Positioning of Acoustic Emission Source by Using Sub-gradient Projection Based on Energy Attenuation Model

Abstract

Because of containing several model waveforms, the source rub-impact acoustic emission(AE) signal transmitting in complicated body will cause waveform distortion for varying transmission speed of each model and dispersion effect. It is difficult to achieve exact source location by traditional time difference location. An energy attenuation model is established on the basis of the characteristic of approximately inverse ratio between propagation energy and source distance, the location of the AE source is limited in a hypersphere in which the circle centre and radius are all the energy ratio functions of a sensors pair, and uses adaptive sub-gradient projection to approximate to the source location. As the method is based on energy ratio instead of energy, the location accuracy will not be significantly affected even if the energy of AE source has a significant change. When multiple sensors pairs are installed more hyperspheres can be decided, so this method is also applicable to positioning array composed of multiple sensors. The experiment results show that this algorithms has higher location accuracy than Time Delay Estimation algorithm, it also has good convergence and lower computation complexity.