是涡流检测技术的一个新兴分支。分析了InSb磁敏电阻器作为脉冲涡流检测元件的工作原理。应用InSb磁敏电阻器的涡流探头检测金属裂纹特征的信息提取方法。对采集的信号首先通过同步累加法处理后再经多项式拟合、小波变换实现对信号的滤波与平滑,最终选用小波变换提取裂纹的特征。实验表明:采用InSb磁敏电阻器作为脉冲涡流检测敏感元件,具有较高的裂纹灵敏度,且可以较好地反映裂纹的深度。

Study on signal processing method based on pulsed eddy current sensor of InSb magnetoresistor

The pulsed eddy current testing is a new development field of eddy current testing technology.The working principle of InSb magnetoresistor which is used as the eddy current testing sensor is analyzed.The method of evaluating character of flaw signals by using the eddy current probe with InSb magnetoresistor is put forward.The acquisition data are firstly processed by synchronous accumulating average method.Polynomial fitting and wavelet transform are secondly used in noise reduction and curve smooth.And it is concluded that the character of flaw signals is better extracted through wavelet transform method.The testing results show that crack-sensitivity is better and crack-depth testing is satisfactory by using InSb magnetoresistor as the pulsed eddy current testing sensor.