Apparatus For The Centralized Control Of The Operation Of Trains

Abstract

An apparatus for the centralized control of the operation of trains travelling in a network divided into zones, each zone being controlled by a central station that transmits coded messages to a bilateral communication system. A coded name is given by the central station to each train entering a zone. The train retains its coded name while in the zone and considers only messages intended to it. The train transmits to the central station data relating to its speed, its zone of origin and the distance it has travelled in the zone as well as other characteristics. Such data is stored in a memory portion of the central station and serves to send the coded messages to the train based on that data, on the obstacles lying ahead of the train and on the true distance travelled by the train at the time of sending the codes messages. The central station calculates at all times such true distance by means of the distance stored in the above-mentioned memory portion of the central station, of the speed of the train and of the time interval elapsed between the storing of the above-mentioned distance and the transmission of the coded messages.

Parent Case Text

This application is a continuation-in-part of application Ser. No. 672,170 filed Oct. 2, 1967, and now abandoned.

Description

This invention relates to an apparatus for the centralized control of the operation of trains.

The object of the present invention is to furnish, from a central station, operating instructions to trains travelling on a railway network. The instructions worked out by the central station are functions of obstacles to be met along the railway network such as speed limits, signals, etc. and of data supplied by the train itself concerning its position, its speed, its own characteristics, etc.

The invention has numerous advantages as compared to known techniques. Apparatus are known in which the railway network is divided into zones each dependent on a central station which establishes a bilateral communication with the trains circulating in the zone under concern through a cable defining a loop arranged between the rails and travelled by carrier currents. Such a loop has marking points in the form of evenly spaced crossings dividing the zone into sections and permitting to a particular train to know in which section it is located. Periodically, the central station sends out messages called searching messages intended for trains located in predetermined sections and those effectively in such predetermined sections answer by a message called an occupation message containing data that is stored at the central station in a memory the content of which is analyzed and used to establish the operating instructions which are communicated to the trains during the next searching cycle.

One of the major disadvantages of the above system is that the operating instructions which are communicated to a train at a predetermined time only take into account prior data which no longer corresponds to the exact location of the train at that instant.

In the apparatus in accordance with the invention, the central station sends out operating instructions not only to trains located in such or such section of the zone under concern, but to all trains located in the zone, each of the trains taking into consideration only the operating instructions that are accompanied by a coded reference given to it by the central station when it enters the zone, these operating instructions being established by the central station while taking into account the exact location of the train when the operating instructions are given. In other words, the progression of each train in a zone is followed step by step by the central station and the operating instructions are transmitted to it as a function of the conditions existing at the corresponding moment.

The apparatus according to the invention which permits a bilateral communication between the central station controlling a zone and the trains circulating in said zone, and wherein the central station cyclically sends out coded messages to each train, is mainly characterized in that each train entering the zone is given a coded name by the central station, which name is held, in principle, by the train during its full travel in the zone, and permits the train to receive and consider only the messages which are intended to it. The train transmits to its central station data indicating its speed, its zone of origin, the distance travelled in the zone under concern and other characteristics. Such data is stored in a memory portion of the central station which is allotted to the train under concern and the central station sends out operating instructions to the train based on such data, on obstacles located ahead of the train and on the true distance travelled by the train at the time of sending the operating instructions. The central station calculates at all times such true distance by means of the distance stored in the memory portion, the speed of the train and the time interval elapsed between the storage of the distance in the above-mentioned memory portion and the transmission of the operating instructions.

The apparatus in accordance with the invention which is to be located in a train and in bilateral communication with a central station controlling a zone, comprises a receiver and a transmitter connected respectively to a decoder and to an encoder, and equipped with antennas coupled to a cable forming a loop which is located along the railway network and defines the zone. The loop which is fed by the central station has marking points in the form of crossings and the counting of such crossings by the receiver gives a measure of the distance travelled by the train. The apparatus in accordance with the invention is characterized in that it comprises a series of registers including one or plural bistable circuits for storing the informations received by the decoder, transfer circuits connected to such registers, memory circuits connected to such transfer circuits, logic circuits controlling the transfer circuits, comparator circuits for comparing the content of at least a part of the registers with the informations contained in corresponding memory circuits pertaining to the train, or with informations worked out in the train, the comparator circuits determining the state of the logic circuits and allowing or not the acceptation of the messages received and the sending of data to the central station, which data permit to such central station to work out the working instructions to be transmitted to the train.

Other characteristics of the invention will become apparent in the following description having reference to the accompanying drawings relating to a particular embodiment of the invention and in which:

FIG. 1 illustrates schematically a zone Z.sub.0 of a railway network controlled by a central station, such zone being adjacent to other zones Z.sub.1, Z.sub.2 and Z.sub.3 ; and

FIG. 2 illustrates schematically an apparatus installed in a train for controlling the train.

FIG. 1 illustrates schematically a zone Z.sub.0 of a railway network controlled by a central station (not shown), such zone Z.sub.0 being adjacent to other zones Z.sub.1, Z.sub.2 and Z.sub.3 from which trains may come to enter zone Z.sub.0. The zones Z.sub.1, Z.sub.2 and Z.sub.3 may or may not be controlled by a central station similar to the one of zone Z.sub.0. If, for instance, a train comes from zone Z.sub.1 to enter into zone Z.sub.0, such train is said to be placed in a state of availability caused, for example, by a silent gap, that is by a distance between two zones wherein no communication means exist, by a detecting device or by any other means. The train in the state of availability knows the coded designation of the zone from which it comes either by means of messages received by the central station associated with such zone or by means of a detecting device located at the exit of the zone. On the other hand, the central station associated with the zone Z.sub.0 is warned of the entry of a train therein coming from the zone Z.sub.1, for example, by a pedal or by an answer received from the train following a message hereinafter called a "tentative" message which is periodically transmitted during each cycle of messages to all trains in the state of availability which are located in a predetermined section in the neighborhood of the entry of the zone, or else following a message received from the central station associated with zone Z.sub.1 from which the train originates. It is obvious that the same would happen if the train was coming from other zones Z.sub.2 or Z.sub.3 contiguous to Z.sub.0.

FIG. 2 illustrates schematically an embodiment of an apparatus for providing operating instructions to a train, such apparatus being located aboard a train which is about to enter into zone Z.sub.0. The apparatus comprises a receiver 1 connected to an antenna 2 coupled to a cable 3 which is fed by the signal emitted by a central station 4 controlling zone Z.sub.0. The passage of the train in the above-mentioned silent gap preceding zone Z.sub.0 causes a level detector 5 connected to receiver 1 and consisting of a bistable circuit to be placed in a state 0. Such causes a register 6 connected to level detector 5 to be also reset to 0. The function of register 6 was to count the crossings of the cable so as to provide an indication of the distance travelled by the train in the preceding zone. The train is then said to be in the state of availability. The output of receiver 1 is connected to a decoder 7 the function of which is to energize, in accordance with the content of the messages received, a number of registers comprising one or plural bistable circuits. In particular, a bistable circuit 8 is set to 0 when the message received is a tentative message or a message hereinafter called "naming" message, that is a message containing a coded indication or a name given to the train by the central station. In the present example, the tentative message and the naming message are combined in a single message. The bistable circuit 8 will, as it will be seen later on, take the state 1 when the message received is a hereinafter called "instruction" message, that is a message containing operating instructions for the train.

In its naming message, the central station includes, apart from the coded name given to the train, an indication of the zone of origin of the train, an indication of the zone in which the train is now travelling and the distance travelled in the zone, such distance being of course null. There is also provided a bistable circuit 10 which is set to 0 by the level detector 5 at the passage of the train in the silent gap as mentioned above. The state 0 of both bistable circuits 8 and 10 is inversed by inverters 11 and 12 connected to the output of the bistable circuits 8 and 10. The output of inverters 11 and 12 are connected to a logic circuit 13 of the AND type. In a preceding operation, the indication of the zone in which the train was travelling prior to its entering zone Z.sub.0 was stored in a register 14. When the indication of the zone stored in register 14 is identical to the one contained in the message received from the central station and stored in a register 44, a comparator 15 provides a digital output 1 which is also applied to logic circuit 13. The indication of the zone now travelled by the train is stored in registor 16 and will be transferred, upon entering of the train in the zone following zone Z.sub.0, into register 14 under control of transfer circuit 45 when the level detector 5 will be set to 0 as mentioned previously. On the other hand, the distance travelled in zone Z.sub.0 is measured by a crossing detector 18 which operates register 6. The indication of the distance contained in the message of the central station received by decoder 7 is introduced into a register 17. The output of register 17 is compared with the output of register 6 in a comparator 19 the output of which takes the state 1 when the indication of registers 6 and 17 are identical, or nearly identical within a predetermined limit. The output of comparator 19 is applied to logic circuit 13 whose inputs are now all in state 1. Consequently, the output of logic circuit 13 also takes state 1. One output of logic circuit 13 is applied to the first input of bistable circuit 10 the second input of which is connected to level detector 5 which is now in state 1 due to the entering of the train in zone Z.sub.0. The above sets the output of bistable circuit 10 in state 1 and the train is then put in a state hereinafter called "reception" state. The coded name given to the train by the central station has been stored in a register 9 and the first output of logic circuit 13 energizes a transfer circuit 20 which causes the transfer of the coded name into a memory 21 in which such coded name will be stored during the full travel of the train in the zone Z.sub.0. The above will permit the device in accordance with the invention, as will be later seen, to take into consideration by means of a comparator 22 only the messages addressed to a train having such coded name.

The next message that the train will receive will be an instruction message which will put bistable circuit 8 in a state 1. In the meantime, the train sends to the central station by means of the transmitter which will be disclosed later on, a message hereinafter called "acknowledgement" message pertaining to the difference between the true distance travelled by the train and the one registered in the central station as provided by comparator 19, to the speed of the train measured by a speed detector circuit 36, and to the type of train (from the point of view of braking capacity, etc.) stored in a register 34. The above message is sent to the central station under the control of the second output of logic circuit 13 which is applied to logic circuit 43 as it will be explained later. The above data will permit the central station to determine the operating instructions to be sent to the train relating to the maximum speed permitted, to the distance from the above-mentioned obstacles along the railway network, to the speed of the train upon encountering such obstacles, which are stored by decoder 7 into respective transient registers 23, 24 and 25. Such data is intended to be introduced into memories 26, 27 and 28 respectively by transfer circuits 29, 30 and 31 when the input of such transfer circuits are placed in state 1 by a logic circuit 32 of the AND type the input of which are connected to the output of circuits 8, 10, 15, 22, 19 and 33. The output of registor circuit 8 is in state 1 as mentioned previously. The bistable circuit 10 is also in state 1 since the train is in the state of reception. The comparator circuit 15 takes the state 1 if the indication of the preceding zone contained in the message decoded by decoder 7 coincides with the one stored in memory 14. The comparator circuit 22 is in state 1 if the name contained in the message decoded by decoder 7 is identical to the one stored in memory circuit 21. The comparator circuit 19 is in state 1 if the distance travelled by the train in zone Z.sub.0 coincides, within a predetermined value, with the one provided by the central station and stored in registor 17. Finally, the comparator 33 is in state 1 if the indication of the type of train stored in register 34 is identical to the one stored in register 35 by decoder 7. If all the above conditions are satisfied, the logic circuit 32 takes the state 1 and the transfer circuits 29, 30 and 31 transfer the operating instructions received into an indicating circuit 39. The speed of the train the measure of which is provided by circuit 36 is compared with the operating instruction relating to such speed and contained in memory 26 and, if such speed is exceeded, as detected by a comparator 37, an automatic braking device 38 will be operated.

The type of train, its speed and the correction to be made to the data stored in the central station concerning the distance from any obstacle on the railway network (correction provided by the comparator circuit 19) are introduced into a encoder 40 which modulates a transmitter 41 for transmitting the above information to the central station by means of an antenna 42 coupled with cable 3. The encoder 40 is placed under control of a logic circuit 43 of the OR type whose inputs are connected to the outputs of logic circuits 13 and 32. This information is stored in the central station in a portion of the memory thereof associated with the train having such coded name. The above information will permit the central station to determine, for a predetermined time of transmission t.sub.e following a time t.sub.r of transmission of an acknowledgement message, the maximum speed permitted for the train, which speed depends on its location, on its braking capacity (type of train) and on the obstacles located ahead of the train. If the distance travelled by the train at time t.sub.r since its point of entry into zone Z.sub.0 is called X.sub.tr and the speed of the train at that time V.sub.t, the distance X.sub.te travelled by the train at the instant t.sub.e will be:

X.sub.te = X.sub.tr + V.sub.t (t.sub.e - t.sub.r) assuming that the speed of the train has not changed in the time interval t.sub.e - T.sub.r which is very small in practice.

A central station will then be able to determine at any instant t.sub.e of transmission of a message pertaining to operating instructions to the train (by means of any known apparatus) the maximum speed permitted to the train from the information received at instant t.sub.r of reception of the acknowledgement message and taking into consideration the obstacles located ahead of the train.

Claims

I claim:

1. An apparatus for the centralized control of the operation of trains travelling in a network divided into zones each being controlled by a central station cyclically sending messages to the trains travelling in the concerned zone, each zone being defined by a loop formed by a cable located in the track and having regularly spaced crossings or other marking points, said cable serving as inductive transmission means between the central station and the trains, said apparatus comprising aboard each train a receiver responsive to an antenna coupled to the cable, a decoder connected to said receiver, counting means for the marking points of the cable operated from said receiver, first register means connected to said decoder for storing informations received by said receiver and comprising data relative to a coded name of the train, the type of train, the zone of origin of the train, the zone in which the train is actually travelling and the distance travelled in the zone, means for storing corresponding data existing aboard the train, comparator means connected to said first register means and to said means for storing data existing aboard the train, AND gates the inputs of which are connected to the outputs of said comparator means, second register means connected to said decoder for storing informations received by said receiver and comprising instructions for the control of the train, transfer circuits controlled by said AND gates for transmitting the informations stored in said second register means to memories which supply instructions for the driver or operate the automatic control of the train, said apparatus further comprising an encoder fed by the signals representative of the type of train, the speed of the train, and the distance travelled by the train in the zone, said encoder being controlled by one of said logic AND gates, and a transmitter connected to an antenna coupled to the cable and modulated by the output of said encoder.

2. An apparatus according to claim 1, further comprising a level detector connected to said receiver and responsive to a silent gap preceding said zone for resetting said counting means to zero before the entry of the train in said zone.

3. An apparatus as defined in claim 2, comprising a memory circuit for storing said coded name of the train during its full travel in said zone, and means for feeding said memory circuit during the first message received by the train and containing said coded name.