| 摘要 |
The purpose of the present invention is to improve position detection accuracy after passage through an intersection. A positioning unit (10) of a vehicle-mounted device (1) comprises an intersection information storage unit (12) for storing intersection information in which the coordinates of intersection positions are associated with combinations of the directions of entry into an intersection and course change directions therein and registered, in an intersection region set at each intersection, detects, as a reference detection position, the position of a mobile object when a predetermined condition is satisfied, on the basis of the direction of entry into the intersection region and the course change direction therein, acquires the coordinates of an intersection position corresponding thereto, and using the positional coordinates of the intersection position and the reference detection position, corrects positional information relating to the mobile object and acquired by a positional information acquisition unit (11). |
