JP5196376B2 - Railway vehicle communication equipment - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a railway vehicle communication apparatus applied to a railway vehicle LAN communication system that performs LAN communication between a plurality of railway vehicles connected to each other.

In recent years, it has been proposed to perform LAN (Local Area Network) communication applying so-called Ethernet (Ethernet: registered trademark), which is called The Institute of Electrical and Electronics Engineers Inc. (IEEE) 802.3 standard, in railway vehicles. Has been put to practical use.
By using this IEEE802.3 standard LAN communication, communication between multiple railway vehicles is performed, and communication devices for LAN communication that are widely used for communication with various computer devices and peripheral devices are applied as they are. Thus, there is an effect that relatively high-speed data communication is possible between a plurality of railway vehicles.

  By the way, in a railway vehicle, even when transmission using the IEEE 802.3 standard is performed, there are restrictions on the cables and connectors that can be arranged at the connecting portion between the vehicles, and the cable for the IEEE 802.3 standard is used as it is. It is not possible. As for the cable to be used, a cable with a proven track record is used for a railway vehicle, and the connector that can be attached to the terminal block of the connecting portion between the vehicles is also used only for the railway vehicle that can be attached to the terminal block. . Furthermore, the number of cables that can be arranged at the connecting part between the vehicles is also limited by the mechanism of the connecting part, etc., and a general IEEE 802.3 standard cable is configured with two cores for transmission and two cores for reception. However, railway vehicles are required to be able to transmit and receive with a two-core single-pair cable.

Patent Document 1 describes a configuration example in which transmission and reception are performed with one pair of cables.
JP 2000-13283 A

As described in Patent Document 1 and the like, various configurations for transmitting and receiving with a pair of cables have already been put into practical use in wired communication, but it is difficult to apply them as they are for railway vehicles.
That is, in a railway vehicle communication system, a special cable with a track record in a railway vehicle is required, and a cable with good frequency characteristics is not always used. Further, a terminal block is provided on the transmission path between the vehicles, and the cable impedance on the transmission path varies depending on the transmission conditions due to the connection of the terminal block of the cable. When such a device is used to enable two-way communication with a two-core cable, the phase of the reflected signal from the cable changes, so in a conventional signal cancellation system, transmission that leaks into the receiver. Although the signal can be canceled, it is difficult to cancel the reflected signal bounced off the cable.

  The present invention has been made in view of these points, and an object of the present invention is to apply the IEEE 802.3 standard in a railway vehicle communication system so that two-way cable can satisfactorily communicate with each other. To do.

The present invention relates to a railway vehicle communication apparatus that is applied to a railway vehicle LAN communication system that performs LAN communication between a plurality of railway vehicles connected to each other. A transmission path distribution / combination unit that inputs a signal received via the path to the reception unit, and a transmission that leaks into the transmission path by adding the transmission signal from the transmission unit to the reception signal from the transmission path distribution / synthesis unit Based on an output signal of a cancellation circuit unit that cancels a leakage signal that is a signal, a phase amplitude control unit, a transmission signal from the transmission unit and an output signal of a reception amplification unit that amplifies the output signal of the phase amplitude control unit, , the transmission signal detects the level of the reflected signal returned by rebound of the transmission path, the leakage reflected signal detecting section for generating an amplitude control signal and the phase control signal based on the detection Provided, the phase and amplitude controller, the amplitude of the transmission signal from the transmitting unit, an amplitude control unit for controlling based on the amplitude control signal from the leakage reflected signal detecting unit, amplitude control transmission signal from the amplitude control unit And the output signal of the cancellation circuit unit, the first signal cancellation unit for canceling the leakage signal and the reflection signal, and the phase of the transmission signal from the transmission unit from the leakage reflection signal detection unit The leakage control signal and the reflection signal are canceled by adding the phase control unit controlled based on the phase control signal, the phase-controlled transmission signal from the phase control unit, and the signal from the first signal cancellation unit. And a second signal cancellation unit.

  According to the present invention, a transmission signal that leaks into the reception unit even when the transmission signal and the reception signal are transmitted using a two-core cable using a special cable or connector for a railway vehicle. And the reflected signal that bounces off the cable can be canceled. For this reason, the LAN communication of the IEEE 802.3 standard can be applied to the railway vehicle to enable good bidirectional communication, and high-speed data communication in the railway vehicle can be realized at a relatively low cost. In an environment where there is a restriction using a cable of the specification, it is possible to meet the needs for a transmission path compatible with high-capacity and high-speed communication with the introduction of IT in vehicles.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
First, a configuration example of the entire system according to the present embodiment will be described with reference to FIG.
FIG. 2 shows an example of a system for the entire train. Here, three railway vehicles 1, 2 and 3 are connected, and each vehicle 1, 2 and 3 has one information processing device 30a and 30b, respectively. 30c, and one or two LAN communication devices 10a, 10b, 10c, 10d are connected to the information processing devices 30a, 30b, 30c. Specifically, one LAN communication device 10a is connected to the information processing device 30a of the leading vehicle 1, two LAN communication devices 10b and 10c are connected to the information processing device 30b of the intermediate vehicle 2, and the rear One LAN communication device 10d is connected to the information processing device 30c of the end vehicle 3. In FIG. 2, for the sake of simplicity, three-car trains are shown. However, in the case of car trains composed of more vehicles, they are similarly connected in order. Each of the information processing devices 30a, 30b, and 30c is composed of a computer device or the like, and any one device transmits information, and the other device receives the transmitted information, and receives the information when necessary. The information is transmitted again to another device, and the information is transmitted in order to each vehicle in the train.

Each of the LAN communication devices 10a, 10b, 10c, and 10d is a communication device that performs LAN communication conforming to the IEEE 802.3 standard, and includes a transmission unit and a reception unit, and is originally a transmission channel on the transmission side and a transmission channel on the reception side. As a communication device for performing communication using different twisted pair cables.
As shown in FIG. 2, the communication devices 10a, 10b, 10c, and 10d are configured to be connected by a transmission line 40 between adjacent vehicles. The transmission line 40 is composed of a two-core cable, and a railway cable with a track record is used. Here, although not shown in FIG. 2, in this embodiment, the distribution / combination processing device 20 is connected between the communication devices 10 a, 10 b, 10 c, 10 d and the transmission path 40. In addition, a special connector for a railway vehicle may be arranged in the middle of the transmission path 40 in the vicinity of a connecting portion between vehicles.

Next, the configuration of the distribution / synthesis processing apparatus 20 according to the present embodiment will be described with reference to FIG.
The LAN communication device 10 corresponds to the LAN communication devices 10a, 10b, 10c, and 10d shown in FIG. 2, and includes a transmission unit and a reception unit, respectively.
As shown in FIG. 1, a distribution / combination processing device 20 is connected to an output port of a transmission unit and an input port of a reception unit of the LAN communication device 10, and one end of a transmission line 40 is connected via the distribution / combination processing device 20. Is connected to. The transmission signal output from the output port of the transmission unit of the LAN communication apparatus 10 and the reception signal input from the input port of the reception unit are signals conforming to the IEEE 802.3 standard. The voltage value of the transmission signal output from the output port and the voltage value of the reception signal input from the input port are, for example, 5V. The LAN communication device 10 on the adjacent vehicle side is similarly connected to the other end side of the transmission path 40 via the distribution / combination processing device 20. The distribution composition processing device 20 on the adjacent vehicle side has the same configuration.

  The configuration of the distribution / combination processing device 20 will be described. A transmission amplification unit 21 is connected to the transmission unit of the LAN communication device 10, and amplification is performed with a predetermined gain. The transmission amplifying unit 21 is connected to the transmission line distribution / combination unit 22 via a transmission transmission line, and a transmission signal is transmitted to the transmission line 40 connected to the transmission line distribution / combination unit 22.

  The received signal supplied from the transmission path 40 to the transmission path distribution / combination unit 22 is supplied to the cancel circuit unit 23. The cancel circuit unit 23 is also supplied with the transmission signal output from the transmission unit of the LAN communication device 10, and cancels the leakage signal that is the transmission signal that has leaked into the reception transmission path. That is, a cancel process for canceling the leakage signal (transmission signal) is performed by adding a signal with the transmission signal having an opposite phase to the reception signal. Then, the reception signal from which the leakage signal is canceled is supplied to the phase amplitude control unit 24. This is for further removing transmission signal components that cannot be removed by the phase amplitude control unit 24. That is, the phase / amplitude control unit 24 adjusts the phase and amplitude of the reflected signal returned from the transmission signal supplied from the transmission unit of the LAN communication device 10 via the transmission transmission line by the bounce of the transmission line 40, Processing for canceling the reflected signal is performed. The detailed configuration of the phase amplitude control unit 24 will be described later.

  The signal subjected to the cancellation process by the phase amplitude control unit 24 is supplied to the reception amplification unit 25 via the reception transmission path, and the reception amplification process is performed. The amplification gain in the reception amplification unit 25 is controlled based on the reception signal detected by the reception signal detection unit 28. That is, the output of the reception amplification unit 25 is detected by the reception signal detection unit 28, and the reception amplification unit 25 is controlled so that the detection level becomes an appropriate reception level. The amplified received signal is supplied to the input port of the receiving unit of the LAN communication device 10.

  The distribution / combination processing device 20 of this example includes a transmission signal detection unit 26 that detects a transmission signal supplied from the output port of the transmission unit of the LAN communication device 10. Information on the transmission signal detected by the transmission signal detection unit 26 is supplied to the leaked reflection signal detection unit 27 and the reception signal detection unit 28.

  The leakage reflection signal detection unit 27 detects the leakage level of the transmission signal from the reception signal level output from the reception amplification unit 25. Based on the detection, an amplitude control signal and a phase control signal are generated, and the generated amplitude control signal and phase control signal are supplied to the phase amplitude control unit 24. The phase amplitude control unit 24 is also supplied with a transmission signal.

FIG. 3 is a diagram showing a detailed configuration of the phase amplitude control unit 24.
The transmission signal output from the LAN communication device 10 is supplied to the phase inversion unit 241. The phase inversion unit 241 has a function of inverting the phase of the transmission signal from the transmission unit by 180 degrees, and supplies the transmission signal inverted by 180 degrees to the amplitude control unit 242 and the phase control unit 244.

  The amplitude control unit 242 receives the signal from the leaky reflection signal detection unit 27, controls the amplitude of the signal from the phase inversion unit 241, and supplies the signal to the first signal cancellation unit 243. The first signal cancellation unit 243 has a function of adding the leakage and reflection signals from the cancel circuit unit 23 and the signal from the amplitude control unit 242 to cancel the signal amplitude to a minimum.

  The phase control unit 244 leaks the signal from the phase inversion unit 241 according to the control signal from the inversion signal detection unit 27 and supplies the signal to the second signal cancellation unit 245. The second signal cancellation unit 245 has a function of adding the signal from the first signal cancellation unit 243 and the signal from the phase control unit 244 to cancel the signal amplitude to a minimum, and has been canceled. The signal is supplied to the reception amplification unit 25.

Next, a processing example when performing transmission / reception with such a configuration will be described with reference to the flowcharts of FIGS. 4 and 5.
First, cable length loss compensation processing for cable loss when transmitting with a two-core cable constituting the transmission path 40 will be described with reference to FIG.
When the reception signal detection unit 28 detects a reception signal from the LAN communication device 10 of the communication partner when there is no transmission from the own station, that is, the transmission unit of the LAN communication device 10 in the reception signal detection unit 28 (step S1). The received signal detector 28 determines whether the amplitude of the received signal is a specified value determined by the IEEE 802.3 standard (step S2). If the value is outside the standard value, the gain of the reception amplification unit 25 is controlled (step S3), and the amplitude of the reception signal is adjusted to the standard value of the IEEE 802.3 standard.

Next, with reference to FIG. 5, a leak signal cancellation compensation process when the leak signal is detected by the leak signal detection unit 27 in the absence of a reception signal from the LAN communication apparatus 10 of the communication partner will be described. explain.
First, the reception signal detection unit 28 detects a reception signal from the LAN communication apparatus 10 of the communication partner (step S11), and determines whether or not there is a reception signal (step S12). If there is a received signal, the process returns to step S11.

When there is no reception signal, when the transmission signal is transmitted from the transmission unit of the LAN communication device 10 of the local station, the leakage reflection signal detection unit 27 detects the leakage signal and confirms the amplitude of the leakage signal. (Step S13). Here, it is determined whether the amplitude of the leakage signal is within the range of the standard value of the IEEE 802.3 standard or out of the range (step S14).
When the amplitude of the leaked reflection signal exceeds the allowable leak level determined by the standard, amplitude control is performed by the amplitude control unit 242 in the phase amplitude control unit 24 shown in FIG. 3 (step S15). Then, the amplitude of the leakage signal is adjusted until the addition signal obtained by adding the transmission signal and the leakage signal becomes the minimum value (step S16).

  When the value reaches the minimum value in step S16, it is determined whether the addition signal is within the range of the standard value of the IEEE 802.3 standard or not (step S17). If the phase is out of the range, the phase of the transmission signal and the leakage reflection signal is adjusted by the phase control unit 244 of the phase amplitude control unit 24 (step S18), and the transmission signal and the leakage signal are changed. The phase is adjusted until the added signal is minimized (step S19). In this manner, processing for canceling leakage of the transmission signal transmitted from the transmission unit of the LAN communication device 10 into the reception transmission path is performed.

  As described above, in the present embodiment, the cancel circuit unit 23 in the distribution / combination processing apparatus 20 performs processing for adding a signal having the opposite phase of the transmission signal to the reception signal and canceling the transmission signal component from the reception signal. In addition, a leakage signal having frequency / amplitude characteristics that cannot be removed by the cancel circuit unit 23 and a reflected signal from the transmission line synthesized by the transmission line distribution / combination unit are canceled, and phase and amplitude compensation processing is performed. Therefore, it is possible to reduce the influence of the transmission signal included in the reception signal to the extent that there is no problem, and the bidirectional communication of the IEEE 802.3 standard is satisfactorily performed using a special two-core cable for a railway vehicle. You can do it.

In this case, as shown in the flowchart of FIG. 4, since the cable length loss compensation is first performed, compensation according to the length and characteristics of the two-core cable constituting the transmission path 40 can be performed. Good transmission can be performed.
Then, with the cable length loss compensation performed, as shown in the flowchart of FIG. 5, the transmission signal is sent out in the absence of the reception signal, and the leakage signal or the reflection signal is detected, and the leakage is detected. Since the adjustment is made so that the level of the reflection signal is appropriate, there is an effect that adjustment with very high accuracy is possible.

  It should be noted that the examples described with reference to the embodiments described so far are only a preferred example, and it goes without saying that the configuration and processing can be changed without departing from the gist of the present invention. It is.

It is the block diagram which showed the structural example of the transmission / reception by one embodiment of this invention. 1 is an overall configuration diagram illustrating an example of a system in an entire train according to an embodiment of the present invention. It is the block diagram which showed the structural example of the phase amplitude control part by one embodiment of this invention. It is the flowchart which showed the example of the cable length loss compensation process by one embodiment of this invention. It is the flowchart which showed the example of cancellation compensation processing by one embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1-3 ... Vehicle, 10, 10a, 10b, 10c, 10d ... LAN communication apparatus, 20 ... Distribution combining processing apparatus, 21 ... Transmission amplification part, 22 ... Transmission path distribution combining part, 23 ... Cancel circuit part, 24 ... Phase Amplitude control unit, 25... Reception amplification unit, 26... Transmission signal detection unit, 27 .. leaked reflection signal detection unit, 28... Reception signal detection unit, 30 a, 30 b, 30 c. Phase inversion unit, 242 ... amplitude control unit, 243 ... first signal cancellation unit, 244 ... phase control unit, 245 ... second signal cancellation unit

Claims (1)

In a railway vehicle communication apparatus applied to a railway vehicle LAN communication system that performs LAN communication between a plurality of railway vehicles connected to each other,
A transmission line distribution / combination unit for sending a signal output from the transmission unit to the transmission line, and inputting a signal received via the transmission line to the reception unit;
A cancel circuit unit that cancels a leakage signal that is a transmission signal that has leaked into the transmission path by adding a transmission signal from the transmission unit to a reception signal from the transmission path distribution and synthesis unit;
A phase amplitude controller;
Based on the transmission signal from the transmission unit and the output signal of the reception amplification unit that amplifies the output signal of the phase amplitude control unit , the leakage signal, and the reflection signal that the transmission signal has returned due to the rebound of the transmission path, level detecting of a leak reflected signal detecting section for generating an amplitude control signal and the phase control signal based on the detection,
The phase amplitude controller is
An amplitude control unit for controlling the amplitude of the transmission signal from the transmission unit based on an amplitude control signal from the leaky reflection signal detection unit;
A first signal cancellation unit that cancels the leakage signal and the reflected signal by adding the amplitude-controlled transmission signal from the amplitude control unit and the output signal of the cancellation circuit unit;
A phase control unit that controls a phase of a transmission signal from the transmission unit based on a phase control signal from the leaky reflection signal detection unit;
A second signal cancellation unit that cancels the leakage signal and the reflected signal by adding the phase-controlled transmission signal from the phase control unit and the signal from the first signal cancellation unit; A railway vehicle communication device characterized by comprising:

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