DRILL HEAD POSITION ESTIMATION SYSTEM, DRILL HEAD POSITION ESTIMATION DEVICE AND DRILL HEAD POSITION ESTIMATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a drill head position estimation device and a drill head position estimation method for estimating a three-dimensional position of a drill head under the ground without being affected by attenuation of electromagnetic wave and involving a work to search for the electromagnetic wave.

SOLUTION: In order to estimate a position of a drill head under the ground in an HDD method, the present invention uses sound, instead of electromagnetic wave used in a conventional technology, in a manner that generates sound from a tip of the drill head and receives the same by a plurality of sensor units provided above the ground. The position of the drill head can be estimated by a calculation based on time differences until the sound reaches to respective sensor units as well as distances between the sensor units. However, data obtained through the sensor units located opposite side to a travelling direction of the drill head has large errors due to propagation of the sound through a driving pipe to rotationally drive the drill head. The invention controls emission of LEDs fixed to respective sensor units so as to produce light on the LEDs of sensor units presumed to be ineffective for position estimation, and thereby facilitating visual differentiation between the effective sensor units and the ineffective sensor units as well as enabling an approximate position of the drill head to be grasped.

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