| 摘要 |
Collision warning systems which consist of a directional antenna which radiates linearly polarised signals and receives echo signals polarised orthogonally thereto, of a pulsed radar operating with stochastic pulsing at high duty ratio and of signalling devices, and which warn optically, acoustically and kinetically with each threatening collision, only rarely produce a false alarm due to their high noise immunity. However, so that even the remaining false alarms are eliminated as completely as possible, the reflection characteristic of the traffic objects is improved by equipping them with passive polarisation-rotating reflectors in such a manner that the echo signals of non-traffic objects fall below the receiving threshold. As the false alarm rate disappears, all impact accidents threatening due to inattentiveness of the driver are automatically avoided by reduction of the driving force with each alarm and by appropriate additionally triggered braking measures in the case of an intensive alarm.
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