AE Signal Acquisition Of Geotechnical Based On LabVIEW And Source Location

Coal occupies the leading position in our country’s energy structure, and it will be the main energy source of our country in a long period of time. But with the increase of the depth of coal mining and geological conditions become more complex, water inrush, coal and gas outburst and other serious accidents occur frequently in the safety production of coal mine. In serious accidents of coal mine in china, the number of deaths and the number of times of mine water inrush accident, Second only to coal mine gas accident, but the economic losses caused by the coal mine disaster has been the first. But mine floor, roof, working face water inrush disaster, water source and water inrush channel have strong concealment, so it has important significance to realize the location of water inrush disaster source.In the long term mining and geotechnical engineering practice, it is found that in the process of failure, the rock mass is always accompanied by acoustic emission. In recent years, people mainly through eismic and acoustic emission information in the process of monitoring water inrush to disaster warning and have made a series of innovative results. But at present the microseismic and acoustic emission sensors are based on the design principle of pressure, it is easy to bring the hidden danger to the mine safety, and the research on the existing positioning theory is not mature enough.In view of the above problems. This paper mainly introduces the acoustic emission signal characteristics and signal source of TDOA location method, and analysis of the characteristics of the rock acoustic emission signals through the rock uniaxial compression test. On the basis of the above, the rock acoustic emission monitoring instrument is developed. A piezoelectric acoustic emission sensor with a frequency range of 1Hz-15KHz is adopted, and the preamplifier is connected to the sensor. The weak acoustic emission signal is amplified, and the sampling frequency of the system is 200KHz, the sampling frequency of the system can be controlled by software, and the system has the function of damp proof and explosion proof. Thesystem uses the LabView programming environment, mainly introduces the communication method between LabView and acoustic emission acquisition card, the module design of acoustic emission acquisition software system is also realized. The software mainly includes multi-channel acquisition module, waveform display module, data storage module and waveform playback module. Single channel and multi-channel acoustic emission signals were collected and tested in the laboratory and the underground mine, and the reliability of the system was verified.In this paper, the acoustic emission source location method is explored, and the time difference between the signal source and the different sensor is extracted by the cross-correlation algorithm of two similar waveform, the average value of the wave velocity is obtained through several tests, and the results of the experiments are carried out on the Dali stone slab for linear positioning and plane positioning. The positioning error is no more than 6%, and the results are satisfactory.