MULTI-COMPUTER VEHICLE CONTROL SYSTEM WITH SELF-VALIDATING FEATURES

摘要

1430641 Automatic train control GENERAL SIGNAL CORP 22 Feb 1973 [22 March 1972] 8825/73 Heading B7N In a central traffic control system for controlling vehicles in a railway network, e.g. of the type described in Specification 1,430,642 and in which two computers operating independently are used at the control station to compute vehicle speeds, validating apparatus is provided on each vehicle for ensuring that both computers were involved in compiling the vehicle speed control signals from the central station. The speed control signals are cyclically transmitted as a vehicle command message 22 from the central office to the vehicles and each message comprises a first part A contributed by one computer a second part B contributed by the other and a third part C which includes the vehicle address and speed control information independently verified by both computers. During one cycle the part A carries binary 1 and part B binary zero and these signal values reverse during successive cycles. The A and B signal are applied via lines 14A, 14B on the vehicle to a relay circuit which energizes relay 84A when line 14A carries binary 1 and energizes relay 84B when line 14B carries this signal. The relays are provided with shunt circuits 85A, 86A and 85B, 86B which hold the relays during the cycle they are not supplied so that a circuit via relay contacts 91A, 91B is maintained to the vehicle speed control unit 71. Should a computer fail its associated relay ceases to obtain an energizing pulse and this drops away to open the circuit whereby the vehicle is brought to a halt.