| 摘要 |
PURPOSE:To precisely collate the estimated present position with the and match it to the most probable position even when a vehicle is traveled on a curved road. CONSTITUTION:An arithmetic processing section 1 receives the change quantity of the azimuth per unit distance, the advance direction of a vehicle, and the travel distance of the vehicle from a direction sensor 2 and a travel distance sensor 3 to estimate the present position. Road data are read out from a memory device each time the vehicle is traveled by a distance l1 while the course of the vehicle is not changed, or by a distance l2. smaller than l1 when the course of the vehicle is changed. A prescribed matching calculation is made with the travel locus of the past distance l1, it is collated with the estimated present position, the most probable position is calculated, and the estimated pres/ent position is matched with it. The distance is made nearly equal to the length of a straight line capable of approximating the curved portion of a road. |
