| 摘要 |
<p>PURPOSE: To prevent an alarm from being erroneously outputted by suppressing the alarm output while judging a target based on the change of the speed ratio of driver's own vehicle speed to relative speed to the target and the measured distance. CONSTITUTION: At a distance detection part 13, the time difference between a signal from a transmission part 11 and a signal from a reception part 12 is calculated and transmitted to a microcomputer 10, the driver's own vehicle speed is calculated by a car speed sensor 14, and the relative speed to the target in front of the vehicle is calculated based on the vehicle speed and the change of a distance value to the target. When the target is regarded as an almost standstill object from the relation of this relative speed and the vehicle speed, the speed ratio of the relative speed and the vehicle speed is calculated. Next, the change in the value of distance to the target is detected and when the target is not changed, the time in which the target is being caught is confirmed. Then, if the calculated speed ratio is still almost equal to the speed ratio of the last target, the detected target is judged as a reflector installed on a curved road side and the alarm is suppressed.</p> |
