| 摘要 |
PURPOSE: To realize a system which accurately calculates a present position of a vehicle by taking an error of a moving distance of the vehicle into consideration, by calculating a reliability for a plurality of candidate points obtained as positions where the vehicle is probably present every time the vehicle runs a predetermined distance. CONSTITUTION: Supposing that a virtual present position A after a vehicle runs from a candidate point 62 on a segment 61 is not on the segment corresponding to a running road, but is displayed at a point 63, segments 64, 65 are taken first which are present in a predetermined range from the position A, and show bearings of a difference not larger than a predetermined value from a bearing of the vehicle. Distances L1 , L2 from the position A are calculated. Correlated error costs, correlated accumulated error costs and correlated reliabilities are calculated, based on the calculated distances and anglesθ1 ,θ2 of the segments 64, 65 and the bearingθcar of the vehicle. Positions a distance R ahead along the segments 64, 65 are set as candidate points 66, 67 and, the point of a larger reliability is designated as a display candidate point. The sequence is repeated every time the vehicle runs a predetermined distance. |
