Showing papers on "Collision avoidance system published in 1984"

Collision avoidance system for aircraft

Abstract: A collision avoidance system for aircraft in which one aircraft is equipped with an interrogation station having a secondary surveillance radar. .[.Coarse.]. .Iadd.A .Iaddend.distance measurement is effected either by passive or active distance measurement or by both of them. If the detected distance lies within a certain limit, the output power and/or period of the interrogation signal of the secondary surveillance radar of the subject aircraft is altered .[.so as to effect fine distance measurement.].. This system can be applied without increasing interference against the existing secondary surveillance radar system by keeping the output power and period of interrogation signal in a minimum required extent. By the same reason the system can keep the interference at a small extent between proximate aircraft, each mounting this collision avoidance system.

Advanced group rapid transit odometer data downlink collision avoidance system design summary. final report

Abstract: This report summarizes the design of the moving block collision avoidance system developed for the Advanced Group Rapid Transit (AGRT) System. As the name implies, the system utilizes the on-board vehicular odometer to track individual vehicle speeds and positions throughout the guideway. The design utilizes eight and sixteen bit microprocessors throughout, and incorporates unique self-exercised software to detect potentially unsafe latent failures within the hardware. Odometer data is downlinked to the wayside via a proven inductive communications system. Wayside equipment computes minimum safe headway for each vehicle based upon a worst-case scenario, and compares this worst-case value to the measured value. Headway violations initiate emergency rate braking for affected vehicles. The design supports a minimum safe headway of 3.08 seconds with a brick-wall stop criterion.