A wire rope defect signal enhancement method based on spatial domain array sensors combined with multi-process adaptive signal processing

For nondestructive testing methods for wire ropes, magnetic flux leakage is one of the most effective testing methods at present. However, under the influence of complex conditions, the signal-to-noise ratio (SNR) of the detected signal is poor for small surface defects. In this paper, based on the spatial domain characteristics of the wire rope magnetic leakage field, the spatial domain array (SDA) sensors for collecting the spatial magnetic leakage field are designed. According to the characteristics of leakage magnetic field and noise time-frequency aliasing, combined with the methods of signal differencing, empirical mode decomposition signal decomposition, wavelet signal noise reduction, and correlation coefficient, energy concentration, SNR coefficient, the signal feedback and evaluation are formed. Then, a multi-process adaptive signal processing method is proposed to superimpose and fuse the SDA signals to improve the SNR of the defective leakage magnetic field signal. The experimental results show that the SDA sensors, combined with the multi-process adaptive signal processing method, can effectively improve the SNR. In addition, by comparing multiple superposition methods and single-sensor noise reduction methods, it is verified that the proposed method is optimal. Multiple case studies also demonstrate the adaptability and effectiveness of the SDA sensors combined with adaptive signal processing methods. Meanwhile, the influence of different processing parameters on the signal processing results was revealed.