Method and apparatus related to on-board message repeating for vehicle consist communications system

(57) The invention provides a communication method for a train (10) of vehicles, including a lead power vehicle (14) and a remote power vehicle (12A / 12V / 12C), wherein the lead power vehicle (14) comprises a first (29A ) and the second (29B) diversity antennas, each of which is connected to a radio station, and the remote power vehicle (12A / 12V / 12C) contains a third (29A) and a fourth (29B) diversity antennas, each of which is associated with a radio station. The method includes transmitting an outgoing message from a leading power vehicle (14), receiving an outgoing message through a third antenna (29A) and supplying a signal to a linked radio station to generate a first received signal, receiving an outgoing message through a fourth antenna (29B) and supplying a signal to a connected radio for generating a second received signal, determining quality parameters of the corresponding first and second received signals, the selection of the first or second received signal for processing by a remote vehicle (12A / 12V / 12C) according to the quality indicators of the first and second signals.

State of the art

By means of distributed traction in trains, the driving force and braking action are supplied from the driving locomotive (or driving unit) and one or more remote locomotives (or driving units) located in the composition far from the head unit. According to one of the configurations, the train with distributed traction contains a driving locomotive located at the head of the train, a remote locomotive located at the end of the train (ЕОТ, еиб о £ Ιηιίη). and one or more locomotives in the middle of the train, distributed between the head and end parts of the train. Trains with distributed traction are preferably used for long trains in order to improve the management of the train and its performance, and, in particular, this applies to trains traveling in mountainous areas.

In distributed traction trains, each driving and remote locomotive provides driving force and braking action for the entire train. Command messages of movement and braking are issued by the driver of the leading locomotive and are sent to the remote locomotives via a radio frequency communication system (such as the LOCOTCO® distributed traction communication system developed by Seiega1 E1ec1ps, Schenectady, NY) containing a radio frequency communication line ( channel), as well as receiving and transmitting equipment installed in the leading and remote units. Remote locomotives receiving commands, in response, apply traction or braking force to the train and notify the lead unit of the receipt and execution of the command. The lead unit also sends other messages to remote units, including status request messages. In response, the deleted units send a status response message back to the host unit.

In a train consisting of two or more directly connected remote locomotives, connected locomotives operate synchronously using control signals transmitted along their connected Mie lines (wide and multiple units). One of the locomotives is assigned as a remote control unit in relation to a distributed traction communication system. Only the controlling remote unit is configured to receive commands transmitted by the leading unit and to transmit the corresponding response message to the leading unit.

One of the most critical aspects in the operation of the train is to ensure the predictable and successful functioning of the pneumatic brake system. The pneumatic brake system includes the brakes of each of the locomotives (including the driving locomotive and all remote locomotives) and the brakes of each of the railway cars. Locomotive brakes of the driving unit are controlled by the locomotive driver by changing the position of the handle of the brake lever of the locomotive, and car brakes are controlled by changing the position of the handle of the lever of the automatic brake. Locomotive brakes can also be controlled by an automatic brake lever.

A lever handle or an automatic brake controller controls the pressure in the brake line with a fluid that runs along the entire length of the train and is connected with the car brake system to apply and release the car brakes in each car in response to pressure changes in the brake line . More specifically, a control valve (typically containing a plurality of valves and an interconnected piping system) in each railroad car responds to changes in fluid pressure in the brake line by applying brakes (in response to decreasing fluid pressure in the brake line) or releasing the brakes (in response to increase in fluid pressure in the brake line). The fluid in the brake line is traditionally compressed air. As a result of a change in the position of the lever of the automatic brake lever in the driving locomotive, a pressure drop occurs in the driving unit, which propagates along the brake line to the end of the train. A control valve in each railway carriage detects a pressure drop and, in response, supplies compressed air from the local tank of the railway carriage to the brake cylinders of the wheel, which in turn move the brake pads to the wheels of the railway carriage. The tank of the railway car is replenished with air discharged from the brake line during operating intervals in which the brake is not used.

The brake release is also controlled by the driver of the driving locomotive by controlling the lever of the automatic brake lever to increase the pressure in the brake line. The increase in pressure is determined in railway cars, and in response the brake pads move away from the wheels of the railway car.

In a train with distributed traction, in addition to regulating the pressure in the brake line for applying and releasing the car brakes, the leading unit controls the process of applying and releasing the brakes of the remote unit by transmitting the corresponding signal to the remote units through the communication channel. As described below, the processes of applying and releasing the brakes, thus, have a more operational impact along the entire length of the composition due to the participation of both the lead unit and the remote unit. With some limitations that are required to maintain control of the train, in a train with distributed thrust, a braking or releasing command may also be transmitted from a driving or remote locomotive.

Brakes of a railway car can be applied in two modes, that is, in the service braking mode or in the emergency braking mode. In the service braking mode, braking forces are applied to the railway car to slow down or stop the train at the point of the rail track located in the direction of travel. During service braking, the brake line pressure slowly decreases, and in response to this, the brakes are gradually applied. The driver controls the speed at which the pressure decreases by manipulating the automatic brake control handle. Forced braking mode is a form of service braking mode in which the pressure in the brake line decreases to zero, but the air is released at a predetermined speed, unlike the emergency braking described below, and railway cars in this mode do not release air from the brake highways.

In emergency braking mode, a command is given to immediately apply the brakes of railway cars by immediately releasing or venting air from the brake line in the drive unit (and remote units of the train with distributed traction). When a railroad car determines a predetermined pressure reduction rate indicating the use of emergency braking, the railroad car also vents air from the brake line to accelerate the spread of air exhaust from the brake line through the train. Unfortunately, since the brake line is stretched several thousand yards (several thousand meters) along the train, emergency braking does not occur instantly along the entire length of the brake line. Thus, to stop the composition, braking forces are applied unevenly to each railway carriage.

In trains with distributed traction, braking is performed by venting air from the brake line in both the driving and remote locomotives, which accelerates the exhaustion of air from the brake line and applying brakes in each railway carriage, especially in railway cars located at the end of the train. It should be noted that air removal from the brake line only in the lead unit in a conventional train requires the spread of the process of reducing pressure in the brake line along the entire length of the train, which slows down the braking of railway cars distant from the lead unit. In a train with distributed traction, equipped with an operative communication channel between the leading and remote units, if the train driver gives a braking command (for example, service or emergency braking) by applying air brake to the handle of the control lever in the drive unit, air is drawn from the brake line, and a braking command is transmitted to each remote unit via a radio frequency communication line. In response, each remote unit also takes air from the brake line. Thus, the braking action in remote locomotives follows the braking action of the driving unit in response to the signals transmitted by the communication system.

The brake release command initiated in the master unit is also transmitted over the radio link to the remote units, so that the brake line is re-filled with air from all locomotives to the nominal pressure, thereby reducing the replenishment time of the brake line.

If emergency braking in the driving locomotive is initiated by the train engineer or in response to a detected emergency condition, the RF communication system transmits emergency braking to each of the remote locomotives via the radio frequency communication line. In response, the remote locomotives release air from the brake line. This method allows you to quickly perform emergency braking, as air is released from the brake line of all locomotives, and not just the leading locomotive, as in a conventional train.

In FIG. 1 and 2 schematically shows an example of a distributed train 10 moving in the direction indicated by arrow 11, with one or more remote units 12A-12C being controlled either from the driving unit 14 (FIG. 1) or from the control room 16 (FIG. . 2). The locomotive 15 is controlled by the leading unit 14 through the Mi line 17 connecting the two units. The ideas of the present invention can be applied to a distributed train structure 10 and to a communication system operating with this composition, as described below.

It should be understood that the only difference between the systems shown in FIG. 1 and 2, is that in FIG. 1, the transmission of commands and messages is performed from the host unit 14, and in FIG. 2 from the control room 16, and certain interconnections in the system shown in FIG. 1 are excluded. Typically, the control room 16 communicates with the lead unit 14, which, in turn, is connected to the remote units 12A-12C.

In one embodiment, the communication channel of the communication system comprises one half-duplex communication channel with a bandwidth of 3 kHz, in which the messages and commands comprise a serial binary data stream encoded using modulation implemented in a frequency-wise manipulation scheme on one of four available carrier frequencies. Different bit positions correspond to information regarding the type of transmission (for example, message, command, alarm), the actual message, command or alarm, address of the receiving unit, address of the transmitting unit, normal start and stop bits and error detection / correction bits. Details of the messages and commands provided by the system and the transmission format of individual messages and commands are discussed in detail in US Pat. No. 4,582,280, which is incorporated herein by reference.

The train 10 shown in FIG. 1 and 2 further comprises a plurality of rail cars 20 located between the remote units 12A / 12B and between the remote unit 12C (in FIG. 1). Placement of locomotives 14 and 12A-12C and wagons 20 shown in FIG. 1 and 2, are given only as an example, while the present invention can be applied in other variants of locomotive / railway carriages placement. Railway cars 20 are equipped with a pneumatic brake system (not shown in FIGS. 1 and 2), which applies the pneumatic brakes of the railway car in response to a pressure drop in the brake line 22 and releases the air brakes with increasing pressure in the brake line 22. The brake line 22 runs along the length of the train to transmit changes in air pressure determined by the individual pneumatic brake control levers 24 in the drive unit 14 and in the remote units 12A, 12B and 12C.

In certain embodiments of the present invention, an external repeater 26, also described below, is located at a radio distance of the train 10 for relaying communication signals between the lead unit 14 and the remote units 12A, 12B and 12C.

The leading unit 14 and the remote units 12A, 12B and 12C are equipped with independent transceivers 28A and 28B, working with the respective antennas 29A and 29B, for receiving and transmitting communication signals over the communication channel. The external repeater 26 and the control room 16 are equipped with a transceiver 28 operating with an antenna 29 for receiving and transmitting communication signals over a communication channel.

The transceiver 28 of the leading unit is connected to the leading station 30 for generating and transmitting commands and messages from the leading unit 14 to the remote units 12A-12C and for receiving response messages from them.

Commands are generated in the master station 30 in response to the actions of the driver associated with driving force and braking, in the master unit 14 (as described elsewhere in the document) or, as necessary, to actions performed automatically. Each remote unit 12A-12C and external relay 26 comprise a remote station 32 for processing, relaying and / or responding to data transmitted from the host unit 14, and for transmitting response messages and commands. The master station 30 and the remote stations 32 are responsible for the independent signals coming from both transceivers 28A and 28B.

The four primary data types of broadcast sessions performed by a communication system include: (1) communication lines from the host unit 14 to each of the remote units 12A-12C that connect the host unit 14 and the remote units 12A-12C, that is, configure or configure the communication system for use by the host unit 14 and the remote units 12A-12C, (2) communication link responses that indicate the receipt and execution of communication line messages, (3) commands from a host unit 14 that controls one or more functions (e.g., applying driving force or braking) to one or more remote units 12A-12C, and (4) status and alarm messages transmitted by one or more remote units 12A12C that update or transmit necessary operational information for the leading unit 14 related to one or more remote units 12A-12C.

Each message and command transmitted from the host unit 14 is broadcast to all remote units 12A-12C and includes a host unit identifier that is used by the remote units 12A-12C to determine that the host unit transmitting the data is the host unit the same train. If this fact is determined, then the remote unit 12A-12C executes the received command.

Messages and alarms transmitted from one of the remote units 12A-12C also contain the address of the transmitting unit. As a result of the previously completed communication process, the receiving unit, that is, the lead or remote locomotive, can determine whether it was the given recipient of the transmitted data by checking the identifier of the transmitting unit included in the message and can respond accordingly.

These four types of messages, each of which contains address information, guarantee a secure transmission line with a low probability of breaking due to interference from the radio transmission distance of the train 10. Messages allow you to control remote units 12A-12C from the leading unit 14 and provide information for the leading unit 14 about the work of the remote unit.

Although most commands are issued by the leading unit 14 and transmitted to the remote units 12A12C for execution as described above, there is one situation in which the remote unit 12A-3 024596

12C issues commands to the other remote units and the lead unit 14. If the remote unit 12A12C determines a condition that requires emergency braking, the remote unit sends an emergency braking command to all other units in the train. The command contains the identifier of the leading locomotive of the train and, thus, will be executed in each remote unit, as if this command was issued by the leading unit.

In the description of the present invention, the terms radio link, KE communication line, KE communication and other similar terms describe a communication method between two lines in a network. It should be borne in mind that the communication line between nodes (locomotives) in the system in accordance with the present invention is not limited to radio systems or KE systems, or similar systems, but it is understood that this term covers all technologies by which messages can be delivered from one node to another node or to many other nodes, including, without limitation, magnetic systems, speakers and optical systems. In the same way, the system used in the framework of the present invention is described according to an embodiment in which radio frequency (KE) communication lines are used between nodes and in which various components are compatible with such communication lines; however, this description is not intended to limit the present invention to this particular embodiment.

In a train with distributed traction that responds to commands initiated by the driver, the communication system in the lead unit transmits a radio frequency (KE) message to each remote unit representing the command. Such commands may include controller or traction commands of the locomotive and commands of the air brake, dynamic brake and electric brake. In the case of a pneumatic brake command, when a message is received, a braking command is executed in each remote unit to speed up the response to the command in the cars, since the remote units receive an RF message before they determine that the pressure in the brake line has changed. For example, if the driver issues a braking command, air is vented from the brake line in the driving unit, and the pressure decreases along the entire length of the train to its last carriage. Depending on the length of the train, before the pressure drops in the area of ​​the last car, several seconds may elapse. Air exhaust from the brake line both in the lead and in remote locomotives, and in the latter in response to the KE message, allows you to accelerate the air exhaust from the brake line and the application of brakes in each railway carriage, especially in railway cars located at the end of the train. Thus, the braking actions in remote locomotives follow the braking actions of the leading unit in response to the KE signals transmitted by the communication system.

The brake release command initiated in the master unit is also transmitted over the radio frequency link to the remote units, so that the brake line is re-filled with air from all locomotives to its nominal pressure, thereby reducing the replenishment time of the brake line.

If the train driver initiates emergency braking in the driving locomotive, the communication system transmits an emergency braking signal to each of the remote locomotives via a radio frequency communication line. Remote locomotives release air from the brake line in order to perform emergency braking faster, since air is released from the brake line of all locomotives, and not just the driving locomotive, as in a conventional train.

In general, messages transmitted through a communication system make it possible to equalize the traction forces applied to railway cars and improve braking performance, since each locomotive can perform braking at the speed of the KE signal rather than at a lower speed with which the signal propagates along the train braking for the pneumatic brake line.

If the train with distributed traction works in an environment in which each remote unit is supposed to receive command messages transmitted by the leading unit, for example, when the train moves along a relatively straight track without immediate obstruction to the radio frequency signal, the communication system operates in normal mode. In this mode, no data loss, interruptions or retransmission of the message is expected during the communication process (since the message was not delivered to the desired destination on the first transmission attempt). Most messages transmitted in normal mode are managed in accordance with a fixed priority message transfer protocol, according to which each remote unit transmits a status message in response to a command message issued by the leading unit after a predetermined time interval after transmitting the command. Thus, each remote unit is assigned a time interval, the counting of which begins from the moment the command message of the leading unit is transmitted and during which each remote unit transmits its message.

The timing diagram shown in FIG. 3 for a train system comprising a lead unit and four remote units, illustrates concepts associated with a fixed priority messaging protocol for normal communications. The concepts described on the basis of FIG. 3 may be applied to a train containing more or less than four remote locomotives.

In accordance with this scheme, at time 1 = 650 ms, the leading unit transmits a command message (for example, a braking command, a traction command, a dynamic braking command, etc.), which is supposed to be received by all remote locomotives in the train distributed traction. As shown in FIG. 3, each transceiver (also called a radio station) is allocated an interval of 30 ms to turn on, and in the example, the length of the command message is 193 ms. After a predetermined interval, counted from the moment of transmission of data by the leading unit, for example, 50 ms, as shown in FIG. 3, the first remote locomotive retransmits a command message and a status message (for example, the first remote locomotive exhausts air from the brake line in response to a braking command). The status message is intended for the lead locomotive in order to notify the train driver of the response of the first remote unit to the command. It should also be noted that each remote unit relays the command message together with its status message to maximize the likelihood of receiving a command by all remote locomotives. The on-time values, message durations, etc. shown in FIG. 3 are given by way of example only and may vary depending on the application and specifications of the components included in the communication system.

The second remote locomotive relays the command message and transmits a message about its status after a predetermined delay, for example, after 50 ms, after the end of the transmission of the first remote unit. The process of relaying a command and transmitting a status message continues until all the remote locomotives relay the command message and transmit the corresponding status message. A message transfer completion state occurs at the moment when the last remote unit transmitted a message about its state, after which the leading unit can transmit another command message to the remote locomotives. In the embodiment of the present invention shown in FIG. 3, the end of the message transmission process is fixed at time 1 = 2896 ms or 2271 ms after the initial transmission initiated by the leading unit.

When transmitting a command message, the lead unit is not aware whether the message has been received by all the remote units in the train, until the message is received a status from each remote unit (status messages indicate the receipt and execution of command messages), or until it was not found that a status message is missing for one or more remote units (the absence of a status message indicates that a command message has not been received). Thus, in accordance with one embodiment of a communication system, each remote unit relays command messages to indicate that these messages have been received.

It should be noted that perhaps one or more messages about the status of the deleted units may not be received by the lead unit. In this case, the lead unit retransmits the command message and awaits a status response message from each remote unit in the train. One of the features of the present invention, described below, increases the likelihood that all status messages will be received in the leading unit, thereby reducing the likelihood of retransmission, without significantly affecting the total transmission session of command messages and status messages.

In addition to the fixed priority messaging protocol described above, certain commands, such as emergency braking, are classified as high priority command messages and transmitted in accordance with a different priority protocol than the fixed priority messaging protocol. However, other command messages, for example, to check the communication system, are processed according to the protocols of other priorities, which control the transmission of these commands and responses to them by remote units.

Since the train with distributed traction passes through a specific terrain or sections of the rail track, characterized by natural or artificial interference, the communication line, which is in direct visibility between the transmitting and receiving units, may be broken. As a result, command messages and status messages by the receiving unit cannot be reliably received by the receiving unit, i.e., the leading locomotive, for messages transmitted from the remote unit, and the remote locomotive for messages transmitted from the leading unit. Although high-power, reliable transceivers can successfully transmit a signal to a receiving unit under certain operating conditions, the cost of such equipment can be significant. In addition, under certain operating conditions, even a high-power transceiver cannot successfully complete a communication session, for example, if a long train travels along a curved section of a rail track in close proximity to natural barriers, such as a mountain, where there is a communication path between the lead unit and one or more deleted units is interrupted by a mountain. In addition, when passing a train through a tunnel

- 5,024,596 certain transceivers may not be able to communicate with other transceivers located on locomotives.

To improve the reliability of the system in one implementation, the distributed train communication system of the train comprises an external relay 26 (see FIG. 1) for receiving messages transmitted from the host unit 14 and relaying (retransmitting) the message for receiving by the remote units 12A-12C . This embodiment can in practice be used along the entire length of the rail track passing, for example, through a tunnel. In such an embodiment, the external repeater 26 comprises an antenna 29 (for example, a leaky coaxial cable mounted along the entire length of the tunnel) and a remote terminal 32 for receiving and retransmitting host unit messages that are received by all remote units 12A-12C within the radio frequency communication range of the antenna 29 repeaters.

SUMMARY OF THE INVENTION

In accordance with one embodiments, the present invention includes a communication method for a vehicle composition consisting of a lead power vehicle and a remote power vehicle, the lead power vehicle comprising first and second spaced antennas, each of which is associated with a radio station, and remote power vehicle contains a third and fourth spaced antennas, each of which is associated with a radio station. The method also includes transmitting an outgoing message from the host power vehicle; receiving an outgoing message in a remote power vehicle through a third antenna and supplying a signal representing this message to a linked radio station to generate a first received signal, as well as receiving an outgoing message through a fourth antenna and feeding a signal representing this message to a connected radio station to form a second received signal; determining a quality indicator of the first received signal; determining a quality indicator of a second received signal; the selection of the first or second received signal for processing by a remote power vehicle according to the quality indicators of the first and second signals; sending an incoming message from a remote power vehicle; receiving an incoming message in the lead power vehicle through the first antenna and supplying a signal representing this message to the associated radio to generate the third received signal, as well as receiving an outgoing message through the second antenna and supplying the signal representing this message to the connected radio to form the fourth received signal; determination of the quality indicator of the third received signal; determination of the quality indicator of the fourth received signal; and selecting a third or fourth received signal for processing by the driving power vehicle according to the quality indicators of the third and fourth signals.

In accordance with another embodiment, the present invention includes a communication system for a composition of vehicles, consisting of a lead power vehicle and a remote power vehicle, each of which is equipped with a head antenna and a tail antenna. The system also comprises a communication channel, said leading power vehicle for transmitting an outgoing message received by a remote power vehicle via a communication channel, a first radio station associated with a head antenna in a remote power vehicle for receiving a first received signal in response to an outgoing message and a second a radio station associated with the tail antenna, in a remote power vehicle to receive a second received signal in response to an outgoing message, wherein the first radio station determines a quality indicator of a first received signal, and the second radio station determines a quality indicator of a second received signal; comparison means for comparing the quality indicators of the first and second signal; a processor for processing the first or second received signal, depending on which quality indicator of which of these signals is better; said remote power vehicle for transmitting, via a communication channel, an incoming message received by the lead power vehicle; a third radio station associated with the lead antenna in the lead power vehicle for receiving the third received signal in response to the incoming message and a fourth radio station associated with the tail antenna in the lead power vehicle for receiving the fourth receive signal in response to the incoming message, wherein the third radio station determines the quality indicator of the third received signal, and the fourth radio station determines the quality indicator of the fourth received signal; means for comparing the quality indicators of the third and fourth signal; a processor for processing the third or fourth received signal, depending on which quality indicator of which of these signals is better.

In accordance with another embodiment, the present invention includes a communication method for a vehicle composition comprising a driving power vehicle equipped with a first antenna associated with a first transceiver and a second antenna associated with a second transceiver, and a remote power vehicle equipped with a third antenna, associated with the third transceiver, and a fourth antenna associated with the fourth transceiver. The method also includes transmitting an outgoing message from a first transceiver through a first antenna or from a second transceiver through a second antenna, wherein the outgoing message

- 6,024,596 contains many bytes of a message, receiving an outgoing message through the third and fourth antennas and associated third and fourth transceivers, determining the correct bytes and erroneous bytes in the outgoing message received in the third transceiver, determining the correct bytes and erroneous bytes in the outgoing message, received in the fourth transceiver, and the assembly of the restored message using the correct bytes of one of the messages, received in the third transceiver or in the fourth transceiver.

In accordance with another embodiment, the present invention includes a communication method for a vehicle composition comprising a driving power vehicle and a plurality of remote power vehicles. The method also includes transmitting an outgoing message from the host power vehicle, wherein the outgoing message contains many bytes of the message; receiving and relaying an outgoing message by one or more of a plurality of vehicles; receiving the first instance of the outgoing message in one of the many remote power vehicles; receiving a second instance of the outgoing message in one of the many remote power vehicles; determining the correct bytes and erroneous bytes in the first instance of the outgoing message, identifying the correct bytes and erroneous bytes in the second instance of the outgoing message and assembling the restored outgoing message in one of the many remote power vehicles using the correct bytes included in the first or second instance of the outgoing message.

Brief Description of the Drawings

The present invention, additional advantages and methods of its use will be better understood when considering the following detailed description in conjunction with the accompanying drawings, in which:

in FIG. 1 and 2 are schematic views of a distributed traction train in which the present invention can be applied;

in FIG. 3 is a timing diagram for a communication system of a conventional prioritized messaging protocol used in the prior art;

in FIG. 4 is a timing chart of an integrated priority messaging protocol in accordance with the present invention applied to a train consisting of four remote units;

in FIG. 5 is a table illustrating the timing of the airborne priority message protocol in accordance with the present invention;

in FIG. 6 is a timing chart of another embodiment of an airborne priority message transmission protocol in accordance with the present invention applicable to a train consisting of four remote units;

in FIG. 7 is a timing chart of an airborne priority message protocol in accordance with the present invention applied to a train consisting of three remote units;

in FIG. 8 is a timing chart of an external message relay system in accordance with the present invention;

in FIG. 9 is a table comparing the time parameters of a conventional priority message transfer protocol, an on-board priority message transmission protocol, and an external priority message transmission protocol;

in FIG. 10 is a diagram illustrating a distributed traction train in accordance with another embodiment of the present invention;

in FIG. 11 and 12 show an algorithm for performing processing steps in accordance with two embodiments of the present invention.

In accordance with general practice, the various features described are not shown to scale, but are depicted in order to emphasize specific features related to the invention.

Reference numerals denote similar elements throughout the drawings and throughout the text.

Detailed Description of the Invention

Before a detailed description of the specific method and device for implementing the priority message transmission protocol for the on-board message relay system in accordance with the present invention, it should be noted that the present invention mainly has new combinations of hardware and software elements associated with the specified method and device. Accordingly, hardware and software elements are presented in the form of conventional elements in the drawings, illustrating only those specific details that relate to the present invention, so as not to complicate the disclosure of the present invention with structural details obvious to a person skilled in the art who wants to take advantage of the advantages set forth in this description.

In accordance with an embodiment of the present invention, there is provided a priority message transmission protocol for an integrated message relay system in a distributed train, such as a distributed train 10, shown in FIG. 7 024596. 1, according to which messages are hopped along the length of the composition from the leading unit 14, starting from the head and ending with the tail of the composition, as each subsequent remote unit 12A-12C receives and relays the message.

In addition, if the train enters an area in which the lead locomotive cannot successfully communicate directly with each remote unit (for example, if the train enters the tunnel), the communication system in accordance with the present invention can automatically switch to the priority protocol for the on-board relaying messages (ΟΒΜΚ, ioBoagb tekkade gereayid). Such a switching occurs, for example, if an interrupt is registered in the communication system, the duration of which exceeds a predetermined fixed time interval, for example, one minute. After activation, protocol ΟΒΜΚ is used for fifteen minutes, after which the communication system returns to the operation mode according to the usual protocol for transmitting priority messages, that is, to the mode described in conjunction with FIG. 3. In another embodiment, the communication system may be configured to operate continuously under protocol ΟΒΜΚ, or protocol ΘΒΜΚ may be manually activated by the driver of the lead locomotive.

In FIG. 4 illustrates an example protocol ΟΒΜΚ for a train comprising a lead unit and four remote units. In this mode, the lead unit transmits a command message (that is, a message ordering the new function to be performed in remote units or containing a status update message requesting information about the status of the remote unit, as well as including the most recently transmitted command). The first remote unit receives an outgoing command message and relays this message so that it can be received by other remote units of the train.

As shown in FIG. 4, a transmission session performed by the host unit begins 625 ms after the time indicated by ί = 0. This interval is provided as an example only and represents a predetermined minimum interval between receiving a message in a leading unit and transmitting a subsequent command from a leading unit. It should be noted that, as an example, a delay interval of 50 ms between the completion of the transmission and retransmission of the message is indicated, and the approximate interval of 30 ms required to turn on the radio (transceiver) is also indicated. Typically, command messages transmitted by a leading unit, messages transmitted by a remote unit, and the interval between message transmission sessions are of a fixed length. However, the lengths of these intervals may, if necessary, vary in the specific application of the present invention, and may also vary with different railway operators.

Unlike the conventional communication mode described above, in accordance with one embodiment of the present invention, the first remote unit does not transmit a status response message after receiving an outgoing message transmitted from the lead locomotive. Instead, the first remote unit (and each subsequent remote unit) relays the outgoing message, as a result of which this message is distributed along the entire length of the train without time delays caused by the transmission of status messages from each remote unit (that is, sent towards the lead locomotive) . As shown in FIG. 4, each remote unit relays the outgoing message in its respective predetermined time interval (a predetermined time interval after receiving the outgoing message) after transmitting the transmitted outgoing message to another remote unit or transmitting the response to another remote unit. Thus, the message is hopped along the length of the train so that each remote unit can receive this message. At the moment when the outgoing message is relayed by the last deleted unit, status messages have not yet been returned to the lead locomotive.

One of the prerequisites of certain embodiments of the present invention is that each train locomotive receives (e.g., listens) messages transmitted from the lead locomotive and from the remote locomotive (s), although this is not always possible due to interference, low signal strength, etc. d. Timing parameters of signals and actions performed by the master and slave units and indicated in this description are based on this premise. If the remote unit does not receive a message from the leading unit, then this situation is detected, for example, when the leading unit does not receive a response from this remote locomotive. The lead locomotive takes corrective action, including retransmission of the original message.

Furthermore, as shown in FIG. 4, each remote locomotive is in a standby state for a predetermined period of time from the moment of receiving the message (either from the moment of receiving the outgoing message or from the moment of receiving the incoming message) from the leading locomotive or from the previous remote locomotive, while the term previous means the locomotive, who received the message earlier and transmits a response message or relays the received message. However, if the preceding remote locomotive is not receiving the message, obviously it cannot transmit the response message or relay the original message. Under these conditions, a remote locomotive awaiting a response from a previous locomotive does not receive this response. A remote locomotive awaiting a response is thus pending in

- 8,024,596 for a predetermined time interval from the moment of receiving the last message to the moment of transmitting your own message or relaying the original message.

When setting up the communication system as described above, each locomotive is configured to display its position in the train. Thus, each message transmitted by the locomotive contains the identifier of the transmitting locomotive. Each locomotive receiving the message can thus determine which locomotive has transmitted the message, and can also determine the position of the transmitting locomotive in the train relative to the position of the receiving locomotive.

If the last remote unit (ηth remote unit) receives a command message, the last remote unit transmits its status message (i.e., incoming message) back to the previous (n-1) th remote unit. In accordance with common practice, if a communication system is configured or the leading and remote units are connected, the farthest remote unit from the leading unit is configured as the last remote unit, i.e. the last remote unit is aware of its position in the train. Thus, if the last remote unit receives an outgoing message, it responds to it by transmitting its status message. The third remote unit (if n = 4) receives a status message from the fourth remote unit and stores the received status message until its designated time interval, in which the third remote unit relayes the status message of the fourth remote unit together with its own a status message, thus transmitting both status messages in the direction of the leading unit, that is, to the second remote unit. The second remote unit receives status messages from the fourth and third remote units and transmits these messages plus its own status message in the direction of the leading unit. This process continues until the status message of each deleted unit reaches the leading unit in the form of a combined message containing the status messages of each deleted unit.

As shown in FIG. 4, this occurs at time 1 = 4377 ms, that is, from the beginning of the transmission of the outgoing command message to the moment of receiving all status messages in the leading unit, a total of 3752 ms passes.

According to the standard procedure for the operation of a distributed train communication system, if a remote unit does not receive an outgoing message after it has been transmitted from the leading unit in its original form or after it has been successfully relayed by remote units, the remote unit that did not receive the message does not return a message about the status of the lead unit. The lead unit expects to receive a status message from each remote unit and can, based on the received status messages (each status message of the remote unit contains the identifier of the deleted unit) determine which remote units, if any, did not receive the command message. Thus, if the lead unit does not receive a status message from one or more remote units, the command is retransmitted by the lead unit. In accordance with one embodiment, the driver of the lead unit is informed about this remote unit that has missed a command by a corresponding indication on the display of the lead unit.

One skilled in the art will understand that a status message transmitted by a remote unit may be received by other remote units, in addition to the remote unit intended to be received located next to the transmitting remote unit in the direction of the leading unit. For example, in FIG. four a distributed draft train contains four remote units, with the second and third remote units receiving a status message transmitted by the fourth remote unit. The second remote unit until the time of transmission of the message stores a message about the state of the fourth remote unit until its designated time interval for transmission or to the designated time interval, counted from the moment the message was received from the last remote unit. Thus, the second remote unit can receive the status message of the fourth remote unit twice: (1) when the message is first transmitted by the fourth remote unit and (2) when the message is relayed by the third remote unit.

The ability to receive a status message repeatedly increases the likelihood that the lead unit will receive a status message from each remote unit that has received the command message.

In one embodiment of the present invention, a remote unit receiving a message twice, as described immediately above, compares two messages byte by byte. Each byte of the message contains an error detection code (for example, parity), which allows you to determine whether each byte is error-free (parity indicates no errors) or contains errors (parity indicates at least one error) . If the byte in the first message does not pass parity, and the same byte in the second message passes parity, then the erroneous byte of the first message is replaced with the correct byte of the second message.

In another embodiment of the present invention, a message is received by two antennas 9 024596 by us 29A and 29B and processed by the associated transceivers 28A and 28B of any of the remote locomotives 15, 12A, 12B and 12C and the driving locomotive 14 (see Fig. 1). Both messages are processed respectively by the master station 30 or the remote station 32, in which two messages are compared byte by byte. Each byte of the message contains an error detection code (for example, parity), which allows you to determine whether each byte is error-free (parity indicates no errors) or contains at least one error (parity indicates at least at least one mistake). If the byte in the first message does not pass parity, and the same byte in the second message passes parity, then the erroneous byte of the first message is replaced with the correct byte of the second message to assemble the corrected message. Then, the corrected message is processed using the corresponding master station 30 or remote station 32.

In FIG. 5 is a table showing the relative transmission order, delay time and message content according to the priority message transmission protocol for the on-board message relay system in a train comprising one lead locomotive and four remote locomotives shown in FIG. 4. However, when the remote unit is transmitting, the time delay period indicated in the third column of the table shown in FIG. 5, for each remote unit transmitting at a later point in time, is reduced, in the manner described below.

In the shown embodiment of the present invention, the time delay between the completion of transmission from one unit and the start of transmission from another unit is 50 ms. As messages are sent by each remote unit, the transmission time delay for each subsequent remote unit decreases by 50 ms, which allows each remote unit to transmit in an orderly manner, while maintaining a 50 ms interval between each unit's transmission sessions. If the remote unit does not transmit after a specified time delay has elapsed, then each subsequent remote unit recognizes this and adjusts its own time delay accordingly when a subsequent unit is transmitting.

For example, if the first remote unit does not transmit data, the second remote unit before the start of the transmission session waits 100 ms after the end of the transmission by the leading unit. If the second remote unit transmits data, then each subsequent transmitting remote unit recognizes that the two remote units require such time frames for transmission, and subtracts 100 ms from its time delay interval; the third remote unit starts transmitting 50 ms (150-100 ms) after the end of the data transfer by the second remote unit, and the transmission delay for the fourth remote unit is set to 100 ms (200-100 ms) after the end of the data transfer by the second remote unit, etc. .

However, if the second remote unit does not transmit data (and the first remote unit does not transmit data), then the third remote unit is configured to transmit after a time interval of 150 ms after the end of the data transmission by the leading unit, and each subsequent transmitting unit when transmitting data by the third remote unit the remote unit recognizes that the three remote units must transmit within this time frame, and each of them subtracts 150 ms from its time delay interval.

Finally, if the first, second, and third remote units do not transmit data, then the fourth remote unit before the start of the transmission session waits 200 ms after the data has been transmitted by the leading unit, and when transmitting data by the fourth remote unit, each subsequent transmitting remote unit recognizes that four remote units must transmit within this time frame, and each of them, therefore, subtracts 200 ms from its time delay interval.

In another example, if the leading unit and the first remote unit transmit data, then the second remote unit transmits data 100-50 = 50 ms after the end of the transmission session of the first remote unit. The third and fourth remote units also subtract 50 ms from their delay period and are set to transmit respectively 100 ms and 150 ms after the end of the data transfer by the first remote unit, if the second remote unit does not transmit data.

If the second remote unit transmits data 50 ms after the end of the data transfer by the first remote unit, then all subsequent remote units subtract 50 ms from their pre-configured delay time interval (that is, from the interval pre-configured as a result of subtracting 50 ms due to data transfer from the first remote unit), and the third remote unit transfers data 100–50 = 50 ms after the end of the transmission by the second remote unit. The fourth remote unit also subtracts 50 ms from its pre-configured delay period and is configured to transmit 150-50 ms = 100 ms after the second remote unit has finished transmitting data if the third remote unit is not transmitting data. If the third remote unit transmits data 50 ms after the end of the data transfer by the second remote unit, then all subsequent remote units again subtract 50 ms from their pre-set delay time interval, and the fourth remote unit transmits data in 100-50 = 50 ms after the end of transmission by the third remote unit.

In general, as a message is transmitted by each remote unit and a message is received by all other remote units, each remote unit that has not yet transmitted a message subtracts 50 ms from its assigned time delay period. This reduction in the time delay period allows to reduce the time interval required for sending a message from the head of the train to its final part, and vice versa.

The following describes a scenario whereby one or more remote units do not transmit. For example, suppose a host unit transmits a command message, and 50 ms after completion of the transmission, the first remote unit transmits this command message. At this point in time, each remote unit listened for data transmitted from the first remote unit, and thus reduced its assigned time delay interval by 50 ms. Suppose also that the second remote unit does not transmit data 50 ms after the completion of data transfer by the first remote unit. The third remote unit, thus, reduces its time delay to 150-5 = 100 ms, and a decrease of 50 ms is caused by the transmission of data by the first remote unit. The third remote unit starts transmission 100 ms after the end of the last transmission session, which in this case is the data transfer session from the first remote unit.

Instead, suppose that the first remote unit does not transmit a message from the leading unit and the second remote unit also does not transmit a message. Consequently, the third remote unit transmits data 150 ms after the end of the transmission of data by the leading unit. The fourth remote unit subtracts 150 ms (because it recognizes that the remote units 1, 2, and 3 should transmit data in this time frame) from the time delay interval assigned to it: 200-150 = 50 ms. The fourth remote unit transmits data 50 ms after the end of the data transfer by the third remote unit.

As can be seen from the description, an interval of 50 ms is a moving interval, so that whenever a remote unit sends a signal, the next remote unit waits 50 ms from the end of the transmission before initiating its transmission session. If the remote unit does not transmit the signal, then subsequent remote units during their assigned time delay period, reduced by 50 ms, wait for the signal of each remote unit that transmitted or should transmit the signal.

According to a variant of the protocol ΘΒΜΚ described in conjunction with FIG. 4 and 5, during the period of transmitting status messages by the remote units towards the leading unit, the outgoing command message is also transmitted by the remote units to maximize the likelihood of receiving a command message by each remote unit. This scenario shown in FIG. 6, allows to increase the time interval between the transmission of a command message from the leading unit and the receipt of status messages in the leading unit, thereby mainly increasing the likelihood that each remote unit will receive an outgoing message.

In FIG. 7 is a timing chart of a priority message transmission protocol for an on-board message relay system in a train comprising a lead locomotive and three remote locomotives. The principles for implementing the present invention for a distributed train comprising three remote locomotives are identical to those for a distributed train containing four remote units and described above using the example of FIG. 4. One skilled in the art should understand that the embodiment of the present invention shown in FIG. 6, according to which the remote units relay the command message, can also be applied to a train containing a lead unit and three remote locomotives (or to a train containing any number of remote units).

In FIG. 8 is a timing chart for a conventional communication synchronization protocol when operating with an external message relay 26 described above with reference to FIG. 1. The lead unit transmits a command message during the time interval 200, and this message is received and relayed by the relay 26 messages during the time interval 202. Each of the four remote units receives a relayed command message and in response transmits its status message in the time interval allocated for this unit. The relay 26 receives all status messages transmitted by the remote unit and relays them to the leading unit 14 in the time interval 206, after which the message transmission interval ends.

The service message 210 shown in FIG. 8 is a message transmitted by repeater 26 to all leading units in the radio range of repeater 26, whereby all receiving leading units delay the start of transmission sessions. For example, a service message prevents data from being transmitted simultaneously by a leading unit located outside the tunnel and a remote unit located in the tunnel.

In FIG. 9 compares the delay intervals for transmitting messages using the conventional protocol for transmitting messages of the prior art, the protocol ΘΒΜΚ disclosed in the present invention, and the conventional message synchronization protocol when operating with an external message relay.

In other embodiments of the present invention, the communication system according to the present invention also performs the functions of diversity of antennas / radios and / or signal selection, which mainly helps to prevent disturbances in the signal transmission path, caused, for example, by the passage of the signal along multiple paths, signal reflections and obstacles signal passing (e.g. a current collector mounted on the locomotive for supplying electric power to the locomotive via cables laid on top).

Each train of two locomotives contains a head locomotive 250A / 250V / 250C and a tail locomotive 252A / 252V / 252C (see Fig. 10), each of which also contains a head radio station 260A / 260V / 260C and a tail radio station 262A / 262B / 262C, moreover, each head radio station works together with the antenna 266A / 266B / 266C, and each tail radio station works together with the antenna 268A / 268B / 268C, respectively, to receive messages transmitted from other locomotives of the railway train 270. The composition of the locomotives is connected with a cable 253А / 253В / 253С МИ (шиШр1е иш1, multiple unit). In accordance with the usual railway term, the lead locomotive 250A / 250V / 250C is denoted by unit A controlling the locomotive 252A / 252V / 252C or unit B by means of control signals initiated by the train driver in unit A and supplied to unit B via cable 253A / 253B / 253C MI.

It should be noted that the concepts described here also apply to a single locomotive containing two radio stations and two associated antennas, one from each end of the locomotive, with a current collector or other obstruction located between the two antennas.

If the communication system is activated, the head radio stations 260A / 260V / 260C and the tail radio stations 262A / 262V / 262C in each locomotive structure are also activated. Thus, the radio stations in each train receive messages transmitted by other units of the train 270. Both the lead radio stations 260A / 260B / 260C and the tail radio stations 262A / 262B / 262C determine the signal quality indicators (such as level, bit error rate or reception of valid data) for each received message. Signal quality indicators are compared in a comparison tool / processor 276A / 276B / 276C, and as a working message used by the locomotive composition, a message with the best signal quality indicators is selected.

According to an embodiment of the present invention, in order to select a working message for a particular composition, signal quality indicators are determined for all messages received at the head radio stations 260A / 260V / 260C and at the tail radio stations 262A / 262B / 262C. For example, each received radio message can be checked for correctness by applying an error detection and correction algorithm to it, after which the processing according to the present invention is carried out to determine the quality indicators of the signal received at each radio station of the composition, on the basis of which a working message is selected for the link.

Alternatively, to determine the quality of the message signal, instead of processing the entire signal, the first group of message bits is analyzed. As a working message for the composition, a message with the best signal quality indicators is selected.

Typically, outgoing messages are transmitted from the lead train antenna / radio 268A / 262A, and status messages are sent from the remote train antennas / radio stations 266B / 260V and 266C / 260C. In yet another embodiment of the present invention, to minimize interference that may affect the accuracy of signal reception, one of the antennas 266A / 266V / 266C (and the corresponding radio station 260A / 20V / 260C) or one of the antennas 268A / 268V / 268C (and the corresponding radio station 262A / 262B / 262C) is selected as the transmitting antenna depending on the desired direction of the transmitted signal. It should be noted that antennas 266A / 266B / 266C are located closer to the head of the corresponding composition of locomotives (assuming that the direction of movement is indicated by arrow 11), and antennas 268A / 268B / 268C are located in the tail of the corresponding composition of locomotives.

Radio 260A / 260V / 260C / 262A / 262V / 262C determines the desired direction of the transmitted signal (for example, incoming or outgoing) based on the type of signal and / or information contained in the signal, and selects the transmitting antenna / radio station that is closest to desired receiving antenna / radio station. For example, if the composition of locomotives, consisting of locomotives 250A and 252A, is leading and you want to send an outgoing message to the composition of locomotives, consisting of locomotives 250V and 252B, then the antenna / radio station 268A / 262A is selected as the working antenna. This property can be especially useful if each locomotive is equipped with a current collector 280 designed to supply current to the locomotives from a current source located above (not shown in FIG. 10). According to this embodiment of the present invention, the antenna (and the corresponding radio station) is selected so that in a desired direction the signal propagates far from the current collector. For example, if the remote train of locomotives, consisting of locomotives 250V and 252V, should transmit a signal to the train of locomotives, consisting of locomotives 250A and 252A, then the antenna / radio station 266V / 260V is chosen as the working antenna / radio station.

In FIG. 11 is a flowchart illustrating a method for implementing a signal selection function in accordance with one embodiment of the present invention. In one embodiment of the present invention, the method shown in FIG. 11 is implemented by a microprocessor and associated memory elements located in locomotives of a train, for example, in locomotives 260A / 260V / 260C / 262A / 262V / 262C. In such an embodiment of the present invention, the steps shown in FIG. 11 correspond to a program stored in a memory element and executed by a processor. When implementing the algorithm in a microprocessor, the program code configures the microprocessor to generate logical and arithmetic operations in order to process the steps of the algorithm. The invention can also be implemented in the form of computer program code written in any of the well-known programming languages ​​and containing instructions stored on physical media, such as floppy disks, SI-COM disks, hard disks, ICI disks, removable media, or any other machine-readable medium data carrier. When downloading and executing program code into a universal or specialized computer controlled by a microprocessor, the computer becomes a device for putting the invention into practice. The invention can also be implemented in the form of computer program code, which, for example, is either stored on a storage medium and downloaded and / or executed by a computer, or transmitted through a transmission medium, for example, via electric wires or cable connections, via fiber-optic connections or with using electromagnetic radiation, in this case, after downloading the program code to the computer and execution by the computer, this computer becomes a device for implementing the invention in practice.

Shown in FIG. 11, the algorithm begins at step 300, in which the communication system is activated, as a result of which the head radio stations (260A / 260V / 260C shown in FIG. 10) and the tail radio stations (262A / 262B / 262C shown in FIG. . 10). As shown in step 302, both radios in each train receive messages transmitted by other train units 270. As shown in step 304, both the head radio stations and the tail radio stations determine signal quality indicators (such as level, bit error rate, or reception of valid data) for each received message. The signal quality indicators are compared at step 306, and as the working message used by the locomotive structure, the message with the best signal quality indicators is selected (see step 310).

In FIG. 12 is a flowchart illustrating an antenna / radio diversity function according to one embodiment of the present invention. At step 330, a signal is generated for transmission to another locomotive of the train. At 332, the desired direction for the transmitted signal (e.g., incoming or outgoing) is determined based on the type of signal and / or information contained in the signal. At step 334, a transmit antenna / radio station that is closest to the desired receive antenna / radio station is selected.

Certain embodiments of the present invention are described herein by train. Any of such embodiments, unless otherwise indicated (for example, in the claims), is also applicable to rail vehicles or other vehicle compositions, in general to a vehicle composition, which is a group of connected vehicles that move together on one route. For example, the term composition of railway vehicles defines a group of related vehicles moving together on rails or other guides. Another example is the term marine composition of vehicles, which refers to a group of ships connected to each other to move along the fairway. In addition, other embodiments of the present invention are described by the example of locomotives. Any of such embodiments, unless otherwise indicated (for example, in the claims), is also applicable to a power railway vehicle or, in general, to another power vehicle. A power vehicle is a vehicle (sea, road, off-road, etc.) capable of independent progressive movement. Power railway vehicle is a vehicle made with the possibility of movement along a pair of rails or along another guide.

While the invention has been described with reference to various embodiments, those skilled in the art will appreciate that various changes may be made and equivalent elements may be replaced with other elements without violating the scope of the present invention. The scope of the present invention further includes any combination of elements from various embodiments set forth herein. In addition, to adapt a particular situation to the ideas of the present invention, changes can be made without violating the scope of the present invention. Therefore, it is understood that the invention should not be limited to the particular embodiment disclosed as the best considered embodiment of the present invention, and includes all embodiments included within the scope of the appended claims.