Patent GB-1117123-A (GB)
Title: Vehicle communication systems
IPC: B61L13/04
Filed: 1965-08-13
Abstract: 1,117,123. Automatic train control. SIEMENS A.G. 13 Aug., 1965 [13 Aug., 1964], No. 34882/65. Heading B7N. In an automatic train control system, each track region is divided by cross-overs in a lineside loop into a series of sections and trains in each region are controlled by information supplied by a regional control office which includes coded information defining the shape of the speed/distance curve to be followed by each train. The arrangement is described with reference to a track region including sections AB1-AB9 each 100 metres in length and including two slow speed sections LF30 (30 Km/h.) and LF10 (1OKm/h and a stop signal LP3. Six pieces of information are passed by the office to control a train, the first is a track code characteristic of the region, the second is the number of the section occupied by the train, the third Z is the distance from the end of the section to the next change of speed point, the fourth Vz is the speed to be assumed at that point, the fifth XS is the nominal braking distance at the end of the section in which the train is travelling, this defines the speed of the train at the end of the section and sixth the code sign, LA, BR, BL and LB defining the speed-distance curve shape. The code sign LA, see Section AB5, is used to signal constant speed, the sign BR is used to signal a constant deceleration such that the braking distance XS reduces by 100 metres in the section, the sign BL signals constant deceleration for the first half of the section then constant speed for the rest of the section whereby the braking distance is reduced by 50 metres and sign LB indicates that the speed should remain constant over half the section and then reduce over the remaining part of the section so that the braking distance reduces by 50 metres. These signals to the train are produced in the control office which includes a track simulator store which stores the position of trains in the region, a speed limiting store which stores details of the slow speed zones and signalling information, means for interrogating these stores, computer and store means for the information to be transmitted, transmitter means and a link to the regional control office in advance which provides information for the control of trains in the last sections of the region. The train is provided with means driven from the train wheels which provides an indication of the speed of the train and also generates a pulse for each metre travelled by the train, these metre pulses reduce the count of 100 in a pair of counters to zero as the train passes through a section. The first two signals i.e. the region and section numbers are checked to ensure that the information is addressed to the correct train and then the train speed at the next speed change point and the distance to this point which comprises the distance signal transmitted plus the count in the metre pulse counters are displayed on a drivers indicating panel which also displays the actual train speed. The nominal braking distance signal is modified by the count from the metre pulse counters in dependance on the code signal issued from the office and the result ant braking distance is converted to a desired speed which is compared with the actual speed to automatically control the speed of the train. The train supplies signals to the office, generated during passage over the crossover points of the lineside loop, which indicate the track section occupied by the train.