| 摘要 |
PROBLEM TO BE SOLVED: To easily inform a user of the position relation between user's own car and another vehicle by outputting an alarm tone at the moment when the distance between this vehicle and opposite vehicle becomes larger than a specific value or becomes smaller than a specific value. SOLUTION: When users own vehicle always monitors the position of another vehicle, the current position of the other vehicle on a road acquired periodically from an opposite-vehicle communication part 110 through a portable telephone line outputted to a map display control part 107 to display a map showing the other vehicle in the center, thereby informing the user of the presence of the other vehicle. To merely confirm whether or not a missing vehicle is nearby users own vehicle, the user inputs an alarm sound border radius for setting an alarm sound border through an input operation part 106 in advance. A vehicle-to-vehicle distance judging part 111 finds the distance to user's own vehicle euery time the current position of the opposite vehicle is receives by the opposite-vehicle communication part 110, and compared with the vehicle-to- vehicle distance when the other position is received, and when it is judged that the previously alarm sound border on the map is crossed, an alarm sound is outputted to a speaker 112. |
