基于相关性的钢轨缺陷漏磁检测提离干扰抑制

Method of lift-off interference suppression for rail defect magnetic leakage detection based on correlation

钢轨是铁路交通的基础设施,漏磁技术常用来检测诸如钢轨之类的铁磁性材料的表面缺陷。针对缺陷漏磁检测信号容易受到提离变化干扰的问题,提出了一种基于相关性的滤波算法。先根据缺陷尺寸、巡检速度和采样速度把检测数据分段,然后在每一段中,比较相邻磁敏传感器x方向采样数据的相关性、各个磁敏传感器x和z方向采样数据的相关性的相对大小,确定本段数据中提离干扰的幅值,以此实现滤波。构建了实验系统对钢轨表面的缺陷进行了检测实验,实验结果表明该算法能有效抑制提离干扰,信噪比增益在1.7以上。

Rail is the infrastructure of railway traffic,and magnetic leakage technology is commonly used to detect the surface defects of ferromagnetic materials such as rail.For the problem of the leakage magnetic detection signal,a correlation-based filtering algorithm is proposed.The detection data is segmented according to the damage size,inspection speed and sampling speed,and then the amplitude of the lift-off interference is determined by comparing the correlation of the sampling data of the adjacent magnetic sensitivity sensor x direction and the relative size of the sampling data of each magnetic sensitivity sensor xand z direction.The experimental system is constructed to detect the artificial and natural defects of the rail surface,and the experimental results show that the proposed algorithm can effectively inhibit the lift-off method,the SNR gain is above 1.7.