| 摘要 |
A radar system for sensing the presence of obstacles in a vehicle's "blind spots" and generating a signal (41) to the vehicle operator indicative of the presence of such an obstacle. The system uses a common radar transceiver (7) that transmits a radio frequency signal directed at a blind spot of the vehicle. A Doppler shift in the received reflected frequency generally indicates that an obstacle has moved into the blind spot. Doppler frequencies attrributable to objects which are of no interest, such as stationary objects, are filtered out. Only obstacles that are traveling at approximately the same speed and direction as the vehicle are considered to be of interest, and will cause the blind spot sensor to generate an indication that an obstacle is present in the blind spot. The indication is preferably an unobstrusive illuminated indicator which is affixed to one of the vehicle's mirrors. An obstrusive audible indicator is provided which creates an audible tone, whistle, or buzz when an obstacle is present and the vehicle's turn signal is active. |
