An Improved Automatic Picking Method for Arrival Time of Acoustic Emission Signals

In this paper, an improved automatic method for picking arrival times of acoustic emission (AE) signals, has been proposed to overcome the interference of spike noise and channel crosstalk. First, median filter is applied to eliminate spike noise presented in signals. Second, the preliminary arrival time is obtained by the AIC picker. Then a judgment whether the signal is disturbed by channel crosstalk is conducted. If the signal is triggered normally, the preliminary arrival time is regarded as the final arrival time of the AE signal. If the signal is triggered in advance, the signal series is selected from the preliminary arrival time to the time corresponding to the maximum of absolute values of signal series. At last the AIC picker is used again to pick the arrival time of selected series and the second AIC arrival time is interpreted as the final arrival time. To validate the performance of the improved automatic method, AIC picker, AIC picker applied after the median filter (MF-AIC) are also used simultaneously to pick the arrival times of AE signals and perform event location. The results show that the improved automatic method has better waveform adaptability and location accuracies than other two methods.