Channel equalization method for MFL signals of wire rope defects

To obtain the detailed distribution of three dimensional magnetic flux leakage(MFL) from wire rope defect,and to improve the accuracy of the quantitative recognition,Hall sensor array was used to detect the three dimensional magnetic flux leakage.In the detection process,variation of lift-off,the magnetic excitation heterogeneity and other factors will cause the dissimilarity of MFL signals obtained from the Hall sensor array,which is not conducive to quantitative inversion of wire rope defects.In this paper,a method combined with baseline estimation and normalization of peak-peak value of MFL signals is presented,by which the dissimilarity of each channel is compensated and the signal-noise ration of MFL signal and the contrast of MFL image are improved.The experimental results show that the defects are inspected more accurately with the channel-equalized MFL image.