APPROACH ALARM METHOD, APPROACH ALARM SYSTEM, NAVIGATION SYSTEM AND ITS COMPUTER PROGRAM

摘要

PROBLEM TO BE SOLVED: To accurately and appropriately provide a pedestrian with the approach alarm of a vehicle. SOLUTION: The navigation system 1 mounted on the vehicle computes the current position of its own system and estimates the location of its own system (the vehicle) after a prescribed time on the basis of the computed current positional information. Further, when determining that the relative distance between the navigation system 2 and a portable unit 3 is smaller than a prescribed distance, on the basis of the estimated result and the current position information received from the portable unit 3. the navigation system 1 provides the portable unit 3 with alarm information for alarming the approach of the vehicle and the pedestrian. The portable unit 3 informs the pedestrian carrying the portable unit 3, of the alarm information received from the navigation system 2.