基于时间差映射方法的钢板声发射源定位

When the acoustic emission source is located by the Time of Arrival (TOA) method, the wave velocity is required to be constant and propagation paths between the sound source and sensors are continuous.The wave velocity of signals propagating in different directions in the plate may be inconsistent in practical applications.This paper proposes a Time Difference Mapping (TDM) method.This method use the prebuilt database method, avoiding consider the wave velocity in the plate, the wave propagation modes, and the layout of sensors in experiments.This method simulates acoustic emission sources by artificial, records the time when the signal reaches each sensor, finds the arrival time difference of different sensor paths, and filters the equal time difference within the error range in the generated time difference contour map.The minimum difference method is used to find the point where the difference between the actual sound source data and the training map data is the smallest, that is, the position of the sound source.In this experiment, four acoustic emission sensors were arranged on the steel plate, and eight points were randomly selected for experimental verification.Compared with the TOA method, the positioning error of the TDM method is reduced from 1.41% to 0.38%.Therefore acoustic source localization is more accurate by using this proposed method.