Patent GB-1232302-A (GB)
IPC: B60L15/20
Filed: 1968-08-22
Abstract: 1,232,302. Automatic train control. SOC. ANON. DES ATELIERS DE SECHERON. 22 Aug., 1968 [23 Oct., 1967], No. 40289/68. Heading B7N. [Also in Division H2] An electronic device for the automatic control of a railway train along an itinerary comprising several zones, delimited between geographical points along this itinerary, in each of which the feed current of the motors is cut off automatically before each zone end if the distance counted from the beginning of the zone becomes equal to the distance the train must have travelled at that instant of time in order to reach the end of the zone on schedule with the motor supply thus cut off, comprises means for comparing a function of the distance travelled in the respective zone with the time elapsed from the beginning of the zone thereby to provide a signal which causes the said automatic cut-off of motor current and also to provide a signal at the end of the zone; and further comprises a generator for generating the functions corresponding respectively to the different zones, sets of electronic components for the registration of the parameters of these functions, these sets of components each comprising as many components as there are zones, and means are provided for the commutation of the components of each of these sets upon receipt of the respective end-of-zone signal. The various parameters are represented by resistances in sets 3 to 12, one resistor of each set being switched in for each zone by an electromagnetic stepping device 2 actuated by end-of-zone signals FZ. Pulses are fed into a decade counter 34 as functions of train travel and when counter 34 corresponds to a rail time counter 39 an output pulse P cc  cuts off the current to the motors. A short distance adjacent each station (G 1 , G 2  &c., Fig. 1, not shown) allows the train to accelerate before entering the next controlled zone and the output of a distance-measuring device 13 is compared with a resistor 3 (kilometres) and a resistor 4 (hectometres) to provide a pulse O when the beginning of a controlled zone is reached. The forward flank of pulse O resets the counter 34 to zero and the end of the pulse O causes a preset number of pulses to be fed to the counter from analogue-digital converters 20 and 21. In a first embodiment, Fig. 3, the counter 34 then advances by pulses in accordance with a resistor 7 by means of logic circuits 22, 31, and 33 under control of pulses P from a logic circuit 48 receiving pulses E 1  for each 10 metres travelled by the train. Circuit 48 is controlled by a resistor 8 via logic circuits 23 and 32. Flip-flops 50 and 51 provide signals FA and FB which, by logic circuits 28, 29 and 30, successively bring into use the resistor pairs 7 and 8, 9 and 10, 11 and 12, whereby a zone is divided into three contiguous linear functions approximating the desired overall function for a zone. At the end of a zone, circuit 52 provides signal FZ which steps the device 2 and resets counter 13 to zero. In a second embodiment (Fig. 5, not shown) the resistor sets 7 to 12 are replaced by three sets (100, 101, 102), the first representing the initial slope of the desired function of a zone, the second representing the final slope of the function, and the third controlling the provision of pulses P which are fed to circuitry (106 to 111) to give pulses S of increasing width which change the control by a first resistor (100) to control by a second resistor (101) in sixteen steps, thereby approximating a smooth curve. There may be more than three linear sections in the first embodiment, or more than sixteen steps in the second.