| 摘要 |
PURPOSE: To provide a present location calculating device which can prevent it map matching accuracy from being deteriorated by an azimuth error. CONSTITUTION: A processor 18 determines the most probable present location of the vehicle having the system along a road based on the distance to a segment contained in road data from a virtual present location estimated from the relative displacement of the vehicle found from the azimuth and traveling distance of the vehicle and the present location of the vehicle determined the previous time and the difference between the azimuth of the segment and vehicle. Then the processor 18 corrects the latest azimuth of the vehicle in accordance with the difference between the azimuth of the road and vehicle which is the difference between the azimuths of the vehicle and segment at the present location at one or more points of time in the past determined by map matching and executes map matching, based on the corrected azimuth of the vehicle. The processor 18 does not correct the azimuth while the vehicle travels a prescribed distance after the vehicle passes a junction. |
