| 摘要 |
<p>PURPOSE:To detect the position of a ground embedded object with high accuracy, by allowing an induced current to flow to the conductive ground embedded object from a transmitter by electromagnetic induction and eliminating the effect of other ground embedded object close to the ground embedded object to be detected. CONSTITUTION:A pair of coils 3a, 3b whose axes are turned in vertical and horizontal directions with respect to the surface of the ground are provided to a transmitter 2 and, by respectively changing the magnitudes of the AC currents flowing to the coils 3a, 3b, the magnetic flux interlinkage state to a ground embedded object is changed. Herein, magnetic fields are generated from the coil 3a whose axis l1 is turned in the vertical direction and the coil 3b whose axis l2 is turned in the horizontal direction. When these two magnetic fields are superposed each other, a synthetic magnetic field is formed and the axis in this synthetic magnetic field is inclined by an angle theta from the axis l1 (l2) and this angle theta can be changed by changing the currents flowing to the coils 3a, 3b. Next, in a receiver 4, a data transmitting part 7 transmits the signal from a signal processing part 8 to the data receiving control part 6 of the transmitter 2 through a medium 9 such as a radio wave or an optical fiber. A magnetic sensor 6' is constituted of a plurality of sensor parts S1-Sn.</p> |
