| 摘要 |
<p>A position measuring device that is capable of detecting the position of an underground excavator with ease and accuracy, especially its position on the horizontal plane, when excavating the underground by a shield machine, etc. For this purpose, it is provided with a transmitter (10) that generates an alternating current magnetic field and consists of at least two sets of cables (10a, 10b), a receiver (30) that receives the magnetic field, and a computing unit (60) that discriminates a received signal and computes the position of the underground excavator (20). The cables (10a, 10b) are installed crossing each other nearly at right angles. The receiver (30) is constituted of two sets of magnetic field detecting elements (S1, S2) installed crossing each other nearly at right angles and supported by a receiver supporting device (40) that turns so that these elements always maintain a specified angle to the two sets of cables.</p> |
