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SIGNALLING SYSTEM
BACKGROUND OF THE INVENTION Field of the Invention
The present invention relates to a signalling apparatus that can achieve travelling of a train with safety and without collision. Description of the Related Art
In order to avoid collision of a train and ensure safety in travelling of a train, it is necessary to detect a position on a railway of a train, and control each train so that the trains do not collide with one another. Therefore, an apparatus for train position detection and an apparatus for controlling a train is needed. In those railway sections in which there are few trains operating (for example, railway sections having a train interval such that at most 1 (one) train or so is present on the railway between stations), the initial cost and the maintenance cost for the above-described apparatus will be a problem.
Then, in those railway sections in which the number of trains is small, there are many cases where the thought of "one block between two stations" is adopted, according to which only one train can be present on the railway between two adjacent stations to ensure security

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since there may be no problem with operation even if a relatively rough precision in train position detection is used, and for the reason that there are many sections in which solely single tracks are present.
As a method for implementing the "one block between two stations" system, there are old schemes, such as a staff blocking system and a tablet block system. These schemes use a license for travelling between stations, which is called a token. Both of the staff blocking system and the tablet block system allow the presence of only one token in between any two adjacent stations at the same time, and only those trains which have the tokens are allowed to travel between the stations, thereby achieving "one block between two stations".
There are also systems in which the token is computerized. One such system is disclosed in, e.g. Japanese Patent Laid-Open Publication No. 2-6268 (Patent Document 1). This system prepares a token as electronic data unique to the section in between any two adjacent stations. On departure of a train, a token is transmitted wirelessly to the train from a ground apparatus installed in a departure side station. After the transmission, both ground apparatus of the departure station and ground apparatus of a station on the destination side to which the train is bounded, are locked and no token is transmitted until the lock is

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released. After the departure of the train, when it arrives at the next station, the token is transmitted to the ground apparatus of the arrival station, and the token is verified on the ground apparatus. When the verification is successful, the .J.ock is released in the ground apparatuses for both the departure station and the arrival station of the train, thus again allowing transmission of a token to a train. In this way, by-performing locking of and releasing the lock for transmission of a token, the number of trains travelling between each pair of two adjacent stations with tokens is limited to 1 (one), thus achieving "one block between two stations" to ensure safety.
In old staff blocking system and the tablet block systems, a token is a physical object, and it needs to be dealt with by a station officer and a motorman at stations. Therefore, those systems involve expenses in time and effort and cannot address an increased number of trains. Moreover, those systems cannot be free from human errors by station officers and the motormen.
It is possible, by computerizing the token, to reduce the works of the motormen and the station officers, and in particular, to prevent a human error of a station officer in the work of passing the token to the train. However, even in a structure as described in Japanese Patent Laid-Open Publication No. 2-6268 (Patent Document

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1) in which the ground apparatus has a function to prepare a computerized token, it is not possible to prevent the human errors of a motorman as explained in the following. First, it is not possible to prevent a human error by a motorman that the train leaves the station although the reception of the token is yet to be done. Moreover, it is not possible to prevent a human error in which a motorman mistakenly recognize the direction of travel allowed by the token and the motorman operates the train to invade into a section that is not allowed by the token. Examples of the cases where a motorman mistakenly recognizes the direction of travel include a case where the train travels without return at a station where the train must return after receiving a token, and another case where the train travels by returning at a station where the train must go forward after receiving the token. As stated above, there have been problems, in the conventional techniques, of failure to prevent human errors of a motorman.
Therefore, an object of the present invention is to provide a signalling system that can ensure the sufficient safety even if there is a human error by a motorman.
SUMMARY OF THE INVENTION

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The system comprises an onboard controller provided for a train, a ground apparatus provided for a station, an electronic token that is transmitted and received between the onboard controller and the ground apparatus and that allows the train to travel between the two adjacent stations, wherein the onboard controller allows the train to travel according to an instruction from a motorman in a case where the electronic token is received from the ground apparatus of a departure station, and prevents the train from travelling when the electronic token is not received from the ground apparatus of the departure station.
Or, when the token is transmitted from the ground apparatus to the onboard controller, when the train departs from the station, the ground apparatus transmits the token and the direction infoinnation designating a valid direction in which the token is valid to the onboard controller, and the onboard controller, based on the direction information designating the valid direction, allows travelling in a same direction as designated in the direction information, and prevents the travelling in a reverse direction of the direction designated in the direction information.
By constructing such a signalling system, it becomes possible to ensure the safety in the travelling of a train even if there is a human error caused by a motorman.

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According to the above-described structure, it becomes possible to ensure the safety of the train even on emergence of human errors caused by a motorman.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual diagram showing the overview
of a signalling process in the embodiment;
FIG. 2 is a flowchart showing the flow of process of
the train in the embodiment, from the departure from one
station to the arrival at the next station of the train;
and
FIG. 3 is a flowchart showing the flow of the
process of the ground apparatus from the departure from
one station to the arrival at the next station of the
train in the embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A simple configuration is provided to achieve the following object: to achieve "one block between two stations" in a railway section in which ingression of multiple trains into one section in between two adjacent stations at the same time is prevented by determining a section in between any two adjacent stations as one block section, and achieve safety in travelling of the train without collision, even if there arises a human error.

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Hereafter, the embodiment of the present invention will be described based on the drawings.
FIG. 1 shows the concept of the signalling system according to the embodiment of the present invention.
Although not shown, a train 102 comprises an onboard controller that stores an electronic token (i) 101 received from a ground apparatus of a station, and controls the travel of the train based on the electronic token (i) 101 stored and the direction information stored together with the electronic token. Further, each station comprises a ground apparatus that stores an electronic token (i) 101 and a station-train transmission apparatus that performs transmission to and from a train.
FIG. 1 is depicted as if there were a plurality of electronic tokens (i) 101, which means allowance of a travel between the station A and the station B, for convenience in the explanation of the flow of the process of the system as a whole. However, in fact, only one electronic token (i) exists, and it resides in a memory of any of the train 102, the ground apparatus 103a of the station A, and the ground apparatus 103b of the station B: the token (i) never exist at a plurality of locations at the same time.
Further, a unique electronic token is provided between any two adjacent stations, in such a manner that the electronic token (i) 101 means allowance of travel

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between the station A and the station B, and the electronic token (ii) 101 means allowance of travel between the station C and the station A.
First, a flow of the process is described in which the electronic token (i) 101 resides in the ground apparatus 103a of the station A, and the train 102 departs from the station A toward station B. A direction from the station A to the station B is assumed to be a downbound direction.
The train 102 at the station A transmits a departure allowance request requesting allowance of departure to the station B together with direction information representative of "downbound direction" that is toward the station B, to the ground apparatus 103a via the station-train transmission apparatus 105. The station-train transmission apparatus 105 is an apparatus that enables transmission and reception of information between the ground apparatus 103 and the train 102, and it suffices if the station-train transmission apparatus 105 can perform communication within a limited range of short distance, and various apparatuses including a transponder, a Balise aided system, a general radio transceiver, can be employed. In the present invention, the station-train transmission apparatus 105 is not particularly specified.
The ground apparatus 103a of the station A, having received the departure allowance request for departure

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from the train 102, in the case where the ground apparatus 103a itself has the electronic token (i) 101 corresponding to the downbound direction from the station A (between station A and station B), transmits the electronic token (i) 101 to the train 102 via the station-train transmission apparatus 105 together with direction information representative of "downbound direction" which is the direction to the station B. After confirming the train 102 has received the electronic token (i) 101, the ground apparatus 103a deletes the electronic token (i) 101 having been residing in the ground apparatus 103a.
If the ground apparatus 103a is not in possession of the electronic token (i) 101 corresponding to the downbound direction from the station A, the ground apparatus requests for the electronic token (i) 101 against the ground apparatus 103b of the station B through a station transmission line 104. Having received the request, the ground apparatus 103b, if it is in possession of the electronic token (i) 101, transmits the electronic token (i) 101 to the ground apparatus 103a through the station transmission line 104, and after confirming that the ground apparatus 103a has received the token (i) 101, deletes the electronic token (i) 101 having been residing in the ground apparatus 103b. The station transmission line 104 can operate with a small

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communication capacity since it is used only for transmitting and receiving the electronic token (i) 101. Various transmission lines including twisted pair wires, ISDN dedicated lines, Ethernet (registered trademark) are applicable, and the present invention does not particularly specify the station transmission line 104.
The ground apparatus 103a, having received the electronic token (i) 101 from the ground apparatus 103b, transmits the electronic token (i) 101 to the train 102 via the station-train transmission apparatus 105 together with direction information representative of "downbound direction". After confirming the train 102 has received the electronic token (i) 101, the ground apparatus 103a deletes the electronic token (i) 101 having been residing in the ground apparatus 103a.
Where both of the ground apparatus 103a and the ground apparatus 103b are not in possession of the electronic token (i) 101, such case means there is a train travelling between the station A and the station B with the electronic token (i) 101, in which neither station A nor station B can allow departure of a train therefrom, and the ground apparatus 103a does not transmit the electronic token (i) 101 to the train 102. The ground apparatus 103a transmits the electronic token (i) 101 to the train 102 when the electronic token (i) 101 is received from another train arrived from the

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station B to the station A or from the ground apparatus 103b.
The train 102 receives the electronic token (i) 101 from the ground apparatus 103a together with the direction information. The onboard controller of the train 102 prevents travelling of the train by causing the train to apply a braking force regardless of the presence or absence of any input from the motorman until the electronic token (i) 101 is received together with the direction information. When the electronic token (i) 101 is received together with the direction information from the ground apparatus 103a, the onboard controller of the train 102 eases the braking force applied by the train so that the train can travel in the direction designated in the direction information. Where it is detected that the train 102 is travelling in the reverse direction of the direction designated in the direction information, the onboard controller of the train 102 controls the train to apply the braking force so as not to travel in the other than the designated direction, regardless of presence or absence of an input from the motorman.
The train 102 receives the electronic token (i) 101 from the ground apparatus 103a together with direction information, and starts travelling. When the train 102 has arrived at the station B, the train 102 transmits the electronic token (i) 101 possessed by the train 102 to

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the ground apparatus 103b via the station-train transmission apparatus 105. After confirming that the ground apparatus 103b has received the electronic token (i) 101, the train 102 deletes the electronic token (i) 101 which it had possessed.
The ground apparatus 103b, having received the electronic token (i) 101 from the train 102, holds the electronic token (i) 101. In this stage, it is only the ground apparatus 103b that holds the electronic token (i) 101, and no other ground apparatuses, or trains hold the electronic token (i) 101.
For the control of the turn-out switch at the station, use of a spring turn-out switch eliminates the necessity of any control. Or, it becomes possible to control a turn-out switch with safety by installing a linkage, performing shifting and locking of the turn-out switch to secure the course and thereafter transmitting the electronic token (i) 101 to the train 102.
By constructing the signalling system as described above, only one electronic token (i) 101 is allowed to be present. Therefore, it becomes possible to achieve the travelling of the train 102 with safety by exclusively allowing only the train 102 having the electronic token (i) 101 to travel between the station A and the station B to limit the number of trains present on the railway in between any pair of two adjacent stations to only 1 (one),

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and to prevent a train from collide with any other train. Furthermore, by transmitting the electronic token (i) 101 that is transmitted from the ground apparatus 103 to the train 102 together with the direction information in which the electronic token is valid, it becomes possible to prevent the train 102 from travelling by the human error of the motorman in the direction in which the train 102 is not allowed to travel.
FIG. 2 shows the flow of processing the train 102 in the present embodiment from the departure of the train 102 until the arrival at the next station. With step 201 to step 212 in FIG. 2, the safety in the travel of the train 102 is ensured.
Step 201: The onboard controller applies the brake until the train 102 receives the electronic token (i) 101 and the direction information from the ground apparatus 103. The process proceeds to step 202.
Step 202: A departure allowance request for departing from the station is transmitted to the ground apparatus 103 together with the direction information of the direction in which the train is requesting to departure. The process proceeds to step 203.
Step 203: Step 204 is repeated until the train 102 receives the electronic token (i) 101 and the direction information from the ground apparatus 103. If the

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electronic token (i) 101 is received, the process proceeds to step 205.
Step 204: In the same way as step 202, the departure allowance request is transmitted to the ground apparatus 103 for departure from the station together with the direction information of the direction in which the train is requesting to depart.
Step 205: Since the status of the train 102 has become a status of having received the electronic token (i) 101 and direction information, the onboard controller eases up on the brake and the process proceeds to step 206.
Step 206: It is checked whether the direction of travel of the train 102 agrees with the direction information received from the ground apparatus 103, and when they do not agree with each other, the process proceeds to step 207. If they agree with each other, the process proceeds to step 208.
Step 207: Since the disagreement means that the train is travelling in a direction different from the direction allowed by the electronic token, the onboard controller applies the brake to ensure safety.
Step 208: When the train arrives at the next station, the train applies the brake. The process proceeds to step 209.

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Step 2 09: The electronic token (i) 101 is transmitted to the ground apparatus 103 of the station at which the train has arrived. The process proceeds to step 210.
Step 210: Step 211 is repeated until it is confirmed that the ground apparatus 10 3 has received the electronic token. If the reception is confirmed, the process proceeds to step 212.
Step 211: In the same way as step 209, the electronic token (i) 101 is transmitted to the ground apparatus 103 of the station at which the train has arrived.
Step 212: the electronic token (i) 101 possessed by the train 102 is deleted.
By implementing the process of the train 102 with a flow as described above, it becomes possible to allow the train 102 to travel only in the direction in which the train 102 is allowed to travel in the case where it has the electronic token (i) 101, to ensure the safety of the travel.
FIG. 3 shows the flow of the process performed by the ground apparatus 103 in the present embodiment, from the departure of the train 102 from the station A until the arrival at the next station B. With step 3 01 to step 312 in FIG. 3, the safety in travelling of the train 102 is ensured.

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Step 301: A departure allowance request for departure from the station A is received together with direction information of the direction in which the train is requesting to departure (here, the direction is assumed to be the downbound direction, which is toward station B) from the train 102. The process proceeds to step 302.
Step 302: The ground apparatus 103 confirms if it possesses the electronic token (i) 101 corresponding to the section in between the stations (station A to station B) in the direction requested by the train 102. If the ground apparatus 103 possesses the electronic token (i) 101, the process proceeds to step 3 07. If the ground apparatus 103 does not possess the electronic token (i) 101, the process proceeds to step 303.
Step 303: The processes of step 304 to step 306 are repeated until the electronic token (i) 101 corresponding to the section in between the two adjacent stations (station A to station B) in the direction' requested by the train 102 is received. If the electronic token (i) 101 is received, the process proceeds to step 307.
Step 304: The ground apparatus 103 requests the electronic token (i) 101 to a station (station B) adjacent in the direction requested by the train 102 (downbound direction). The process proceeds to step 305.

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Step 305: It is confirmed whether the electronic token (i) 101 is received from the adjacent station (station B) to which the request is transmitted in step 304. The process proceeds to step 306.
Step 306: It is confirmed whether the electronic token (i) 101 is received from another train that has arrived at the station (station A) from which the train 102 is to depart.
Step 307: The ground apparatus 103 transmits the electronic token (i) 101 corresponding to the section in between the two adjacent stations in the direction requested by the train 102 (station A to station B) and the direction information corresponding to the electronic token (i) 101 to the train 102. The process proceeds to step 308.
Step 308: The processes of step 309 are repeated until it is confirmed that the train 102 has received the electronic token. If the reception is confirmed, the process proceeds to step 310.
Step 309: In the same way as step 307, the ground apparatus 103 transmits the electronic token (i) 101 corresponding to the section in between the two adjacent stations in the direction requested by the train 102 (station A to station B) and the direction information corresponding to the electronic token (i) 101 to the train 102.

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Step 310: If it is confirmed that the train 102 has received the electronic token (i) 101, the electronic token (i) 101 possessed by the ground apparatus 103 is deleted. The process proceeds to 311.
Step 311: The electronic token (i) 101 is received from the train 102 which has arrived at the next station (station B) . The process proceeds to step 312.
Step 312: the electronic token (i) 101 received from the train 102 is held in the memory of the ground apparatus 103.
By performing process by the ground apparatus in the manner as described above, it becomes possible to control the electronic token (i) 101 so that only one train having the electronic token (i) 101 is present in between any pairs of two adjacent stations. Further, by transmitting the direction information of the direction in which the train is allowed to travel, the train is prevented from travelling by an erroneous operation by the motorman in an erroneous direction in which the train is not allowed to travel, thereby ensuring the safety in the travelling of the train.

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What is claimed is: 1. A signalling system in which a section in between two adjacent stations is defined as a block section, the signalling system comprising:
an onboard controller provided for a train;
a ground apparatus provided for a station;
an electronic token that is transmitted and received between the onboard controller and the ground apparatus and that allows the train to travel between the two adjacent stations, wherein the onboard controller:
allows the train to travel according to an instruction from a motorman in a case where the token is received from the ground apparatus of a departure station; and
prevents the train from travelling when the token is not received from the ground apparatus of the departure station.
2. The signalling system according to claim 1, wherein, when the train departs from the station,
the ground apparatus transmits the token and direction information designating a valid direction in which the token is valid to the onboard controller, and
the onboard controller, based on the direction information designating the valid direction, allows travelling in a same direction as designated in the

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direction information, and prevents the travelling in a reverse direction of the direction designated in the direction information.
3. The signalling system according to claim 1, wherein
the onboard controller controls the train to apply a
braking force when the onboard controller is in the state
of not having received the token, to prevent the train
from departing from the station.
4. The signalling system according to claim 2, wherein
the onboard controller receives the token and the
direction information, and controls the train to apply a braking force when the train is travelling in a reverse direction of the direction designated in the direction information.
5. The signalling system according to any one of claims
1 to.4, wherein the ground apparatus transmits the token
from the ground apparatus to the onboard controller when
the train departs from the departure station, and deletes
the token having been held by the ground apparatus, and
the onboard controller holds the token while the train is travelling between the two adjacent stations, and transmits the token having been held by the onboard controller to the ground apparatus of an arrival station

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and deletes the token having been held by the onboard controller when the train has arrived at the arrival station.
6. A method for signalling in which a section in
between two adjacent stations is defined as a block
section, the method comprising:
providing an electronic token between the two
adjacent stations to allow a train to travel between the
two adjacent stations;
transmitting and receiving the token between an
onboard controller provided for the train and a ground
apparatus provided for the station;
allowing the train to travel according to an instruction from a motorman in a case where the token is received from the ground apparatus of a departure station, and preventing the train from travelling when the token is not received from the ground apparatus of the departure station.
7. The method for signalling according to claim 6, further comprising:
transmitting, when the train departs from the departure station, the token and the direction information designating a valid direction in which the

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token is valid from the ground apparatus to the onboard controller,
allowing, based on the direction information designating the valid direction, travelling in a same direction as designated in the direction information, and preventing travelling in a reverse direction of the valid direction designated in the direction information.
8. The method for signalling according to claim 6, further comprising controlling the train to apply a braking force when the onboard controller is in the state of not having received the token, to prevent the train from departing from the station.
9. The method for signalling according to claim 7, further comprising:
controlling the train to apply a braking force when the onboard controller receives the token and the direction information and the train is travelling in the reverse direction of the direction designated in the direction information.
10 . The method for signalling according to any one of claims 6 to 9, further comprising:
transmitting the token from the ground apparatus to the onboard controller when the train departs from the

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departure station and deleting the token having been held by the ground apparatus;
holding the token on the onboard controller while the train is travelling between the two adjacent stations; and
transmitting the token having been held by the
onboard controller to the ground apparatus of the arrival
station, and deleting the token having been held by the
onboard controller when the train has arrived at an arrival station.
11. A signaling system, substantially as herein described with reference to accompanying drawings and example.
12. A method, substantially as herein described with reference to accompanying drawings and example.