| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To surely detect relative relationships between other vehicles and one's own vehicle, even when mutual interference between its electric wave and electric waves being transmitted signals emitted by the other vehicles occurs. <P>SOLUTION: The electric wave whose frequency is modulated, wherein radar regions to be emitted by first modulation width and cooperating-among-vehicles regions to be emitted by second modulation width narrower than the first modulation width appear alternately by a predetermined time period, is outputted as a transmission signal. In addition, a beat signal having as a fluctuation frequency the difference in frequency between the transmission signal and a received signal, is generated. Moreover, if the amplitude of fluctuation of the beat signal is larger than a predetermined minimum threshold, when the output state of the transmission signal is in the cooperating-among-vehicles region, it is judged that electric-wave interference between the transmission signal of the own vehicle and a transmission signal of another vehicle occurs, and the transmission timing of the transmission signal of the own vehicle is changed so as to diminish the phase difference between both signals. A relative distance between the own vehicle and the other vehicle is detected on the basis of the difference in phase between the transmission signal and the received signal, after the transmission timing is changed. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
