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US 4,254,418 AGranted
Collision avoidance system using short pulse signal reflectometry
AssigneeSperry Corporation
InventorsHarry M. Cronson, Gerald F. Ross, Basrur R. Rao, Werner Lerchenmueller, Prentis B. Drew
Life of this patent
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Abstract
A collision avoidance system for rapid transit vehicles employing baseband radar principles in which signals with duration in the order of nanoseconds are transmitted down track along a surface wave transmission line. Reflections from a passive target located on the preceding vehicle are processed to establish the distance between the vehicles to within an accuracy previously unachievable.
Claims6
A collision avoidance system for a vehicle travelling a prescribed route with a wave guiding structure extending therealong comprising:
- means on said vehicle and coupled to said wave guiding structure for transmitting short pulse signals;
- means on said vehicle and coupled to said wave guiding structure for receiving short pulses reflected from an obstacle preceding said vehicle and for providing at an output terminal thereof short pulse signals representative of said received reflected short pulses;
- a transmission line coupled at one end to said transmitting means and at the other end to said output terminal of said receiver means, said transmission line having taps thereon with electrical spacings therebetween which are substantially equal to a distant measurement increment;
- and
- means coupled to said taps for determining and indicating a tap at which a short pulse coupled to said one end and a short pulse coupled to said other end coincide, whereby the distance between said vehicle and said obstacle is determined by noting said coincidence tap for said short pulses coupled from either end of said transmission line.
2 more elements
Dependencies are inferred from the claim text.