Anti-collision safety device for a passenger transport system on tracks

Abstract

An anti-collision safety control for vehicles travelling on tracks; the control comprises two safety loops per vehicle, linked to two common loops in a central control station. Each vehicle loop comprises control circuits for determining the distance to the next preceding vehicle, for determining a safe stopping distance for the vehicle, and for stopping the vehicle if the distance to the preceding vehicle becomes smaller than the safe stopping distance or if there is a failure of a safety circuit. The distance control circuit comprises a detector for detecting reference points provided along the track, a counter for calculating the distance of a vehicle from a given zero location, and a delay circuit for converting this distance into a position signal timed to a synchronization pulse received by all vehicles. Position signals from all vehicles are transmitted to the central control and back to the vehicles; the distance to an immediately preceding vehicle is determined by comparing the position pulses.