| 摘要 |
PROBLEM TO BE SOLVED: To report information on an object installation position inexpensively and precisely, even if positional information or moving speed cannot be acquired. SOLUTION: Positional information regarding a measuring device e of speed in a tunnel and induction points b, c, d provided on positions on a road in the tunnel guiding to the device e position is stored in a database. The induction point b is set at a position which lies within 1 km from a position which can be positioned by a GPS receiver, before entering the tunnel, and the distance between each induction point is set within 1 km. The present position is updated, by assuming that traveling is performed at a speed immediately prior to positioning becoming impossible, toward the induction point b from a present position immediately prior to positioning becoming impossible at the tunnel entering point a, and when reaching each induction point position, and the present position is updated similarly toward the next induction point. If the next induction point does not exists, the present position is likewise updated toward the measuring device of the speed in the tunnel. When the relation between the measuring device e of the speed in the tunnel and the present position reaches 2 km, 1 km and 500 m, an approach alarm is issued, respectively. COPYRIGHT: (C)2011,JPO&INPIT |
