| 摘要 |
<p>In order to detect during travelling, an abnormality such as a drop in sensitivity, or a fault in a radar apparatus comprising a radar beam transmission device 30 and a reception device 40, and a processing unit 51 for detecting the position of a target object from transmission signals and reception signals, the processing unit 51 has a preceding vehicle judgment circuit 51a for judging if a vehicle travelling in front of a subject vehicle in the same direction is the same vehicle or not, and a signal strength comparing device 51c for comparing the signal strength of a current reception signal reflected from the preceding vehicle, with a signal strength of a reception signal reflected from the preceding vehicle a predetermined comparison reference time prior, to thereby calculate a change amount in signal strength. When the change amount calculated by the signal strength comparing device 51c drops beyond a previously set threshold value when it is judged by the preceding vehicle judgment device 51a that the preceding vehicle is the same vehicle, it is judged that the detection sensitivity of the radar apparatus has dropped. <IMAGE></p> |
