| 摘要 |
PURPOSE:To correctly obtain the inclination and positional shift to the reference position even when an object to be measured is inclined by providing a first and a second magnetic field detectors in front of and in the back of a magnetic field generator. CONSTITUTION:An underground excavator 10 at the reference position has a magnetic field generator 14 at the front face of a cutter drum 12. An exciting current is fed from alternating current sources 16a, 16b to transmission loop cables 14a, 14b of the generator 14, thereby generating an alternating current magnetic field. Moreover, a boring machine 24 of small diameter of a consolidation type is provided in front of an underground excavator 20 which is an object to be measured. A first magnetic field detector 26 is placed near an end of the machine 24, while a second magnetic field detector 28 is provided therebehind with a distance L from the detector 26. The machine 24 is advanced toward the excavator 10, and the end of the machine 24 reaches the front face of the excavator 10. A detecting signal of the detector 26 at this time is input to an operating device, and the amount of the displacement in the Y-axis and Z-axis directions of the detector 26 is obtained. Similarly, the amount of the displacement in the Y-axis and Z-axis directions of the detector 28 is obtained by the operating device. Moreover, an inclining angle of the machine 24 to the excavator 10 can be calculated. |
