Single-Sensor Defect Localization for Low-Speed Bearing Based on Acoustic Emission Signal Dispersion Characteristics

Direct localization of low-speed bearing defect sources to diagnose bearing failures can be done independently by rotational speed information. However, acoustic emission (AE) source localization of defect based on sensor arrays requires high testing costs. In this article, a bearing damage source localization method by time difference of arrival (TDOA) curve matching is proposed, which requires only one sensor. First, the dispersion characteristics of AE signals inside the outer ring of a bearing are determined by combining the frequency dispersion of rectangular rod waveguide theory and continuous wavelet transform (CWT), and the theoretical TDOA curves are established for the bearing outer ring structure. Second, the TDOA of the measured AE signal is extracted from the time-frequency representation based on CWT and matched with the theoretical TDOA curve to realize the damage source localization of the target bearing. Finally, the performance of the proposed method is verified by the broken lead signal and the measured bearing defect signal.