GB1506376A - Vehicle supervisory systems and apparatus therefor - Google Patents

Abstract

1506376 Automatic train control GECGENERAL SIGNAL Ltd 20 March 1975 [20 Dec 1973] 59079/73 Heading B7N Transmission of an interrogating pulse from trackside unit 4 via live wire 3 to vehicles 5 in a track section, e.g. section A, produces a response pulse from each vehicle in the section at a time from receipt of the interrogating pulse which is a function of the distance the vehicle has travelled into the track section. Vehicle apparatus.-When a vehicle enters a track section a line side marker acts via unit 11 to reset a counter 10 to zero. The counter thereafter counts tachometer pulses from unit 9 and registers a count which is a function of the distance travelled into the section. On receipt of an interrogating pulse in receiver 12 a gate 13 is opened to allow pulses from a generator 14 (operating at a much faster rate than the tachometer pulse generator) to enter counter 15. The count in counters 10 and 15 are compared in unit 16 and agree after a time interval which is a function of the count in counter 10, i.e. after a time which is a function of the distance travelled and comparator 16 triggers transmitter 17 to provide a response pulse. Trackside apparatus.-As the trackside pulse generator 25 supplies the interrogating pulses via hybrid 27 at a time selected by timing circuit 26 and at the pulse transmission time a counter 28 is reset to zero. Thereafter a pulse generator 29, operating at the same rate as generator 14 on the vehicle, supplies pulses to the counter and on receipt of a response pulse from a vehicle gate 30 is momentarily opened to supply the count at that time, which is a function of the distance a vehicle has travelled into the section to memory 31 in processor 32. On the vehicle the comparator output which produces the response pulse also triggers a bi-stable 18 which provides an output to open gate 19 whereby pulses from generator 14 are supplied to counter 20 until a response pulse issued by a vehicle ahead in the section in response to the same, interrogating pulse is received and applied to switch the bi-stable back to its first state and close gate 19. The count in counter 20 is a measure of the distance between vehicles and is supplied to an alarm circuit for control of the vehicle if the distance is not sufficient for safe operation. This distance can be transmitted from each vehicle to the trackside unit as a check of vehicle apparatus operation. The trackside unit can also simulate a response pulse defining the first vehicle in the next ahead section.