JP2009029237A - In-vehicle communication system - Google Patents

Abstract

An in-vehicle device that includes a plurality of in-vehicle devices and a plurality of distribution devices that store data received from each in-vehicle device and distribute the stored data to the in-vehicle devices. A communication system is provided.
In a situation where an in-vehicle device 1a transmits data to a distribution device 2a via an in-vehicle communication line 3a and receives data from the distribution device 2b via an in-vehicle communication line 3b, the in-vehicle communication line 3a is connected. If the data cannot be transmitted from the in-vehicle device 1a to the distribution device 2a via the in-vehicle device 1a, the in-vehicle device 1a transmits the data transmitted to the distribution device 2a via the in-vehicle communication line 3a via the in-vehicle communication line 3b. Send to 2b. On the other hand, when the data cannot be distributed from the distribution device 2b to the in-vehicle device 1a via the in-vehicle communication line 3b, the in-vehicle device 1a uses the in-vehicle communication for the data received from the distribution device 2b via the in-vehicle communication line 3b. Received from the distribution device 2a via the line 3a.
[Selection] Figure 4

Description

  The present invention relates to an in-vehicle communication system including a plurality of in-vehicle devices and a plurality of distribution devices that store data received from each in-vehicle device and distribute the stored data to each in-vehicle device.

  In recent years, the number and types of electronic control units (ECUs) that electrically control onboard equipment or driving assistance functions have increased with the increase in equipment mounted on automobiles (vehicles) and driving assistance functions. Tend to. Further, as the number of ECUs increases, the amount of data transmitted / received via an in-vehicle communication line to which the ECUs are connected also increases.

  The in-vehicle communication line is generally configured by connecting an ECU in a bus form to a serial bus conforming to CAN (Controller Area Network) or the like. For this reason, data used only by some ECUs is also transmitted to all ECUs connected to the same in-vehicle communication line. Therefore, an increase in the amount of data transmitted / received through the in-vehicle communication line causes data delay or loss due to collision (collision). A significant delay or loss of data may be fatal to driving assistance functions such as brake control by the ECU.

  Therefore, a configuration in which the in-vehicle communication line is divided into a plurality of parts and the ECUs are connected to different in-vehicle communication lines is common. This is because the waste of use of the in-vehicle communication line can be suppressed by collecting ECUs that commonly use data. In addition, in order to efficiently use the in-vehicle communication line against the increase in the type of ECU, a configuration in which the ECU group is classified according to the type of data to be transmitted and received and connected to the in-vehicle communication line having a different communication speed for each group. There is also. In these configurations, different in-vehicle communication lines are connected by a gateway device that controls transmission and reception of data. In this case, the gateway device functions as a distribution device that temporarily stores the data received from the ECU and distributes and transmits the stored data to the in-vehicle device that requires the data.

In Patent Document 1, the ECU is divided into a plurality of groups and connected to the in-vehicle communication line for each group, and the in-vehicle communication line is further connected by a gateway device, and the priority for identifying the priority order for the transmitted and received data If the gateway device transmits / receives data between different in-vehicle communication lines, the priority is determined from the priority information of the received data, and data with higher priority is preferentially transmitted. A technique is disclosed in which transmission of data with high priority is not greatly delayed even when the communication load increases.
JP 2005-159568 A

  However, Patent Document 1 aims at preferentially transmitting high-priority data when the communication load is high so as not to cause a large delay, and does not suppress an increase in the amount of data transmitted and received in the in-vehicle communication system. Absent.

  In addition, when the ECUs are divided into a plurality of groups and the groups are connected via the gateway device, the contents of the data updated by the ECU in one group can be changed via the gateway device after the update. Therefore, there is a time when the data contents do not match between one group and the other group. Furthermore, when a plurality of groups are connected in series to the gateway device, there is a possibility that a time difference will occur in steps in the data contents between one group and another group. In this case, the reliability of data in the in-vehicle communication system is not ensured.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an in-vehicle communication system capable of reducing the amount of data transmitted and received between the in-vehicle device and the distribution device. is there.

  Another object of the present invention is to provide an in-vehicle communication system capable of ensuring the same content of data distributed from each distribution device to the in-vehicle device.

  Another object of the present invention is to provide an in-vehicle communication system capable of preventing the operation of the entire system from being hindered when a failure occurs in a part of the system and improving the reliability of the system. .

  An in-vehicle communication system according to the present invention includes a plurality of in-vehicle devices that transmit and receive data, a storage unit that receives and stores data from the in-vehicle devices, and a plurality of distribution devices that have means for distributing the stored data to the in-vehicle devices. Is connected to the plurality of distribution devices via the first communication line or the second communication line, and is connected via the first communication line. Means for transmitting data to the distributed device and means for receiving data from the distribution device connected via the second communication line, wherein the distribution device is connected to the first communication line. In this case, data received via the first communication line is configured to be stored in the storage unit, and when connected to the second communication line, the in-vehicle device is connected via the second communication line. Distribute data to Characterized in that it is configured so that.

  According to the present invention, a plurality of distribution devices that receive data transmitted from an in-vehicle device, store the data in a storage unit, and distribute the stored data to the in-vehicle device are provided, and each in-vehicle device includes a plurality of distribution devices. To the first communication line or the second communication line. Data is transmitted from each in-vehicle device to the distribution device connected via the first communication line, and the data received by the distribution device is stored in the respective storage means. Further, data is distributed from each distribution device to each in-vehicle device via the second communication line.

  In the in-vehicle communication system according to the present invention, the distribution device is configured to transmit data stored in the storage unit to another distribution device, and to store data transmitted from the other distribution device in the storage unit. It is characterized by providing.

  According to the present invention, data stored in the storage means is transmitted and received between the distribution devices. Therefore, the data contents of the storage means are synchronized among the plurality of distribution devices.

  In the in-vehicle communication system according to the present invention, when the in-vehicle device detects a communication interruption with the distribution device connected via the second communication line, and the communication interruption is detected, the communication is interrupted. Means for transmitting a data transmission request received from the distribution device via the second communication line to a distribution device connected via the first communication line, and receiving the transmission request. The device is configured to distribute data based on the transmission request to the in-vehicle device via the first communication line.

  According to the present invention, when the in-vehicle device detects the interruption of communication with the distribution device connected via the second communication line, that is, the data from the distribution device connected via the second communication line is detected. When reception is interrupted, the transmission request of the data received from this distribution apparatus is transmitted to the distribution apparatus connected via the 1st communication line. The distribution device that has received the transmission request distributes data based on the transmission request to the in-vehicle device via the first communication line.

  In the in-vehicle communication system according to the present invention, when the in-vehicle device detects a communication interruption with the distribution device connected through the second communication line, the communication through the second communication line is interrupted. Is provided to the distribution device.

  According to the present invention, when the in-vehicle device stops receiving data from the distribution device connected via the second communication line, the in-vehicle device notifies the distribution device that communication via the second communication line has been interrupted. To do.

  In the in-vehicle communication system according to the present invention, when the in-vehicle device detects a communication interruption with the distribution device connected via the first communication line, and the communication interruption is detected, the communication is interrupted. Means for transmitting the data transmitted to the distribution device via the first communication line to the distribution device connected via the second communication line.

  According to the present invention, when the in-vehicle device detects a disconnection of communication with the distribution device connected via the first communication line, that is, the data is transmitted to the distribution device connected via the first communication line. When the transmission is interrupted, the data transmitted to the distribution device is transmitted to the distribution device connected via the second communication line.

  In the present invention, by setting in advance a communication line when each in-vehicle device transmits data to the distribution device and a communication line when each distribution device distributes data to the in-vehicle device, the in-vehicle device is set. The communication load on each communication line can be reduced as compared with a configuration in which data is transmitted and received on all communication lines connecting the distribution device and the distribution device.

  In the present invention, data is transmitted from the in-vehicle device to the distribution device via the communication line for data transmission from the in-vehicle device to the distribution device, and from the distribution device via the communication line for data distribution from the distribution device to the in-vehicle device. In the situation where data is distributed to the in-vehicle device, the data contents of the storage means possessed by each distribution device are synchronized, so that the data transmitted from the in-vehicle device to the distribution device for storage in each storage means The amount of data can be reduced, and the occurrence of problems such as different contents of data distributed from each distribution device to the in-vehicle device can be prevented.

  In the present invention, when trouble occurs in any of the plurality of distribution devices, or when trouble occurs in any of the communication lines when each distribution device distributes data to the in-vehicle device. Even when data is not distributed from any of the distribution devices, it is possible to distribute data from other distribution devices. Therefore, not only can each vehicle-mounted device ensure the same data received from the distribution device, but if any of the distribution devices fails, the connection between the distribution device and the vehicle-mounted device has occurred. Even in the case where a failure occurs in a part of the system, it is possible to prevent the operation of the entire in-vehicle communication system from being hindered and improve the reliability of the system.

  In the present invention, when data is not distributed from any of the distribution devices, the distribution device notifies the distribution device that the data distribution has been interrupted, so that the distribution device grasps that the data distribution has been interrupted. Even if it is not possible, the distribution process of data from the distribution apparatus can be stopped. Therefore, useless data communication can be prohibited, and the communication load on the communication line where the trouble has occurred can be further reduced.

  In the present invention, when trouble occurs in any of the plurality of distribution devices, or when trouble occurs in any of the communication lines when each in-vehicle device transmits data to the distribution device. Even if the distribution device that should originally receive data from the in-vehicle device becomes unable to receive data, the data is received by another distribution device. The data contents of the storage means possessed by each distribution device are synchronized, and the data received by other distribution devices is stored in the storage means of all distribution devices via other distribution devices. It is possible to prevent the operation of the entire in-vehicle communication system from being hindered and improve the reliability of the system.

  Hereinafter, the present invention will be specifically described with reference to the drawings illustrating embodiments thereof. FIG. 1 is a block diagram showing a configuration of an in-vehicle communication system according to the present invention. The in-vehicle communication system of the present invention includes a plurality of in-vehicle devices 1a, 1b, 1c, 1d, and 1e using an electronic control unit (ECU), an in-vehicle communication line 3a to which the in-vehicle devices 1a and 1b are connected, and an in-vehicle device 1a. , 1b, 1c, 1d, an in-vehicle communication line 3b to which the in-vehicle devices 1c, 1d, 1e are connected, an in-vehicle communication line 3d to which the in-vehicle device 1e is connected, and an in-vehicle communication line 3a , 3b, 3c, and 3d, and distribution devices 2a, 2b, 2c, and 2d, and a communication line 4 that connects the distribution devices 2a, 2b, 2c, and 2d to each other.

  In the present embodiment, the configuration shown in FIG. 1 will be described as an example. However, the number of in-vehicle devices, the number of distribution devices, the number of in-vehicle communication lines, and the like are not limited to these. In addition, white arrows in FIG. 1 show examples of the flow of data transmitted and received between the in-vehicle devices 1a, 1b, 1c, 1d, and 1e and the distribution devices 2a, 2b, 2c, and 2d, respectively. Yes. The data flow will be described later.

  The in-vehicle devices 1a and 1b are respectively connected to the in-vehicle communication line 3a in a bus form, and the in-vehicle devices 1a and 1b and the distribution device 2a connected to the in-vehicle communication line 3a receive the data transmitted to the in-vehicle communication line 3a. Receive in common. The in-vehicle devices 1a, 1b, 1c, and 1d are connected to the in-vehicle communication line 3b in a bus form, and the in-vehicle devices 1a, 1b, 1c, and 1d and the distribution device 2b connected to the in-vehicle communication line 3b are in-vehicle communication. The data transmitted to the line 3b is received in common.

  The in-vehicle devices 1c, 1d, and 1e are connected to the in-vehicle communication line 3c in a bus form, and the in-vehicle devices 1c, 1d, and 1e and the distribution device 2c connected to the in-vehicle communication line 3c transmit to the in-vehicle communication line 3c. The received data is received in common. The in-vehicle device 1e is connected to the in-vehicle communication line 3d in a bus form, and the in-vehicle device 1e and the distribution device 2d connected to the in-vehicle communication line 3d commonly receive the data transmitted to the in-vehicle communication line 3d. .

  The in-vehicle communication lines 3a, 3b, 3c, 3d are communication lines based on the CAN protocol, for example, and the in-vehicle devices 1a, 1b, 1c, 1d, 1e are connected via the in-vehicle communication lines 3a, 3b, 3c, 3d. It is possible to transmit and receive data by generating or detecting a signal based on. The in-vehicle communication lines 3a, 3b, 3c, and 3d used in the in-vehicle communication system of the present invention are not limited to this, and data transmission / reception based on protocols such as LIN (Local Interconnect Network) and FlexRay (registered trademark) is possible. You may comprise. Furthermore, you may comprise in-vehicle communication line 3a, 3b, 3c, 3d from which the speed of transmission / reception differs according to the kind of data transmitted / received.

  The in-vehicle communication lines 3a, 3b, 3c, and 3d based on CAN include two signal lines, detect a differential voltage generated between the signal lines, detect a signal, and receive data. The potentials of the two signal lines are set to the CAN_H level and the CAN_L level, respectively. The state where there is no differential voltage between the two signal lines is “1” of the digital signal, and the state where there is a differential voltage is “ 0 ”. The in-vehicle devices 1a, 1b, 1c, 1d, 1e and the distribution devices 2a, 2b, 2c, 2d connected to the in-vehicle communication lines 3a, 3b, 3c, 3d are respectively in-vehicle communication lines 3a, 3b, 3c, By generating a differential voltage between the 3d signal lines, signals represented by “0” and “1” are generated and data is transmitted.

  The in-vehicle devices 1a, 1b, 1c, 1d, and 1e use electronic control devices, for example, measured values such as temperature, angle, and speed detected by a connected sensor (not shown), calculated values obtained by calculation, Transmission / reception of data including numerical information (data values) of various physical quantities such as control values, or control by a microcomputer such as an engine and a brake is possible. For example, one in-vehicle device 1a is connected to a sensor that detects the vehicle speed, and transmits data including the data value of the vehicle speed detected by the sensor to the connected distribution devices 2a and 2b.

  In CAN, an ID (Identifier) is assigned for each physical quantity. Therefore, the data transmitted and received between the in-vehicle devices 1a, 1b, 1c, 1d, and 1e and the distribution devices 2a, 2b, 2c, and 2d in the present embodiment are the data ID assigned for each physical quantity and the physical quantity. Includes measured values (data values). The in-vehicle devices 1a, 1b, 1c, 1d, 1e and the distribution devices 2a, 2b, 2c, 2d are transmitted from any of the in-vehicle devices 1a, 1b, 1c, 1d, 1e and the distribution devices 2a, 2b, 2c, 2d. Based on the data ID included in the received data, it is possible to determine which of the physical quantities the transmitted data includes data values.

  The distribution devices 2a, 2b, 2c, 2d have storage areas used as databases (hereinafter referred to as DBs) 21a, 21b, 21c, 21d, and are connected to in-vehicle devices 1a, 1b, 1c, 1d, 1e. The data transmitted from is received and stored in DB (storage means) 21a, 21b, 21c, 21d, and the data read from the DBs 21a, 21b, 21c, 21d are connected to the in-vehicle devices 1a, 1b, 1c, Distribute to 1d and 1e.

  The distribution devices 2a, 2b, 2c and 2d are connected by a communication line 4, and the distribution devices 2a, 2b, 2c and 2d can transmit and receive data to and from each other. In the present embodiment, an example in which the communication line 4 is configured by a packet switching network is shown. However, the communication line 4 connecting the distribution devices 2a, 2b, 2c, and 2d of the in-vehicle device communication system of the present invention is not limited to this as long as data can be transmitted and received between the distribution devices 2a, 2b, 2c, and 2d. A communication line based on CAN may be used.

  Also, an in-vehicle communication line 3a connecting the in-vehicle devices 1a, 1b and the distribution device 2a, an in-vehicle communication line 3b connecting the in-vehicle devices 1a, 1b, 1c, 1d and the distribution device 2b, and the in-vehicle devices 1c, 1d, 1e The topology of the in-vehicle communication line 3c for connecting the distribution device 2c, the in-vehicle communication line 3d for connecting the in-vehicle device 1e and the distribution device 2d, and the communication line 4 for connecting the distribution devices 2a, 2b, 2c, 2d is a bus. Any form such as a mold, a star mold, or a daisy chain mold may be used.

  Distribution devices 2a, 2b, 2c, and 2d are also connected to other in-vehicle devices (not shown) via other in-vehicle communication lines (not shown), and connected in-vehicle devices 1a, 1b, and 1c. , 1d, 1e may be transmitted to other in-vehicle devices. In this case, the data to be transmitted to the other in-vehicle devices is not all the data transmitted from the in-vehicle devices 1a, 1b, 1c, 1d, 1e, but only the data necessary for the other in-vehicle devices is DB 21a, 21b, 21c, 21d. The communication load in the in-vehicle communication system is reduced by adopting a configuration in which data is read from and transmitted.

  FIG. 2 is a block diagram showing an internal configuration of the in-vehicle device 1a and the distribution device 2a constituting the in-vehicle communication system of the present invention. Since the in-vehicle devices 1b, 1c, 1d, and 1e have the same internal configuration as the in-vehicle device 1a, detailed description is omitted, and the distribution devices 2b, 2c, and 2d have the same internal configuration as the distribution device 2a. I omit the explanation

  The in-vehicle device 1a includes a control unit 10 that controls the operation of each component described below, a power supply circuit 11 that supplies power to each component, and a volatile memory such as a DRAM (Dynamic Random Access Memory). Unit 12, a first communication unit 13 that controls communication with the in-vehicle communication line 3a, and a second communication unit 14 that controls communication with the in-vehicle communication line 3b. Note that some in-vehicle devices may be connected to one distribution device via a single in-vehicle communication line. In this case, only one of the first communication unit 13 and the second communication unit 14 may be provided. . In addition, some in-vehicle devices may be connected to three or more distribution devices via three or more in-vehicle communication lines. In this case, communication having the same configuration as the first communication unit 13 and the second communication unit 14 It is sufficient to provide as many units as the number of in-vehicle communication lines to be connected.

  The control unit 10 of the in-vehicle device 1a receives power supply from a power supply device (not shown) such as an alternator and a battery of the vehicle via a power supply circuit 11, and reads a control program stored in the storage unit 12. And control the operation of each component.

  The storage unit 12 of the in-vehicle device 1a stores in advance various control programs necessary for operating the in-vehicle device 1a as the in-vehicle device of the in-vehicle communication system according to the present invention. The storage unit 12 temporarily stores various information such as control values and calculation values generated by the processing of the control unit 10. Further, the storage unit 12 stores data IDs that are allocated to physical quantities that the in-vehicle device 1a transmits to the distribution devices 2a and 2b via the in-vehicle communication lines 3a and 3b, and for identifying the physical quantities. The storage unit 12 is a volatile memory, but incorporates a battery (not shown) and holds various information stored therein.

  The first communication unit 13 of the in-vehicle device 1a implements data transmission / reception with the distribution device 2a connected via the in-vehicle communication line 3a. The 2nd communication part 14 implement | achieves transmission / reception of data between the distribution apparatuses 2b connected via the in-vehicle communication line 3b. Specifically, the control unit 10 generates a differential voltage between the signal lines of the in-vehicle communication line 3a (or 3b) via the first communication unit 13 (or the second communication unit 14) and transmits data. The differential voltage between the signal lines is detected to receive data. The control unit 10 of the in-vehicle device 1a acquires data values of various physical quantities by executing a control program stored in the storage unit 12, and adds the data ID stored in the storage unit 12 to the acquired data values. The given data is transmitted from the first communication unit 13 (or the second communication unit 14) to the distribution device 2a (or 2b), for example, at regular intervals of 10 milliseconds.

  The distribution device 2a includes a control unit 20 that controls the operation of each component described below, a power supply circuit 22 that supplies power to each component, a storage unit 23 that includes a volatile memory such as a DRAM, and in-vehicle communication. A first communication unit 25 that controls communication with the line 3 a and a second communication unit 26 that controls communication with the communication line 4 are provided.

  The control unit 20 of the distribution device 2a is supplied with power from a power supply device such as a vehicle alternator or battery via the power supply circuit 22, reads out and executes a control program stored in the storage unit 23, and Control the operation of the unit. Specifically, the control unit 20 stores the data ID and the data value included in the data received from the in-vehicle device 1a in the DB 21a of the storage unit 23 in association with each other.

  The 1st communication part 25 of distribution device 2a realizes transmission and reception of data between in-vehicle devices 1a connected via in-vehicle communication line 3a. The second communication unit 26 implements data transmission / reception with the distribution device 2b (or 2c, 2d) connected via the communication line 4. In the present embodiment, when the control unit 20 of the distribution device 2a transmits data read from the DB 21a from the second communication unit 26 to the distribution device 2b (or 2c, 2d), the data stored in the DB 21a is stored. Among them, only the data updated for each data stored in the DB 21b (or 21c, 21d) of the distribution device 2b (or 2c, 2d) is transferred from the second communication unit 26 to the distribution device 2b (or 2c, 2d). ).

  However, for example, the controller 20 of the distribution device 2a transmits all the data read from the DB 21a to the distribution device 2b (or 2c, 2d), and the control unit of the distribution device 2b (or 2c, 2d) The data stored in the own DB 21b (or 21c, 21d) may be compared, and only the updated data may be updated to the DB 21b (or 21c, 21d). However, in this case, it is necessary to add information for comparing which data is newer data to each data.

  The storage unit 23 of the distribution device 2a stores in advance various control programs necessary for operating the distribution device 2a as a distribution device of the in-vehicle communication system according to the present invention. The storage unit 23 temporarily stores various information generated by the processing of the control unit 20. Further, the storage unit 23 is provided with a storage area for the DB 21a as shown in FIG. 3A, and a transmission information table 24 as shown in FIG. 3B is also stored. Although the storage unit 23 is a volatile memory, a battery (not shown) is built in to hold the stored data.

  FIG. 3 is a schematic diagram showing registration contents of the DB 21a and the transmission information table 24. As shown in FIG. As shown in FIG. 3A, in the DB 21a, the data ID of the data received by the control unit 20 from the in-vehicle devices 1a, 1b and the distribution devices 2b, 2c, 2d and the data value of each data are registered in association with each other. ing. As shown in FIG. 3B, in the transmission information table 24, as the transmission information of each data, the data ID of each data, the distribution cycle when distributing each data, and the transmission destination are registered in association with each other. ing. FIG. 3B shows the transmission information table 24 in which 1g, 1h, and 1i are registered as information for identifying each in-vehicle device in the transmission destination column. The information is not limited to the device, and may be information indicating an in-vehicle communication line.

  In the distribution device 2a configured as described above, when the first communication unit 25 receives data from the in-vehicle devices 1a and 1b, the control unit 20 extracts a data ID and a data value included in the received data. And the control part 20 searches the extracted data ID from the column of data ID of DB21a, and when it can be searched, the data value extracted from data is memorize | stored in the column of the data value corresponding to this data ID. Thereby, the distribution apparatus 2a can update the data value of each data memorize | stored in DB21a sequentially based on the data sequentially transmitted from the vehicle equipment 1a, 1b.

  Here, the in-vehicle devices 1a, 1b, 1c, 1d, and 1e and the distribution devices 2a, 2b, 2c, and 2d in the present embodiment have synchronized timers and operate in synchronization based on a shared cycle. Therefore, the control unit 10 of the in-vehicle devices 1a, 1b, 1c, 1d, and 1e and the control unit 20 of the distribution devices 2a, 2b, 2c, and 2d each function as a timer according to a built-in clock (not shown).

  The control unit 20 measures each distribution cycle registered in the transmission information table 24, and reads the corresponding data ID and transmission destination from the transmission information table 24 each time each distribution cycle elapses. Then, the control unit 20 reads the data value of the data indicated by the read data ID from the DB 21a, and transmits the data including the data ID and the data value from the first communication unit 25a to the transmission destination read from the transmission information table 24. . Thereby, the distribution apparatus 2a can distribute each data to a preset transmission destination in each distribution cycle according to each transmission information registered in the transmission information table 24.

  Further, the control unit 20 exchanges data by transmitting and receiving data stored in the DBs 21a, 21b, 21c, and 21d between the other distribution devices 2b, 2c, and 2d at predetermined intervals. , DB 21a, 21b, 21c, 21d data contents are synchronized. In this embodiment, the procedure for synchronizing the data contents of the DBs 21a, 21b, 21c, and 21d is not limited. After the synchronization process is executed every predetermined cycle, the contents of the DBs 21a, 21b, 21c, and 21d of the distribution devices 2a, 2b, 2c, and 2d are all synchronized.

  Thus, based on the latest data sequentially transmitted from the in-vehicle devices 1a, 1b, 1c, 1d, and 1e, the data of the DBs 21a, 21b, 21c, and 21d of the distribution devices 2a, 2b, 2c, and 2d are sequentially updated. Since the data in the DBs 21a, 21b, 21c, and 21d are synchronized at a predetermined cycle, the data is distributed from the distribution devices 2a, 2b, 2c, and 2d to the in-vehicle devices 1a, 1b, 1c, 1d, and 1e. Data identity can be ensured.

  Here, in the in-vehicle communication system of the present invention, when each of the in-vehicle devices 1a, 1b, 1c, 1d, and 1e is connected to the plurality of distribution devices 2a, 2b, 2c, and 2d, the in-vehicle device is changed to the distribution device. An in-vehicle communication line for transmitting data and an in-vehicle communication line for distributing data from the distribution device to the in-vehicle device are set in advance. As a result, the data transmission / reception is performed on all the in-vehicle communication lines 3a, 3b, 3c, 3d connecting the in-vehicle devices 1a, 1b, 1c, 1d, 1e and the distribution devices 2a, 2b, 2c, 2d. Thus, the amount of data transmitted and received via the in-vehicle communication lines 3a, 3b, 3c, 3d can be reduced.

  In the present embodiment, as indicated by white arrows in FIG. 1, the in-vehicle communication line 3a is a communication line for the in-vehicle devices 1a and 1b to transmit data to the distribution device 2a, and the in-vehicle communication line 3b is The distribution device 2b is a communication line for distributing data to the in-vehicle devices 1a, 1b, 1c, and 1d. The in-vehicle communication line 3c is a communication line for the in-vehicle devices 1c, 1d, and 1e to transmit data to the distribution device 2c, and the in-vehicle communication line 3d is for the distribution device 2d to distribute data to the in-vehicle device 1e. Communication line.

  Therefore, in the present embodiment, in the in-vehicle device 1a, the first communication unit 13 only transmits data via the in-vehicle communication line 3a, and the second communication unit 14 transmits data via the in-vehicle communication line 3b. Perform receive only. In the distribution device 2a, the first communication unit 25 only receives data via the in-vehicle communication line 3a.

  Although not shown, the first communication unit of the in-vehicle device 1b is connected to the in-vehicle communication line 3a and executes only data transmission via the in-vehicle communication line 3a, and the second communication unit is connected to the in-vehicle communication line 3a. It is connected to 3b and only receives data via the in-vehicle communication line 3b. The first communication unit of the in-vehicle devices 1c and 1d is connected to the in-vehicle communication line 3c, and only transmits data via the in-vehicle communication line 3c, and the second communication unit is connected to the in-vehicle communication line 3b, Only data reception via the communication line 3b is executed. The first communication unit of the in-vehicle device 1e is connected to the in-vehicle communication line 3c, and only transmits data via the in-vehicle communication line 3c. The second communication unit is connected to the in-vehicle communication line 3d, and the in-vehicle communication line Only receive data via 3d.

  Furthermore, although not shown in figure, the 1st communication part of distribution device 2b performs only transmission of data via in-vehicle communication line 3b, and the 1st communication part of distribution device 2c is in-vehicle communication line 3c. Only the data reception is performed, and the first communication unit of the distribution device 2d only executes the data transmission via the in-vehicle communication line 3d.

  In the storage unit 12 of the in-vehicle devices 1a, 1b, 1c, 1d, and 1e, data to be transmitted to the distribution devices 2a, 2b, 2c, and 2d is transmitted via the first communication unit 13, and the distribution devices 2a, Information indicating that data received from 2b, 2c, and 2d is received via the second communication unit 14 is stored.

  With the configuration described above, in the in-vehicle communication system according to the present embodiment, the in-vehicle devices 1a, 1b, 1c, 1d, and 1e are distributed to the distribution devices 2a and 2c via the in-vehicle communication lines (first communication lines) 3a and 3c, respectively. The distribution devices 2a and 2c transmit the data, and sequentially store the data received via the in-vehicle communication lines 3a and 3c in the DBs 21a and 21c. The distribution devices 2b and 2d distribute the data stored in the DBs 21b and 21d to the in-vehicle devices 1a, 1b, 1c, 1d, and 1e via the in-vehicle communication lines (second communication lines) 3b and 3d, respectively. The in-vehicle devices 1a, 1b, 1c, 1d, and 1e receive data via the in-vehicle communication lines 3b and 3d, respectively.

  Here, the control unit 10 of the in-vehicle devices 1a, 1b, 1c, 1d, and 1e interrupts communication with the distribution devices 2a, 2b, 2c, and 2d connected via the in-vehicle communication lines 3a, 3b, 3c, and 3d. Is configured to detect. As a method for the control unit 10 of the in-vehicle devices 1a, 1b, 1c, 1d, and 1e to detect the interruption of communication with the distribution devices 2a, 2b, 2c, and 2d, for example, in-vehicle communication lines 3a, 3b, 3c, and 3d are used. That the alive packet is transmitted / received at a predetermined period to / from the distribution devices 2a, 2b, 2c, 2d connected via the communication device, and the communication is interrupted when the transmission / reception of the alive packet is interrupted for a predetermined time or more. There is a way to detect.

  In addition, when the control unit 10 of the in-vehicle devices 1a, 1b, 1c, 1d, and 1e transmits data via the in-vehicle communication lines 3a, 3b, 3c, and 3d, for example, a transmission buffer (see FIG. (Not shown) is configured to store each data, and when the data transmission order has come, the data stored in the transmission buffer is sequentially transmitted, and after transmitting the data, the data in the transmission buffer is erased. ing. Therefore, the control unit 10 of the in-vehicle devices 1a, 1b, 1c, 1d, and 1e can detect that the communication is interrupted when the data in the transmission buffer is not reduced. This method can detect the interruption of communication via the in-vehicle communication lines 3a and 3c in which data is transmitted from the in-vehicle devices 1a, 1b, 1c, 1d, and 1e to the distribution devices 2a and 2c.

  Further, when the control unit 10 of the in-vehicle devices 1a, 1b, 1c, 1d, and 1e cannot receive data through the in-vehicle communication lines 3a, 3b, 3c, and 3d for a predetermined time or more, specifically, the second communication unit If the differential voltage between the signal lines cannot be detected by 14, it is possible to detect that communication has been interrupted. In this method, the on-vehicle devices 1a, 1b, 1c, 1d, and 1e can detect communication interruption via the in-vehicle communication lines 3b and 3d that receive data from the distribution devices 2b and 2d.

  Hereinafter, as described above, when communication between the in-vehicle devices 1a, 1b, 1c, 1d, and 1e and the distribution devices 2a, 2b, 2c, and 2d is interrupted, the in-vehicle devices 1a, 1b, 1c, 1d, and 1e perform. Processing will be described. FIG. 4 is an explanatory diagram for explaining processing when communication between the in-vehicle devices 1a, 1b, 1c, 1d, and 1e and the distribution devices 2a, 2b, 2c, and 2d is interrupted. For simplification of description, only data transmission / reception between the in-vehicle device 1a and the distribution devices 2a and 2b will be described.

  In the present embodiment, the in-vehicle device 1a normally transmits data to the distribution device 2a via the in-vehicle communication line 3a, and receives data from the distribution device 2b via the in-vehicle communication line 3b. As shown in FIG. 4 (a), when some trouble occurs in the in-vehicle communication line 3a or the distribution device 2a, and data cannot be transmitted from the in-vehicle device 1a to the distribution device 2a via the in-vehicle communication line 3a, the in-vehicle device 1a switches processing so that the data transmitted to the distribution device 2a via the in-vehicle communication line 3a is transmitted to the distribution device 2b via the in-vehicle communication line 3b.

  Specifically, when the control unit 10 of the in-vehicle device 1a cannot transmit data from the first communication unit 13 to the distribution device 2a through the in-vehicle communication line 3a, the second communication unit through the in-vehicle communication line 3b. 14 transmits data to the distribution device 2b. That is, transmission / reception of data via the in-vehicle communication line 3b is started between the in-vehicle device 1a and the distribution device 2b.

  Also, as shown in FIG. 4 (b), when some trouble occurs in the in-vehicle communication line 3b or the distribution device 2b, the in-vehicle device 1a cannot receive data from the distribution device 2b via the in-vehicle communication line 3b. The in-vehicle device 1a switches the process so that the data received from the distribution device 2b via the in-vehicle communication line 3b is received from the distribution device 2a via the in-vehicle communication line 3a.

  Specifically, when the control unit 10 of the in-vehicle device 1a cannot receive the data from the distribution device 2b via the in-vehicle communication line 3b by the second communication unit 14, the control unit 10 of the data received from the distribution device 2b A transmission request signal for requesting transmission is generated and transmitted to the distribution device 2a via the in-vehicle communication line 3a. The transmission request signal includes the data ID of data requesting transmission, the distribution cycle, and identification information of the in-vehicle device 1a as the transmission destination. The control unit 20 of the distribution device 2a that has received such a transmission request signal extracts the data ID, the distribution cycle, and the transmission destination from the received transmission request signal, and registers them in the transmission information table 24 of the storage unit 23.

  Since the control unit 20 of the distribution device 2a transmits the data including the corresponding data ID and data value to the corresponding transmission destination each time the distribution cycle elapses according to the registered content of the transmission information table 24, the in-vehicle device The control unit 10 of 1a can receive data normally received from the distribution device 2b via the in-vehicle communication line 3b from the distribution device 2a via the in-vehicle communication line 3a. That is, transmission / reception of data via the in-vehicle communication line 3a is started between the in-vehicle device 1a and the distribution device 2a.

  Since the data in the DBs 21a, 21b, 21c, and 21d of the distribution devices 2a, 2b, 2c, and 2d are synchronized every predetermined period, each on-vehicle device 1a, 1b, 1c, 1d, and 1e is any distribution device. Even when data is transmitted to 2a, 2b, 2c, and 2d, the same data is stored in each DB 21a, 21b, 21c, and 21d.

  Therefore, in the in-vehicle communication system of the present invention, when any trouble occurs in any of the distribution devices 2a, 2b, 2c, 2d, or the in-vehicle communication line to which each of the distribution devices 2a, 2b, 2c, 2d is connected. Even when a failure occurs in a part of the in-vehicle communication system, such as when any trouble occurs in any of 3a, 3b, 3c, and 3d, in-vehicle communication lines 3a and 3b in which communication is not interrupted. , 3c, 3d, data is transmitted from the in-vehicle devices 1a, 1b, 1c, 1d, 1e to the distribution devices 2a, 2b, 2c, 2d, and the in-vehicle devices 1a, 1b, 2d from the distribution devices 2a, 2b, 2c, 2d, Since the data is distributed to 1c, 1d, and 1e, it is possible to prevent the operation of the entire in-vehicle communication system from being hindered and improve the reliability of the system.

  Below, the process which the vehicle-mounted apparatus 1a performs when the vehicle-mounted apparatus 1a detects the interruption of communication with the distribution apparatus 2a via the in-vehicle communication line 3a is demonstrated based on a flowchart. FIG. 5 is a flowchart showing a processing procedure when the in-vehicle device 1a detects a communication interruption with the distribution device 2a. Since the same processing is performed when the in-vehicle devices 1b, 1c, 1d, and 1e detect the disconnection of communication with the distribution devices 2a and 2c via the in-vehicle communication lines 3a and 3c, detailed description is omitted. .

  The control unit 10 of the in-vehicle device 1a detects the interruption of transmission of the data output from the first communication unit 13 to the distribution device 2a while performing a normal operation (S1), and does not detect the transmission interruption ( S1: NO), normal operation is continued. When the transmission interruption is detected (S1: YES), the control unit 10 stores information stored in the storage unit 12 and indicating that the data to be transmitted to the distribution device is transmitted via the first communication unit 13. The data to be transmitted to the distribution device is changed to information indicating that the data is transmitted via the second communication unit 14, and the transmission destination when transmitting the data is changed from the distribution device 2a to the distribution device 2b (S2).

  Hereinafter, processing performed by the in-vehicle device 1a and the distribution device 2a when the in-vehicle device 1a detects the interruption of communication with the distribution device 2b via the in-vehicle communication line 3b will be described based on a flowchart. FIG. 6 is a flowchart showing a processing procedure when the in-vehicle device 1a detects a communication interruption with the distribution device 2b. Even when the in-vehicle devices 1b, 1c, 1d, and 1e detect the disconnection of communication with the distribution devices 2b and 2d through the in-vehicle communication lines 3b and 3d, the in-vehicle devices 1b, 1c, 1d, and 1e and the distribution device are detected. Since 2a and 2c perform the same processing, detailed description is omitted.

  When the control unit 10 of the in-vehicle device 1a performs the normal operation, the interruption of the reception by the second communication unit 14 of the data distributed from the distribution device 2b is detected (S11), and the reception interruption is not detected (S11: NO), normal operation is continued. When reception interruption is detected (S11: YES), the control unit 10 generates a transmission request signal including the data ID, distribution period, and transmission destination of the data received from the distribution device 2b, and the generated transmission request signal Is transmitted from the first communication unit 13 to the distribution device 2a (S12).

  The control unit 20 of the distribution device 2a receives the transmission request signal transmitted from the in-vehicle device 1a (S13), extracts the data ID, the distribution cycle, and the transmission destination from the received transmission request signal, and transmits the information including these information. The information is registered in the transmission information table 24 of the storage unit 23 (S14). Thereby, the distribution apparatus 2a distributes each data to the transmission destination corresponding to each distribution period based on not only the transmission information registered in advance in the transmission information table 24 but also the newly registered transmission information. can do.

  Hereinafter, a synchronization process performed by the distribution apparatus 2a at predetermined intervals and a data distribution process performed based on the registered contents of the transmission information table 24 will be described with reference to flowcharts. FIG. 7 is a flowchart showing a processing procedure of normal operation of the distribution apparatus 2a. Since the distribution devices 2b, 2c, and 2d perform the same processing, detailed description thereof is omitted.

  The control unit 20 of the distribution device 2a functions as a timer, and data stored in the DB 21a of the storage unit 23 and data stored in the DBs 21b, 21c, and 21d of the other distribution devices 2b, 2c, and 2d. It is determined whether or not a predetermined period when synchronizing with the elapse of time (S21). When it is determined that the predetermined period has passed (S21: YES), the control unit 20 executes a synchronization process (S22). Specifically, the control unit 20 updates the latest data updated with respect to the data of the DBs 21b, 21c, and 21d of the other distribution devices 2b, 2c, and 2d among the data of the DB 21a to the other distribution devices 2b, 2c and 2d.

  When it is determined that the predetermined period has not elapsed (S21: NO), the control unit 20 skips the process of step S22 and determines whether the distribution period of each data registered in the transmission information table 24 has elapsed. Is determined (S23). When it is determined that the distribution cycle has passed (S23: YES), the control unit 20 reads the corresponding data ID and transmission destination from the transmission information table 24 (S24). Then, the control unit 20 reads the data value corresponding to the data ID from the DB 21a (S25), and transmits the data including the data ID and the data value from the first communication unit 25 to the transmission destination read from the transmission information table 24 ( S26). When it is determined that the distribution cycle has not elapsed (S23: NO), the control unit 20 skips the processes of steps S24 to S26.

  The control unit 20 determines whether or not the end of the above-described process has been instructed, for example, when the supply of power from the power supply circuit 22 has ended (S27), and when the end of the process has been instructed (S27: YES), the above-described process is terminated, and if the end of the process is not instructed (S27: NO), the process returns to step S21, and the above-described process is repeated until the end of the process is instructed.

  As described above, in the in-vehicle communication system of the present invention, each in-vehicle device is connected to two distribution devices via two in-vehicle communication lines, and in-vehicle communication for data transmission from the in-vehicle device to the distribution device. When communication via the line is interrupted, the data is transmitted from the in-vehicle device to the distribution device by transmitting / receiving data via the other in-vehicle communication line, that is, the in-vehicle communication line for data distribution from the distribution device to the in-vehicle device. Data to be transmitted can be reliably transmitted to the distribution device. In addition, when communication via the in-vehicle communication line for data distribution from the distribution device to the in-vehicle device is interrupted, the other in-vehicle communication line, that is, via the in-vehicle communication line for data transmission from the in-vehicle device to the distribution device. By transmitting and receiving data, data to be distributed from the distribution device to the in-vehicle device can be reliably transmitted to the in-vehicle device.

  The data distributed by the distribution devices 2a, 2b, 2c, and 2d to the in-vehicle devices 1a, 1b, 1c, 1d, and 1e is synchronized at predetermined intervals among the DBs 21a, 21b, 21c, and 21d. The in-vehicle devices 1a, 1b, 1c, 1d, and 1e can acquire the same data from any of the distribution devices 2a, 2b, 2c, and 2d. Therefore, even if communication via any of the in-vehicle communication lines 3a, 3b, 3c, 3d is interrupted, the operation of the entire in-vehicle communication system is not hindered.

  In the above-described embodiment, the in-vehicle devices 1a, 1b, 1c, 1d, and 1e have been described as being connected to the two distribution devices 2a, 2b, 2c, and 2d. The configuration is not limited to this. For example, one in-vehicle device is connected to each of three distribution devices via three in-vehicle communication lines, and communication for data transmission from the in-vehicle device to the distribution device via two of the three in-vehicle communication lines. A configuration may be adopted in which a line is used, and the remaining one is a communication line for data distribution from the distribution device to the in-vehicle device.

  Further, in the in-vehicle devices 1a, 1b, 1c, 1d, and 1e having the above-described configuration, the control unit 10 detects the interruption of reception of data distributed from the distribution devices 2b and 2d via the in-vehicle communication lines 3b and 3d. In this case, the distribution devices 2b and 2d may be configured to notify that the data distribution has been interrupted. For example, when distribution of data from the distribution device 2b is interrupted, the control unit 10 of the in-vehicle device 1a transmits a transmission request signal to the distribution device 2a, so that the control unit 20 of the distribution device 2a receives the signal from the distribution device 2b. It is possible to grasp that the distribution of data has been interrupted. Therefore, the control unit 20 of the distribution device 2a may transmit information indicating that data distribution has been interrupted to the distribution device 2b via the communication line 4.

  As a result, even if the distribution devices 2b and 2d cannot grasp that the distribution of data via the in-vehicle communication lines 3b and 3d is interrupted, the data from the distribution devices 2b and 2d whose data distribution has been interrupted Since the distribution process can be stopped, useless data communication can be prohibited, and the communication load on the communication line where the trouble has occurred can be further reduced.

  Each distribution device 2a, 2b, 2c, 2d knows to which in-vehicle device 1a, 1b, 1c, 1d, 1e each distribution device 2a, 2b, 2c, 2d distributes data. When the distribution of data from the distribution device 2b is interrupted, the control unit 20 of the distribution device 2a simply transmits information indicating that the distribution of data is interrupted to the distribution device 2b via the communication line 4. Alternatively, it may be transmitted to other distribution devices 2c and 2d.

It is a block diagram which shows the structure of the vehicle-mounted communication system which concerns on this invention. It is a block diagram which shows the internal structure of the vehicle equipment and distribution device which comprise the vehicle-mounted communication system of this invention. It is a schematic diagram which shows the registration content of DB and a transmission information table. It is explanatory drawing for demonstrating the process when communication with a vehicle-mounted apparatus and a distribution device stops. It is a flowchart which shows the process sequence when a vehicle-mounted apparatus detects the interruption of communication with a distribution apparatus. It is a flowchart which shows the process sequence when a vehicle-mounted apparatus detects the interruption of communication with a distribution apparatus. It is a flowchart which shows the process sequence of normal operation | movement of a distribution apparatus.

Explanation of symbols

1a, 1b, 1c, 1d, 1e On-vehicle device 2a, 2b, 2c, 2d Distribution device 21a, 21b, 21c, 21d DB (storage means)
3a, 3b, 3c, 3d In-car communication line

Claims (5)

An in-vehicle communication system in which a plurality of in-vehicle devices that transmit and receive data, a storage unit that receives and stores data from the in-vehicle devices, and a plurality of distribution devices that have means for distributing the stored data to the in-vehicle devices are connected Because
The in-vehicle device is
Connected to the plurality of distribution devices via a first communication line or a second communication line,
Means for transmitting data to a distribution device connected via the first communication line;
Means for receiving data from a distribution device connected via the second communication line,
The distributor is
When connected to the first communication line, it is configured to store the data received via the first communication line in the storage means;
When connected to the second communication line, the vehicle-mounted communication system is configured to distribute data to the vehicle-mounted device via the second communication line. The distributor is
Means for transmitting data stored in the storage means to another distribution device;
The vehicle-mounted communication system according to claim 1, further comprising: means for storing data transmitted from another distribution device in the storage means. The in-vehicle device is
Means for detecting interruption of communication with a distribution device connected via the second communication line;
When a communication interruption is detected, a data transmission request received via the second communication line from the distribution apparatus with the communication interruption is transmitted to the distribution apparatus connected via the first communication line. Means and
The in-vehicle communication according to claim 2, wherein the distribution device that has received the transmission request is configured to distribute data based on the transmission request to the in-vehicle device via the first communication line. system.   The in-vehicle device, when detecting a communication interruption with the distribution device connected via the second communication line, means for notifying the distribution device that the communication via the second communication line has been interrupted. The in-vehicle communication system according to claim 3, further comprising: The in-vehicle device is
Means for detecting disruption of communication with the distribution device connected via the first communication line;
Means for transmitting data transmitted via the first communication line to the distribution device for which communication has been interrupted, to the distribution device connected via the second communication line when communication interruption is detected; The in-vehicle communication system according to any one of claims 2 to 4, further comprising:

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