POSITION DETECTING DEVICE FOR UNDERGROUND EXCAVATOR

摘要

This invention intends to provide a position detecting device for an underground excavator, which device is capable of automatically measuring three-dimensional relative positions of two underground excavators distantly located opposite to each other or such two positions relative to a reference position, and is free from errors in measurement even in the case of excavation over a long distance. The position detecting device is provided with a plurality of magnetic field generating units (4a, 4b, 4c) disposed on the first underground excavator (l), a plurality of diametrally small boring units (3a, 3b, 3c) disposed in the positions opposite to the first underground excavator, a plurality of magnetic field detecting units (6a, 6b, 6c) disposed on the respective tips of the diametrally small boring units, and a calculation unit (14) to find relative positions of the first underground excavator with respect to the positions opposite thereto on the basis of detection signals outputted by the magnetic field detecting units and lengths excavated by respective boring units.