| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve reliability in estimating a collision by surely correcting a shift of a peak frequency of reflecting waves and detecting a highly accurate relative speed. SOLUTION: FM modulation waves are transmitted to an automobile 1 as an obstacle via a transmitting antenna 2, a receiving antenna 3, a radar head 4, a low pass filter 5, an amplifier 6, an A/D converter 7 and a triangular wave signal generator 8. Reflecting waves are received and a frequency spectrum is extracted at a spectrum extraction part 9a of an MPU 9. A peak frequency is detected by a peak frequency detection part 9b. A distance to the automobile 1 and a relative speed are detected from the peak frequency by a distance.relative speed detection part 9c. A collision estimation part 9e estimates a collision based on the distance and relative speed. At this time, stability for a fixed time of the distance to the automobile 1 and relative speed is judged based on the extracted frequency spectrum by a relative speed correction value detection part 9d, so that a correction value for the relative speed is detected. The relative speed is corrected by the detection part 9c on the basis of the correction value.</p> |
