| 摘要 |
899,863. Automatic braking systems. ATELIERS DE CONSTRUCTIONS ELECTRIQUES DE CHARLEROI. Nov. 16, 1959 [Nov. 17, 1958], No. 38762/59. Class 105. In an automatic braking system for railway vehicles based on the linear relationship between the square of the vehicle speed under constant deceleration and the distance travelled, a signal is produced on the vehicle which is a function of the square of its speed and this is continuously compared with a signal representing the square of the speed limit for the vehicle, which will ensure that it will stop in a predetermined distance, to produce a difference signal which controls the braking of the vehicle. At each of a number of points on the track section over which the vehicle is retarded a signal is transmitted to the vehicle from track apparatus which initiates a signal thereon which is a function of the square of the speed limit at that point and on this signal is superimposed a second signal which varies with the distance travelled by the train to produce a continuous speed-limiting signal which decreases proportionately to the distance to be travelled by the vehicle and which is corrected at each track signalling point. A signal v which is a function of vehicle speed is produced by a tachometer 1 and applied via a squaring circuit 2 to a comparator 13. As the vehicle passes over a track signalling point a voltage from the sources 5-8 proportional to the square of the limit speed V2(1-4) at that point is introduced into the circuit 4 by the operation of one of the contacts 9-12 and on this voltage is superimposed a voltage u which is a function of the distance travelled by the vehicle derived from circuit 3 in which the voltage v is integrated. The combined signal c is compared in the circuit 13 with the voltage proportional to v<SP>2</SP>. The difference voltage f is used to control the braking of the vehicle. |
