Abstract
Recently, pipes like a water pipe or a gas tube are buried in wide area. Horizontal Directional Drilling (HDD) method is used as a pipe embedding method because the method requires no open cuts. However, the position of the drill-bit in underground is instability, and it must be estimated by extend sensors. We focused on the estimation method using the sound generated by the drill-bit itself. In this study, an estimation method of the drill-bit position using the reflected sound from ground surface as well as the direct sound from the drill-bit is proposed. Although the conventional method, which only uses the direct sound, requires a lot of geophones, the proposed method only requires an array consisting of some geophones. From some experiments in actual soil, it was verified that the proposed method was effective for estimating the position of the drill-bit. As the results, the proposed method enabled to estimate 3.42 times more accurately than the conventional method.
