| 摘要 |
<p>PURPOSE: To provide a speed-measuring apparatus which measures a speed of an object approaching to the apparatus. CONSTITUTION: A part of an ultrasonic wave transmitter/receiver 19 having a plurality of elements arranged is vibrated by a signal from a driving signal source 20, thereby to generate ultrasonic waves in a target area. A receiving signal detected by the transmitter/receiver 19 from a reflecting body is amplified by an amplifier 21, digitized by an analog-digital converter 22 and input to a speed-operating part 23. The speed-operating part 23 operates/calculates a speed. The presence/absence of a colliding object or a relative speed is displayed by hues, luminance or numerals at a display part 24. A two-dimensional receiving signal in an arranging direction of the plurality of elements of the receiving means and a time series direction which is obtained by repeating the transmitting and receiving operations a plurality of number of times is subjected to two-dimensional Fourier transformation to measure a moving speed of the object towards the receiving means 19. Accordingly, only a truly dangerous object can be detected.</p> |
