Continuous Leak Detection and Location through the Optimal Mother Wavelet Transform to AE Signal

Abstract

This study is interested in executing an optimal wavelet transform (WT) to interpret the continuous leak acoustic emission signal precisely. Thus, this paper proposes detailed guidelines on how to select an optimal mother wavelet. The recurring dominant signal patterns were first isolated from the raw leak AE signal. Having their correlation similarity with available standard mother wavelets led to the optimal choice of mother wavelet. The WT spectrogram with mother wavelet cmor1-1.5 presents an excellent leak frequency band and peak leak frequency in comparison with other mother wavelets. Cross-correlation tests were further carried out to evaluate the ability of cmor1-1.5 for locating the leak source with WT coefficients on the leak characteristic frequency. Furthermore, through directly transferring the raw leak AE signals into the cross-correlation function to recalculate their time difference of arrival (TDOA), the location results of the leak source have a huge deviation or are fundamentally impossible. Thus, comparison incredibly indicates the significance of the choice of suitable mother wavelet, which also further highlights that having an optimal choice of the mother wavelet in the proposed method led to the accurate location for the leak source.