A fundamental study for long-distance noncontact shallow underground exploration technology by acoustic irradiation-induced vibration

摘要

A fundamental study was conducted to investigate the possibility of shallow underground exploration from a long distance by acoustic irradiation-induced vibration. To detect buried objects in shallow underground, our method is proposed to excite the ground surface directly from above with sound waves and measure the vibration velocity distribution with a laser Doppler vibrometer. From the experimental results, it was found that the detection frequency is inversely proportional to the size of the buried object, but does not change much even if the buried depth is changed. It was also clarified that the buried object can be detected even if the grazing angle of the laser is about 20 degrees, and that it can be explored even at a distance of about 20 m. From these experiment results, it became clear that there is a possibility of shallow underground exploration using an unmanned aerial vehicle equipped with a small sound source.