ONBOARD CONTROL DEVICE, WAYSIDE COIL, GROUND CONTROL DEVICE, WIRELESS TRAIN CONTROL SYSTEM, AND TRAIN LOCATION CORRECTION METHOD

An onboard control device includes an obtaining unit to obtain information from a wayside coil, for identifying a location of the wayside coil, and a control unit to correct train location information, or not, on a basis of correction permission information, the permission information being associated with the wayside coil and including information that indicates whether correction to the train location information is permissible. When the permission information indicates that the correction is permissible, the control unit corrects the train location information by using the wayside coil information at the time when the onboard pickup coil has passed through the wayside coil, and when the permission information indicates that the correction is not permissible, the control unit does not correct the train location information at the time when the onboard pickup coil has passed through the wayside coil.

FIELD

The present invention relates to an onboard control device including an onboard pickup coil, a wayside coil, a ground control device, a wireless train control system, and a train location correction method.

BACKGROUND

A known train traveling on a track detects its train location and transmits information on the train location to a wayside device. The wayside device controls the operation of the train on the basis of the train location obtained from the train. One of the detection methods, which a train carries out for detecting its current train location, is to connect a rate generator to an axle of the train, calculate a traveling distance from a predetermined reference location on the basis of an output pulse signal generated by rotation of the axle, and detect the current train location by using the calculated traveling distance. Unfortunately, the detection method as described above may include an error between the actual traveling distance and the calculated traveling distance due to wheel slipping or skidding during travelling of the train.

According to technique disclosed in Patent Literature 1, an additional length extending from a front part of the train in the traveling direction and an additional length extending from a rear part of the train in a direction opposite to the traveling direction are provided on the basis of a measurement error. A location of the train location is then detected regarding a location of the train having these additional lengths as the train location. The train described in Patent Literature 1 transmits, to a wayside device, information on the location of the train with the additional lengths provided on the basis of the measurement error.

CITATION LIST

Patent Literature

SUMMARY

Technical Problem

In general, when an onboard pickup coil installed in a train receives wayside-coil location information transmitted from a wayside coil installed on the wayside, the train corrects a train location on the basis of the the wayside-coil location information. When the train described in Patent Literature 1 receives location information transmitted from the wayside coil, the train brings the additional length provided on the basis of the measurement error to 0. That is, at the point in time when the train corrects its train location, a phenomenon in which the location having been regarded as a front-part location of the train is displaced rearward by the added measurement error occurs. As a result of the correction to the train location, a stop-limit position of the train shifts from a position past a signal back to a position before the signal in which case, the wayside device changes indication of the signal from “go” to “stop”. This is a problem because a sudden change in the indication of the signal from “go” to “stop” causes the train to be urgently stopped.

The present invention has been achieved to solve the above problem, and an object of the present invention is to provide an onboard control device capable of controlling correction to a train location.

Solution to Problem

To solve the above problem and achieve the object, the present invention provides an onboard control device to be installed along with an onboard pickup coil in a train. The onboard control device comprising: an obtaining unit to obtain wayside coil information from a wayside coil through the onboard pickup coil, the wayside coil information being capable of identifying a location of the wayside coil; and a control unit to correct train location information, or not to correct the train location information on a basis of correction permission information, the train location information indicating a location of the train, the correction permission information being associated with the wayside coil, the correction permission information including information that indicates whether correction to the train location information is permissible, wherein when the information included in the correction permission information indicates that the correction is permissible, the control unit corrects the train location information by using the wayside coil information at a time when the onboard pickup coil has passed through the wayside coil, and when the information included in the correction permission information indicates that the correction is not permissible, the control unit does not correct the train location information at a time when the onboard pickup coil has passed through the wayside coil.

Advantageous Effects of Invention

The onboard control device according to the present invention has an effect that it is possible to control the correction to the train location.

DESCRIPTION OF EMBODIMENTS

An onboard control device, a wayside coil, a ground control device, a wireless train control system, and a train location correction method according to embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The present invention is not limited to the embodiments.

First Embodiment

FIG. 1is a diagram illustrating a configuration example of a wireless train control system100according to a first embodiment of the present invention. The wireless train control system100includes trains10aand10b, wayside coils20aand20b, and a ground system30. Where appropriate, the trains10aand10bare hereinafter referred to as trains10without being distinguished from each other. The train10may be made up of a plurality of vehicles, or a single vehicle. Where appropriate, the wayside coils20aand20bare hereinafter referred to as “wayside coils20” without being distinguished from each other.

The train10has an onboard pickup coil installed therein as described later. The train10is capable of correcting a calculated location of the train10, by using information intended for location correction. The information intended for location correction is obtained from the wayside coil20through the onboard pickup coil. The train10transmits train location information to the ground system30. The train location information indicates the location of the train10. In the wireless train control system100, the ground system30obtains train location information from the train10, determines a path and a stop-limit position of the train10on the basis of the train location information on the train10, and controls the operation of the train10. While inFIG. 1, the number of trains10is two, this is merely an example. The ground system30is capable of controlling the operation of one train10or more than two trains10.

The configuration of the ground system30is described below. The ground system30includes a wireless device40, a ground control device50, and an electronic interlocking device60.

The wireless device40wirelessly communicates with the train10. Specifically, the wireless device40receives train location information from the train10, and transmits, to the train10, control information generated by the ground control device50.

The ground control device50controls the operation of the train10that communicates with the wayside coil20through an onboard pickup coil. On the basis of train location information obtained from the train10, the ground control device50determines a path and a stop-limit position of the train10, and generates control information for the train10.

On the basis of train location information on the train10obtained from the ground control device50, the electronic interlocking device60determines on which of track circuits81to85the train10is present. The electronic interlocking device60then controls signals71and72.

In the wireless train control system100, at the time when the train10having an onboard pickup coil installed therein passes through the wayside coil20, the wayside coil20communicates with the onboard pickup coil. A configuration of the wayside coil20is described below.FIG. 2is a block diagram illustrating a configuration example of the wayside coil20according to the first embodiment. The wayside coil20includes a storage unit21and a communication unit22. The wayside coils20aand20bare identical in configuration to each other, although the wayside coils20aand20bhave different pieces of information stored in their storage units21.

The storage unit21stores therein wayside-coil location information and correction permission information. The wayside-coil location information indicates the location where the wayside coil20is installed. The correction permission information includes information indicating whether it is permissible for the train10to correct train location information. The train location information indicates the location of the train10in the train10. The wayside-coil location information is wayside coil information capable of identifying the location where the wayside coil20is installed. The correction permission information, which is associated with the wayside coil20, includes information that indicates whether correction to train location information indicating the location of the train10is permissible.

The communication unit22transmits, to the train10, the wayside-coil location information that is the wayside coil information, and the correction permission information, both of which are stored in the storage unit21.

A configuration of the train10is described below.FIG. 3is a block diagram illustrating a configuration example of the train10according to the first embodiment. The train10includes an onboard pickup coil11, a tachometer generator12, a communication unit13, and an onboard control device14. The train10has these devices installed therein. The onboard control device14includes an obtaining unit15and a control unit16. The trains10aand10bare identical in configuration to each other.

The onboard pickup coil11communicates with the wayside coil20. The onboard pickup coil11obtains, from the wayside coil20, wayside coil information capable of identifying the location where the wayside coil20is installed, and correction permission information. In the first embodiment, the wayside coil information is wayside-coil location information that indicates the location where the wayside coil20is installed.

The tachometer generator12is connected to an axle of the train10, and outputs a pulse signal in response to rotation of the axle.

The communication unit13wirelessly communicates with the ground system30. The communication unit13transmits, to the ground system30, train location information on the train10calculated by the onboard control device14. The communication unit13receives, from the ground system30, control information for the train10to move or stop.

The onboard control device14controls the operation of the train10. The onboard control device14calculates the location of the train10, by using a signal output from the tachometer generator12. The onboard control device14can correct the calculated location of the train10, by using wayside coil information obtained from the wayside coil20through the onboard pickup coil11.

The obtaining unit15obtains wayside coil information and correction permission information from the wayside coil20through the onboard pickup coil11.

The control unit16calculates the location of the train10, by using a signal output from the tachometer generator12. The control unit16can correct the calculated location of the train10in accordance with the correction permission information, by using the wayside coil information obtained from the wayside coil20through the obtaining unit15and the onboard pickup coil11. Specifically, when information included in the correction permission information indicates that correction is permissible, the control unit16corrects the train location information by using the wayside coil information at the time when the onboard pickup coil11has passed through the wayside coil20. When information included in the correction permission information indicates that correction is not permissible, the control unit16does not correct the train location information at the time when the onboard pickup coil11has passed through the wayside coil20.

Operations of the trains10aand10bare described next.

In the train10a, the control unit16in the onboard control device14calculates a train location of the train10aon the basis of a signal output from the tachometer generator12. Unfortunately, there is a possibility that wheel slipping or skidding may cause an error in the train location of the train10a. To address this, the control unit16in the train10aprovides allowances for the length of the train10a. That is, the control unit16regards a length of the train10aas being larger than the real length. Specifically, the control unit16in the train10aadds a front-part allowance length91ato the front part of the train10a, and adds a rear-part allowance length92ato the rear part of the train10a. As a result, the train10atravels, having the front part of the train10adeemed to be located the front-part allowance length91aahead of the real location of the front part of the train10a. The train10atravels, having the rear part of the train10adeemed to be located the rear-part allowance length92abehind the real location of the rear part of the train10a. The train10atransmits, to the ground system30, the location information on the train with the front-part allowance length91aand the rear-part allowance length92aadded. The ground control device50in the ground system30performs a process of determining, for example, a path and a stop-limit position on the basis of the transmitted train location information. The control unit16in the train10ais capable of changing the front-part allowance length91aand the rear-part allowance length92adepending on the traveling distance since the last correction to the train location. For example, the control unit16in the train10aincreases the front-part allowance length91aand the rear-part allowance length92ain proportion to the traveling distance since the last correction to the train location.

InFIG. 1, the wayside coil20ais more distant from the next station than the wayside coil20bis, and is not close to the signals71and72. It is thus believed that there are no problems with the train10aeven when the location of the train10ais suddenly changed correcting the train location at the time when the train10ahas passed through the wayside coil20a. For this reason, the wayside coil20atransmits, to the train10a, wayside-coil location information indicating the location where the wayside coil20ais installed, and correction permission information associated with the wayside coil20a, as well.

FIG. 4is a diagram illustrating an example of the correction permission information to be transmitted by the wayside coil20aaccording to the first embodiment.FIG. 4illustrates a target for correction to the train location of the train10a. Specifically,FIG. 4shows that the train10ahaving passed through the wayside coil20acorrects the front-part location of the train10a, and corrects the rear-part location of the train10a. Information included in the correction permission information illustrated inFIG. 4, that is, information that indicates whether correction to the front-part location of the train10ais permissible is defined as first information, and information that indicates whether correction to the rear-part location of the train10ais permissible is defined as second information. Specifically, inFIG. 4, the first information indicates that the correction target is the front-part location and correction to the front-part location is permissible, and the second information indicates that the correction target is the rear-part location and correction to the rear-part location is permissible. Whether correction to the front-part location is permissible is determined on a case-by-case basis. The correction is determined to be “not permissible”, for example, in a case where there is an installation such as a signal near the train in the traveling direction of the train10and thus a change in the location of the train10probably causes a change in the state of the installation. Otherwise, the correction is determined to be “permissible”. Whether correction to the rear-part location is permissible is determined on a case-by-case basis. The correction is determined to be “not permissible”, for example, in a case where whether the train10has a length that allows the train10to fit within a facility such as when stopping at a station is being checked. Otherwise, the correction is determined to be “permissible”.

The correction permission information to be transmitted from the wayside coil20to the train10can be expressed in two bits of information located at a certain position within a signal transmitted from the wayside coil20to the train10. For example, when a first one of the two bits is 1, correction to the front-part location is permissible. When the first bit is 0, correction to the front-part location is not permissible. When a second one of the two bits is 1, correction to the rear-part location is permissible. When the second bit is 0, correction to the rear-part location is not permissible.

At the time when the train10ahas passed through the wayside coil20a, the control unit16in the train10aobtains wayside-coil location information and correction permission information transmitted from the wayside coil20athrough the onboard pickup coil11. The control unit16in the train10acorrects the front-part location and the rear-part location of the train10aon the basis of the obtained wayside-coil location information and the obtained correction permission information. Specifically, the control unit16in the train10aresets, that is, eliminates the front-part allowance length91aadded to the front part of the train10a, and also resets, that is, eliminates the rear-part allowance length92aadded to the rear part of the train10a. In the manner as described above, the control unit16in the train10acan accurately acquire the location of the train10aby correcting the location of the train10aat the time when the train10ahas passed through the wayside coil20a.

Next, the train10bis described. The control unit16in the train10badds a front-part allowance length91bto the front part of the train10b, and adds a rear-part allowance length92bto the rear part of the train10b. As a result, the train10btravels, having the front part of the train10bdeemed to be located the front-part allowance length91bahead of the actual location of the front part of the train10b. The train10btravels, having the rear part of the train10bdeemed to be located the rear-part allowance length92bbehind the actual location of the rear part of the train10b. The train10btransmits, to the ground system30, the location information on the train with the front-part allowance length91band the rear-part allowance length92badded. The ground control device50in the ground system30performs a process of, for example, determining a path and a stop-limit position on the basis of the transmitted train location information. The control unit16in the train10bis capable of changing the front-part allowance length91band the rear-part allowance length92bdepending on the traveling distance since the last correction to the train location. For example, the control unit16in the train10bincreases the front-part allowance length91band the rear-part allowance length92bin proportion to the traveling distance since the last correction to the train location.

InFIG. 1, the wayside coil20bis less distant from the next station than the wayside coil20ais, and is close to the signals71and72. When the location of the train10bis suddenly changed correcting the train location at the time when the train10bhas passed through the wayside coil20b, the train10bmay encounter a problem due to such a sudden change. For example, when the correction to the front-part location of the train10bchanges the stop-limit position (not illustrated) of the train10bfrom a position between the station and the signals71and72to a position before the signals71and72, the electronic interlocking device60suddenly switches indication of one of the signals71and72, which corresponds to the path of the train10b, from “go” to “stop”. As a consequence, the train10bneeds to suddenly stop due to a sudden change in the signal indication. For this reason, the wayside coil20btransmits, to the train10b, wayside-coil location information indicating the location where the wayside coil20bis installed, and transmits correction permission information associated with the wayside coil20b, as well.

FIG. 5is a diagram illustrating an example of the correction permission information to be transmitted by the wayside coil20baccording to the first embodiment.FIG. 5illustrates a target for correction to the train location of the train10b. Specifically,FIG. 5shows that the train10bhaving passed through the wayside coil20bdoes not correct the front-part location of the train10b, but corrects the rear-part location of the train10b. In the correction permission information illustrated inFIG. 5, information that indicates whether correction to the front-part location is permissible is defined as first information, and information that indicates whether correction to the rear-part location is permissible is defined as second information. Specifically, inFIG. 5, the first information indicates that the correction target is the front-part location and correction to the front-part location is not permissible, and the second information indicates that the correction target is the rear-part location and correction to the rear-part location is permissible.

At the time when the train10bhas passed through the wayside coil20b, the control unit16in the train10bobtains wayside-coil location information and correction permission information transmitted from the wayside coil20bthrough the onboard pickup coil11. The control unit16in the train10bcorrects the rear-part location of the train10b, but does not correct the front-part location of the train10bon the basis of the obtained wayside-coil location information and the obtained correction permission information. Specifically, the control unit16in the train10bdoes not reset the front-part allowance length91badded to the front part of the train10b, but resets, that is, eliminates the rear-part allowance length92badded to the rear part of the train10b. In this manner, the control unit16in the train10bcan avoid an incident such as a sudden stop of the train10bby partially correcting the location of the train10bat the time when the train10bhas passed through the wayside coil20b.

An operation of the onboard control device14installed in the train10is described below with reference to a flowchart.FIG. 6is a flowchart illustrating the operation of the onboard control device14according to the first embodiment. In the onboard control device14, the control unit16calculates a train location of the train10on the basis of an output signal from the tachometer generator12(Step S1). The control unit16determines whether the obtaining unit15has obtained wayside coil information that is wayside-coil location information indicating the location where the wayside coil20is installed, and correction permission information, from the wayside coil20through the onboard pickup coil11(Step S2).

When the obtaining unit15has obtained the wayside-coil location information and the correction permission information from the wayside coil20through the onboard pickup coil11(YES at Step S2), the control unit16checks whether the first information included in the correction permission information indicates that correction is permissible (Step S3). When the first information indicates that correction is permissible (YES at Step S3), the control unit16corrects the front-part location of the train10by using the wayside-coil location information (Step S4). When the first information indicates that correction is not permissible (NO at Step S3), the control unit16does not correct the front-part location of the train10, that is, omits the process at Step S4.

After Step S4or when the determination at Step S3is NO, the control unit16checks whether the second information included in the correction permission information indicates that correction is permissible (Step S5). When the second information indicates that correction is permissible (YES at Step S5), the control unit16corrects the rear-part location of the train10by using the wayside-coil location information (Step S6). When the second information indicates that correction is not permissible (NO at Step S5), the control unit16does not correct the rear-part location of the train10, that is, omits the process at Step S6.

When the determination at Step S2is NO, or when the determination at Step S5is NO, or after Step S6, the control unit16transmits train location information on the train10including the front-part location of the train10and the rear-part location of the train10to the ground system30through the communication unit13(Step S7). The control unit16returns to Step S1to repeat the operations described above.

An operation of the wayside coil20is described below with reference to a flowchart.FIG. 7is a flowchart illustrating the operation of the wayside coil20according to the first embodiment. The communication unit22checks whether the onboard pickup coil11in the train10has passed through the wayside coil20, that is, whether the wayside coil20has detected the onboard pickup coil11in the train10(Step S11). When the wayside coil20does not detect the onboard pickup coil11(NO at Step S11), the communication unit22is on standby until the wayside coil20detects the onboard pickup coil11. When the wayside coil20has detected the onboard pickup coil11(YES at Step S11), the communication unit22reads wayside-coil location information and correction permission information from the storage unit21and transmits the read information to the onboard pickup coil11(Step S12). The communication unit22returns to Step S11to repeat the operations described above.

The correction permission information stored in the storage unit21in the wayside coil20is set in advance by personnel of a railway operating company in charge, taking nearby installations into account. Although the correction permission information to be transmitted from the wayside coil20has been described with reference toFIGS. 4 and 5as an example, the correction permission information is not limited thereto. The correction permission information to be stored in the storage unit21in the wayside coil20may include, for example, the first information indicating that correction to the front-part location is permissible, and the second information indicating that correction to the rear-part location is not permissible. Alternatively, the correction permission information may include the first information indicating that correction to the front-part location is not permissible, and the second information indicating that correction to the rear-part location is not permissible. Alternatively, correction permission information to be stored in the storage unit21in the wayside coil20may include only the first information, targeting only the front-part location for correction, or include only the second information, targeting only the rear-part location for correction. When the correction permission information includes only the first information, the control unit16in the train10omits the operations at Steps S5and S6in the flowchart inFIG. 6. When the correction permission information includes only the second information, the control unit16in the train10omits the operations at Steps S3and S4in the flowchart inFIG. 6.

Next, a hardware configuration of the onboard control device14is described. In the onboard control device14, the obtaining unit15is an input interface to obtain information received by the onboard pickup coil11. The control unit16is implemented by a processing circuitry. It is allowable that the processing circuitry is either dedicated hardware, or a processor and a memory that execute programs stored in the memory.

FIG. 8is a diagram illustrating an example of a case where the processing circuitry included in the onboard control device14according to the first embodiment is configured by a processor and a memory. In a case where the processing circuitry is configured by a processor201and a memory202, the functions of the processing circuitry of the onboard control device14are implemented in software, firmware, or a combination of the software and the firmware. The software or the firmware is described as a program and stored in the memory202. In the processing circuitry, the processor201reads and executes the program stored in the memory202to thereby implement each of the functions. That is, the processing circuitry includes the memory202that stores therein programs that eventually execute the processing of the onboard control device14. These programs are also regarded as causing a computer to execute the procedure and the method of the onboard control device14.

The processor201may be a device such as a CPU (Central Processing Unit), a processing device, an arithmetic device, a microprocessor, a microcomputer, or a DSP (Digital Signal Processor). For example, a nonvolatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), and an EEPROM® (Electrically EPROM), or a magnetic disk, a flexible disk, an optical disk, a compact disk, a MiniDisk, or a DVD (Digital Versatile Disc) corresponds to the memory202.

FIG. 9is a diagram illustrating an example of a case where the processing circuitry included in the onboard control device14according to the first embodiment is configured by dedicated hardware. When the processing circuitry is configured by dedicated hardware, then for example, a single circuit, a combined circuit, a programmed processor, a parallel-programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof corresponds to a processing circuitry203illustrated inFIG. 9. The functions of the onboard control device14may be respectively implemented by each individual processing circuitry203or may be collectively implemented by a single processing circuitry203.

As for the respective functions of the onboard control device14, it is possible to configure that some parts of the functions are implemented by dedicated hardware and other parts thereof are implemented by software or firmware. In this manner, the processing circuitry can implement each function described above by dedicated hardware, software, firmware, or a combination of these elements.

A hardware configuration of the wayside coil20is now described. In the wayside coil20, the communication unit22is a transmission device to transmit information stored in the storage unit21when the wayside coil20detects radio waves and the like irradiated from the onboard pickup coil11in the train10. The storage unit21is implemented by a memory.

As described above, according to the present embodiment, in the train10, the control unit16in the onboard control device14obtains wayside-coil location information and correction permission information from the wayside coil20, and corrects or does not correct train location information in accordance with the details of the correction permission information. This enables the train10to control correction to the train location information in accordance with whether there are facilities in the vicinity of the wayside coil20, that is, there is a signal in the above example, such that it is possible to avoid an incident such as a sudden stop as a result of a sudden change in the train location information.

Although not illustrated inFIG. 1, it is also possible to additionally install a wayside coil20inside a station, so that the train10having passed through the signals71and72can correct the train location information, specifically, correct the front-part location of the train10by using the wayside coil20installed inside the station.

Second Embodiment

In the first embodiment, the train10obtains correction permission information from the wayside coil20. In this case, all of the trains10passing through the wayside coil20obtain, from the wayside coil20, pieces of correction permission information that contain the same details, and accordingly correct the train locations in the same manner. In a second embodiment, a description is made as to a case in which the train10holds correction permission information therein.

In the second embodiment, the configuration of the wireless train control system100is identical to that of the wireless train control system100according to the first embodiment illustrated inFIG. 1. The configuration of the wayside coil20is also identical to that of the wayside coil20according to the first embodiment illustrated inFIG. 2. However, in the second embodiment, the storage unit21has wayside coil information that is wayside-coil identification information stored therein. The wayside-coil identification information is capable of identifying the wayside coil20. The wayside-coil identification information is, for example, an ID (IDentification) that can uniquely represent each wayside coil20in the wireless train control system100. The communication unit22transmits, to the train10, wayside-coil identification information stored in the storage unit21. The storage unit21may have wayside-coil location information stored therein similarly to the first embodiment. In a case where the storage unit21has wayside-coil location information stored therein, the communication unit22transmits the wayside-coil location information along with the wayside-coil identification information.

FIG. 10is a block diagram illustrating a configuration example of the train10according to the second embodiment. The train10includes the onboard pickup coil11, the tachometer generator12, the communication unit13, and the onboard control device14. The onboard control device14includes the obtaining unit15, the control unit16, and a storage unit17. The trains10aand10bare identical in configuration. The storage unit17stores therein correspondence information in which wayside-coil identification information capable of identifying the wayside coil20is associated with correction permission information.

FIG. 11is a diagram illustrating an example of the correspondence information stored in the storage unit17in the onboard control device14according to the second embodiment. In the correspondence information illustrated inFIG. 11, the wayside-coil identification information is an ID that can uniquely represent each wayside coil20in the wireless train control system100as described above. In the correspondence information illustrated inFIG. 11, correction permission information is set for each wayside-coil identification information, and indicates whether correction to the train location is permissible. InFIG. 11, information in the field “front-part location” in the correction permission information corresponds to the first information, and information in the field “rear-part location” in the correction permission information corresponds to the second information. InFIG. 11, the wayside-coil location information indicates the location where the wayside coil20is installed, the wayside coil20being indicated by the wayside-coil identification information. In a case where the wayside-coil location information is transmitted from the wayside coil20, the wayside-coil location information may be deleted from the correspondence information illustrated inFIG. 11. The onboard control device14may obtain the wayside-coil location information along with the wayside-coil identification information from the wayside coil20, or include the wayside-coil location information in the correspondence information stored in the storage unit17.

In the second embodiment, when the onboard pickup coil11in the train10has passed through the wayside coil20, the wayside coil20transmits, to the train10, wayside coil information that is wayside-coil identification information. The wayside coil20may transmit the wayside-coil location information along with the wayside-coil identification information similarly to the first embodiment.

In the train10, when the control unit16in the onboard control device14obtains wayside-coil identification information from the wayside coil20through the onboard pickup coil11and the obtaining unit15, the control unit16searches the correspondence information stored in the storage unit17on the basis of the wayside-coil identification information. For example, when the wayside-coil identification information obtained from the wayside coil20is “A1”, the control unit16searches the correspondence information with the wayside-coil identification information “A1”, and obtains correction permission information associated with the wayside-coil identification information “A1”. In the example inFIG. 11, the control unit16obtains correction permission information indicating that correction to the front-part location is not permissible, and correction to the rear-part location is permissible. When the control unit16does not obtain wayside-coil identification information from the wayside coil20through the onboard pickup coil11and the obtaining unit15, the control unit16obtains wayside-coil location information “B1” associated with the wayside-coil identification information “A1” in the example inFIG. 11. The control unit16executes control to correct the location of the train10on the basis of the correction permission information obtained by searching the correspondence information and associated with the wayside-coil identification information “A1”.

The operation of the onboard control device14installed in the train10is described below with reference to a flowchart.FIG. 12is a flowchart illustrating the operation of the onboard control device14according to the second embodiment. In the onboard control device14, the control unit16calculates a train location of the train10on the basis of an output signal from the tachometer generator12(Step S1). The control unit16determines whether the obtaining unit15has obtained wayside-coil identification information from the wayside coil20through the onboard pickup coil11(Step S21).

When the obtaining unit15has obtained wayside-coil identification information from the wayside coil20through the onboard pickup coil11(YES at Step S21), the control unit16searches correspondence information stored in the storage unit17by using the obtained wayside-coil identification information (Step S22), and obtains correction permission information associated with the obtained wayside-coil identification information (Step S23). The operations at Steps S3to S7subsequent to Step S23are the same as the operations in the first embodiment illustrated inFIG. 6. However, when the determination at Step S21is NO, or when the determination at Step S3is NO, or when the determination at Step S5is NO, or after Step S6, the control unit16transmits train location information on the train10to the ground system30through the communication unit13(Step S7).

The operation of the wayside coil20is described below with reference to a flowchart.FIG. 13is a flowchart illustrating the operation of the wayside coil20according to the second embodiment. The communication unit22checks whether the onboard pickup coil11in the train10has passed through the wayside coil20, that is, whether the wayside coil20has detected the onboard pickup coil11in the train10(Step S31). When the wayside coil20does not detect the onboard pickup coil11(NO at Step S31), the communication unit22is on standby until the wayside coil20detects the onboard pickup coil11. When the wayside coil20has detected the onboard pickup coil11(YES at Step S31), the communication unit22reads wayside-coil identification information from the storage unit21and transmits the read wayside-coil identification information to the onboard pickup coil11(Step S32). The communication unit22returns to Step S31to repeat the operations described above.

The correspondence information stored in the storage unit17in the onboard control device14is set in advance by personnel of a railway operating company in charge, taking account of the type of the train10, nearby installations, and other factors. In the correspondence information illustrated inFIG. 11, wayside-coil identification information and wayside-coil location information are common to all the trains10. However, different pieces of correction permission information may be set for different types of the train10. For the wayside coil20installed before some station (defined as “station A”), for example, details of correction permission information set for a train10that is supposed to stop at the station A are different from those for another train10that is not supposed to stop at the station A. In this case, personnel of a railway operating company in charge can set different pieces of correction permission information for different types of the train10. Similarly to the correction permission information stored in the storage unit21in the wayside coil20according to the first embodiment, correction permission information stored in the storage unit17in the onboard control device14may include only the first information, targeting only the front-part location for correction, or may include only the second information, targeting only the rear-part location for correction.

In the hardware configuration of the onboard control device14, the storage unit17is implemented by a memory. In the onboard control device14, the hardware configuration of the obtaining unit15and the control unit16is identical to that of the obtaining unit15and the control unit16according to the first embodiment.

As described above, according to the present embodiment, the onboard control device14in the train10holds correction permission information therein, obtains wayside-coil identification information from the wayside coil20, and corrects or does not correct train location information in accordance with the details of the correction permission information associated with the wayside-coil identification information. With this configuration, the wireless train control system100can provide a setting per wayside coil20such that whether correction to the train location information is permissible is determined in accordance with the type of the train10.

Third Embodiment

In the first embodiment, the train10obtains correction permission information from the wayside coil20. In the second embodiment, the train10holds correction permission information therein. In a third embodiment, a description is made as to a case in which the train10obtains correction permission information from the ground control device50.

In the third embodiment, the configuration of the wireless train control system100is identical to that of the wireless train control system100according to the first embodiment illustrated inFIG. 1. The configuration of the wayside coil20is also identical to that of the wayside coil20according to the second embodiment. The configuration of the train10is also identical to that of the train10according to the first embodiment illustrated inFIG. 3. However, in the third embodiment, the train10obtains, from the ground control device50, correction permission information in a form of correspondence information in which the correction permission information is associated with wayside-coil identification information.

FIG. 14is a block diagram illustrating a configuration example of the ground control device50according to the third embodiment. The ground control device50includes a storage unit51and a control unit52. The storage unit51stores therein correspondence information in which wayside-coil identification information capable of identifying the wayside coil20is associated with correction permission information. The correspondence information has the same details as those of the correspondence information stored in the storage unit17in the onboard control device14according to the second embodiment. Similarly to the second embodiment, in a case where the wayside-coil location information is transmitted from the wayside coil20to the train10, the wayside-coil location information may be deleted from the correspondence information illustrated inFIG. 11. The onboard control device14may obtain the wayside-coil location information along with the wayside-coil identification information from the wayside coil20, or include the wayside-coil location information in the correspondence information obtained from the ground control device50.

FIG. 15is an explanatory diagram for describing the operations of the train10and the ground control device50according to the third embodiment. In the third embodiment, the control unit16in the onboard control device14transmits train location information to the ground system30through the communication unit13.

When the control unit52in the ground control device50obtains train location information from the train10through the wireless device40, the control unit52determines paths86and87of the train10and determines a stop-limit position88of the train10on the basis of the train location information obtained from the train10. The control unit52in the ground control device50searches for the wayside coils20aand20bpresent on the paths86and87extending from the rear-part location of the train10to the stop-limit position88. The control unit52in the ground control device50searches correspondence information stored in the storage unit51on the basis of wayside-coil identification information on the wayside coils20aand20b. For example, when the wayside-coil identification information on the wayside coil20ais “A4”, the control unit52obtains correspondence information about the wayside-coil identification information “A4”. In the example inFIG. 11, the control unit52obtains correspondence information that the wayside-coil identification information is “A4”, correction to the front-part location is permissible, and correction to the rear-part location is permissible. For another example, when the wayside-coil identification information on the wayside coil20bis “A5”, the control unit52obtains correspondence information about the wayside-coil identification information “A5”. In the example inFIG. 11, the control unit52obtains correspondence information that the wayside-coil identification information is “A5”, correction to the front-part location is not permissible, but correction to the rear-part location is permissible. The control unit52in the ground control device50executes control to transmit, to the train10, control information including the obtained correspondence information.

The control unit16in the train10executes control to correct the location of the train10on the basis of the correspondence information included in the control information obtained from the ground control device50. At the time when the train10passes through the wayside coil20a, the control unit16in the train10resets, that is, eliminates the front-part allowance length91, and resets, that is, eliminates the rear-part allowance length92on the basis of the correspondence information obtained from the ground control device50.

The operation of the onboard control device14installed in the train10is described below with reference to a flowchart.FIG. 16is a flowchart illustrating the operation of the onboard control device14according to the third embodiment. In the onboard control device14, the control unit16calculates a train location of the train10on the basis of an output signal from the tachometer generator12(Step S1). The control unit16determines whether the obtaining unit15has obtained wayside-coil identification information from the wayside coil20through the onboard pickup coil11(Step S41). When the obtaining unit15has obtained wayside-coil identification information from the wayside coil20through the onboard pickup coil11(YES at Step S41), the control unit16determines whether the obtaining unit15has obtained, from the ground control device50, correspondence information in which the wayside-coil identification information is associated with correction permission information (Step S42). When the obtaining unit15has obtained correspondence information from the ground control device50(YES at Step S42), the control unit16searches the correspondence information by using the wayside-coil identification information obtained from the wayside coil20, and checks whether first information indicates that correction is permissible, the first information being included in the correction permission information associated with the wayside-coil identification information obtained from the wayside coil20(Step S3). The operations at Steps S3to S7are the same as the operations in the first embodiment illustrated inFIG. 6. However, when the determination at Step S41is NO, or when the determination at Step S42is NO, or when the determination at Step S5is NO, or after Step S6, the control unit16transmits train location information on the train10to the ground system30through the communication unit13(Step S7).

FIG. 17is a flowchart illustrating an operation of the ground control device50according to the third embodiment. The control unit52checks whether the ground control device50has obtained train location information from the train10(Step S51). When the ground control device50does not obtain train location information from the train10(NO at Step S51), the control unit52is on standby until the ground control device50obtains train location information. When the ground control device50has obtained train location information from the train10(YES at Step S51), the control unit52determines the paths86and87of the train10(Step S52) and determines the stop-limit position88of the train10(Step S53) on the basis of the train location information. The control unit52searches for the wayside coil20present on the path extending from the rear-part location of the train10to the stop-limit position88(Step S54). The control unit52generates control information including the result of the search for the wayside coil20, and transmits the control information to the train10through the wireless device40(Step S55). Specifically, the control unit52executes control to transmit, to the train10, correspondence information associated with the wayside coil20detected as a consequence of the search. The control unit52in the ground control device50repeats the operations described above.

The operation of the control unit52to search for the wayside coil20at Step S54in the flowchart illustrated inFIG. 17is described below in detail.FIG. 18is a flowchart illustrating the operation by which the control unit52in the ground control device50according to the third embodiment searches for the wayside coil20. The control unit52in the ground control device50searches for the wayside coil20present on the paths86and87extending from the rear-part location of the train10to the stop-limit position88(Step S61). When the control unit52has detected the wayside coil20(YES at Step S62), the control unit52obtains, from the storage unit51, correspondence information about wayside-coil identification information on the detected wayside coil20, and sets the obtained correspondence information in control information as a result of the retrieval (Step S63). When the control unit52cannot detect the wayside coil20(NO at Step S62), the control unit52sets “no correction permission information” as a result of the retrieval in the control information (Step S64).

The train10may detect the wayside coil20, and transmits, to the ground control device50, wayside-coil identification information obtained from the wayside coil20. In this case, in the ground control device50, the control unit52obtains, from the storage unit51, correspondence information about the wayside-coil identification information obtained from the train10, generates control information including the obtained correspondence information, and transmits the generated control information to the train10through the wireless device40. That is, when the control unit52obtains wayside-coil identification information from the train10, the control unit52executes control to transmit, to the train10, the correspondence information including correction permission information associated with the obtained wayside-coil identification information. In the ground control device50, in a case where the control unit52obtains a single piece of wayside-coil identification information from the train10, the control unit52may obtain correction permission information about the obtained wayside-coil identification information from correspondence information stored in the storage unit51, generate control information including the obtained correction permission information, and transmit the generated control information to the train10through the wireless device40.

The ground control device50may have correspondence information stored in the storage unit51in accordance with the type of the train10. When the control unit52in the ground control device50obtains train location information from the train10, the control unit52also obtains train identification information capable of identifying the type of the train10. The control unit52in the ground control device50can generate control information having a setting per wayside coil20such that whether correction to the train location information is permissible is determined in accordance with the type of the train10, and can transmit the generated control information.

In the hardware configuration of the ground control device50, the storage unit51is implemented by a memory. The control unit52is implemented by a processing circuitry. The processing circuitry included in the ground control device50is of an identical configuration to the processing circuitry included in the onboard control device14according to the first embodiment.

As described above, according to the present embodiment, in the wireless train control system100, the ground control device50holds correction permission information therein. The train10can obtain, from the ground control device50, correction permission information associated with the wayside coil20present on the path. In the wireless train control system100, the ground control device50is the only device that holds correspondence information therein. In modifying the correction permission information for each wayside coil20, therefore, personnel of a railway operating company in charge only need to modify the data stored in the storage unit51in the ground control device50. This can help the personnel do work more efficiently.

The configurations described in the above embodiments are only examples of the content of the present invention. The configurations can be combined with other well-known techniques, and part of each of the configurations can be omitted or modified without departing from the scope of the present invention.

REFERENCE SIGNS LIST