CN100413243C - information transmission system - Google Patents

Abstract

An information transmission system, a series 1 NCP (11), is connected to a series 1 trunk transmission line (1N) through a series 1 switching hub (12). Through the 1-series control information transmission unit (13), it is connected to the 1-series machine control device (15), the 2-series machine control device (25) and the 2-series switching hub (22). It is connected with a series of information equipment (16) through a series of media information transmission parts (14). The same goes for the 2 series. The switching hub (2) gives priority to sending the control information when receiving the control information and the media information. The control information transmission unit (3) receives data from two main transmission lines N, and sends data from the same system as the own station to the machine control device (5). When transmission is interrupted on one main transmission line N due to a failure, data received by the other main transmission line (N) is relayed to the main transmission line (N) whose transmission was interrupted.

Description

information transmission system

technical field

The invention relates to an in-vehicle network of a railway vehicle, in particular to an information transmission system of a backbone network.

Background technique

The in-vehicle network of railway vehicles has been developed for the purpose of simplifying the wiring in the vehicle, etc., and it was first used as a monitor (collection of status information) of equipment on the vehicle. Currently, a network with a data transmission speed of 2 to 3 Mbps has been put into practical use, and the transmission of control information (commands to control vehicle equipment, etc.) is also possible. Moreover, the demand for multimedia servers in vehicles has increased, and at the same time, the transmission of large-capacity multimedia information due to the in-vehicle network or Internet connection has been realized. As an example of the in-vehicle network of railway vehicles, two transmission stations are provided for each vehicle, the transmission stations of each vehicle are connected by a first transmission line loop, and two transmission stations are installed inside each vehicle When the first transmission line between vehicles is disconnected in multiple places through the connection of the second transmission line, there is a technique of constructing a zigzagging line according to the second transmission line in the vehicle (see Patent Document 1).

However, if the media information for the multimedia server is simultaneously transmitted by the in-vehicle network, it will be mixed with the control information for vehicle equipment control, and the real-time performance of the control information will be damaged due to the transmission of the media information. The problem. Thus, the responsiveness necessary for controlling the vehicle machine cannot be ensured. Moreover, for the on-board network, it is necessary to have such high reliability that even if a fault occurs, the train will not stop on the line immediately but can be moved to the repair site. surplus.

Patent Document 1: Japanese Unexamined Patent Publication No. 11-154891 (paragraphs 0020 to 0024, FIGS. 1 and 2 )

Contents of the invention

Therefore, the object of the present invention is, in view of the above-mentioned problems, to provide an in-vehicle network of a railway vehicle, which can ensure the real-time performance of control information even while transmitting media information, and at the same time ensure high reliability against network failures. organization.

In order to solve the above-mentioned problems, the present invention is composed of an in-vehicle network connecting each vehicle between railway vehicles; and a transmission control device installed in each vehicle to connect the above-mentioned in-vehicle network and equipment in the vehicle The information transmission system mainly has the following characteristics. First, the information transmission system has a transmission control device, which will be used to control the control information of the vehicle equipment connected to the in-vehicle network, and transmit the data at 100 Mbps or more through the transmission line of the metal medium. Transmission speed transmission. In this way, the operability and responsiveness of the vehicle machinery in the railway vehicle is ensured.

Then, the transmission control device is equipped with: a control information transmission part, which performs transmission and reception of control information (control series data) with the vehicle equipment; a media information transmission part, which performs transmission and reception of media information (information series data) with the information equipment; A hub, which is connected to the in-vehicle network, the control information transmission unit, and the media information transmission unit, relays the control information between the in-vehicle network and the control information transmission unit, and performs media transmission between the in-vehicle network and the media information transmission unit. relay of information. Among them, when the switching hub transmits the control information received from the control information transmission unit and the media information received from the media transmission unit to the in-vehicle network, it refers to the data indicating the priority set in various information, and according to the priority Send various information in high and low order. At this time, according to the priority set in the control information, which is higher than the priority set in the media information, the switching hub preferentially transmits the control information. In this way, even if the control information and the media information are mixed together, the real-time performance of the control information will not be damaged.

Next, as a redundant configuration, each vehicle is connected through two in-vehicle networks. In each vehicle, a switching hub is connected to each in-vehicle network, and two control information transmission units are connected between the two switching hubs. When the control information transmission unit receives control information from the vehicle equipment, it transmits the received control information to the two switching hubs. Then, the control information transmitting unit that has received the control information transmits the control information to the other switching hub that has not received the control information when receiving the control information from one of the switching hubs. In this way, even if a part of the in-vehicle network fails, information transmission can continue by switching lines. Also, the control information transmission unit transmits information at a predetermined cycle when transmitting control information. Then, when the control information transmission unit that receives the control information does not receive the control information within a time corresponding to a predetermined multiple of the period, it is judged that the in-vehicle network has failed. In this way, line switching is performed for a short time when a failure occurs.

According to the present invention, even if control information and media information are simultaneously transmitted in an in-vehicle network of a railway vehicle, the real-time performance of the control information can be ensured. Furthermore, high reliability can be ensured against network failures.

Description of drawings

FIG. 1 is a diagram showing an in-vehicle network configuration of an information transmission system in a railway vehicle according to an embodiment of the present invention.

FIG. 2 is a diagram showing the configuration of an NCP and its surroundings in one vehicle according to the embodiment of the present invention.

3 is a diagram showing the types and data volumes of control information in the information transmission system according to the embodiment of the present invention.

FIG. 4 is a diagram showing the occurrence of NCP delays according to the embodiment of the present invention.

FIG. 5 is a diagram showing the structure of a transmission frame according to the embodiment of the present invention.

FIG. 6 is a diagram showing the configuration of functional blocks for priority processing by the switching hub in the embodiment of the present invention.

FIG. 7 is a diagram showing detour control performed by NCP in the embodiment of the present invention.

Among them: 1-NCP (transmission control device), 2-switching hub, 3-control information transmission department, 4-media information transmission department, 5-machine control device, 6-information equipment, N-trunk transmission line (in-vehicle network ), 11-1 series NCP (transmission control device), 12-1 series switching hub, 13-1 series control information transmission unit, 14-1 series media information transmission unit, 15-1 series machine control device, 16-1 series Information equipment, 1N-1 series backbone transmission line (in-vehicle network), 21-2 series NCP (transmission control device), 22-2 series switching hub, 23-2 series control information transmission unit, 24-2 series media information transmission Department, 25-2 series machine control device, 26-2 series information machine, 2N-2 series backbone transmission line (in-vehicle network), 31-vehicle machine.

Detailed ways

Hereinafter, best modes for carrying out the present invention (hereinafter referred to as "embodiments of the present invention") will be described in detail with reference to the drawings.

(Network configuration and outline of the information transmission system)

Referring to FIG. 1 , a network configuration of an information transmission system in a railway vehicle according to an embodiment of the present invention will be described. In each vehicle (No. 1 car 10a, No. 2 car 10b, No. 3 car 10c, ...), two NCPs (Network Control Processor, transmission control device) of series 1 and series 2 are respectively set. Then each NCP1 (1 series NCP11, 2 series NCP21) is connected across each vehicle to the main transmission line N (1 series main transmission line 1N, 2 series main transmission line 2N) of the in-vehicle network set up by the dual system.

In addition, in the description of this embodiment, when indicating the constituent elements of the 1st series or the 2nd series, it is described as "1st series NCP11" or "2nd series NCP21", for example, when describing general constituent elements regardless of the 1st series or the 2nd series , expressed as, for example, "NCP1".

The backbone transmission path N is a transmission path using metal or optical fiber as a communication medium. The NCP 1 transmits data at a data transmission rate of 100 Mbps or higher through the main transmission line N, and can ensure operability or responsiveness of the vehicle equipment 31 by transmitting control information for controlling the vehicle equipment 31 (see FIG. 2 ). Furthermore, NCP1 monitors the main transmission line N of the dual system, and detours the data as necessary. NCP1 is independent (not exchanged with other NCP1) for fault detection and detour processing, and can switch lines at high speed. In addition, the equipment control device 5 is connected to the NCP 1 and also connected to the vehicle equipment 31 (see FIG. 3 ) via a branch line network. Here, the vehicle equipment 31 is, for example, doors, brakes, switches, etc. of the vehicle.

(NCP (transmission control device) and its peripheral configuration)

Referring to FIG. 2 , the configuration of the NCP and its surroundings in one vehicle in the embodiment of the present invention will be described.

First, the configuration of NCP1 and its surroundings will be described. The NCP 1 is composed of a switching hub 2 , a control information transmission unit 3 , and a media information transmission unit 4 .

The switching hub 2 is a public switching hub, and the transmission mode is a store-and-forward mode. In this method, frames received from each port are buffered (stored) and then output to an appropriate port (forwarded). At this time, frames of different ports can be processed in parallel. Therefore, unlike the repeater system that directly outputs received signals, frame collision does not occur. Furthermore, the switch hub 2 is a device corresponding to priority communication stipulated by IEEE802.1Q/p. In this standard, the extended MAC (Media Access Control) header of record priority is defined. The switching hub 2 has an output buffer (queue) for each priority, and the one with the higher priority is output first. Using this function, the simultaneous transmission of control information and media information can be realized based on the fact that the frame of the control system has a higher priority than the frame of the information system. In addition, the switching hub 2 is a dedicated LSI (Large Scale Integrated Circuit, that is, a large scale integrated circuit), and operates by hardware.

As shown in FIG. 2 , the transmission data of the main transmission line N passes through the switching hub 2 of the NCP 1 when passing through each vehicle. The switching hub 2 regenerates the received frame through store-and-forward relay. The transmission distance between the switching hubs 2 is about 20 m as long as one vehicle. This value is much shorter than 100m which is a standard of 100Base-TX of Ethernet (registered trademark of Ethernet). Therefore, there is no problem of signal degradation due to long-distance transmission. Furthermore, in the standard of Ethernet (registered trademark of Ethernet), unlike a repeater, the switching hub 2 is not limited to the number of connected devices. Therefore, long-distance transmission can be carried out in the constituent ensemble of the train.

The control information transmission unit 3 has a function of transmitting and receiving signals with the equipment control device 5 and a detour control function when the main transmission line N fails. These functions are realized according to the program processing of CPU (Central Processing Unit, central processing unit). Dual-system main transmission line N (1 series main transmission line 1N, 2 series main transmission line 2N) and dual machine control device 5 (1 series machine control device 15, 2 series machine control The device 25) is connected to both sides and provided with four Ethernet (registered trademark of Ethernet) ports.

The media information transmission unit 4 handles sending and receiving information with the information device 6 . Moreover, since the information device 6 transmits interference or wrong information, in order not to hinder the transmission of control information, the media information transmission unit 4 has a firewall function. This can also be realized by program processing of the CPU, and two Ethernet (registered trademark of Ethernet) ports connected to the main transmission line N (switching hub 2 ) and the information device 6 are provided. As a specific firewall function, when the information of the information device 6 is output to the switching hub 2, the information is checked, and the information that is not media information, such as the same information as the control information, is discarded so that it will not be output to the switching hub 2 . To determine the type of information, an identifier written in a part of the information (in the case of Ethernet (registered trademark of Ethernet), an address, a port number, etc.) is used. Here, the information device 6 is, for example, a notification display device for passengers in the vehicle or a flight attendant, a voice transceiver device, or the like.

In addition, the control information transmission unit 3 and the media information transmission unit 4 can write programs to replace themselves via the network (remote download), which facilitates maintenance work. In this case, a program that is wrong with the information device 6 is not written. That is, the media information transmission unit 4 has two network interfaces (Ethernet (registered trademark of Ethernet) ports), and the reception of the program is only received from the main transmission line N (switching hub 2), even if the program is received from the information device 6 destroyed. Moreover, the data downloaded remotely is handled as control information (control system data), and the above-mentioned firewall function prevents the information equipment 6 from being transmitted to the main transmission line N (switching hub 2).

In NCP1, the machine control device 5 is connected by Ethernet (registered trademark of Ethernet), and one or more vehicle machines 31 are connected from the machine control device 5 by a branch line network. In the branch line network, CAN (Control Area Network) with good real-time performance, large-capacity Ethernet (Ethernet registered trademark), RS-485, etc. are used. The equipment control device 5 collects data from each vehicle equipment 31 and transmits it to the main transmission line N, divides the data received from the main transmission line N, and transmits it to the necessary vehicle equipment 31 . In this way, the number of frames propagated on the backbone transmission line N can be limited, and the network load and NCP processing load can be reduced. Here, a configuration may be adopted in which the control information transmission unit 3 and the vehicle equipment 31 are directly connected without passing through the equipment control device 5 .

In addition, it is necessary to be able to flexibly arrange the equipment in the vacated space, which is limited to the installation space of the equipment in the railway vehicle. Therefore, the media information transmission unit 4 of the NCP 1, the switching hub 2, the control information transmission unit 3, and the machine control device 5 are connected via a serial bus (network). In the case of a parallel bus connection in the past, since information was sent and received through a large number of signal lines, it was impossible to set it apart from each machine, but in a serial bus, information can be transmitted between machines with fewer signal lines. The location of each machine can also be set. In this case, it is also possible to centrally install them in one place as in the past.

Next, a description will be given of the connection configuration of the two systems in one vehicle. The series 1 NCP 11 is connected to the series 1 backbone transmission line 1N through the switching hub 12 of the series 1. Furthermore, the series 1 control information transmission unit 13 is connected to the series 1 equipment control device 15 , the series 2 equipment control device 25 , and the series 2 switching hub 22 . Also, it is connected to a series of information equipment 16 through a series of media information transmission unit 14 . On the one hand, the 2-series NCP 21 is connected to the 2-series backbone transmission line 2N through the 2-series switching hub 22 . Furthermore, it is connected to the series 1 equipment control device 15 , the series 2 equipment control device 25 and the series 1 switching hub 12 via the series 2 control information transmission unit 23 . In addition, it is connected to the 2-series information equipment 26 through the 2-series media information transmission unit 24 . In addition, since the 1st series control information transmission unit 13 is connected to the 2nd series switching hub 22, and the 2nd series control information transmission unit 23 is connected to the 1st series switching hub 12, detour control can be performed when the trunk transmission line N fails.

The series 1 equipment control device 15 and the series 2 equipment control device 25 are connected to the vehicle equipment 31 . In this way, the vehicle equipment 31 can be controlled by two series of equipment control devices 5, and even if one of the equipment control devices 5 fails, it can be controlled.

(Embodiment for securing real-time control information)

The trunk transmission line N is composed of a plurality of switching hubs 2 connected in series. Therefore, the speed at which the frame passes through the switching hub 2 is the delay time of the main transmission line N. Since the switching hub 2 operates according to the store-and-forward method, a delay corresponding to the frame length occurs when a frame passes through. Furthermore, even when other frames are already being transmitted from the same port, such a delay may occur until the transmission is completed.

Since the delay time depends on the frame length, first, collate about the collation of the transmitted data. Fig. 3 shows the types and data volumes of control information in the information transmission system. The exact amount of data varies depending on the machine configuration. The value in FIG. 3 is the standard information amount required for collection of vehicle control and maintenance information. These are all transmitted according to UDP/IP (User Datagram Protocol/Internet Protocol). The amount of data also includes MAC header (22 bytes including CRC data), IP header (20 bytes) and UDP header (8 characters) section) totaling 50 bytes. Among them, the real-time requirements are higher, 10ms cycle data and sound data. The 10 ms cycle data transmits control information related to the safety of the train, such as commands to control converters and brakes of the vehicle equipment 31 . Furthermore, voice data is required to be real-time in order to enable communication between passengers and flight attendants even in the event of an accident or the like.

Referring to Fig. 4, description will be given regarding the occurrence of delay in NCP. When media information (information series data) and control information (control series data) are mixed and transmitted, the control information is transmitted preferentially over the media information waiting for transmission according to the priority processing. However, it cannot exceed the media information (up to 1518 bytes) already being sent and the control information stored in the previous sending buffer. Under these simultaneous conditions, the transmission delay is at a maximum. As shown in FIG. 4 , frame A is received from the information device 6 , frame B is received from the device control device 5 at the time of start of transmission, and then frame C is received from an adjacent vehicle. At this time, frame C is transmitted after frame A and frame B are transmitted, and the transmission time of frame C (time corresponding to the length of the frame) is also a factor of delay. For example, if frame B is used as maintenance data (1522 bytes) and frame C is used as audio data (314 bytes), since the data transmission speed is 100 Mbps, the delay time is as follows.

Media information sending time + maintenance data sending time + sound data sending time

＝(1518+1522+314)bytes×8 bits/100Mbps

＝268.32μS/terminal station

This value is much smaller than the maximum delay time 1 [ms/terminal station] allowed by the responsiveness of machine control, and can ensure the real-time performance required for the in-vehicle network.

As a response to the delay described above, priority processing by switching hubs will be described. The priority protocol adopts IEEE802.1Q/p. Based on this standard, an extended frame in which a 4-byte tag defining priority is added to the transmission of information is adopted. Fig. 5 shows the structure of this frame. Label, defined internally by the MAC header. In the standard, priority can be defined as 8 levels, and in the information transmission system, it is defined as 2 levels of priority of "control system" and "information system". In this way, the control information transmission unit 3 of the NCP 1 sets the "control system" in the tag of the MAC header of the received control information by the machine control device 5 to increase the priority of transmission control information. Furthermore, the media information transfer unit 4 of the NCP 1 can lower the priority of transferring multimedia information by setting "information system" in the tag of the MAC header of the media received from the information device 6 . In addition, the control information transmission unit 3 and the media information transmission unit 4 do not set the priorities in the same way, but may set them according to the type of received information. For example, the control information transmission unit 3 may set the highest priority for the 10 ms cycle data or voice data shown in FIG. 3 . Furthermore, "data" in FIG. 5 includes an IP header and a UDP header.

FIG. 6 shows the configuration of functional blocks in the priority processing of the switching hub. The switching hub 2 is composed of an output scheduler 63 , a priority queue 64 , a non-priority queue 65 , a receiving port 66 , and a sending port 67 . The data (frame) input in the receiving port 66 is stored in the priority queue 64 or the non-priority queue 65 according to the priority indicated by the label. The output scheduler 63 outputs data to the sending port 67 after inputting data from the priority queue 64 or the non-priority queue 65 . FIG. 6 shows processing in the case of accepting that data should be output from a plurality of receiving ports 66 to the same sending port 67 . Each receiving port 66 receives data independently (operating in parallel at the same time). Then the data is stored in the priority queue 64 or the non-priority queue 65 of each priority output queue according to the label of the MAC header. At this time, the priority queue 64 and the non-priority queue 65 are prepared for each sending port 67 . Here, the important data 61 is stored in the priority queue 64 , and the data 62 is stored in the non-priority queue 65 . The output scheduler 63 sends the data of the priority queue 64 first, and sends the data of the non-priority queue 65 because there is no data in the priority queue 64 . Therefore, as shown in FIG. 6 , important data 61 and data 62 are transmitted in order.

According to the priority processing of the switching hub as described above, the real-time performance of the control information and the simultaneous transmission of the media information can be realized.

(Explanation on correspondence with delay time in information transmission)

From a viewpoint different from the embodiment in which the real-time performance of the control information described above is ensured, the correspondence with delay time in information transmission will be described.

In the case of adopting the switching hub method as a bus access method to the backbone transmission line N, the switching hub 2 receives all frames and then forwards them, so it is a store-and-forward method. In this case, there is no conflict problem and the number of switching hubs 2 is limited. However, since the relay starts after receiving the frame, a frame length delay occurs. The minimum frame size of 10 Mbps Ethernet (registered trademark of Ethernet) is 64 bytes, the maximum frame size is 1518 bytes, and the time required for frame reception is 0.05 ms and 1.2 ms, respectively. This delay occurs every time passing through the switching hub 2 (passing the vehicle). Furthermore, when a plurality of nodes transmit data at the same time, they are processed in the order of the first arrival when the priority is the same, and the later data will be delayed until the earlier data is sent.

This delay time can be reduced by increasing the data transmission speed of the trunk transmission line N. If the data transmission speed is 100 Mbps, the receiving time of the minimum frame and the maximum frame of Ethernet (registered trademark of Ethernet) are 0.005 ms and 0.12 ms respectively. Secondly, calculate the specific delay time. If the data transmission speed is 100Mbps, it can be applied to the in-vehicle network because the delay is smaller than that of the repeater method.

Moreover, as an advantage of the store-and-forward method, due to the compatibility of the switching hub 2 detection frame (according to the CRC (Cyclic Redundancy Check, cyclic redundancy check) data in Figure 5), it is possible to prevent error data from flowing to the backbone transmission line N inadvertently. .

Here, the delay time from when the first node (for example, the machine control device 5 ) transmits the control information to when the last node receives it is calculated based on the following assumptions.

(a) The number of nodes is set to 10 (consists of 8 vehicles, and each vehicle has 2 nodes at both ends).

(b) The data length (including the header) is 114 bytes (0.01 ms) for control information, and 1522 bytes (0.12 ms) for maintenance data (failure information from the vehicle equipment 31, etc.).

(c) In each node, before the control information, the maintenance data of the same priority is transmitted.

In assumption (c), if considering that the frequency of actual maintenance data may not be realistic, it can be considered as the maximum transmission volume. Also, media information is not considered due to low priority (accurately speaking, there is a slight delay, but due to priority processing, there is no major impact).

The relay delay of the switching hub 2 is 0.01 (ms) x 10 (tags) = 0.1 ms because it occurs for each node.

According to the delay of the maintenance data sent before the control information, since every node located in the middle of the transmission line will happen, it is 0.12(ms)×8(label)=0.96ms.

Therefore, the minimum value of the delay is 0.1ms and the maximum value is 1.06ms. This is the delay time occurring in switching hub 2 of NCP1. Actually, this is added to the processing delays of the control information transmission unit 3 of the NCP 1 and the equipment control device 5 on the sending side and the receiving side respectively. The control information transmission unit 3 performs program processing by the CPU after receiving the frame. The delay at this time is about several hundred μs, and here it is assumed that the maximum is 1 ms. In addition, the machine control device 5 performs cycle processing of 10 ms first, and a delay corresponding to the cycle is generated at the most. As described above, the transmission device delay from the device control device 5 on the sending side to the device control device 5 on the receiving side is 1.06+(1+10)×2=23.06 ms (maximum value).

(Embodiment to ensure high reliability of the backbone transmission line)

Each NCP1 is connected to the main transmission line N of the dual system, and high reliability is ensured by active detour control in the event of a failure. The detour control will be described with reference to FIG. 7 (see FIG. 2 as appropriate). FIG. 7 shows the data transmission line in the No. 1 car 10a where a disconnection occurred at two places on the trunk transmission line N. "X" in the figure is the place where the line is broken. The 1st series NCP 11 of the No. 1 car 10a that is the source of data always transmits the same data to the main transmission line N of the dual system, that is, the 1st series main transmission line 1N and the 2nd series main transmission line 2N. The control information transmission part 3 of each NCP1, after receiving these from the main transmission line N of the dual system, sends the data received from the main transmission line N of the same system as this station to the machine control device 5, and usually the data of one party has been received. destroy. After a fault occurs in the main transmission line N, when the transmission of one main transmission line N is interrupted, the data received by the other main transmission line N is transmitted to the machine control device 5 and at the same time, the data is sent to the party whose transmission was interrupted. The trunk transmission line N relays (sends). In the case of Figure 7, after the 2nd series NCP21 of the 2nd car 10b detects the transmission interruption through the 2nd series trunk transmission line 2N, the data of the 1st car 10a received by the 1st series trunk transmission line 1N is sent to the 2nd series trunk transmission line 2N continue. Similarly, the first-series NCP 11 of the No. 3 car 10c relays the data of the No. 1 car 10a from the second-series main transmission line 2N to the first-series main transmission line 1N.

As a fault detection mechanism for the main transmission line N, it is conceivable to (1) detect the state of the physical layer of the network (link state, etc.), (2) detect the transmission and reception of fault detection data, and (3) detect the state of reception of transmission data. With or without detection. In the method (1), a failure in which a link is established but a message cannot be transmitted or received cannot be detected. Furthermore, in method (2), for high-speed detection, it is necessary to transmit fault detection data at a cycle faster than the control data cycle of 10 ms, but this is not practical in consideration of processing performance. Here, the detection of the failure is as (3) detection method based on the receiving state of the transmission data. The control information is several types shown in Fig. 3, among which the acceptance status is verified by the 10ms cycle data. If the data is not received within several times of the transmission period, it is judged that a fault has occurred in the main transmission line N. In this way, the time from the occurrence of a failure to the continuation of transmission by the detour is as short as several tens of ms.

In the above method, faults are detected almost simultaneously for a plurality of NCP1s. At this time, even any one NCP1 detour control can transfer data to the remaining NCP1. In the example of FIG. 7, for the disconnection between No. 2 car 10b and No. 3 car 10c, the first series NCP 11 of No. 3 car 10c is detoured, and even if the first series NCP 11 of No. 4 car 10d detours, data can be transmitted. Furthermore, any one of the 1st series NCP11 and the 2nd series NCP21 of each vehicle may be detoured. As for which NCP1 performs detour control, it is determined by the following rule for simplicity of processing. (1) Carried out by the vehicle closest to the fault location; (2) In the case of detour failure, etc., the next closest vehicle detours; (3) 1 series NCP11, the case of receiving signal interruption from 1 series main transmission line 1N Next, data is relayed from the 2 series trunk transmission line 2N to the 1 series trunk transmission line 1N. The 2-series NCP21 relays data from the 1-series main transmission line 1N to the 2-series main transmission line 2N when a signal interruption is received from the 2-series main transmission line 2N.

These are realized as follows. Each NCP 1 waits for a time corresponding to the distance between the transmission source and the own vehicle when the transmission is interrupted (the adjacent vehicle waiting time is set to 0). During the waiting time, another NCP 1 starts detour to receive data, and stops detour preparation. If the waiting time of the state of not receiving data has elapsed, the data received from other systems is then relayed. In this way, once a failure occurs, adjacent vehicles at the failure location immediately start to detour. When an adjacent vehicle cannot make a detour due to some kind of failure, the next closest vehicle performs detour control. These are voluntary operations and do not require transmission of line information or the like between the NCP1s.

In this way, even if a failure occurs on the main transmission line N, the NCP 1 adjacent to each other for several tens of milliseconds can proactively perform detour control, ensuring the reliability required for the in-vehicle network.

As above, the embodiment of the present invention has been described. The program executed by each constituent element shown in FIG. The information transmission system in the embodiment of the present invention is realized.

As mentioned above, although the suitable embodiment of this invention was illustrated, the embodiment of this invention is not limited to this, In the range which does not deviate from the summary of this invention, a suitable change is possible.

Claims (5)

1. an information transmission system is by in rolling stock, connects the in-vehicle network between each vehicle, constitutes with the transmission control unit that is provided with in each vehicle, be connected the machine in above-mentioned in-vehicle network and the vehicle, it is characterized in that,

Above-mentioned transmission control unit comprises:

The control information transport part, it is connected with the vehicle machine, carries out the transmitting-receiving of control information with this vehicle machine;

The media information transport part, it is connected with information machine, carries out the transmitting-receiving of media information with this information machine; And

Switching hub, it is connected with above-mentioned in-vehicle network, above-mentioned control information transport part and above-mentioned media information transport part, the relaying that carries out above-mentioned control information between above-mentioned in-vehicle network and above-mentioned control information transport part; Between above-mentioned in-vehicle network and above-mentioned media information transport part, carry out the relaying of above-mentioned media information,

Wherein, the data of expression high priority when above-mentioned vehicle machine receives control information, are set in above-mentioned control information transport part in the control information that this receives, send to above-mentioned switching hub,

The data of expression low priority when above-mentioned information machine receives media information, are set in above-mentioned media information transport part in the media information of this acceptance, send to above-mentioned switching hub,

Above-mentioned switching hub, in the control information that will receive and when the media information that above-mentioned media delivery portion receives sends to above-mentioned in-vehicle network from above-mentioned control information transport part, with reference to the data of the above-mentioned priority of expression, send various information in proper order according to the height of this priority.

2. the information transmission system according to claim 1 is characterized in that,

Above-mentioned control information transport part is when needing the machine control information of high responsiveness or acoustic information in above-mentioned control information, sets the data of expression limit priority in this control information.

3. according to the claim 1 or the 2 described information transmission systems, it is characterized in that,

Above-mentioned media information transport part when the information of accepting from above-mentioned information machine is not media information, does not send to above-mentioned switching hub with this information.

4. the information transmission system according to claim 3 is characterized in that,

Above-mentioned control information transport part is carried out the rewriting of program from above-mentioned in-vehicle network via above-mentioned switching hub,

Above-mentioned media information transport part is carried out program rewriting from above-mentioned in-vehicle network via above-mentioned switching hub, can not carry out program rewriting from above-mentioned information machine.

5. the information transmission system according to claim 1 is characterized in that,

Between above-mentioned media information transport part, above-mentioned switching hub, above-mentioned control information transport part and the above-mentioned equipment control device each connects, and undertaken by universal serial bus.

Images