| 摘要 |
PROBLEM TO BE SOLVED: To reduce the difference between a position of own vehicle displayed by an on-vehicle device and the actual position of own vehicle, while preventing the accuracy of estimation of the vehicle position from lowering, due to a change in the state of the vehicle. SOLUTION: A navigation system is so configured that the travel-distance calculation section of the on-vehicle device calculates a first travel distance in a predetermined section, based on a speed of own vehicle calculated, by using vehicle-speed pulses output from own vehicle and a vehicle-speed calculating coefficient; the travel-distance calculating section of a portable terminal device calculates a second travel distance of the vehicle in the predetermined section, based on the GPS information provided from a positioning satellite; a learning section corrects the vehicle-speed calculating coefficient, based on a comparison result between the first travel distance and the second travel distance; and own-vehicle position estimating section of the portable terminal device estimates the position of the vehicle, based on the own-vehicle speed calculated by using the vehicle-speed pulses and the corrected vehicle-speed calculating coefficient. COPYRIGHT: (C)2011,JPO&INPIT |
