| 摘要 |
PURPOSE: To accurately discriminate a dangerous obstruction from an undangerous obstruction by comparing the difference between the relative speed, obtained from transmit-receive signals of a frequency modulated continuous wave signal and a continuous wave signal, with the predetermined threshold value. CONSTITUTION: In response to control signals 51, 52 from a digital processor 49, a modulator 47 with multiple functions outputs (60) constant DC voltage or linear lamp voltage, and continuous wave(CW) or frequency modulated continuous wave(FM-CW) radar signals are outputted (61) from a voltage controlled oscillator(VCO) 45. A mixer 44 inputs part of these radar transmit signals and a radar reflection signal received by a receiving antenna 42 and generates an IF signal which is amplified-filtered (46), A/D-converted (48) and sent to the processor 49. The processor 49 determines distance from an obstruction and relative speed on the basis of these signals and compares the difference of the relative speed determined by FM-CW and CW with the predetermined threshold value, and judges the obstruction to be dangerous at the time of exceeding the threshold value and to be undangerous at the time of not exceeding the threshold value. |
