JP2010247745A - Information network device in railroad vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information network device in a railroad vehicle, capable of increasing the transmission speed of the image data for in-vehicle display. <P>SOLUTION: In the information network device in the railroad vehicle, a server 10 outputs image data to be displayed on a display 101 on each vehicle 15 to a modulation transmission device 11a on a predetermined vehicle 15a. Modulation transmission devices 11b, 11c relay the image data transmitted from other modulation transmission device, and keep the image data on an image data storage means 181. After relaying the image data, the image data kept in the image data storage means is transmitted to and displayed on the display 101 by an image data resending means 17in. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an information network apparatus in a railway vehicle that uses a modulation transmission apparatus that transmits a signal modulated in accordance with the characteristics of a transmission line and demodulates the received signal.

  Network transmission is performed for data transmission / reception between control devices and display devices in a railway vehicle. When performing high-speed communication by baseband transmission in a railway vehicle, it is necessary to use a transmission line for high-frequency communication, for example, a coaxial cable or a shielded stranded wire. On the other hand, for example, by converting a modulation transmission apparatus using a frequency division multiplexing method into an electrical signal that matches the characteristics of the transmission medium and performing communication, a general single core is used without using a transmission line for high frequency communication. High-speed communication can be performed using shielded wires, multi-core shielded wires, unshielded twisted wires or single wires.

  A relay device is connected to a network device to which a terminal in a vehicle is connected, and a communication frame is modulated and transmitted alternately with a relay device of another adjacent vehicle. Some have improved communication stability while using a lead-out line that is a signal line for trains (see, for example, Patent Document 1).

  In addition, as a transmission device for a railway vehicle, there is one in which a CSMA / CD method using two pairs of twisted pair cables can be adopted in the own vehicle, and a network can be constructed between the vehicles using a pair of twisted pair cables (for example, Patent Document 2).

  However, transmission lines in railway vehicles are often wired close to equipment for other uses and equipment that is a source of noise, and are easily affected by noise. As shown in FIG. 9, when the modulation transmission apparatuses 11 a and 11 b are connected by the transmission line 12 and there is a wiring 13 close to the transmission line 12, the influence of noise from the adjacent wiring 13 is affected. Will receive. Further, as shown in FIG. 10, even when the noise generation source device 14 is installed in the vicinity of the transmission line 12, it is affected by noise from the noise generation source device 14. Furthermore, when the transmission lines 12 are wired close to each other as shown in FIG. 11, signals may interfere with each other between the transmission lines 12. If the signals interfere with each other, a transmission error may occur or a transmission speed may decrease. Will occur.

  As a railway vehicle information network device that solves such technical problems, a modulation transmission device that transmits a signal modulated in accordance with the characteristics of the transmission line and demodulates the received signal, and modulation between adjacent vehicles A transmission line for connecting signals to each other and transmitting signals and a transmission line for transmitting signals by connecting to in-vehicle devices such as display devices in each vehicle. The frequency adjustment circuit is used as a means for preventing deterioration of transmission characteristics to avoid the influence of signal interference and the frequency band region used for transmission between modulation transmission devices between vehicles and in-vehicle devices such as display devices in the vehicle. A system has been proposed in which a frequency band region used for transmission between the transmission lines is divided to prevent signal interference between the transmission lines. According to the proposed railway vehicle information network device, even if transmission lines are arranged close to each other, signals do not interfere with each other, preventing transmission errors and lowering transmission speed. There is an advantage that can be secured from stable and high-speed data transmission.

JP 2008-113103 A JP 2005-80253 A

  It is an object of the present invention to provide a railway vehicle information network device capable of further improving the transmission speed with respect to such a proposed rail vehicle information network device.

  The present invention relates to a modulation transmission device that is mounted on each vehicle and relays received data, a display device that is mounted on each vehicle, between the modulation transmission devices on adjacent vehicles, and a modulation transmission device on each vehicle. In a railway vehicle information network device comprising: a transmission line that connects between the display device and a display device; and a server that is installed on a specific vehicle and that sends image data to a modulation transmission device on the vehicle. The modulation transmission apparatus is used by dividing a frequency band used for data transmission between the adjacent other modulation transmission apparatuses and data transmission to the display apparatus into transmission frequency bands that can avoid the influence of signal interference. Frequency adjustment means, image data storage means for holding the image data sent from another modulation transmission device, and image data held in the image data storage means for the display Image data retransmission means for transmitting to a device, wherein the server outputs image data to be displayed on a display device on each vehicle to the modulation transmission device on the specific vehicle, and the modulation transmission device The image data sent from the modulation transmission apparatus is relayed and held in the image data storage means, and the image data held in the image data storage means is relayed to the image data retransmission means after the image data is relayed. And a railcar information network device that transmits the information to the display device.

  According to the present invention, the frequency band used for data transmission between other modulation transmission apparatuses adjacent to each other on each vehicle and data transmission to a display apparatus in the same vehicle is avoided from the influence of signal interference. It can be divided into transmission frequency bands that can be used, and image data is temporarily stored in a display device in a vehicle and retransmitted after relaying, thereby preventing signal interference and improving transmission speed. It is possible to provide a railway vehicle information network device that can be achieved.

1 is a block diagram showing an information network device in a railway vehicle according to one embodiment of the present invention. The block diagram which shows the internal structure of the modulation | alteration transmission apparatus in the information network apparatus in a rail vehicle of the said embodiment. The block diagram of the modulation / demodulation circuit provided in the modulation | alteration transmission apparatus in the information network apparatus in a rail vehicle of the said embodiment. Explanatory drawing of operation | movement of the data transmission between the modulation | alteration transmission apparatuses in the information network apparatus in a rail vehicle of the said embodiment. Explanatory drawing of the frequency division | segmentation in the modulation transmission apparatus in the information network apparatus in a rail vehicle of the said embodiment. The block diagram which shows the state which uses a different frequency for every area | region of the transmission line in the information network apparatus in the rail vehicle of the said embodiment. Explanatory drawing which shows the other example of the frequency division in the modulation transmission apparatus in the information network apparatus in a rail vehicle of the said embodiment. Explanatory drawing of another example of the frequency division | segmentation in the modulation transmission apparatus in the information network apparatus in a rail vehicle of the said embodiment. Explanatory drawing when there exists other wiring adjacent to the transmission line which connects between the modulation | alteration transmission apparatuses of the information network in a rail vehicle, and it receives to the influence of noise. Explanatory drawing when there exists a noise generation source apparatus in the vicinity of the transmission line which connects between the modulation | alteration transmission apparatuses of the information network apparatus in a railway vehicle, and it receives to the influence of noise. Explanatory drawing in case the transmission line which connects the modulation | alteration transmission apparatus problem of an information network apparatus in a rail vehicle adjoins, and a signal interferes between transmission lines.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the vehicle has a three-car train of 15a, 15b, and 15c, and the letters a, b, and c are used to identify the devices mounted on each vehicle. Further, when the description is made without distinguishing the vehicle on which the equipment is mounted, the description will be made without attaching the subscripts a, b, and c. The number of vehicles may be two or four or more. In the case of the formation of four or more cars, in the middle two cars, if the frequency of the A region is used on the upside of one vehicle and the frequency of the B region is used on the downside, it is adjacent to the downside of this vehicle. In the other vehicle, the frequency in the B region is used on the upstream side, and the frequency in the downstream D / A region is used. Further, a description will be given assuming that the server 10 is mounted only on the leading vehicle 15a as a specific vehicle. This server 10 may be mounted on the last vehicle 15c.

  As shown in FIG. 1, in the railway vehicle information network device according to one embodiment of the present invention, each vehicle 15 is provided with a modulation transmission device 11 that relays, transfers, and distributes data. Display devices 101 to 104 are installed. A server 10 for sending image data is also installed in the leading vehicle 15a.

  The modulation transmission devices 11 between the adjacent vehicles 15 are connected to each other by a transmission line 12, and the modulation transmission device 11 and the display device 101 in each vehicle are connected by a transmission line 121. Between the railway vehicles 15a to 15c, a plurality of display devices 101 to 104 installed in each vehicle are also connected repeatedly.

  As shown in FIG. 2, the modulation / transmission device 11 of each vehicle 15 is provided with three modulation / demodulation circuits 17up, 17dw, and 17in for the upside, the downside, and the interior of the vehicle, and these modulation / demodulation circuits 17up, 17dw, and 17in Signals are transmitted to and received from the transmission lines 12 and 121. The modulation transmission device 11 of each vehicle 15 is also provided with a relay processor 18 and a use frequency setting device 19. The relay processor 18 is connected to the modem circuits 17up, 17dw, and 17in. The use frequency setting unit 19 is also connected to each of the modulation / demodulation circuits 17up, 17dw, and 17in, and sets the frequency used by each of the modulation / demodulation circuits 17up, 17dw, and 17in. The relay processor 18 includes an image data storage unit 181 that temporarily stores received image data.

  As shown in FIG. 3, the modulation / demodulation circuit 17 includes a transmission circuit unit 21, a reception circuit unit 22, a power-on / reset unit 24, and a modulation control unit 25. The modulation control unit 25 includes a use frequency adjustment unit 31. ing.

  Next, the data transmission operation by the railway vehicle information network device of the present embodiment will be described. As shown in FIG. 4, the modulation transmission devices 11 a and 11 b are connected via a transmission line 12 and transmit / receive signals to / from each other. Now, a case where a signal is transmitted from the modulation transmission apparatus 11a to the modulation transmission apparatus 11b will be described. Since the modulation transmission apparatuses 11a and 11b have the same configuration, the modulation transmission apparatus 11a will be described.

  During normal system operation, the modulation control unit 25 transmits a signal to the transmission line 12 via the transmission circuit unit 21, receives a signal from the transmission line 12 by the reception circuit unit 22, and inputs the signal to the modulation control unit 25. is doing. In the modulation transmission device 11a of the leading vehicle 15a, the use frequency setting unit 19 outputs a setting signal to the modulation / demodulation circuit 17dw for the downstream transmission line 12 so as to use the band of the frequency A, and the upstream transmission line 12 A setting signal using the frequency B band is output to the modulation / demodulation circuit 17up.

  In the modulation transmission device 11b of the vehicle 15b adjacent to the leading vehicle 15a, the use frequency setting unit 19 outputs a setting signal so that the modulation / demodulation circuit 17dw for the downstream transmission line 12 uses the frequency B band. Then, a setting signal using the frequency A band is output to the modulation / demodulation circuit 17up for the upstream transmission line 12.

  The use frequency setting unit 19 outputs a setting signal to use the frequency C band for the modulation / demodulation circuit 17in for the display device 101a. The frequency bands A, B, and C will be described later. In the operation mode in which the relay processor 18 performs data transmission between the modulation transmission apparatuses 11a and 11b on the transmission line 12, the frequency bands A, B is set wide and the frequency band C is narrowed. Conversely, in the operation mode in which the relay processor 18 transmits image data to the display device 101a through the transmission line 121, the frequency bands A and B are narrowed and the frequency band C is widened.

  During such normal system operation, for example, the modulation control unit 25 operates the use frequency adjusting unit 31 at a certain timing or periodically, and is specified by the use frequency setting unit 19 by the use frequency adjusting unit 31. Performs the operation of automatically selecting the operating frequency within the frequency band.

  As shown in FIG. 4, the use frequency adjustment means 31 of the modulation / demodulation circuit 17dw transmits use frequency adjustment data d11 to the modulation / demodulation circuit 17up in the downstream modulation transmission apparatus 11b. When the modulation / demodulation circuit 17up in the modulation transmission apparatus 11b receives the use frequency adjustment data d11, for example, the modulation / demodulation circuit 17up determines the frequency-to-noise ratio and transmits the determination result data d12 to the modulation / demodulation circuit 17dw in the modulation transmission apparatus 11a. . In the modulation / demodulation circuit 17dw in the modulation transmission apparatus 11a, the use frequency adjustment means 31 receives the determination result data d12.

  The use frequency adjusting means 31 that has received the determination result data d12 transmits the result confirmation data d13 to the modulation / demodulation circuit 17up in the modulation transmission apparatus 11b, and automatically selects the use frequency based on the determination result data d12. . For example, a use frequency with less noise is automatically selected. As a result, the modulation / demodulation circuit 17dw in the modulation transmission apparatus 11a determines the used frequency.

  In the above description, the operation of automatically selecting the use frequency by the use frequency adjusting means 31 is performed at a certain timing or periodically. However, the operation may be performed at the time of starting the power supply or resetting the modulation transmission apparatus. At the time of starting the power supply or resetting the modulation transmission device, the power-on reset means 24 operates the use frequency adjusting means 31. It is also possible to automatically select the operating frequency according to a command from a maintenance terminal such as a display operation unit or a personal computer installed in the cab.

  Further, the use frequency adjusting means 31 of the modem circuit 17 selects the use frequency, and when the selected use frequency is fixed, stores it in the selection result recording unit 32 as shown in FIG. That is, when the use frequency is selected, the use frequency adjusting unit 31 stores the use frequency selection value in the selection result recording unit 32, and the modem circuit 17 stores the value when the power is restarted or the modulation transmission device is reset. Transmission is performed at the use frequency selected by the selected use frequency. At the time of starting the power supply or resetting the modulation transmission device, the operating frequency adjusting unit 31 is operated by the power-on reset unit 24. Note that after starting transmission with the stored use frequency selection value, the use frequency may be selected again according to the above description.

  Next, the use frequency adjusting unit 31 divides the frequency band into a plurality of parts by the OFDM method and assigns the divided use frequency band according to the transmission path characteristics so that the influence of signal interference with another network can be avoided. explain.

  FIG. 5 shows an example in which the frequency band is divided into three. Corresponding to the areas of the transmission lines 12 and 121, the frequency band is divided into three areas of A area, B area, and C area. The frequency band is, for example, 2 MHz to 30 MHz. Then, different frequency bands are used for each transmission line region (A region, B castle, C region). In the normal mode, as shown in FIG. 5A, the frequency band is equally divided into the A region, the B region, and the C region. FIG. 6 shows a configuration of an information network device in a railway vehicle when different frequency bands fa to fc are used for each transmission line region (A region, B region, C region). For example, the use frequency band of the transmission line 12a is the frequency band fa of the A region, the use frequency band of the transmission line 12b is the frequency band fb of the B region, and the use frequency bands of the transmission lines 121, 121b, and 121c are all frequencies of the C region. Let it be a band fc. Thereby, the use frequency bands of the adjacent transmission lines 12 and 121 become frequency bands fa to fc in different regions. For example, fa = 2 to 12 MHz, fb = 12 to 22 MHz, and fc = 22 to 30 MHz.

  For example, in the first railway vehicle 15a, transmission lines = 12a and 121a drawn from the modulation transmission device 11a are in different frequency bands fa and fc, respectively, and in the next rail vehicle 15b, the transmission lines are drawn from the modulation transmission device 11b. The transmission lines 12a, 12b, and 121b have frequency bands fa, fb, and fc in different regions, respectively. In the next railway vehicle 15c, the transmission lines 12b and 121c drawn out from the modulation transmission device 11c have frequency bands fb and fc in different regions, respectively. As a result, the signals on the transmission lines 12 and 121 do not interfere with each other.

  In this embodiment, the frequency band is divided into three, but the width of the frequency band area to be divided is changed according to the operation mode. Further, the frequency bands fa and fb, and the frequency bands fb and fc may or may not be continuous. Further, as shown in FIG. 7, the frequency f is further subdivided, and frequencies A0, A1, A2,... Are used for the A region, and B0, B1 are used for the B region. , B2... Frequency fb0, fb1, fb2... May be used, and C0, C1, C2... Frequencies fc0, fc1, fc2. Further, as shown in FIG. 8, the frequency band division of FIG. 5 and the frequency division of FIG. 7 are used in combination, and the frequencies fa0, fa1, fa2,..., Ak of the A0, A1, A2,. , Bm frequencies fbm, fbm + 1, fbm + 2,..., Fbn for the B region, and Cp, Cp + 1, Cp + 2,..., Cq frequencies fcp for the C region. , Fcp + 1,. fcp + 2,..., fq may be used.

[Normal operation mode]
In the normal operation mode, as shown in FIG. 5A, the divided bands A, B, and C are made equal, and the frequency bands A and B are used for the upstream side and the downstream side for data transmission between the adjacent modulation transmission apparatuses 11. The frequency band C is used for data transmission with the display device 101.

[Image data transmission mode from server]
When a large amount of data such as image data is transmitted from the server 10 of the head vehicle 15a to each display device 101, the frequency band is variably divided and used. First, the transmission of image data is notified from the server 10 to each modulation transmission apparatus 11. On the other hand, the relay processor 18 of each modulation transmission apparatus 11 notifies the use frequency setting unit 19 that the image data transmission mode is set. When this operation mode notification is received, the use frequency setting unit 19 sets the A band and the B band from the normal mode to the modulation / demodulation circuits 17up and 17dw for data transmission between the modulation transmission devices as shown in FIG. 5B. Also outputs a command to expand it by a certain width. At this time, a command for narrowing the C band by a certain width from the normal mode is output to the modulation / demodulation circuit 17in for the display device 101. As a result, the modulation transmission apparatus 11 on the downstream side receives the image data in a wide band by the relay processor 18 and sequentially relays it to the modulation transmission apparatus 11 of another adjacent vehicle, and temporarily stores it in the image data storage unit 181. Hold on.

  When the transmission of the image data from the server 10 stops, the relay processor 18 outputs a command for switching to the in-vehicle data transmission mode to the use frequency setting unit 19. In response to this, the use frequency setting unit 19 sets the A band and the B band to a constant width as compared with the normal mode with respect to the modulation / demodulation circuits 17up and 17dw for data transmission between the modulation transmission devices as shown in FIG. In contrast, a command for narrowing the C band by a certain width is output to the modulation / demodulation circuit 17in for the display device 101. As a result, the image data is transmitted to the display device 101 in a wide band so that a large amount of image data can be transmitted quickly. After the image data transmission is completed, the normal operation mode is restored.

  As described above, according to the embodiment of the present invention, the modulation transmission apparatus is provided with transmission output adjustment means, reception sensitivity adjustment means, and use frequency adjustment means for avoiding the effects of external noise and interference. Therefore, it is possible to construct a high-speed information network apparatus in a railway vehicle without using a coaxial cable or a shielded line that is a transmission line for high-frequency communication.

  In addition, when transmitting a large amount of data such as image data from the server 10 to the display device 101 in each vehicle 15, by expanding the frequency band of the transmission line 12 or 121 through which the data is actually transmitted, For example, there is an advantage that the time required for downloading content from the server to the display device 101 in each vehicle 15 can be shortened.

DESCRIPTION OF SYMBOLS 10 ... Server 11 ... Modulation transmission apparatus 12, 121 ... Transmission line 15 ... Railway vehicle 17 ... Modulation / demodulation circuit 18 ... Relay processor 19 ... Use frequency setting device 20 ... Transmission output adjustment means 21 ... Transmission circuit part 22 ... Reception circuit part 24 ... Power-on / reset means 25 ... Modulation control section 31 ... Use frequency adjustment means 32 ... Selection result recording sections 101-104 ... Display device

Claims (2)

A modulation transmission device mounted on each vehicle and relaying received data; a display device mounted on each vehicle; between the modulation transmission devices on adjacent vehicles; and a modulation transmission device and a display device on each vehicle; In a railway vehicle information network device comprising a transmission line that connects between and a server that is installed on a specific vehicle and sends image data to a modulation transmission device on the vehicle,
The modulation transmission device includes:
Use frequency adjusting means for dividing and using a frequency band used for data transmission between the adjacent other modulation transmission apparatuses and data transmission to the display apparatus into transmission frequency bands that can avoid the influence of signal interference,
Image data storage means for holding the image data sent from another modulation transmission device;
Image data resending means for transmitting the image data held in the image data storage means to the display device,
The server outputs image data to be displayed on a display device on each vehicle to the modulation transmission device on the specific vehicle,
The modulation transmission apparatus relays the image data sent from another modulation transmission apparatus and holds it in the image data storage means, and the image held in the image data storage means after relaying the image data A railway vehicle information network device, wherein data is transmitted to the display device by the image data retransmission means. The modulation transmission device includes:
The side that receives the image data from another adjacent modulation transmission device, the side that relays and transmits the image data to another adjacent modulation transmission device, and the side that transmits the image data to the display device are different. Using frequency bands,
When relaying the image data sent from another modulation transmission device and holding it in the image data storage means, both the frequency bands used for data transmission between adjacent modulation transmission devices are limited to a certain range. Widen and narrow the frequency band used for data transmission to and from the display device by a certain range,
When the image data held in the image data storage means is transmitted to the display device by the image data retransmission means after the image data is relayed, it is used for data transmission between adjacent modulation transmission devices. 2. The railway vehicle information network device according to claim 1, wherein both frequency bands to be transmitted are narrowed by a certain range, and a frequency band used for data transmission with the display device is widened by a certain range. .

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