| 摘要 |
PROBLEM TO BE SOLVED: To correctly display the present position of one's own vehicle by calculating a distance coefficient from correct distance data of automatic charging devices thereby obtaining a correct distance travelled. SOLUTION: A GPS receiver 4 receives waves transmitted from a plurality of satellites and calculates to obtain a position where the receiver receives the waves. A CD-ROM(read only memory) drive 5 reads out data from a CD- ROM 6 recording map data and tools. When a vehicle passes automatic charging devices 19A, 19B, the fact is informed to a CPU 9 via an IC card 20 through a communications interface 18. In consequence, the CPU 9 calculates a distance coefficient based on distance data between the automatic charging device 19A and 19B and a count of rotational pulses from a distance sensor 2, thereby the correct the coefficient. A correct distance traveled by the vehicle is thus obtained, and the present position of the vehicle can be displayed more correctly to a liquid crystal display 7A. |
