| 摘要 |
<p>PURPOSE: To stepwisely alter the receiving amplification factor and to accurately calculate the relative speed based on the rangefinding result before or after the factor is varied by reading a previous distance between two vehicles obtained by the same receiving amplification factor as a new suitable receiving amplification factor from reference-distance-between two vehicles preserving means, and giving it to relative speed calculating means. CONSTITUTION: A received signal is amplified at a suitable receiving amplification factor by a signal amplifier 1d to calculate the relative speed of the respective times, binarized by a signal processor 2, then synchronously added and preserved in a memory 3e. Then, the received signal is amplified by altering the factor to the amplification factor raised or lowered by one stage from the suitable receiving amplification factor, binarized, and the distance between two vehicles obtained by totally three times of rangefinding operations for synchronously adding the signal is preserved in the memory 3e. In order to calculate the relative speed, if the suitable receiving amplification factors at the previous time of one set three times of rangefinding operations and at this time of one set three times of the rangefinding operations are altered, a relative speed calculator 3 calculates the relative speed by using the distance between the two vehicles obtained by rangefinding at the suitable receiving amplification factor of this time and the distance between the two vehicles obtained by the same factor of the previous time.</p> |
