Patent ID: 9307369
Filing Date: 2016-04-05
CPC Classification: G01C,G01S,G06F,H04W

Claim Text:
1. A wireless position detection apparatus equipped to a moving object, the apparatus comprising: a coverage map storing unit storing a coverage map correlated to a plurality of map object data elements and a plurality of position information elements of auxiliary points, the coverage map being preliminarily prepared for a road and indicating reception states of wireless signals along the road, the wireless signals being transmitted from a wireless transmission device, the map object data elements being prepared for respective predetermined map objects positioned along the road, each of the map object data elements including one or more sub data elements each of which indicates a property of the corresponding map object, the one or more sub data elements including at least one position data element that expresses a position of the corresponding map object by a positioning coordinate, the predetermined map objects being correlated to the respective auxiliary points on the coverage map, each of the auxiliary points having the position information element expressed by a relative coordinate on the coverage map; a reception state detection unit detecting reception states of wireless signals transmitted from the wireless transmission device in real time; a distance detection unit successively detecting moving distances of the moving object; a generation unit generating a positioning locus that indicates a relation between the moving distances of the moving object detected by the distance detection unit and the reception states of the wireless signals detected by the detection unit in real time correlated to the road travelled by the moving object; a determination unit extracting, from the coverage map, a portion as a target portion when a shape of the positioning locus is similar to a shape of the portion of the coverage map, and the determination unit determining an end point of the target portion as a current position correspondence point of the moving object, the current position correspondence point is a point existing on the coverage map and being correlated to a current position of the moving object; and a calculation unit specifying, on the road, a target point corresponding to the current position correspondence point of the moving object and calculating a positioning coordinate of the target point as a current position information element of the moving object based on (i) a position information element of the current position correspondence point of the moving object on the coverage map, (ii) the position information element of the auxiliary point positioned immediately prior to the current position correspondence point on the coverage map and the position information element of the auxiliary point positioned immediately posterior to the current position correspondence point on the coverage map, and (iii) the position data element of the map object corresponding to the auxiliary point positioned immediately prior to the current position correspondence point on the coverage map and the position data element of the map object corresponding to the auxiliary point positioned immediately posterior to the current position correspondence point on the coverage map.