| 摘要 |
PURPOSE: To calculate the current position of a vehicle in an accurate manner by searching such a road as being considered that the vehicle is properly traveling even in the case where there is no road in and around a vehicle estimated position detected by both distance and direction sensors. CONSTITUTION: An estimated position of a vehicle is determined with an absolute direction calculated by an output value of an azimuthal sensor 12 and a direction variation to be outputted from an angular velocity sensor 11. A pulse number to lee outputted by a car speed sensor 13 is counted, and a distance coefficient is multiplied to the counted value, seeking the traveling distance. A virtual current position is calculated from the traveling direction and distance, seeking a proposed point of the vehicle, and it is stored in a memory 25. After this proposed point has once come to a state that there is none on the road, in the case where a first counting means value is more than the specified value but a second counting means value is less than the specified value, plural second virtual positions are formed in a position being separate as far as the specified distance from the proposed point. On the basis of these virtual positions, a second proposed point is formed, and thus a position of such a proposed point as the largest in reliability value among the proposed points becomes the current position of the vehicle. |
