JP3312901B2 - Time-division multiplex communication system for railways and its transmission / reception device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a railway time-division multiplex communication system for communicating between railway maintenance vehicles such as a bullet train, and a transmission / reception apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, communication between vehicles for maintenance and the like has been performed by:
An intermittent transmission / reception system using one frequency is used. In this intermittent transmission / reception method, each vehicle is equipped with one of transmission / reception units having transmission / reception timings of a plurality of patterns,
It moves or stops while repeating intermittent transmission and reception in the cycle of the form. The transmission / reception timing of the plurality of patterns is fixed, and the timing does not change when the power is turned on or during movement.

In this intermittent transmission / reception method, transmissions may overlap between devices without synchronization, but unless a transceiver having the same pattern timing approaches,
At worst, it can be received twice within one cycle.
The communication between the vehicles is performed by performing the transmission and reception as described above in each communication cycle.

[0004]

However, the number of railway maintenance vehicles is quite large. For example, several hundred vehicles are held even in a specific area, and transceivers having the same pattern timing are arranged. there's a possibility that. For this reason, in a service area where there are actually more maintenance vehicles than the number of patterns, the operation is covered so that maintenance vehicles having the same pattern do not approach.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and when communication between railway maintenance vehicles is performed by time division multiplexing, a communication slot is fixedly allocated to the maintenance vehicles. It is another object of the present invention to provide a railway time-division multiplexing communication system and a transmission / reception apparatus for the same, which can automatically acquire a vacant communication slot according to the communication status of a maintenance vehicle or the like.

[0006]

According to a first aspect of the present invention, there is provided a time-division multiplex communication system for railways, which uses a specific frequency for communication between a plurality of vehicles mounted on a transmission / reception device and moving on a track. In a time-division multiplex communication system for railways, which performs multiplex communication in a time-division manner, time synchronization is set in each vehicle based on the same reference signal, a communication cycle having a predetermined number of communication slots is set, and each vehicle transmits. At times, the communication slot number that can be received and the communication slot number that it transmits are added as transmission status to the transmission data and transmitted.When each vehicle receives, the logical sum of the status from the vehicle that can be received is calculated. If the vehicle has not been able to acquire a communication slot at that time, the communication slot which is ineffective by the logical sum is determined to be an empty communication slot, and the empty communication slot is determined. One of the communication slots and acquires as its own communication slot.

According to a second aspect of the present invention, there is provided a time-division multiplex communication system for railways according to the first aspect of the present invention, wherein when there is no reception from another vehicle at the time of reception, the time-division multiplex communication system is idle. When acquiring one of the communication slots as its own communication slot, the communication slot determined by random number processing is acquired.

According to a third aspect of the present invention, there is provided a time-division multiplex communication system for railways, in which communication between a plurality of vehicles mounted on a transmission / reception device and moving on a track is multiplexed by time division using a specific frequency. In a time-division multiplex communication system for railways, each vehicle sets a communication cycle having a predetermined number of communication slots with time synchronization based on the same reference signal, and each vehicle can receive at the time of transmission. The communication slot number and the communication slot number transmitted by itself are added as transmission status to the transmission data and transmitted.At the time of reception, each vehicle takes the logical OR of the status from the vehicle that has been able to receive, and at that time, If the communication slot transmitted by the vehicle in the logical sum is ineffective when the vehicle has acquired the communication slot, the communication slot transmitted by the Doo is and determines that conflicts with other vehicles.

[0009] The time-division multiplex communication system for railways according to claim 4 of the present invention is a case in which it is determined that there is a conflict in the time-division multiplex communication system for railways according to claim 3,
When there is reception from another vehicle, whether to perform normal transmission or delayed transmission in the communication slot that has already been acquired,
Alternatively, it is characterized in that whether to set transmission restriction is determined by random number processing.

[0010] The time-division multiplex communication system for a railway according to claim 5 of the present invention is a case where it is determined that there is a conflict in the time-division multiplex communication system for a railway according to claim 3,
When there is no reception from another vehicle, a communication slot determined by random number processing is used as its own communication slot.

According to a sixth aspect of the present invention, there is provided a time-division multiplex communication system for railways according to the first to fifth aspects, wherein the reference signal is a GPS PPS signal. And

According to a seventh aspect of the present invention, there is provided a transmission / reception apparatus for a time-division multiplex communication system for railways, which performs communication between a plurality of vehicles traveling on a track by time division multiplex communication using a specific frequency. A communication slot / cycle setting means for setting a communication cycle and a communication slot using a GPS PPS signal as a reference signal, and at least a position for detecting a position. It has a detection sensor and a route database,
Self-information generating means for generating self-information including the position and direction of the vehicle, and slot detecting means for receiving a radio signal from another vehicle and detecting the status of a communication slot from communication status information included in the radio signal And when the own vehicle has already acquired and transmitted a communication slot, a conflict detecting means for detecting a conflict state depending on whether the own vehicle bit of the communication status information is significant, and the conflict detecting means. In the case where the presence of contention is detected, contention arbitration means for arbitrating to eliminate the contention state, and arbitration by the contention arbitration means, when the acquisition of the communication slot fails,
An empty slot detecting means for detecting an empty slot, and when the own vehicle has not yet acquired a communication slot, when the empty slot is detected by the slot detecting means, the own vehicle has already acquired and transmitted a communication slot. When the slot detection means detects that there is no reception from another vehicle and when the empty slot detection means detects an empty slot, one of the empty slots is communicated with the own vehicle. Slot selection means for selecting a slot, a communication slot selected by the slot selection means, a communication slot when the contention detection means detects no contention, and a communication slot as a result of arbitration by the contention arbitration means. Communication slot number that can be received using any of the communication slots in the case of successful acquisition of And a communication status of the communication slot number by itself to transmit, and having a a wireless transmission means for transmitting in addition to transmitting data of the self-information generating means.

According to the time-division multiplex communication system for railways of the present invention and its transmission / reception apparatus, even if the number of maintenance vehicles is large, communication is automatically and flexibly performed only with the maintenance vehicles actually dispatched. Since the slots are allocated, the slots can be used effectively.

[0014] Even when the dispatched maintenance vehicle moves and disperses over a wide area along the railroad track and performs work, a communication slot for performing time division multiplex communication at the time of entering the communicable area is set. Automatically allocated, and conversely, when the mobile terminal goes out of the communicable area, the communication slots used up to that point become empty slots, so time-division multiplex communication between vehicles that are dispersed and move over a wide range Can be performed efficiently without hindrance.

In addition, by using a GPS PPS (Pulse Per Second) signal as a reference signal of the time division multiplex communication system, there is no need to take any other measures such as installing a reference station, and communication between vehicles can be performed. Cycles and communication slots can be set accurately.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings.

FIG. 1 is a diagram schematically showing a railway line such as a bullet train, a maintenance vehicle moving on the railway line, and a track closing device to which the present invention is applied. In addition, the ground child is a sign post indicating about a kilometer, and is arranged at predetermined intervals on a railway line.

Each maintenance vehicle is equipped with an on-vehicle transmission / reception device as shown in FIG. 2, and the line closing device is provided with a line closing transmission / reception device as shown in FIG.

The on-vehicle transceiver 200 shown in FIG. 2 includes an on-vehicle transceiver 210, a GPS antenna 220, a radio antenna 240, a point sensor 250, and a speed sensor 260.

GPS receiver 21 of on-vehicle transceiver 210
1 receives a GPS signal received by the GPS antenna 220 and generates a PPS (Pulse Per Seco) generated from the GPS signal.
nd) The signal is supplied to the control unit 212 as a reference signal, and other position signals are also supplied to the control unit 212 as necessary. Since the PPS signal is obtained every one second, if the reference signal needs to be given, for example, every two seconds, the time data obtained simultaneously from the GPS data is used for every odd second or every even second. Get the PPS signal.

The display operation unit 230 includes an up / down switch 231 with an LED and a 7-segment LED display 23.
2. It has an LED display 233 and a numeric keypad 234, and exchanges signals with the control unit 212.

The point sensor 250 detects a point on the track of the vehicle on the basis of a signal from a ground post (sign post) and supplies the detected signal to the control unit 212. The speed sensor 260 is associated with rotation of wheels of the vehicle. Control unit 2 detects the detection pulse
12

The commercial radio 214 has an antenna 241,
The controller transmits data from the on-vehicle transceiver 210 to the outside via a radio antenna device including an antenna duplexer 242 and a filter 243, and receives data from another external vehicle or a track closing device. 212. In addition, a speaker 215 is provided, and receives a warning signal from the commercial wireless device 214 to notify an approach warning or the like.

The control unit 212 of the vehicle-mounted transceiver 210 includes:
It has a database 213 such as each line of the railway line, and the distance of each ground line for each line, and the situation of the vehicle is extracted from the database 213 and used. Further, the control unit 212 is provided with the display operation unit 23 described above.
0, an operation signal, a point sensor 250, a speed sensor 2
Based on a detection signal such as 60 and data from the database 213, data such as a route on which the own vehicle is traveling, a position, a speed, and a direction are generated. The control unit 212
Performs communication processing required for time-division multiplexing communication by transmitting and receiving to and from another external vehicle or a track closing device via the business radio 214. When the control unit 212 approaches another vehicle or the track closing device, the commercial radio 21
A command signal for causing the speaker 215 connected to the control signal 4 to issue an approach warning and a command signal for a brake for stopping the vehicle are output.

The line closing transceiver 300 shown in FIG. 3 includes a line closing transceiver 310, a GPS antenna 320,
And a wireless device antenna 341. The track closing device is for blocking a specific section of the track from entering a maintenance vehicle. Therefore, the installation location, route, and the like are determined for each task that has occurred, and are set in the track closing transmission / reception device. In addition, since it is fixedly installed during the work, no point sensor or the like is provided.

GPS receiver 31 of on-vehicle transceiver 310
1 receives the GPS signal received by the GPS antenna 320, supplies the PPS signal generated from the GPS time signal to the control unit 312 as a reference signal, and also supplies other position signals to the control unit 312 as necessary. I do. Also,
The display operation unit 330 includes an up / down switch 33 with an LED.
1,7-segment LED display 332, LED display 3
33, and a numeric keypad 334 for exchanging signals with the control unit 312.

The commercial radio 314 is a radio antenna 3
The data from the line closing transceiver 310 is transmitted to the outside via the line 41, and the data is received from an external vehicle or another line closing device and supplied to the control unit 312. Further, a speaker 315 is provided, and the business radio 3
In response to the alarm signal from, an alert such as an approach alarm is issued.

Control section 312 of line closing transceiver 310
Has a database 313, such as each line of the railway line, and the distance of each child up and down for each route, and the like. The operation signal from the display operation unit 330 and the database 3
On the basis of the data from 13, data such as the route on which the track closing device is installed and the position are generated. In addition, the control unit 312 performs communication processing required for time division multiplex communication by transmitting and receiving to and from an external vehicle or another line closing device via the commercial radio 314. The control unit 3
12, when the vehicle approaches, the business radio 314
A command signal for causing the speaker 315 connected to the device to perform an approach warning is output.

A worker engages in maintenance work along this track. FIG. 4 shows a portable receiver 400 carried by such a worker. The portable receiver 400 includes a radio antenna 441 and a portable receiver, has no transmission function, and has a predetermined reception area for transmitting radio waves transmitted from a vehicle-mounted transceiver or a line closing transceiver. It has only the function of receiving, for example, when receiving a radio wave transmitted from an on-vehicle transmitting / receiving device or the like, an alert such as that a vehicle is approaching is generated and the worker is alerted. .

FIG. 5 shows the control unit 2 of the vehicle-mounted transceiver 210.
12 is a diagram illustrating a route database among databases 213 and 313 included in the control unit 312 of the transceiver 12 and the line closing transceiver 310. FIG.

In FIG. 5, the route database includes route types R (1) to R (N) to R (end),
Terrestrial child numbers 1 to n for each route R (N)
A correspondence table of the end and the total number of kilometers is prepared. This grounding element is installed at a predetermined distance (usually 1 km) from the starting point of the track (for example, the platform of Tokyo Station), and when passing through the vehicle, the point sensor 250 mounted on the vehicle detects the grounding element. Is detected, and kilometers are obtained from the route database. While the vehicle is between the grounds, the number of pulses from the speed sensor 260 is detected, and the current position is calculated as in the following equation. P = D (n) + G × (r / R) × m where P: current position (km), D (n): km of ground element n, G: gear ratio, r: wheel circumference R : The number of pulses per rotation of the speed sensor, m: the number of speed sensor pulses after passing through the ground element n.

Incidentally, due to the configuration of the railway track, for example, such as on a bridge or at a branch point of a track, there are cases where ground elements cannot always be arranged at a fixed distance (for example, 1 km). , Even in this case,
The route database including the correspondence table of n to end and the total number of kilometers can always detect the corrected and accurate vehicle position.

FIG. 6 shows an example of point detection in the case where a railway line branches midway. As shown in FIG.
Assuming that the route B is branched from the route, as shown in the route A data and the route B data in FIG.
If it is a, it is determined that there is no branch (the detected ground child is N + 1), and if not, it is determined that it has branched to the route B. Of course, the route data related to this branch is also provided in the database 213 or the like.

FIG. 7 shows an example of wireless communication data transmitted from a vehicle-mounted transmission / reception device or a line closing transmission / reception device configured as described above using a certain communication slot S (i). . As communication data, as shown in the figure,
System ID, base ID, route ID, vehicle ID,
Location information, speed information, direction information and communication status,
Sent. The communication status indicates a communication slot number that can be received at that time and a communication slot number that is transmitted by itself.

Now, a maintenance vehicle equipped with the vehicle transmitting / receiving device configured as described above, a track closing device provided with the track closing transmitting / receiving device, and a portable receiving device for receiving radio waves from these devices are described. The railway time division multiplex communication system according to the embodiment of the present invention to be used will be described.

First, in this time division multiplex communication system,
FIG. 8 shows the configuration of a communication cycle and a communication slot. In the communication cycle, as shown in FIG. 8, the reference signal G is transmitted to each maintenance vehicle and the transmission / reception device of the track closing device.
Each transmission / reception device is started by synchronizing time with the PPS signal of the PS. Then, each communication cycle period is set to 2 seconds, and the number of communication slots is divided into 18 slots. These 18 communication slots allocate communication slots S (1) to S (14) for vehicles and communication slots S (15) to S (18) for track closing devices.

The communication slots S (1) to S (14) allocated for the vehicles are not fixedly allocated to the specific vehicles, and each vehicle has an empty slot according to the availability of these communication slots. Is used flexibly to obtain On the other hand, the communication slots S (15) to S (18) allocated for the track closing device are fixedly allocated to the communication slots when the track closing device is installed because the track closing device is installed in the track closing section. Will be.

Next, the overall communication processing in the vehicle transmitting / receiving apparatus will be sequentially described. FIG. 9 is a diagram showing an outline of the entire communication processing, and is similarly performed in each vehicle transmitting / receiving apparatus.

In FIG. 9, since a communication slot has not been acquired with the start of communication, an empty communication slot is first detected (). The detection of the vacant slot is performed by taking the logical sum of the communication statuses from the transmitting / receiving devices of all the vehicles that can be received at present, and judging that the communication slot in which all vehicles are inactive (logical sum is 0) is a vacant slot. .

As an example of this state, if the communication status received from the vehicles n, m, and k is as follows, as a result of the logical sum, the second communication slot, the seventh communication slot, and the tenth communication slot become: It is determined that the slot is empty. Communication status received from vehicle n 0011010100001010 Communication status received from vehicle m 10011000100101 Communication status received from vehicle k 10110101001010 Logical OR 1 0 1111 0 11 0 1111

If there is no empty communication slot in the detection of the empty slot, the transfer is determined to be impossible. Then, the process proceeds to a standby process, and an empty communication slot is detected again in the next communication cycle. In this case, this process is performed until an empty communication slot is detected.

Next, when there is a free communication slot in the detection of a free slot, a slot selection process is performed. In this slot selection process, when there are a plurality of empty slots, for example, a communication slot with a smaller number among them is acquired as its own communication slot, and the process proceeds to the next communication process.

Here, when all the communication slots are vacant, that is, when there is no data reception from another vehicle, there is no other vehicle transmitting in the vicinity (radio wave reach range). When a vehicle starts communication at the same time or the like, a communication slot is selected and obtained according to a random number in consideration of the possibility of a conflict state.

In the communication processing, the acquired communication slot S
The communication process is performed using (i), and as described with reference to FIG. 7, as communication data, in addition to the system ID, the base ID, the route ID, and the vehicle ID, the position information, the speed information, and the direction information are added to the current time. And the communication status indicating the communication slot number that can be received by itself and the communication slot number transmitted by itself.

Thereafter, communication processing is performed for each communication cycle, and transmission in the acquired communication slot and reception in other slots are performed.

FIG. 10 shows an example of the state of this communication as an entire time division multiplex communication. That is, each communication cycle using the GPS PPS signal as a reference signal is divided into communication slots S (1) to S (n), and each vehicle transmits using the acquired communication slot, and the other slots transmit other data. Of vehicle transmission data.

For example, as shown in FIG. 11, this communication process is performed for a vehicle that has acquired the communication slot S (3). Starts the communication slot S (3). In normal communication that is normally performed, transmission of communication data basically starts at the same time as the start of the communication slot S (3).

However, as a transmission method, the transmission is delayed by a predetermined time td from the start of the communication slot S (3), so that delayed transmission for starting transmission of communication data can be performed.

As described above, communication processing is performed in each communication cycle, transmission in the obtained communication slot and reception in other slots are performed, and time division multiplexing is performed. The communication status based on the received data is checked, and the race condition detection 5 using the same communication slot as the other transmission / reception device is performed.

The race condition is detected by checking the bit of the communication slot of the own vehicle (the slot in which the own vehicle data was transmitted) in the received communication status from the result of data reception from another vehicle. Detects status.

For example, the third communication slot S
When data is transmitted using (3), it is assumed that the following communication status [10 1 11101101111] is added and transmitted. If the bit of the third communication slot S (3) in the logically ORed communication status is 1 based on the data received from all other vehicles, it is determined that there is no conflict, and if the third communication If the bit of slot S (3) is 0, it is determined that a race condition has occurred.

The reason why the bit of the third communication slot S (3) of the own vehicle is determined to be an empty slot may be a case where data is destroyed due to a communication error in addition to a case where a communication conflict occurs. However, since it cannot be distinguished at the time of data reception, when the bit of the communication slot of the own vehicle is not significant, it is determined that a conflict has occurred.

By the way, such “competition” in which a plurality of vehicles use the same communication slot S (i) at the same time is, for example, when a transmitting / receiving device is started up in a plurality of vehicles at the same time, or when a plurality of vehicles are in a certain communication area. A race condition occurs when a vehicle enters from outside the communication area at the same time. FIG. 12 shows an example in which this race condition occurs.

In FIG. 12, vehicle A has a first communication slot S (1), vehicle B has a second communication slot S (2), vehicle C has a third communication slot (1), and vehicle D has a third communication slot S (1). (3) shows the state of transmission. In this example, for the sake of simplicity, it is assumed that the other communication slots are vacant slots, and that each vehicle is within a communicable distance only with the adjacent vehicle.

As shown in this figure, the communication status of the vehicle A is [1100], the received communication status is [0100], and the communication slot S (1) transmitted by the own vehicle has received the communication status. Since the communication status is 0, it is determined that a conflict has occurred. In the vehicle C, the transmitted communication status is [1110], the received communication status is [0110], and the communication status received by the communication slot S (1) transmitted by the own vehicle is 0. Therefore, it is determined that a conflict has occurred.

If it is determined in the conflict detection that there is no conflict, the process returns to the communication process 4. Usually, this is almost always the case. When all the communication slots are empty, that is, when there is no data reception from another vehicle, there is no other vehicle in the vicinity (radio wave reach) or the same communication slot as the own vehicle in the vicinity. Is in a state where there is a vehicle transmitting data, that is, only a competing vehicle exists. At this time, a communication slot is selected and obtained according to a random number for each communication cycle in consideration of the possibility of the latter conflict state, and the process proceeds to the next communication process.

If the conflict is detected in the conflict detection, arbitration processing 6 is performed. FIG. 13 shows specific processing contents in the arbitration processing.

In FIG. 13, upon determining that there is contention, a distribution process 1301 using random numbers is performed. The distribution includes normal transmission 1302, delayed transmission 1303, and transmission regulation 1304. In the case of normal transmission 1302, transmission of communication data starts at the start of communication slot S (i), and the slot is unconditionally acquired 1305. Then, the process returns to the communication process.

In the case of the delayed transmission 1303, as shown in FIG. 11, transmission of communication data is started with a delay of a predetermined time td from the start of the communication slot S (i). During this period, the presence or absence of a communication carrier 1306 from another vehicle is monitored. If there is no communication carrier, the slot S (i) is acquired 1305 and the process returns to the communication process 4. If there is a communication carrier, since another vehicle is using the communication slot S (i), the process proceeds to detection of an empty slot as slot acquisition failure 1307.

In the case of the transmission restriction 1304, the transmission is postponed, and as a slot acquisition failure 1307, the process goes to the detection of an empty slot.

As described above, the normal transmission 130 using a random number is performed.
2. By distributing the delayed transmission 1303 and the transmission restriction 1304, a race condition can be resolved. Even if the distribution of random numbers becomes the same in a plurality of vehicles, the arbitration process is performed in the next communication cycle in the same manner, so that the race condition is resolved.

In the transmission / reception device of the track closing device, slots are dynamically allocated in the four slots for the track closing device, similarly to the vehicle-mounted transmission / reception device.

FIG. 14 is a diagram showing operation blocks of the transmission / reception device of each vehicle in the above time division multiplex communication system.

In FIG. 14, the communication cycle / slot setting means 1401 determines whether the communication cycle / slot setting means 1401 has received the
A reference signal is obtained based on the PS signal and the time signal, and a communication cycle and a communication slot S (1) as shown in FIG.
ＳS (18) are set and supplied to the slot detecting means 1404.

The self information generating means 1402 is provided with the point sensor 250, speed sensor 260,
Based on data such as the database 213, necessary self-information such as a position, a speed, a traveling direction, and a route ID is generated and supplied to the wireless transmission unit 1406.

The radio receiving means 1403, together with the radio transmitting means 1406, comprises the radio antenna device 240 of the on-vehicle transmitting / receiving device 200 and the commercial radio 214, and transmits transmission signals from other vehicles and the track closing device. Receive.

Then, based on the communication slots S (1) to S (18) from the communication cycle / slot setting means 1401, the slot detecting means 1404 determines the communication status logically ORed from the communication status of each received signal. Get,
Understand the reception status. Here, the operation after the slot detection is performed when the transmitting / receiving device of the vehicle has not yet acquired its own communication slot, for example, immediately after the start of communication, or when it has already acquired and communicated with its own communication slot. Are different.

First, a case where the own communication slot is not acquired will be described. If there is an empty communication slot based on the communication status, the communication slot with the smaller number in the empty communication slot is selected as its own communication slot 1405, and the wireless transmitting means 1406 receives the self information from the self information generating means 1402 and A communication status and the like are added, and the data is transmitted to another vehicle or the like in a data format as shown in FIG. If there is no empty communication slot, the slot detection is repeated every communication cycle,
Wait for the occurrence of an empty communication slot.

On the other hand, if the communication slot has already been obtained and communication has been performed, it is determined from the received communication status whether there is another vehicle or not.
When there is no other vehicle, there is a vehicle that is transmitting using the same communication slot as the own vehicle, that is, only a competing vehicle may exist. Is transmitted using an at-random communication slot subjected to random number processing.

In the case where the own communication slot has already been acquired and communication has been performed, and there is a reception from another vehicle, it is determined whether the own vehicle and the other vehicle are using the same communication slot. The conflict detection means 1407 determines from the status of the communication status (specifically, whether or not its own communication slot is significant). In the case of a normal communication state in which there is no contention, transmission is performed from the wireless communication unit 1406 using a communication slot that has already been acquired. This transmission / reception state is a normal communication state.

As a result of the detection by the conflict detecting means 1407,
If the communication slot of the communication status is not significant and a race condition is detected, the race arbitration means 1408 performs arbitration processing as shown in FIG.

As a result of the arbitration process, when the communication slot is successfully obtained, the communication slot is transmitted from the wireless communication unit 1406 using the already obtained communication slot.

If acquisition of a communication slot fails as a result of the arbitration process, the empty slot detecting means 1409
Detects an empty communication slot. If there is an empty communication slot, the communication slot having the smaller number among the empty communication slots is selected as its own communication slot.
405, and the self-information generation unit 1
The self information from 402 and the communication status are added and transmitted. If there is no empty communication slot, the slot detection is repeated every communication cycle, and the occurrence of an empty communication slot is waited.

[0074]

According to the time-division multiplex communication system for railways of the present invention and the transmission / reception apparatus therefor, even if the number of maintenance vehicles is large, only the maintenance vehicles that are actually dispatched are automatically and flexible. Communication slot is assigned to
Slots can be used effectively.

Further, even when the dispatched maintenance vehicle moves and disperses over a wide area along the railroad track and performs work, a communication slot for performing time-division multiplex communication when entering the communicable area is set. Automatically allocated, and conversely, when the mobile terminal goes out of the communicable area, the communication slots used up to that point become empty slots, so time-division multiplex communication between vehicles that are dispersed and move over a wide range Can be performed efficiently without hindrance.

Further, by using a GPS PPS (Pulse Per Second) signal as a reference signal of the time division multiplex communication system, there is no need to take any other measures such as installing a reference station, and communication between vehicles can be performed. Cycles and communication slots can be set accurately.

[Brief description of the drawings]

FIG. 1 is a diagram showing the state of a railway line such as a Shinkansen, a maintenance vehicle, and a line closing device to which the present invention is applied.

FIG. 2 is a configuration diagram of an on-vehicle transmitting / receiving device used in the time division multiplex communication system of the present invention.

FIG. 3 is a configuration diagram of a line closing transmission / reception device used in the time division multiplex communication system of the present invention.

FIG. 4 is a configuration diagram of a portable receiving device used with the present invention.

FIG. 5 is a diagram illustrating a route database.

FIG. 6 is a diagram showing an example of point detection when a railway line branches midway.

FIG. 7 is a diagram showing an example of wireless communication data.

FIG. 8 is a diagram showing a configuration of a communication cycle and a communication slot in the time division multiplex communication system of the present invention.

FIG. 9 is a diagram showing an outline of communication processing in the time division multiplex communication system of the present invention.

FIG. 10 is a diagram exemplifying a situation of the entire time division multiplex communication.

FIG. 11 is a diagram showing a relationship between a communication slot, normal communication, and delayed transmission.

FIG. 12 is a diagram showing an example in which a race condition occurs.

FIG. 13 is a diagram showing processing contents in the arbitration processing.

FIG. 14 is a diagram showing operation blocks of a transmission / reception apparatus of the time division multiplex communication system of the present invention.

[Explanation of symbols]

 Reference Signs List 200 in-vehicle transceiver 210 in-vehicle transceiver 212 control unit 213 database 214 business radio 215 speaker 220 GPS antenna 230 operation display unit 240 radio antenna device 250 point sensor 260 speed sensor 300 line closing transceiver 310 for line closing Transceiver 312 Control unit 313 Database 314 Business radio 315 Speaker 320 GPS antenna 330 Operation display unit 341 Radio antenna 400 Portable receiver 410 Portable receiver 441 Receiving antenna 1401 Communication cycle / slot setting means 1402 Self information generation Means 1403 Wireless receiving means 1404 Slot detecting means 1405 Slot selecting means 1406 Wireless transmitting means 1407 Contention detecting means 1408 Contention arbitration means 1409 Free Lot detection means

──────────────────────────────────────────────────続 き Continuing on the front page (72) Eiji Okabe, 2-2-2 Yoyogi, Shibuya-ku, Tokyo East Japan Railway Company (72) Yoshifumi Kurosawa 2-2-2, Yoyogi, Shibuya-ku, Tokyo East Japan Railway Company Co., Ltd. (72) Inventor Tetsushi Yamada 5-1-1 Shimorenjaku, Mitaka City, Tokyo Japan Radio Co., Ltd. (72) Inventor Hisashi Sato 5-1-1 Shimorenjaku, Mitaka City, Tokyo Sun Inside the Radio Co., Ltd. (72) Inventor Koichi Uchiyama 5-1-1 Shimorenjaku, Mitaka City, Tokyo Japan Within the Radio Co., Ltd. (72) Inventor Kiyohiko Tatebayashi 5-1-1 Shimorenjaku, Mitaka City, Tokyo Japan Inside Radio Co., Ltd. (56) References JP-A-2001-347946 (JP, A) JP-A-2000-252910 (JP, A) Yoshifumi Kurosawa, Eiji Okabe, Prevention of collision accidents for maintenance vehicles Stem the development of the Institute of Electronics, Information and Communication Engineers 2000 Engineering Sciences Society Conference Papers, Japan, The Institute of Electronics, Information and Communication Society, September 7, 2000, 282 pp. (58) investigated the field (Int.Cl. ⁷ H04J 3/00-3/26 H04L 5/22-5/26 H04B 7/24-7/26 H04Q 7/00-7/38 B61L 23/34 JICST file (JOIS)

Claims (7)

(57) [Claims] 1. A railway time-division multiplex communication system in which a transmission / reception device is mounted and communication between a plurality of vehicles moving on a track is performed by time-division multiplex communication using a specific frequency. Time synchronization is performed based on the reference signal, and a communication cycle having a predetermined number of communication slots is set. In each vehicle, at the time of transmission, the communication slot number that can be received and the communication slot number transmitted by itself are used as communication status. At the time of reception, each vehicle takes the logical sum of the status from the vehicle that can be received, and if the vehicle has not been able to acquire the communication slot at that time, the logical sum In this case, it is determined that a communication slot that has become ineffective is determined to be an empty communication slot, and one of the empty communication slots is acquired as its own communication slot. When railway division multiple access communication system to. 2. In the time-division multiplex communication system for a railway according to claim 1, when there is no reception from another vehicle at the time of reception, when acquiring one of the empty communication slots as its own communication slot, A time-division multiplex communication system for railways, wherein a communication slot determined by random number processing is obtained. 3. A railway time-division multiplexing communication system for carrying out communication between a plurality of vehicles moving on a track, each carrying a transmission / reception device, and performing multiplexing in a time-division manner using a specific frequency. Time synchronization is performed based on the reference signal, and a communication cycle having a predetermined number of communication slots is set. In each vehicle, at the time of transmission, the communication slot number that can be received and the communication slot number transmitted by itself are used as communication status. Each vehicle transmits the data in addition to the transmission data, and at the time of reception, a logical sum of the statuses from the vehicle that can be received is obtained, and the vehicle can acquire a communication slot at that time. When the communication slot transmitted by one's own during the sum is invalid, it is determined that the communication slot transmitted by one's own is competing with another vehicle. Time division multiplex communication system for railways. 4. In the time-division multiplex communication system for railway according to claim 3, wherein it is determined that there is a conflict,
When there is reception from another vehicle, whether to perform normal transmission or delayed transmission in the communication slot that has already been acquired,
Alternatively, a time-division multiplex communication system for railways, characterized by determining whether transmission is to be restricted by random number processing. 5. The railway time division multiplex communication system according to claim 3, wherein it is determined that there is a conflict,
A time-division multiplex communication system for railways, wherein a communication slot determined by random number processing is used as its own communication slot when there is no reception from another vehicle. 6. A railway time division multiplex communication system according to claim 1, wherein said reference signal is a GPS PPS signal. 7. A transmission / reception apparatus mounted on a vehicle in a railway time division multiplex communication system for performing multiplex communication in a time division manner using a specific frequency for communication between a plurality of vehicles moving on a track, Communication cycle setting means for setting a communication cycle and a communication slot using the PPS signal as a reference signal, a position detection sensor for detecting at least a position, and a route database, and transmitting self-information including the position and direction of the vehicle. Self-information generating means for generating, a wireless signal from another vehicle, a slot detecting means for detecting a status of a communication slot from communication status information included in the wireless signal, and a vehicle already acquiring a communication slot. Conflict detection for detecting a conflict condition depending on whether the own vehicle bit of the communication status information is significant when transmitting. A stage, when a conflict is detected by the conflict detection unit, a conflict arbitration unit that arbitrates to eliminate a conflict state, and as a result of the arbitration by the conflict arbitration unit, when acquisition of a communication slot fails, An empty slot detecting means for detecting an empty slot, and when the own vehicle has not yet acquired a communication slot, when the slot detecting means detects an empty slot,
When the own vehicle has already acquired and transmitted a communication slot, the slot detecting means has detected that there is no reception from another vehicle, and the empty slot detecting means has detected an empty slot. Sometimes, a slot selecting means for selecting one of the empty slots as a communication slot of the own vehicle; a communication slot selected by the slot selecting means; a communication slot when no conflict is detected by the conflict detecting means; As a result of the arbitration by the contention arbitration unit, when a communication slot is successfully acquired, the communication slot number that can be received and the communication slot number that is transmitted by itself are communicated using any one of the communication slots. Wireless transmission means for adding the status to the transmission data of the self-information generation means and transmitting the status. Transceiver for the time for railway division multiple access communication system that.