Speed measuring system for motor vehicle

摘要

The system records the vehicle speed by means of microwaves, using the Doppler effect, and comprises at least two orthogonally arranged Janus sensors on the lower surface of the vehicle (6). Each Janus sensor has two microwave sensors (1-4) that emit in opposite directions with an angle to the lower surface of the vehicle, on the road surface. The Janus sensors are arranged at an angle of /= /! 45 deg with respect to the longitudinal axis (7) of the vehicle. The Doppler-frequencies determined by the individual microwave sensors are evaluated in an on-board computer. An additional individual microwave sensor (5) is installed at at least one other place of the lower surface of the vehicle, which measures a component of the speed at this point, in a direction with an angle of /= /! 45 deg or /= /! 135 deg .