Propulsion direction finding system null of propulsion machine for jacking method

摘要

PURPOSE:To detect the propulsion direction of a propulsion machine by the measurement at one place, by using a detector in which a plurality of receiving coils whose coil shafts are set horizontally are arranged on a transport basic body, while changing the direction of the coil shaft in the horizontal plane. CONSTITUTION:A propulsion direction detector 10 is constituted by arranging, on a transport basic body 11, a plurality of receiving coils 9a-9c whose coil shafts are set horizontally, in radial form for a common center point 12, while changing the direction of the coil shaft in a horizontal plane. Then, the propulsion direction detector 10 is arranged; above the estimated position for the presence of an expulsion machine. Then, the magnetic field due to the receiving coil is measured by for each of receiving coils 9a-9e. The magnetic field intensity distribution received by each of receiving coils 9a-9e is plotted for the angle in which each of receiving coils 9a-9e exists, and the max. and min. values of the curved line passing through these plotted points are obtained through the approximate calculation thereof. Then, the direction of the propulsion machine is detected from the result of the measurement.