Automatic train control device

Claim 1

In an automatic train control system having a receiver for receiving speed instruction signals, a speed pattern generator for generating a speed pattern according to said instruction signals, said generator being connected to an output of said receiver, a train speed sensor, a comparator unit connected to outputs of said speed pattern generator and said speed sensor for determining whether the speed of the train exceeds the desired speed according to the generated speed pattern, and a braking instruction device for actuating the braking means of the train, a device for optimizing the braking force applied according to the amount by which the train speed exceeds the desired speed according to a newly received speed instruction signal, said device comprising: a signal detector for receiving said speed instruction signals from said receiver and for detecting whether a newly received speed instruction signal is instructing the train to run at a speed which is lower than the desired speed according to an earlier received speed instruction signal and for producing an output signal when such a condition is detected; a differential speed detector for receiving said outputs of said speed sensor and said speed pattern generator for determining the amount by which the speed of the train exceeds the desired speed according to the newly received speed instruction signal; a signal responsive means which is responsive to an output from said signal detector for supplying said output of said speed sensor to said differential speed detector in response to said output from said signal detector; a brake force reducing device including means for storing a plurality of braking force patterns, each of said plurality of patterns respectively corresponding to one of a plurality of different speeds of the train and which is appropriate for braking the train to compensate for the excess train speed within the length of a track section over which braking is to be accomplished, said brake force reducing device being connected to said outputs of said differential speed detector and said speed pattern generator and said arithmetic unit, wherein said brake reducing device generates an output which is supplied to said braking instruction device and which corresponds to the braking force which is optimum for excess speed of the train.