JP2022085574A - In-vehicle communication device, in-vehicle communication system, and in-vehicle communication method - Google Patents

Abstract

To provide an in-vehicle communication device, an in-vehicle communication system, and an in-vehicle communication method that can be expected to improve communication reliability by using a plurality of communication paths provided between a plurality of devices.SOLUTION: An in-vehicle communication device according to an embodiment is connected to another device via a plurality of communication paths and transmits/receives a data frame containing a plurality of pieces of data via the communication paths. Priority is given to the data according to data types. The in-vehicle communication device includes: a processing unit that detects a communication load of the communication path and generates a plurality of data frames to which the plurality of pieces of data included in a data frame to be transmitted to the other device according to the communication load are distributed according to the priority; and a transmission unit that transmits the plurality of data frames generated by the processing unit to the other device via the respective different communication paths.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to an in-vehicle communication device, an in-vehicle communication system, and an in-vehicle communication method for communicating with other devices mounted on a vehicle.

In Patent Document 1, the electronic control unit that communicates with the main electronic control unit is connected to the main electronic control unit when the first communication line between the plurality of external devices is in a predetermined state. A communication method for communicating with the main electronic control unit via a second communication line has been proposed.

Japanese Unexamined Patent Publication No. 2016-86256

In the communication method described in Patent Document 1, the main electronic control unit and the sub electronic control unit switch between the first communication line and the second communication line according to the communication load to perform communication. The data transmitted / received between the main electronic control unit and the sub electronic control unit mounted on the vehicle includes, for example, highly important data related to the behavior or running of the vehicle. When the communication method or communication speed differs between the first communication line and the second communication line, and switching from a fast communication line to a slow communication line is performed, processing using highly important data becomes difficult. There is a risk.

The present disclosure has been made in view of such circumstances, and the purpose of the present disclosure is expected to improve the reliability of communication by utilizing a plurality of communication paths provided between a plurality of devices. It is an object of the present invention to provide an in-vehicle communication device, an in-vehicle communication system, and an in-vehicle communication method that can be used.

The in-vehicle communication device according to this embodiment is an in-vehicle communication device that is connected to another device via a plurality of communication paths and transmits / receives a data frame containing a plurality of data via the communication path. , The priority is given according to the data type, and the communication load of the communication path is detected, and a plurality of data included in the data frame to be transmitted to the other device according to the communication load are given according to the priority. A processing unit that generates a plurality of distributed data frames and a transmission unit that transmits the plurality of data frames generated by the processing unit to the other device via different communication paths are provided.

The present application can be realized not only as a device provided with such a characteristic control unit, but also as a method of performing such a characteristic process as a step, or as a computer program for causing a computer to execute such a step. It can be realized. It can be realized as a semiconductor integrated circuit that realizes a part or all of these devices, or can be realized as another device or system including these devices.

According to the above, it can be expected to improve the reliability of communication by using a plurality of communication paths.

It is a schematic diagram for demonstrating the outline of the in-vehicle communication system which concerns on this embodiment. It is a block diagram which shows the structure of the sub ECU which concerns on this embodiment. It is a schematic diagram which shows an example of a priority table. It is a schematic diagram which shows an example of a distribution table. It is a schematic diagram for demonstrating an example of data distribution. It is a flowchart which shows the procedure of the transmission processing performed by the sub-ECU which concerns on this embodiment. It is a flowchart which shows the procedure of the data distribution processing performed by the sub-ECU which concerns on this embodiment. It is a flowchart which shows the procedure of the reception processing performed by the sub-ECU which concerns on this embodiment. It is a schematic diagram which shows an example of the distribution table of the in-vehicle communication system which concerns on the modification.

[Explanation of Embodiments of the present disclosure]
First, embodiments of the present disclosure will be listed and described. At least a part of the embodiments described below may be arbitrarily combined.

(1) The in-vehicle information processing device according to this embodiment is an in-vehicle communication device that is connected to another device via a plurality of communication paths and transmits / receives a data frame containing a plurality of data via the communication path. The data is prioritized according to the data type, and a plurality of data included in a data frame that detects the communication load of the communication path and transmits the communication load to the other device according to the communication load. It includes a processing unit that generates a plurality of data frames distributed according to priority, and a transmission unit that transmits the plurality of data frames generated by the processing unit to the other device via different communication paths.

In this embodiment, the vehicle-mounted communication device is connected to another device via a plurality of communication paths, and the vehicle-mounted communication device connects a data frame containing a plurality of data to the other device via these communication paths. Send and receive with. The data included in the data frame transmitted / received by the in-vehicle communication device is given a priority in advance according to the data type. The in-vehicle communication device detects the communication load of the communication path and generates and generates a plurality of data frames in which a plurality of data included in the data frames transmitted to other devices according to the communication load are distributed according to the priority. Multiple data frames are transmitted to other devices via different communication paths. As a result, the in-vehicle communication device can transmit and receive data via a plurality of communication paths in consideration of the communication load and the priority of the data.

(2) When the other device is connected via two communication paths, the processing unit detects the communication load of the first communication path, and the communication load of the first communication path exceeds the threshold value. Generates two data frames in which a plurality of data included in the data frames transmitted to the other device are distributed into two, and the transmission unit uses the first data frame generated by the processing unit as the first data frame. It is preferable to transmit to the other device via the communication path of the above, and to transmit the second data frame generated by the processing unit to the other device via the second communication path.

In this aspect, the vehicle-mounted communication device is connected to another device via two communication paths. The in-vehicle communication device detects the communication load of the first communication path, and when the detected communication load exceeds the threshold value, the two devices distribute a plurality of data included in the data frame to be transmitted to another device into two. Generate a data frame. The in-vehicle communication device transmits the first data frame to another device via the first communication path, and transmits the second data frame to the other device via the second communication path. As a result, the in-vehicle communication device can transmit and receive data via the two communication paths in consideration of the communication load of the first communication path and the priority of the data.

(3) When the communication load of the first communication path does not exceed the threshold value, it is preferable that the transmission unit transmits a data frame to the other device via the first communication path.

In this embodiment, if the communication load of the first communication path does not exceed the threshold value, the in-vehicle communication device sets the data frame to another device via the first communication path without distributing the data. Send to. As a result, when the communication load is low, the in-vehicle communication device does not need to perform the process of distributing the data to generate a plurality of data frames, and the processing load can be expected to be reduced.

(4) The processing unit includes the high-priority data in the first data frame transmitted from the first communication path, and the low-priority data is transmitted from the second communication path. It is preferable to distribute a plurality of data to generate two data frames so as to be included in the two data frames.

In this embodiment, the vehicle-mounted communication device includes the high-priority data in the first data frame transmitted from the first communication path, and transmits the low-priority data from the second communication path. A plurality of data contained in a data frame transmitted to another device are distributed to a first data frame or a second data frame so as to be included in the data frame of. By properly using the two communication paths according to the high and low priorities, it can be expected that the in-vehicle communication device properly uses the communication paths according to the priority, for example, when the communication speeds of the two communication paths are different.

(5) The processing unit sets two data frames so that the higher the communication load of the first communication path, the more data is included in the second data frame transmitted from the second communication path. It is preferable to generate it.

In this embodiment, the in-vehicle communication device includes two data frames so that the higher the communication load of the first communication path, the more data is included in the second data frame transmitted from the second communication path. Generate. This can be expected to reduce the communication load of the first communication path.

(6) The communication speed of the first communication path is preferably faster than the communication speed of the second communication path.

In this embodiment, the communication speed of the first communication path is faster than the communication speed of the second communication path. By providing a difference in communication speed between the two communication paths, it can be expected that the cost of the in-vehicle communication system will be reduced as compared with the configuration in which the two communication paths both perform high-speed communication.

(7) A storage unit for storing correspondence information between the priority attached to the data and the communication path for transmitting the data frame including the data is provided, and the processing unit includes the correspondence information stored in the storage unit and reception. It is preferable to determine the data contained in the data frame according to the data length of the data frame.

In this embodiment, the in-vehicle communication device stores corresponding information such as a table in which the priority attached to the data and the communication path for transmitting the data frame including this data are associated with each other. When the in-vehicle communication device receives a data frame via a plurality of communication paths, one or a plurality of data contained in this data frame depends on the stored correspondence information and the data length of the received data frame. To determine. As a result, when data is distributed to a plurality of data frames according to the communication load and transmitted / received, which data is included in the received data frame without detecting the communication load on the receiving side. Can be determined.

(8) The in-vehicle communication system according to this aspect includes a plurality of in-vehicle communication devices connected via a plurality of communication paths, and each in-vehicle communication device transmits / receives a data frame containing a plurality of data via the communication path. In the vehicle-mounted communication system, the data is prioritized according to the data type, the vehicle-mounted communication device detects the communication load of the communication path, and another vehicle-mounted communication system is used according to the communication load. The processing unit that generates a plurality of data frames in which a plurality of data included in the data frames transmitted to the apparatus are distributed according to the priority, and the plurality of data frames generated by the processing unit are transmitted via different communication paths. It has a transmitter for transmitting to another device.

In this aspect, as in the aspect (1), data can be transmitted / received via a plurality of communication paths in consideration of the communication load and the priority of the data.

(9) The in-vehicle communication method according to this aspect is an in-vehicle communication method in which an in-vehicle communication device connected to another device via a plurality of communication paths transmits / receives a data frame containing a plurality of data via the communication path. Therefore, the data is prioritized according to the data type, and the communication load of the communication path is detected, and the data frame is transmitted to the other device according to the detected communication load. A plurality of data frames in which a plurality of included data are distributed according to priority are generated, and the generated plurality of data frames are transmitted to the other device via different communication paths.

In this aspect, as in the aspect (1), data can be transmitted / received via a plurality of communication paths in consideration of the communication load and the priority of the data.

[Details of Embodiments of the present disclosure]
Specific examples of the in-vehicle communication system according to the embodiment of the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to these examples, but is shown by the scope of claims and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

<System configuration>
FIG. 1 is a schematic diagram for explaining an outline of an in-vehicle communication system according to the present embodiment. The in-vehicle communication system according to the present embodiment is configured to include one or a plurality of main ECUs (Electronic Control Units) 2 mounted on the vehicle 1, a plurality of sub-ECUs 3, and a plurality of control targets 4. .. The main ECU 2 and the plurality of sub-ECUs 3 are connected via two communication lines of the first bus 5 and the second bus 6, and communication can be performed via either bus. In the illustrated example, the vehicle-mounted communication system includes one main ECU 2 and two sub-ECUs 3, and one control target 4 is connected to each sub-ECU 3 via a control signal line or the like.

The controlled object 4 is various devices such as a motor, an actuator, a light, or a sensor. The sub ECU 3 sends and receives signals to and from the control target 4 via a control signal line or the like, and controls the operation of the control target 4. The sub-ECU 3 transmits a data frame including data such as a control result of the controlled object 4 to the main ECU 2 or another sub-ECU 3 via the first bus 5 or the second bus 6. The main ECU 2 receives a data frame transmitted by each sub-ECU 3, and performs overall travel control of the vehicle 1 based on one or a plurality of data included in the received data frame. The main ECU 2 transmits a data frame including data such as a control command to the sub ECU 3 via the first bus 5 or the second bus 6. The sub-ECU 3 receives the data frame transmitted by the main ECU 2, and controls the operation of the controlled object 4 based on the data such as the control command included in the received data frame.

In the in-vehicle communication system according to the present embodiment, one or a plurality of data may be included in the data frame transmitted / received between the main ECU 2 and the sub ECU 3. Each sub-ECU 3 generates a data frame containing one or more data to be transmitted to the main ECU 2 or another sub-ECU 3, and transfers the data frame to the first bus 5 or the second bus 6 at a predetermined cycle. Send by outputting. The data included in the data frame is, for example, information such as a sensor detection value or a control value of a motor or the like, but the data included in the data frame is not limited to these information and may be any information. .. For example, as the data of the data frame, a data frame transmitted / received by another communication protocol may be stored.

Further, in the information processing system according to the present embodiment, the main ECU 2 and the sub ECU 3 are connected by two communication lines, the first bus 5 and the second bus 6. The main ECU 2 and the sub ECU 3 can transmit and receive data frames by using either the first bus 5 or the second bus 6. However, in the information processing system according to the present embodiment, communication characteristics such as communication speed are different between the communication performed via the first bus 5 and the communication performed via the second bus 6. In the information processing system according to the present embodiment, for example, high-speed communication by the communication protocol of CAN (Controller Area Network) is performed via the first bus 5, and low-speed communication by the communication protocol of LIN (Local Interconnect Network) is second. It is done via bus 6. However, the communication protocol is an example and is not limited to this, and a communication protocol different from CAN or LIN may be adopted. Further, communication may be performed by the same communication protocol on the two buses, and in this case, some communication characteristics such as communication speed are different.

In the present embodiment, the sub-ECU 3 normally transmits a data frame to the main ECU 2 via the first bus 5, but when the communication load of the first bus 5 increases, the first bus 5 and the sub-ECU 3 A data frame is transmitted to the main ECU 2 using both of the second buses 6. In the present embodiment, priorities are predetermined for a plurality of data to be transmitted / received included in the data frame. When the sub ECU 3 transmits data using both the first bus 5 and the second bus 6 due to an increase in the communication load, the sub ECU 3 transmits a data frame containing high priority data from the first bus 5 and has a priority. A data frame containing low data is transmitted from the second bus 6.

FIG. 2 is a block diagram showing a configuration of the sub ECU 3 according to the present embodiment. Note that this figure illustrates the functional parts related to the communication function common to the plurality of sub ECUs 3 included in the information processing system, and omits the illustration of the functional parts related to other functions, for example, the control function of the controlled object 4. Further, although the configuration of the sub ECU 3 is shown in this figure, since the communication function of the main ECU 2 is the same as that of the sub ECU 3, the block diagram and the description thereof regarding the main ECU 2 are omitted.

The sub-ECU 3 according to the present embodiment includes a processing unit (processor) 31, a storage unit (storage) 32, a CAN communication unit 33, a LIN communication unit 34, a communication load detection unit 35, and the like. The processing unit 31 is configured by using an arithmetic processing unit such as a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit). The processing unit 31 can perform various processes by reading and executing the program stored in the storage unit 32. In the present embodiment, the processing unit 31 reads and executes the program 32a stored in the storage unit 32 to periodically transmit a data frame to the main ECU 2, and the first bus 5 and the second bus. Various processes such as a process of transmitting a data frame using the two buses of No. 6 are performed.

The storage unit 32 is configured by using a non-volatile memory element such as a flash memory or an EEPROM (Electrically Erasable Programmable Read Only Memory). The storage unit 32 stores various programs executed by the processing unit 31 and various data required for processing by the processing unit 31. In the present embodiment, the storage unit 32 transmits to the program 32a executed by the processing unit 31, the priority table 32b in which the priority of each data transmitted / received in the in-vehicle communication system is set, and the two buses. It stores a distribution table 32c in which data distribution is set. Details of the priority table 32b and the distribution table 32c will be described later.

The program 32a may be written in the storage unit 32, for example, at the manufacturing stage of the sub-ECU 3, or may be distributed by a remote server device or the like by the sub-ECU 3 by communication, or may be acquired by communication, for example, a memory card. Alternatively, the sub-ECU 3 may read the program recorded on the recording medium 99 such as an optical disk and store it in the storage unit 32, or the writing device may read the program recorded on the recording medium 99 and store it in the storage unit 32 of the sub-ECU 3. You may write in 32. The program 32a may be provided in the form of distribution via the network, or may be provided in the form recorded on the recording medium 99.

The CAN communication unit 33 is connected to the first bus 5 and communicates with the main ECU 2 and other ECUs 3 via the first bus 5. The CAN communication unit 33 transmits / receives data frames according to the CAN communication protocol. The CAN communication unit 33 may be configured by using an IC such as a CAN controller or a transceiver. The CAN communication unit 33 transmits the data frame by converting the data frame given by the processing unit 31 into an electric signal and outputting it to the first bus 5. Further, the CAN communication unit 33 converts the electric signal on the first bus 5 into digital data by sampling and acquiring the potential of the first bus 5, and sends the converted data to the processing unit 31 as a received data frame. give.

The LIN communication unit 34 is connected to the second bus 6 and communicates with the main ECU 2 and other ECUs 3 via the second bus 6. The LIN communication unit 34 transmits / receives data frames according to the LIN communication protocol. The LIN communication unit 34 may be configured by using an IC such as a LIN controller or a transceiver, for example. The LIN communication unit 34 transmits the data frame by converting the data frame given by the processing unit 31 into an electric signal and outputting it to the second bus 6. Further, the LIN communication unit 34 converts the electric signal on the second bus 6 into digital data by sampling and acquiring the potential of the second bus 6, and sends the converted data to the processing unit 31 as a received data frame. give.

The communication load detection unit 35 monitors the communication by the CAN communication unit 33 via the first bus 5, and detects the communication load on the first bus 5. The communication load detection unit 35 uses the first bus 5 per unit time, for example, for the maximum amount of data (bytes, bits, etc.) that can be transmitted / received via the first bus 5 per unit time (for example, 1 second or 1 minute). The ratio (%) of the amount of data actually transmitted / received via the above is detected as a communication load, and the detection result is given to the processing unit 31. However, the communication load detected by the communication load detection unit 35 is not limited to the above, and may be any value. Further, in this figure, the communication load detection unit 35 is provided separately from the processing unit 31, but the communication load detection unit 35 may be provided in the processing unit 31.

Further, in the present embodiment, the sub ECU 3 reads and executes the program 32a stored in the storage unit 32 by the processing unit 31, so that the data distribution unit 31a, the frame generation unit 31b, the transmission processing unit 31c, and the data discrimination unit 31d are executed. Etc. are realized in the processing unit 31 as a software-like functional unit. When the communication load of the first bus 5 is low, the data distribution unit 31a transmits a plurality of data transmitted via the first bus 5 included in one data frame, and the communication load of the first bus 5 is high. In this case, the process of distributing the data to be transmitted via the first bus 5 and the data transmitted via the second bus 6 is performed. The data distribution unit 31a distributes a plurality of data based on the information set in the priority table 32b and the distribution table 32c stored in the storage unit 32.

The frame generation unit 31b performs a process of generating a data frame including one or more data to be transmitted to the main ECU 2 or another sub ECU 3. When the communication load of the first bus 5 is low, the frame generation unit 31b includes a plurality of data to be transmitted in one data frame. On the other hand, when the communication load of the first bus 5 is high, the frame generation unit 31b has a data frame transmitted via the first bus 5 and a first data frame based on the data distribution result by the data distribution unit 31a. 2 Generates two data frames, one is a data frame transmitted via the bus 6.

The transmission processing unit 31c feeds the data frame generated by the frame generation unit 31b to the CAN communication unit 33 or the LIN communication unit 34 to the main ECU 2 and other sub-ECUs 3 via the first bus 5 or the second bus 6. Performs the process of sending a data frame. When the communication load of the first bus 5 is low, the transmission processing unit 31c gives one data frame generated by the frame generation unit 31b to the CAN communication unit 33, and transmits this data frame via the first bus 5. On the other hand, when the communication load of the first bus 5 is high, the transmission processing unit 31c gives one data frame to the CAN communication unit 33 for the two data frames generated by the frame generation unit 31b, and the other. By giving a data frame to the LIN communication unit 34, two data frames are transmitted via the first bus 5 and the second bus 6. The frame generation unit 31b separately generates a data frame to be transmitted via the first bus 5 and a data frame to be transmitted via the second bus 6, and the transmission processing unit 31c according to this distinction. A data frame is given to the CAN communication unit 33 or the LIN communication unit 34.

The data discrimination unit 31d performs a process of discriminating which data is included in the data frame from the main ECU 2 or another ECU 3 received by the CAN communication unit 33 or the LIN communication unit 34. In the data frame, for example, information such as an ID for identifying the source of the data frame is set in a header or the like, and the data discrimination unit 31d is included in the data frame based on the information such as the ID of the data frame. It is possible to determine the type of one or more data to be stored. However, in the in-vehicle communication system according to the present embodiment, as described above, there may be a case where a plurality of data are included in one data frame and transmitted, and a case where the data is distributed and transmitted in two data frames. Therefore, the data discrimination unit 31d discriminates the type of data included in the data frame according to the information such as the ID included in the received data frame and the data length of the received data frame.

<Transmission processing>
In the in-vehicle communication system according to the present embodiment, the priority is set in advance for the data included in the data frame. The priority of the set data is stored in the storage unit 32 of the sub ECU 3 as the priority table 32b. FIG. 3 is a schematic diagram showing an example of the priority table 32b. In the illustrated example, there are two sub-ECUs 3 in the in-vehicle communication system, one of which is referred to as a sub-ECU (1) and the other of which is referred to as a sub-ECU (2). It is assumed that the sub-ECU (1) periodically and repeatedly transmits one set of data frames 1 and the sub-ECU (2) periodically and repeatedly transmits two sets of data frames 1 and 2. Further, in order to simplify the explanation, it is assumed that the main ECU 2 does not transmit the data frame.

In the in-vehicle communication system according to the present embodiment, the data length of the data frame is variable, and one data frame can include 1 to 8 1-byte data. The priority table 32b stores each of the 1 to 8 data included in the data frame transmitted by each sub-ECU 3 in association with the priority and the data type. Further, in the priority table 32b, the storage positions of data in the data frame are indicated by numbers 1 to 8. Further, the set priority indicates that the lower the numerical value, the higher the priority. In this example, the priority 1 is the highest priority and the priority 8 is the lowest priority. The data type is, for example, vehicle speed or engine speed, but in this example, it is described as types A to H.

In the illustrated priority table 32b, the data frame 1 transmitted by the sub-ECU (1) includes 1 byte of priority 8 type A data, 2 bytes of priority 1 type B data, and 1 byte. It is shown that the data of the type C of the priority 6 of the above are stored in this order. When the communication load is low and the data frame is transmitted only via the first bus 5, the sub-ECU (1) stores the type A data in the first position and the type B in the second and third positions. Data is stored, a data frame containing type C data is generated at the fourth position, and the data is transmitted via the first bus 5.

Further, in the illustrated priority table 32b, the data frame 1 transmitted by the sub-ECU (2) includes 2-byte priority 2 type D data, 1-byte priority 5 type E data, and 2 bytes. It is shown that the data of the type F of the byte priority 3 are stored in this order. When the communication load is low and the data frame 1 is transmitted only via the first bus 5, the sub-ECU (2) stores the data of the type D in the first and second positions, and the type E is stored in the third position. Data is stored, a data frame in which the data of type F is stored at the 4th and 5th positions is generated, and the data is transmitted via the first bus 5.

Further, in the illustrated priority table 32b, the data frame 2 transmitted by the sub-ECU (2) contains 2-byte priority 7 type G data and 1-byte priority 4 type H data. It is shown to be stored in this order. When the communication load is low and the data frame is transmitted only via the first bus 5, the sub-ECU (2) stores the data of the type G in the first and second positions, and the data of the type H is stored in the third position. A data frame 2 storing data is generated and transmitted via the first bus 5.

In the in-vehicle communication system according to the present embodiment, the priority of each data is not set for each device (for each sub ECU 3), but the priority value is set for all the data handled by the entire system. It is set so that there is no duplication. However, this is only an example, and the priority may be set for each device, or duplicate priorities may be set for a plurality of types of data.

In the in-vehicle communication system according to the present embodiment, the communication load detection unit 35 detects the communication load of the first bus 5, and the sub ECU 3 is based on the detected communication load and the priority set in the data. Then, it is determined whether the data to be transmitted is included in one data frame and transmitted, or whether the data to be transmitted is distributed in two data frames and transmitted. At this time, the sub-ECU 3 refers to the distribution table 32c of the storage unit 32 to determine whether or not to distribute the data and to which data frame the data is distributed.

FIG. 4 is a schematic diagram showing an example of the distribution table 32c. The distribution table 32c according to the present embodiment associates the priority (1 to 8) set in the data with the range of the value of the communication load, and assigns this data to the first communication path (first bus 5). Alternatively, it is a table that stores information indicating which of the second communication paths (second bus) should be transmitted. In the distribution table 32c of this example, when the communication load is 30% or less, it is set that all the data are transmitted via the first bus 5 without distributing the data. That is, in the present embodiment, the threshold value for determining whether or not to distribute the data is set to 30% of the communication load.

Further, in the distribution table 32c of this example, when the communication load exceeds 30% and is 35% or less, the data of priority 1 to 7 is transmitted via the first bus 5, and the data of priority 8 is transmitted to the first. 2 It is set to transmit via bus 6. Further, in the distribution table 32c, when the communication load exceeds 35% and is 40% or less, the data of priority 1 to 6 is transmitted via the first bus 5, and the data of priority 7 and 8 are second. It is set to transmit via the bus 6. When the communication load exceeds 40% and is 45% or less in the distribution table 32c, the data of priority 1 to 5 is transmitted via the first bus 5, and the data of priority 6 to 8 is transmitted to the second bus. It is set to transmit via 6. When the communication load exceeds 45%, the data of priority 1 to 4 is transmitted via the first bus 5 and the data of priority 5 to 8 is transmitted via the second bus 6 to the distribution table 32c. Is set.

FIG. 5 is a schematic diagram for explaining an example of data distribution. This figure shows an example in which the data frame of the sub-ECU (1) shown in the priority table 32b of FIG. 3 is transmitted according to the setting contents of the distribution table 32c shown in FIG. According to the priority table 32b of FIG. 3, the data frame transmitted by the sub-ECU (1) includes the data of the type A of the priority 8 (hereinafter referred to as data A) and the data of the type B of the priority 1 (hereinafter referred to as data A). Hereinafter, three types of data are included: data B) and type C data of priority 6 (hereinafter referred to as data C).

For example, when the communication load of the first bus 5 is 30% or less, all the data of the priorities 1 to 8 are transmitted via the first communication path (first bus 5) according to the distribution table 32c of FIG. Is set to be done. The sub-ECU (1) creates a data frame of a CAN communication protocol including data A, data B, and data C. As shown in the upper part of FIG. 5, this data frame has a configuration in which data A, data B, and data C are stored in this order between the header and the footer. The header contains information that can identify the source, such as the CAN ID. The footer contains information for performing, for example, error detection or error correction. The sub-ECU (1) transmits the generated data frame to the main ECU 2 or another sub-ECU 3 by outputting the generated data frame to the first bus 5 by the CAN communication unit 33.

For example, when the communication load of the first bus 5 exceeds 30% and is 40% or less, according to the distribution table 32c of FIG. 4, the data of priority 1 and 6 use the first communication path (first bus 5). The data of priority 8 is set to be transmitted via the second communication path (second bus 6). The sub-ECU (1) creates a data frame of the CAN communication protocol including the data B of the priority 1 and the data C of the priority 6, and also creates a data frame of the communication protocol of the LIN including the data A of the priority 8. Create a data frame. The sub-ECU (1) outputs the generated CAN communication protocol data frame to the first bus 5 by the CAN communication unit 33 and transmits the generated CAN communication protocol data frame, and also outputs the LIN communication protocol data frame to the LIN communication unit 34. 2 Output to bus 6 and transmit.

For example, when the communication load of the first bus 5 exceeds 40%, according to the distribution table 32c of FIG. 4, the data of the priority 1 is transmitted via the first communication path (first bus 5), and the priority 6 , 8 data is set to be transmitted via the second communication path (second bus 6). The sub-ECU (1) creates a data frame of the CAN communication protocol including the data B of the priority 1, and also creates a data frame of the LIN communication protocol including the data A of the priority 8 and the data C of the priority 6. Create a data frame. The sub-ECU (1) outputs the generated CAN communication protocol data frame to the first bus 5 by the CAN communication unit 33 and transmits the generated CAN communication protocol data frame, and also outputs the LIN communication protocol data frame to the LIN communication unit 34. 2 Output to bus 6 and transmit.

FIG. 6 is a flowchart showing a procedure of transmission processing performed by the sub ECU 3 according to the present embodiment. The processing unit 31 of the sub-ECU 3 according to the present embodiment periodically repeatedly transmits the data frame, and determines whether or not the timing of the periodic transmission of the data frame has been reached (step S1). If the transmission timing has not been reached (S1: NO), the processing unit 31 waits until the transmission timing of the data frame is reached. When the transmission timing is reached (S1: YES), the processing unit 31 detects the communication load of the first bus 5 by the communication load detection unit 35 (step S2).

The processing unit 31 determines whether or not the detected communication load of the first bus 5 exceeds 30% (step S3). When the communication load exceeds 30%, the data distribution unit 31a of the processing unit 31 refers to the distribution table 32c of the storage unit 32 (step S4). The data distribution unit 31a transfers a plurality of data to be included in the data frame via the first communication path (first bus 5) based on the communication path for each priority set according to the communication load in the distribution table 32c. The data frame to be transmitted and the data frame to be transmitted via the second communication path (second bus) are distributed (step S5), and the process proceeds to step S6. When the communication load does not exceed 30% (S3: NO), the processing unit 31 proceeds to step S6 without distributing the data.

Next, the frame generation unit 31b of the processing unit 31 attaches a header, a footer, or the like to the data to be transmitted, and generates a data frame (step S6). At this time, when the data is distributed by the data distribution unit 31a, the frame generation unit 31b has two data frames, a CAN communication protocol data frame and a LIN communication protocol data frame, according to the distribution result. Generate a data frame. When the data is not distributed, the frame generation unit 31b generates only the data frame of the CAN communication protocol.

Next, the transmission processing unit 31c of the processing unit 31 transmits the generated data frame to the main ECU 2 and the other ECU 3 (step S7), and ends the processing. At this time, when the two data frames are generated, the transmission processing unit 31c gives the data frame of the CAN communication protocol to the CAN communication unit 33 and outputs the data frame to the first bus 5, and the LIN communication protocol. The data frame is output to the LIN communication unit 34, and the two data frames are transmitted via the first bus 5 and the second bus 6. When only one data frame is generated, the transmission processing unit 31c gives a data frame of the CAN communication protocol to the CAN communication unit 33 and outputs the data frame to the first bus 5, and outputs the data frame to the first bus. It is transmitted via 5.

FIG. 7 is a flowchart showing a procedure of data distribution processing performed by the sub ECU 3 according to the present embodiment. The process shown in this figure is the details of the process performed in steps S3 to S5 of the flowchart shown in FIG. 6, and shows the details of the case of the sub ECU (1) shown in FIG. The detailed processing of the data frames 1 and 2 of the sub-ECU (2) will be omitted from the illustration and description.

The processing unit 31 of the sub-ECU (1) according to the present embodiment determines whether or not the communication load of the first bus 5 exceeds 30% (step S11). When the communication load does not exceed 30% (S11: NO), the processing unit 31 determines that all the data included in the data frame and transmitted is transmitted via the first communication path (first bus 5) (1st bus 5). Step S12), the process is terminated.

When the communication load exceeds 30% (S11: YES), the data distribution unit 31a of the processing unit 31 further determines whether or not the communication load exceeds 40% (step S13). When the communication load does not exceed 40% (S13: NO), the data distribution unit 31a determines that the data of priority 8 is transmitted via the second communication path (second bus 6), and the priority 1, 6 Is determined to be transmitted via the first communication path (first bus 5) (step S14), and the process is terminated. When the communication load exceeds 40% (S13: YES), the data distribution unit 31a determines that the data of priority 6 and 8 are transmitted via the second communication path (second bus 6), and the priority 1 It is determined that the data is transmitted via the first communication path (first bus 5) (step S15), and the process is terminated.

<Reception processing>
In the in-vehicle communication system according to the present embodiment, data is appropriately distributed to the first bus 5 and the second bus 6 according to the communication load of the first bus 5, and a data frame is transmitted. In the in-vehicle communication system according to the present embodiment, for example, even when the data frame is transmitted only via the first bus 5, the data frame is transmitted via the two communication paths of the first bus 5 and the second bus 6. Is transmitted, the same value is set for the identification information such as CAN-ID set in the header of the data frame. Therefore, the main ECU 2 and the sub-ECU 3 that have received the data frame via the first bus 5 and the second bus 6 need to determine which data is included in the received data frame.

Hereinafter, the process will be described assuming that the sub-ECU 3 receives the data frame, but the same applies to the case where the main ECU 2 receives the data frame. The sub-ECU 3 that has received the data frame transmitted from the main ECU 2 or another sub-ECU 3 includes whether the data frame is received via the first bus 5 or the second bus 6 and is included in the header of the received data frame. The source device specified from the information, the data length (frame length, data size, etc.) of the received data frame, and the information set in the priority table 32b and the distribution table 32c stored in the storage unit 32. Based on, it is determined which type of data the one or more data included in the received data frame is.

Here, the data discrimination process will be described by taking as an example the case where the data frame transmitted by the sub-ECU (1) shown in FIG. 5 is received. The CAN communication protocol data frame transmitted by the sub ECU (1) via the first bus 5 includes a data frame including data A, B, C, a data frame including data B, C, and data B. There are three types of data frames. Since the data lengths of these three types of data frames are different from each other, the sub ECU 3 that has received this data frame examines the data length of the received data frame to determine which of the three types of data frames it corresponds to. It can be specified, and it is possible to determine which type of data the one or more data included in the data frame is.

Similarly, there are two types of LIN communication protocol data frames transmitted by the sub-ECU (1) via the second bus: a data frame including data A and a data frame including data A and C. Since the data lengths of these two types of data frames are different from each other, the sub ECU 3 that has received this data frame checks the data length of the received data frame to determine which of the two types of data frames it corresponds to. It can be specified, and it is possible to determine which type of data the one or more data included in the data frame is. The data length examined by the sub ECU 3 that has received the data frame may or may not include the data lengths of the header and footer.

Further, the sub-ECU 3 determines how many types of data frames are transmitted to each of the sub-ECU 3 and the main ECU 2 which are the transmission sources of the data frames based on the priority table 32b and the distribution table 32c, and the data length of the data frame for each type. , And the type of data contained in the data frame can be determined. For example, the data frame 1 of the sub-ECU (2) shown in FIG. 3 may contain data of priorities 2, 5 and 3, and according to the distribution table 32c of FIG. 4, the data of priorities 2 and 3 may be included. Is always transmitted via the first communication path (first bus 5), so that the data frame transmitted via the first communication path (first bus 5) contains data of priority 2, 5 and 3. It can be determined that there are two types, a data frame including data and a data frame containing data having priority 2 and 3. The data frame transmitted via the second communication path (second bus 6) is one type of data frame including the data of priority 5.

Further, for example, the data frame 2 of the sub-ECU (2) shown in FIG. 3 may contain data of priorities 7 and 4, and according to the distribution table 32c of FIG. 4, the data of priority 4 is always the first. Since it is transmitted via one communication path (first bus 5), the data frame transmitted via the first communication path (first bus 5) includes a data frame containing data of priority 7 and 4 and a data frame. It can be determined that there are two types, a data frame containing data of priority 4. The data frame transmitted via the second communication path (second bus 6) is one type of data frame including the data of priority 7.

Therefore, the sub-ECU 3 that has received the data frame checks whether the data frame is received via the first bus 5 or the second bus 6, determines the source of the received data frame, and receives the received data frame. By determining the data length of, it is possible to determine which of the plurality of types of data frames determined from the priority table 32b and the distribution table 32c is the received data frame. Then, the sub ECU 3 can determine the type of one or a plurality of data included in the received data frame.

FIG. 8 is a flowchart showing a procedure of reception processing performed by the sub ECU 3 according to the present embodiment. The data discrimination unit 31d of the processing unit 31 of the sub-ECU 3 according to the present embodiment determines whether or not the CAN communication unit 33 or the LIN communication unit 34 has received a data frame from the main ECU 2 or another ECU 3 ( Step S21). When the data frame has not been received, the data discrimination unit 31d waits until the data frame is received (S21: NO).

When the data frame is received (S21: YES), the data discrimination unit 31d determines the communication path for receiving the data frame, that is, whether the data frame is received via the first bus 5 or the second bus 6. Is determined (step S22). Further, the data discrimination unit 31d determines which device (main ECU 2 or other ECU 3) is the source of the data frame based on the information such as the ID included in the header of the data frame (step S23). ). Further, the data discrimination unit 31d determines the data length of the received data (step S24).

The data discrimination unit 31d includes one or a plurality of received data frames based on the discrimination results of steps S22 to S24 and the contents set in the priority table 32b and the distribution table 32c stored in the storage unit 32. The type of data is determined for each of the data in (step S25), and the process is terminated.

<Summary>
In the in-vehicle communication system according to the present embodiment having the above configuration, in-vehicle communication devices such as the main ECU 2 and a plurality of sub-ECUs 3 mounted on the vehicle 1 are connected via a plurality of communication paths, and these plurality of communication paths are connected. Send and receive data frames containing one or more data via. The data included in the data frame transmitted / received by the in-vehicle communication device is given a priority in advance according to the data type. The in-vehicle communication device detects the communication load of the communication path, and generates a plurality of data frames in which a plurality of data included in the data frames transmitted to other devices according to the communication load are distributed according to the priority. The in-vehicle communication device transmits a plurality of generated data frames to other devices via the corresponding communication lines. As a result, the in-vehicle communication device can transmit and receive data frames using a plurality of communication paths in consideration of the communication load and the priority of data, and is expected to improve the reliability of communication.

Further, in the vehicle-mounted communication system according to the present embodiment, a plurality of vehicle-mounted communication devices such as the main ECU 2 and the sub-ECU 3 are connected via two communication paths of the first bus 5 or the second bus 6. The in-vehicle communication device detects the communication load of the first bus 5, and when the detected communication load exceeds a threshold value such as 30%, the plurality of data included in the data frame to be transmitted to another device is divided into two. Generate two distributed data frames. The in-vehicle communication device transmits the first data frame to another device via the first bus 5, and transmits the second data frame to the other device via the second bus 6. As a result, the in-vehicle communication device can transmit and receive data via the two communication paths in consideration of the communication load of the first bus 5 and the priority of the data.

Further, in the in-vehicle communication system according to the present embodiment, when the communication load of the first bus 5 does not exceed a threshold value such as 30%, the in-vehicle communication device uses the first bus 5 without distributing data. Send the data frame to another device via. As a result, when the communication load of the first bus 5 is low, the in-vehicle communication device does not need to perform a process of distributing data to generate a plurality of data frames, and a reduction in the processing load can be expected.

Further, in the in-vehicle communication system according to the present embodiment, the high-priority data is included in the first data frame transmitted from the first bus 5, and the low-priority data is transmitted from the second bus 6. A plurality of data to be transmitted to other devices are distributed into two data frames so as to be included in the frame. By properly using the two communication paths according to the high and low priorities, it can be expected that the in-vehicle communication device properly uses the communication paths according to the priority, for example, when the communication speeds of the two communication paths are different.

Further, in the in-vehicle communication system according to the present embodiment, the in-vehicle communication device includes two data frames so that the higher the communication load of the first bus 5, the more data is included in the data frame transmitted from the second bus 6. Generate. This can be expected to reduce the communication load of the first bus 5.

Further, in the in-vehicle communication system according to the present embodiment, the communication speed of the first bus is faster than the communication speed of the second bus 6. By providing a difference in communication speed between the two communication paths, it can be expected that the cost of the in-vehicle communication system will be reduced as compared with the configuration in which the two communication paths both perform high-speed communication.

Further, in the in-vehicle communication system according to the present embodiment, the in-vehicle communication device stores the distribution table 32c in which the priority of the data and the communication path for transmitting the data frame including the data are associated with each other in the storage unit 32. When the in-vehicle communication device receives a data frame via a plurality of communication paths, the vehicle-mounted communication device includes one or a plurality of the data frames included in the data frame based on the stored information in the distribution table 32c and the data length of the received data frame. Determine the data of. As a result, when data is distributed to multiple data frames according to the communication load and transmitted / received, the data included in the received data frame is any data without detecting the communication load on the receiving device. It is possible to determine whether or not there is.

In the present embodiment, the main ECU 2 and the sub ECU 3 have been described as an example of the in-vehicle communication device, but the present invention is not limited to this, and the in-vehicle communication device may be various other in-vehicle devices. Further, as the communication path of the in-vehicle communication system, the first bus 5 and the second bus 6 have been described as an example, but the description is not limited to this, and the communication path is a configuration other than the bus type, for example, a star type or a ring type. Various network configurations can be adopted. Further, the plurality of communication paths may include wireless communication. Further, the communication via the first bus 5 is used as the communication protocol of CAN, and the communication via the second bus 6 is used as the communication protocol of LIN, but these communication protocols are examples and are not limited thereto. Further, the number of data included in the data frame shown in the priority table 32b of FIG. 3, the priority of the data, the type of data, and the like are examples, and the present invention is not limited thereto. Further, the communication load, which is the threshold value shown in the distribution table 32c of FIG. 4, and the correspondence between the data priority and the communication path are examples, and the present invention is not limited to this.

<Modification example>
Further, the in-vehicle communication system according to the present embodiment is configured to connect a plurality of in-vehicle communication devices via two communication paths, but the number of communication paths may be three or more. FIG. 9 is a schematic diagram showing an example of a distribution table of an in-vehicle communication system according to a modified example. In the vehicle-mounted communication system according to the modified example, a plurality of vehicle-mounted communication devices are connected via the first to third communication paths. Further, it is assumed that the communication speeds of the three communication paths are different, the communication speed of the first communication path is the fastest, and the communication speed of the third communication path is the slowest. The distribution table according to the modified example associates the priority (1 to 8) set in the data with the range of the communication load of the first communication path, and assigns this data to the first communication path, the second communication path, or the second communication path. It stores information indicating which of the third communication paths should be transmitted.

In the distribution table shown in FIG. 9, when the communication load of the first communication path is 30% or less, it is set that all the data are transmitted via the first communication path without distributing the data. There is. Further, in the distribution table, when the communication load exceeds 30% and is 35% or less, the data of priority 1 to 7 is transmitted via the first communication path, and the data of priority 8 is sent to the second communication path. It is set to send via. Further, when the communication load exceeds 35% and is 40% or less in the distribution table, the data of priority 1 to 6 is transmitted via the first communication path, and the data of priority 7 and 8 are transmitted in the second communication. It is set to send via a route. Further, when the communication load exceeds 40% and is 45% or less in the distribution table, the data of priority 1 to 5 is transmitted via the first communication path, and the data of priority 6 to 8 is transmitted to the second communication. It is set to send via a route.

Further, when the communication load exceeds 45% and is 50% or less in the distribution table, the data of priority 1 to 4 is transmitted via the first communication path, and the data of priority 5 to 7 is transmitted to the second communication. It is set to transmit the data via the route and transmit the data of priority 8 via the third communication route. Further, when the communication load exceeds 50% and is 55% or less in the distribution table, the data of priority 1 to 3 is transmitted via the first communication path, and the data of priority 4 to 6 is transmitted to the second communication. It is set to transmit the data via the route and transmit the data of priority 7 and 8 via the third communication route. When the communication load exceeds 55%, the data of priority 1 and 2 are transmitted via the first communication path, and the data of priority 3 to 5 are transmitted via the second communication path to the distribution table. , It is set to transmit the data of priority 6 to 8 via the third communication path.

In the in-vehicle communication system according to the modification of the above configuration, a plurality of in-vehicle communication devices are connected via three communication paths, and the in-vehicle communication device distributes data according to the communication load of the first communication path and the priority of data. Then, a data frame is generated, and the generated data frame is transmitted from the corresponding communication path. In this example, the in-vehicle communication device distributes the data so that the data frame transmitted from the second communication path and the third communication path contains more data as the communication load of the first communication path is higher. Send.

In this modification, a configuration in which a plurality of vehicle-mounted communication devices are connected via three communication paths has been described, but a plurality of vehicle-mounted devices may be connected via four or more communication paths. Further, in this modification, the data is distributed in consideration of the communication load of the first communication path, but for example, the data may be distributed in consideration of the communication load of the first communication path and the second communication path. .. For example, the data transmitted in the first communication path and the other data are separated according to the communication load of the first communication path, and the other data is set to the second communication path according to the communication load of the second communication path. It is possible to separate the data to be transmitted by the third communication path and the data to be transmitted by the third communication path.

Each device in the in-vehicle communication system includes a computer including a microprocessor, ROM, RAM, and the like. An arithmetic processing unit such as a microprocessor reads a computer program including a part or all of each step of a sequence diagram or a flowchart as shown in FIGS. 6 to 8 from a storage unit such as a ROM or a RAM and executes the program. It's okay. The computer programs of these plurality of devices can be installed from an external server device or the like, respectively. Further, the computer programs of these plurality of devices are distributed in a state of being stored in a recording medium such as a CD-ROM, a DVD-ROM, or a semiconductor memory, respectively.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The scope of the present disclosure is expressed by the scope of claims, not the above-mentioned meaning, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Vehicle 2 Main ECU (vehicle-mounted communication device)
3 Sub ECU (vehicle-mounted communication device)
4 Control target 5 First bus (communication path)
6 Second bus (communication route)
31 Processing unit 31a Data distribution unit 31b Frame generation unit 31c Transmission processing unit (transmission unit)
31d Data discrimination unit 32 Storage unit 32a Program 32b Priority table 32c Distribution table 33 CAN communication unit 34 LIN communication unit 35 Communication load detection unit 99 Recording medium

Claims (9)

An in-vehicle communication device that is connected to another device via a plurality of communication paths and transmits / receives a data frame containing a plurality of data via the communication path.
The data is prioritized according to the data type.
A processing unit that detects the communication load of the communication path and generates a plurality of data frames in which a plurality of data included in the data frames transmitted to the other device according to the communication load are distributed according to the priority.
An in-vehicle communication device including a transmission unit that transmits a plurality of data frames generated by the processing unit to the other device via different communication paths. Connected to the other device via two communication paths,
The processing unit detects the communication load of the first communication path, and when the communication load of the first communication path exceeds the threshold value, 2 sets a plurality of data included in the data frame to be transmitted to the other device. Generates two data frames distributed in one,
The transmission unit transmits the first data frame generated by the processing unit to the other device via the first communication path, and the second data frame generated by the processing unit is transmitted to the second communication. Sending to the other device via the route,
The vehicle-mounted communication device according to claim 1. The vehicle-mounted communication device according to claim 2, wherein when the communication load of the first communication path does not exceed the threshold value, the transmission unit transmits a data frame to the other device via the first communication path. The processing unit includes the high-priority data in the first data frame transmitted from the first communication path, and the low-priority data is transmitted from the second communication path. Generate two data frames by distributing multiple data so that they are included in the frame.
The vehicle-mounted communication device according to claim 2 or 3. The processing unit generates two data frames so that the higher the communication load of the first communication path, the more data is included in the second data frame transmitted from the second communication path.
The vehicle-mounted communication device according to any one of claims 2 to 4. The communication speed of the first communication path is faster than the communication speed of the second communication path.
The vehicle-mounted communication device according to any one of claims 2 to 5. It is equipped with a storage unit that stores correspondence information between the priority attached to the data and the communication path for transmitting the data frame containing the data.
One of claims 1 to 6, wherein the processing unit determines data contained in the data frame according to the corresponding information stored in the storage unit and the data length of the received data frame. The in-vehicle communication device described in 1. An in-vehicle communication system including a plurality of in-vehicle communication devices connected via a plurality of communication paths, and each in-vehicle communication device transmits / receives a data frame containing a plurality of data via the communication path.
The data is prioritized according to the data type.
The in-vehicle communication device is
A processing unit that detects the communication load of the communication path and generates a plurality of data frames in which a plurality of data included in the data frames transmitted to other devices according to the communication load are distributed according to the priority.
An in-vehicle communication system including a transmission unit that transmits a plurality of data frames generated by the processing unit to the other device via different communication paths. An in-vehicle communication device connected to another device via a plurality of communication paths is an in-vehicle communication method in which a data frame containing a plurality of data is transmitted / received via the communication path.
The data is prioritized according to the data type.
Detects the communication load of the communication path and
According to the detected communication load, a plurality of data frames in which a plurality of data included in the data frames to be transmitted to the other device are distributed according to the priority are generated.
An in-vehicle communication method for transmitting a plurality of generated data frames to the other device via different communication paths.

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