Vehicle communication system

Abstract

This invention provides a vehicle communication system that ensures communication of non-control data, such as diagnostic data, without requiring a dedicated communication line for diagnostic data, and expands and / or redundants the allowable communication volume for control data. The vehicle communication system includes: a relay device that relays data communication between multiple vehicle control ECUs mounted in the vehicle; and two communication buses that connect the relay device to each vehicle control ECU. The relay device and the vehicle control ECUs use a first communication bus (one of the two communication buses) to communicate control data related to vehicle control actions, and a second communication bus (the other of the two communication buses) to communicate control data and / or non-control data.

Description

Technical Field

[0001] This invention relates to a vehicle communication system for communicating between multiple electronic control devices mounted in a vehicle. Background Technology

[0002] Traditionally, multiple electronic control units (ECUs) mounted in a vehicle are connected via a communication bus, such as one conforming to standards like CAN, to communicate control data required for vehicle operation. In addition to the aforementioned communication bus, these ECUs are also connected to communication lines for transmitting diagnostic data used to diagnose whether each ECU is operating correctly. Typically, a standard is set for the response time of the ECU to communication requests from a diagnostic device connected to the vehicle from outside the vehicle. By separating the communication lines for transmitting diagnostic data from the communication bus used for transmitting control data, the response signals sent by the ECU to response requests from the diagnostic device can be received by the diagnostic device without delay.

[0003] On the other hand, with the increasing complexity and diversification of vehicle functions such as ADAS and autonomous driving in recent years, the amount of information communication between ECUs has increased. In order to improve the reliability of control actions, a scheme has been proposed to connect ECUs using multiple communication buses to achieve redundancy of data communication between ECUs (for example, see Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2021-175140 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] However, increasing the number of communication lines (including the communication bus, hereinafter the same) connecting the ECUs would increase the number and size of communication devices required for each ECU, and would also increase the overall cost and power consumption of the vehicle, which is inappropriate.

[0009] In view of the above background, the object of the present invention is to ensure good communication of non-control data such as diagnostic data without setting up a dedicated communication line for transmitting diagnostic data, and to increase and / or redundancy the communication volume of control data communication required for vehicle movement control.

[0010] The above objectives are to reduce the number of communication lines in vehicles, improve energy efficiency in in-vehicle communication, and contribute to the achievement of the SDGs (SDGs 7.3, 12.2, etc.) by realizing an efficient and sustainable vehicle society.

[0011] means for solving problems

[0012] One aspect of the present invention is a vehicle communication system comprising: a relay device for relaying data communication between a plurality of vehicle control ECUs mounted in a vehicle; and two communication buses connecting the relay device to each of the vehicle control ECUs, wherein the relay device and the vehicle control ECUs use a first communication bus, which is one of the two communication buses, to communicate control data related to the control actions of the vehicle, and the relay device and the vehicle control ECUs use a second communication bus, which is the other of the two communication buses, to communicate the control data and / or non-control data other than data related to the control actions of the vehicle.

[0013] According to another aspect of the invention, data used for communication between the relay device and the vehicle control ECU is prioritized, with the relay device and the vehicle control ECU communicating with data assigned a higher priority over other data, and control data being assigned a higher priority than non-control data.

[0014] According to another aspect of the invention, the relay device includes a priority management unit that manages the allocation of priorities for the non-control data, and when the vehicle is parked, the priority management unit assigns a higher priority to the non-control data compared to when the vehicle is not parked.

[0015] According to another aspect of the invention, the relay device includes a priority management unit that manages the allocation of priority for the non-control data, which includes diagnostic data that is communicated between a vehicle diagnostic device and a vehicle control ECU, the vehicle diagnostic device being connected to the relay device from outside the vehicle. When the vehicle diagnostic device is connected to the relay device, the priority management unit assigns a higher priority to the non-control data compared to when the vehicle diagnostic device is not connected.

[0016] According to another aspect of the invention, the communication bandwidth of the communication between the relay device and the vehicle control ECU via the second communication bus is narrower than the communication bandwidth of the communication via the first communication bus.

[0017] According to another aspect of the invention, the relay device includes a first communication management unit for managing communication via the second communication bus, and the vehicle control ECU includes a second communication management unit for managing communication via the second communication bus. When there is no control data to be transmitted via the second communication bus, the first and second communication management units communicate the non-control data via the second communication bus.

[0018] According to another aspect of the invention, the relay device includes a first communication management unit for managing communication via the second communication bus, and the vehicle control ECU includes a second communication management unit for managing communication via the second communication bus. When there is control data that should be transmitted via the second communication bus, the first and second communication management units do not communicate the non-control data via the second communication bus.

[0019] The effects of the invention

[0020] According to the present invention, good communication of non-control data such as diagnostic data can be ensured without setting up a dedicated communication line for transmitting diagnostic data, and the communication volume of control data communication required for vehicle movement control can be increased and / or redundant. Attached Figure Description

[0021] Figure 1 This is a structural diagram of the vehicle-mounted control system of a vehicle communication system as an embodiment of the present invention.

[0022] Figure 2 This is a diagram showing the structure of the second area ECU, which is an example of a vehicle control ECU.

[0023] Figure 3 This is a diagram showing the structure of the central ECU, which serves as a relay device.

[0024] Figure 4 This is a flowchart illustrating the steps of communication processing in the second region ECU.

[0025] Figure 5 This is a flowchart illustrating the communication processing steps in the central ECU.

[0026] Explanation of reference numerals in the attached figures

[0027] 1…Control system, 2…Central ECU, 3…First communication line, 4, 4a, 4b, 4c…Second communication line, 19…DLC, 20…Regional ECU, 20a…First regional ECU, 20b…Second regional ECU, 20c…Third regional ECU, 30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, 30i…ECU, 40…Vehicle diagnostic device, 41, 41a, 41b, 41c…First communication bus, 42, 42a, 42b, 42c…Second communication bus, 50, 70…Processor, 51, 71…Memory, 52…First communication device 53…Second communication device, 54…Control program, 55…First transmit code list, 56…First receive code list, 57…Control unit, 58…Update unit, 59…Diagnostic unit, 60…First communication management unit, 72…Third communication device, 73…Fourth communication device, 74…Fifth communication device, 75…Relay control program, 76…ID list, 77…Second transmit code list, 78…Second receive code list, 80…Relay unit, 81…OTA management unit, 82…Diagnostic communication unit, 83…Second communication management unit, 84…Priority management unit, 721, 722, 723, 731, 732, 733…Transceivers. Detailed Implementation

[0028] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0029] Figure 1 This is a diagram showing the structure of a vehicle control system 1 mounted on a vehicle, which is an embodiment of the vehicle communication system of the present invention.

[0030] Control system 1 includes a central ECU 2 for overall vehicle control and information processing. Hereinafter, the vehicle equipped with control system 1 will be referred to as "this vehicle". The central ECU 2 is connected to the first communication line 3 and the second communication lines 4a, 4b, and 4c, and also functions as a gateway managing the transmission and reception of communication data between these communication lines. Furthermore, the central ECU 2 is connected to a wireless device (not shown) conforming to the communication standards of mobile communication systems to perform OTA (Over-The-Air) management. OTA management includes the following control: downloading update programs for the vehicle's onboard devices from an external server and applying these update programs to the onboard devices.

[0031] A DLC (Data Link Connector) 19 is provided in the first communication line 3. For example, a vehicle diagnostic device 40 is connected to the DLC 19 from outside the vehicle.

[0032] The second communication lines 4a, 4b, and 4c are connected to ECU 20a in region 1, ECU 20b in region 2, and ECU 20c in region 3, respectively. ECU 20a in region 1 is connected to ECUs 30a, 30b, and 30c, and ECU 20b in region 2 is connected to ECUs 30d, 30e, and 30f. In addition, ECU 20c in region 3 is connected to ECUs 30g, 30h, and 30i.

[0033] Hereinafter, ECU20a (region 1), ECU20b (region 2), and ECU20c (region 3) will be collectively referred to as region ECU20, and ECUs30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h, and 30i will be collectively referred to as ECU30.

[0034] The ECU30 may include, for example, an MPU (Map Positioning Unit), an MVC-ECU (Multi View Camera), a PKS-ECU (Parking Support), and / or an ADAS-ECU (Advanced Driver-Assistance System), as well as other ECUs that control the operation of various devices or sensors present in the vehicle. Such devices or sensors may include: a drive motor to move the vehicle, accelerator or brake actuators, a VSA (Vehicle Stability Asist) device, a battery, headlights and other lamps, window motors to drive doors and windows, actuators to drive door locking mechanisms, door lock sensors, door opening and closing sensors, temperature sensors, exterior cameras, interior cameras, etc.

[0035] The regional ECU 20 is connected to multiple ECUs 30 located in the same partition of the vehicle's body space, or to multiple ECUs 30 that control the operation of devices or sensors located in the same partition.

[0036] In addition to the regional ECU20 being able to connect to the central ECU2, other control devices and equipment can also be connected to the central ECU2. Such control devices or equipment can include: ICB (Infotainment Control Box), speakers, microphones, instrument panel, turn signals, GNSS sensors, touch panels, etc.

[0037] Here, control system 1 and central ECU 2 correspond to the vehicle communication system and relay device in this invention, respectively. Furthermore, first region ECU 20a, second region ECU 20b, and third region ECU 20c correspond to the multiple vehicle control ECUs mounted on the vehicle in this invention.

[0038] In this embodiment, the second communication lines 4a, 4b, and 4c, which connect the central ECU2 (serving as a relay device) to the first region ECU 20a, second region ECU 20b, and third region ECU 20c (serving as vehicle control ECUs), are each composed of two communication buses. Specifically, the second communication line 4a is composed of the first communication bus 41a and the second communication bus 42a. Similarly, the second communication line 4b is composed of the first communication bus 41b and the second communication bus 42b, and the second communication line 4c is composed of the first communication bus 41c and the second communication bus 42c.

[0039] Hereinafter, the second communication lines 4a, 4b, and 4c will also be collectively referred to as the second communication line 4. Furthermore, the first communication buses 41a, 41b, and 41c will be collectively referred to as the first communication bus 41, and the second communication buses 42a, 42b, and 42c will be collectively referred to as the second communication bus 42. In this embodiment, the first communication bus 41 and the second communication bus 42 are CAN buses used for communication conforming to the CAN communication standard.

[0040] The following description, using the second-area ECU 20b as an example, illustrates the structure and communication operation of the control system 1 as part of the vehicle communication system. However, the communication operation between the second-area ECU 20b and the central ECU 2, as shown below, can also be performed between other vehicle control ECUs and the central ECU 2.

[0041] [1. Communication Actions of the Control System]

[0042] In the control system 1 of this embodiment, communication between the second area ECU 20b (vehicle control ECU) and the central ECU 2 (relay device) is performed in the following manner.

[0043] The communication data between the central ECU2 and the second area ECU20b includes: control data for transmitting data related to the control actions of the vehicle, and non-control data for transmitting data other than data related to the control actions of the vehicle.

[0044] The central ECU2 and the second zone ECU20b communicate control data via the first communication bus 41b of the second communication line 4b, and communicate control data and non-control data via the second communication bus 42b. Therefore, in the control system 1, good communication of non-control data such as diagnostic data can be ensured without setting up a dedicated communication line for transmitting diagnostic data, and redundancy and / or increased allowable communication volume are achieved for the communication of control data required for vehicle operation control. In this embodiment, the non-control data includes diagnostic data, OTA-related information, and update programs for the vehicle control ECUs. The diagnostic data is the data communicated between the vehicle diagnostic device 40, which is connected externally to the central ECU2, and the vehicle control ECUs such as the second zone ECU20b.

[0045] Communication data is allocated with priority. Central ECU2 and second-region ECU20b will have higher-priority communication data assigned to them, allowing them to communicate over other communication data. In this embodiment, the communication data consists of data packets constructed according to the CAN communication standard, and the priority is represented by the ID contained in each piece of communication data. The ID may also include an identification code indicating whether the communication data is non-control data or control data, and a category code indicating the content category of the data contained in the communication data.

[0046] In this embodiment, control data is specifically assigned a higher priority than non-control data. This prevents a decrease in control data communication speed due to the generation of non-control data, and ensures good responsiveness of vehicle control actions performed collaboratively by multiple vehicle control ECUs.

[0047] The central ECU2, acting as a relay device, manages the priority allocation for non-control data. In this embodiment, when the vehicle is parked, the central ECU2 assigns a higher priority to non-control data compared to when the vehicle is not parked. Therefore, during periods when the vehicle is parked and rapid vehicle control is not required, the communication speed of non-control data can be increased, thus enabling, for example, the rapid execution of updates to the vehicle control ECU.

[0048] Furthermore, when the vehicle diagnostic device 40 is connected from outside the vehicle, the central ECU 2 assigns a higher priority to non-control data compared to when the vehicle diagnostic device 40 is not connected. Since the connection of the vehicle diagnostic device 40 from outside the vehicle is limited to when the vehicle is stationary, the speed of diagnostic communication containing diagnostic data can be ensured without affecting the speed of vehicle control while in motion. For example, according to this configuration, it is easy to ensure that the response time from the instruction issued by the vehicle diagnostic device 40 to the vehicle control ECU to the receipt of the response from the vehicle diagnostic device 40 by the vehicle control ECU falls within the range specified by a common standard.

[0049] Here, the communication bandwidth for communication between the central ECU2 and the second region ECU20b via the second communication bus 42b can be set to be narrower than the communication bandwidth for communication via the first communication bus 41b. This reduces the communication bandwidth of the second communication bus 42b, which is used for communication of non-control data at speeds slower than control data. Therefore, the cost of communication devices using the second communication bus 42b can be reduced without impacting the traffic volume of communication data.

[0050] When no control data is required to be transmitted via the second communication bus 42b, the central ECU2 and the second-region ECU20b communicate non-control data via the second communication bus 42b. This prevents a decrease in control data communication speed due to the generation of non-control data on the second communication bus 42b, ensuring good responsiveness of vehicle control actions performed collaboratively by multiple vehicle control ECUs.

[0051] When control data that should be transmitted via the second communication bus 42b exists, the central ECU2 and the second-region ECU20b do not communicate non-control data via the second communication bus 42b. Therefore, in the second communication bus 42b, when control data communication is required during non-control data communication, the non-control data communication can be stopped, thereby maintaining a high control data communication speed.

[0052] Alternatively, the central ECU2 and the second-region ECU20b can be configured to periodically transmit control data and non-control data via the second communication bus 42b. In this case, when the communication data to be communicated is control data, communication is implemented by increasing the priority of the control data, which can maintain a high communication speed and achieve good responsiveness. On the other hand, when non-control data communication is desired, the priority of the non-control data can be increased.

[0053] [2. Structure of the Vehicle Control ECU]

[0054] The following description uses ECU 20b (Region 2) as an example to illustrate the structure of the vehicle control ECU. While the vehicle control actions of each vehicle control ECU may differ, other vehicle control ECUs also possess the communication function-related structures shown in ECU 20b (Region 2). Here, the aforementioned "communication function-related structures" include... Figure 2 The structural elements in the second region ECU20b shown are other than the control unit 57 and the control program 54.

[0055] Figure 2 This is a diagram showing an example of the structure of the second region ECU20b.

[0056] The second region ECU20b includes: a processor 50, a memory 51, a first communication device 52, and a second communication device 53.

[0057] The first communication device 52 and the second communication device 53 each have a CAN transceiver, which is used to communicate with the central ECU 2 via the first communication bus 41b and the second communication bus 42b, which constitute the CAN communication bus of the second communication line 4b. The first communication device 52 and the second communication device 53 respectively receive communication data for transmission from the first communication management unit 60, which will be described later. In accordance with the prior art, the first communication device 52 and the second communication device 53 respectively store the communication data received from the first communication management unit 60 in a transmission buffer (not shown), which serves as a temporary storage location for transmission data, and send these communication data to the first communication bus 41b and the second communication bus 42b in descending order of priority represented by the ID of each communication data.

[0058] In addition, the first communication device 52 and the second communication device 53 receive communication data from the first communication bus 41b and the second communication bus 42b respectively, and send the received communication data to the first communication management unit 60.

[0059] The first communication device 52 is used for communication of control data, and the second communication device 53 is used for communication of both control data and non-control data. Furthermore, the second communication device 53 can utilize a communication device with a narrower communication bandwidth than the first communication device 52.

[0060] The memory 51 is, for example, composed of volatile and / or non-volatile semiconductor memory. The memory 51 stores a control program 54 to be executed in the processor 50. The memory 51 also stores a first transmit code list 55 and a first receive code list 56.

[0061] The first transmit code list 55 is a list that maps together a category code representing the content category of the transmit data generated by the processor 50, a priority to be assigned to the transmit data, and an identification code representing whether the communication data containing the transmit data corresponds to control data or non-control data. Furthermore, the first receive code list 56 is a list that maps together a category code representing the communication data to be received by the second region ECU 20b, and information representing the destination of the communication data (i.e., any one of the control unit 57, update unit 58, and diagnostic unit 59 described later).

[0062] The processor 50 is a computer provided in the second area ECU20b, and may consist of one or more CPUs (Central Processing Units). The processor 50 may also be configured to have ROM (Read Only Memory) with programs written to it, RAM (Random Access Memory) for temporary data storage, etc.

[0063] The processor 50 includes a control unit 57, an update unit 58, a diagnostic unit 59, and a first communication management unit 60 as functional elements or units. These functional elements of the processor 50 are implemented, for example, by the processor 50, which functions as a computer, executing a control program 54 stored in the memory 51. Furthermore, the control program 54 can be pre-stored in any computer-readable storage medium such as an optical disc, magnetic disk, or flash memory. The control program 54 and its update program are received from an external server device (not shown) communicatively connected to the vehicle via the central ECU 2 with OTA functionality, and then downloaded to the memory 51.

[0064] Control unit 57 controls, for example, the driving actions of the vehicle. For example, based on the driver's operation of the control device connected to the second area ECU 20b, control unit 57 controls the power supply operation from the vehicle's battery to the driving motor, and controls braking and other actions to ensure driving stability.

[0065] Furthermore, the control unit 57 operates in cooperation with, for example, the first area ECU 20a which performs autonomous driving control, to perform vehicle control operations such as automatic driving and parking support. Through these cooperative operations, the control unit 57 transmits and receives control data with other vehicle control ECUs, such as the first area ECU 20a, via the first communication device 52 and / or the second communication device 53.

[0066] Specifically, the control unit 57 generates transmission data containing control-related data to be transmitted. Then, the control unit 57 sends the generated transmission data, along with a category code indicating the content category of the transmission data, to the first communication management unit 60. As will be described later, the first communication management unit 60 generates communication data containing control-related data based on the aforementioned transmission data and sends the generated communication data to other vehicle control ECUs.

[0067] Furthermore, the control unit 57 receives communication data containing control-related data sent from other vehicle control ECUs via the first communication device 52 and / or the second communication device 53 and the first communication management unit 60. Here, the aforementioned communication data containing control-related data is an example of control data.

[0068] When receiving communication data containing an ECU information request from the central ECU2, the update unit 58 determines whether the download object represented by the object information included in the ECU information request is the second region ECU 20b. Then, if the download object is the second region ECU 20b, it generates transmission data containing ECU information, including the model and hardware version of the second region ECU 20b and the software version of the currently used control program 54. The update unit 58 sends the generated transmission data along with a category code indicating the content category of the transmission data (i.e., a category code indicating ECU information) to the first communication management unit 60. The first communication management unit 60 generates communication data containing ECU information based on the aforementioned transmission data and sends the generated communication data to the central ECU2.

[0069] Furthermore, the update unit 58 receives communication data containing program code of the updated control program 54 from the central ECU 2 via the first communication management unit 60. The update unit 58 stores the received program code in the memory 51. Here, the aforementioned communication data containing ECU information requests, communication data containing ECU information, and communication data containing program code are non-control data.

[0070] The diagnostic unit 59 receives communication data containing a diagnostic data request from the vehicle diagnostic device 40, which is connected to the vehicle from outside via the DLC 19, via the central ECU 2. Correspondingly, the diagnostic unit 59 generates transmission data including diagnostic data requested by the received diagnostic data request. Then, the diagnostic unit 59 sends the generated transmission data, along with a category code indicating the content category of the transmission data, to the first communication management unit 60. The first communication management unit 60 generates communication data containing diagnostic data based on the aforementioned transmission data and sends the generated communication data to the vehicle diagnostic device via the central ECU 2. Here, the communication data containing the diagnostic data request and the communication data containing the diagnostic data are non-control data.

[0071] The first communication management unit 60 manages communications within the second region ECU 20b via the first communication bus 41b and the second communication bus 42b. Specifically, when the first communication device 52 or the second communication device 53 receives communication data from the first communication bus 41b or the second communication bus 42b, respectively, the first communication management unit 60 extracts a category code representing the content category from the ID of the communication data. Referring to the first receive code list 56 stored in the memory 51, the first communication management unit 60 discards the received communication data if the extracted category code is not included in the first receive code list 56.

[0072] On the other hand, when the extracted category code is included in the first receive code list 56, the received communication data is sent to the control unit 57, the update unit 58, or the diagnostic unit 59 according to the sending destination corresponding to the category code indicated in the first receive code list 56.

[0073] Furthermore, when the first communication management unit 60 receives transmission data from the control unit 57, the update unit 58, or the diagnostic unit 59, it refers to the first transmission code list 55 and generates an ID that includes a category code assigned to the transmission data, a priority corresponding to the category code, and an identification code. Then, the first communication management unit 60 generates communication data that includes the received transmission data and the generated ID.

[0074] Furthermore, the first communication management unit 60 determines whether the communication data is control data or non-control data based on the identification code of the ID of the generated communication data. Then, when the generated communication data is control data, the first communication management unit 60 sends the communication data to the first communication bus 41b or the second communication bus 42b via the first communication device 52 or the second communication device 53, respectively.

[0075] Specifically, the first communication management unit 60 determines the redundancy of the transmission operation of the first communication device 52. If the generated communication data is control data and the first communication device 52 has sufficient transmission capacity, the first communication management unit 60 sends the generated communication data to the first communication device 52. On the other hand, if the generated communication data is control data and the first communication device 52 does not have sufficient transmission capacity, the first communication management unit 60 sends the generated communication data to the second communication device 53.

[0076] As described above, the first communication device 52 and the second communication device 53 send these communication data to the first communication bus 41b and the second communication bus 42b in descending order of priority represented by the ID of the communication data.

[0077] Here, the redundancy of the transmission operation of the first communication device 52 can be determined, for example, based on the average dwell time of communication data in the transmission buffer of the first communication device 52 within the most recent specified time period (i.e., the average time from when the communication data is saved in the transmission buffer until it is transmitted to the first communication bus 41b). The first communication management unit 60, for example, compares the above-mentioned average dwell time in the first communication device 52 with a predetermined threshold, and if the average dwell time is above the threshold, it determines that the corresponding transmission operation of the first communication device 52 has no redundancy.

[0078] On the other hand, when the generated communication data is non-control data, the first communication management unit 60 transmits the communication data to the second communication bus 42b via the second communication device 53. In this case, when there is no control data to be transmitted via the second communication bus 42b, the first communication management unit 60 can perform non-control data communication via the second communication bus 42b. Specifically, when the transmission buffer of the second communication device 53 connected to the second communication bus 42b does not contain communication data as control data, the first communication management unit 60 transmits communication data as non-control data to the second communication device 53.

[0079] Furthermore, when control data to be transmitted via the second communication bus 42b exists, the first communication management unit 60 does not perform communication of non-control data via the second communication bus 42b. Specifically, when communication data as control data is stored in the transmission buffer of the second communication device 53 connected to the second communication bus 42b, or when the second communication device 53 receives control data from the second communication bus 42b within the most recent predetermined time, the first communication management unit 60 does not send communication data as non-control data to the second communication device 53. Alternatively, when communication data as non-control data is stored in the transmission buffer of the second communication device 53, and communication data as control data is sent to the second communication device 53, the first communication management unit 60 instructs the second communication device 53 to discard (i.e., delete) the communication data as non-control data in the transmission buffer. The first communication management unit 60 can temporarily store the non-control data in advance and then retry transmitting the discarded non-control data.

[0080] In the above-described manner, the first communication device 52 can measure the average dwell time and send the measurement result to the first communication management unit 60. Furthermore, the second communication device 53 can send a list of IDs of communication data stored in the transmission buffer to the first communication management unit 60 upon request from the first communication management unit 60. Thus, the first communication management unit 60 can determine, based on the aforementioned ID list, whether communication data as non-control data and / or communication data as control data is stored in the transmission buffer of the second communication device 53.

[0081] Furthermore, in response to receiving communication data containing a priority change request from the central ECU2, the first communication management unit 60 increases the priority of non-control data listed in the first transmission code list 55 by a predetermined level. Additionally, in response to receiving communication data containing an initialization request from the central ECU2, the first communication management unit 60 sets the priority of non-control data listed in the first transmission code list 55 to a predetermined initial value.

[0082] [3. Structure of the relay device]

[0083] Next, the structure of the central ECU2, which serves as a relay device, will be explained.

[0084] The central ECU2 relays data communication between multiple vehicle control ECUs installed in this vehicle.

[0085] Figure 3This diagram illustrates an example of the structure of the central ECU2. The central ECU2 includes: a processor 70, a memory 71, a third communication device 72, a fourth communication device 73, and a fifth communication device 74. The third communication device 72 includes three transceivers 721, 722, and 723 that communicate via each of the three first communication buses 41a, 41b, and 41c. Furthermore, the fourth communication device 73 includes three transceivers 731, 732, and 733 that communicate via each of the three second communication buses 42a, 42b, and 42c. These transceivers 721, 722, 723, and 731, 732, and 733 are, for example, CAN transceivers for CAN communication.

[0086] The transceivers 721, 722, and 723 of the third communication device 72 and the transceivers 731, 732, and 733 of the fourth communication device 73, according to existing technology, store the communication data for transmission received from the second communication management unit 83 (described later) in a transmission buffer (not shown), which serves as a temporary storage location for the transmission data of each transceiver. Then, these transceivers send the communication data to the first communication bus 41 and the second communication bus 42 in descending order of priority represented by the ID of each communication data.

[0087] The third communication device 72 is used for communication of control data, and the fourth communication device 73 is used for communication of both control data and non-control data. Furthermore, a communication device with a narrower communication bandwidth than the third communication device 72 can be used in the fourth communication device 73.

[0088] Memory 71 is, for example, a volatile and / or non-volatile semiconductor memory. Memory 71 stores a relay control program 75 that should be executed in processor 70. Memory 71 also stores an ID list 76. The ID list 76 is a list of IDs of communication data communicated via the first communication bus 41 and the second communication bus 42.

[0089] The memory 71 also stores a second transmit code list 77 and a second receive code list 78. The second transmit code list 77 is a list that maps the content category of the transmit data generated by the OTA management unit 81, diagnostic communication unit 82, and priority management unit 84 of the processor 70 (described later), the priority to be assigned to the transmit data, and an identification code indicating whether the communication data containing the transmit data corresponds to control data or non-control data. Furthermore, the second receive code list 78 is a list that maps the category code of the communication data to be received by the central ECU 2, and information indicating the destination of the communication data (i.e., the OTA management unit 81 or the diagnostic communication unit 82 described later).

[0090] The processor 70 is a computer provided by the central ECU2, and may consist of one or more CPUs. The processor 70 may also be configured to have a ROM with a program written to it, RAM for temporary data storage, etc.

[0091] The processor 70 includes a relay unit 80, an OTA management unit 81, a diagnostic communication unit 82, a second communication management unit 83, and a priority management unit 84 as functional elements or units. These functional elements of the processor 70 are implemented, for example, by the processor 70, which functions as a computer, executing a relay control program 75 stored in the memory 71. Furthermore, the relay control program 75 can be pre-stored in any computer-readable storage medium such as an optical disc, magnetic disk, or flash memory. In addition, the relay control program 75 and its update program can be downloaded to the memory 71 from a server device communicatively connected to the vehicle.

[0092] The relay unit 80 relays data communication between multiple vehicle control ECUs. Specifically, the relay unit 80 receives communication data received from the second communication management unit 83 via the third communication device 72 or the fourth communication device 73 from one of the second communication lines 4a, 4b, and 4c, along with receiving line information indicating which of the second communication lines 4a, 4b, and 4c the communication data was received from. The relay unit 80 compares the ID contained in the received communication data with the IDs of valid communication data represented in the ID list 76. Then, if the ID of the received communication data does not match any of the valid communication data IDs, the relay unit 80 discards the received communication data.

[0093] On the other hand, when the ID of the received communication data matches one of the IDs of valid communication data, the relay unit 80 sends the received communication data along with its receiving line information to the second communication management unit 83. The second communication management unit 83 then sends the received communication data to the second communication lines 4a, 4b, and 4c, excluding the second communication line indicated by the receiving line information.

[0094] The OTA management unit 81 downloads the update program of the control program of the vehicle control ECU (e.g., the control program 54 of the second area ECU 20b) to the corresponding vehicle control ECU via the TCU12 from a server device (not shown) that is communicatively connected to the vehicle.

[0095] Specifically, the OTA management unit 81 receives the update program download instruction and update program from the server device via the TCU 12 and stores them in the memory 71. The download instruction includes application information indicating the application conditions of the update program and object information for specifying the vehicle control ECU as the download target.

[0096] In response to receiving the download instruction, the OTA management unit 81 generates transmission data containing an ECU information request, which includes the aforementioned object information. The OTA management unit 81 sends the generated transmission data, along with a category code indicating the content category of the transmission data, to the second communication management unit 83. The second communication management unit 83 generates communication data containing the ECU information request based on the transmission data and sends the generated communication data to the second communication lines 4a, 4b, and 4c.

[0097] The OTA management unit 81 receives communication data containing ECU information from the vehicle control ECU. Based on the application information of the download instruction received from the server device and the model, hardware version, and software version of the vehicle control ECU represented by the ECU information contained in the received communication data, the OTA management unit 81 determines whether an update program should be downloaded to the vehicle control ECU.

[0098] Then, when the OTA management unit 81 determines that the ECU information matches the application information and that the update program should be downloaded to the vehicle control ECU, it generates transmission data containing the update program received from the server device and stored in the memory 71. The OTA management unit 81 sends the generated transmission data along with a category code indicating the content category of the transmission data to the second communication management unit 83.

[0099] The second communication management unit 83 generates communication data containing the update program based on the aforementioned transmission data, and sends the generated communication data to the corresponding vehicle control ECU via the second communication line 4. Furthermore, the update program can be divided into multiple communication data segments for transmission according to existing technology.

[0100] In response to receiving a diagnostic data request from the vehicle diagnostic device 40 connected to DLC19, the diagnostic communication unit 82 generates transmission data containing the received diagnostic data request. The diagnostic communication unit 82 sends the generated transmission data, along with a category code indicating the content category of the transmission data, to the second communication management unit 83. The second communication management unit 83 generates communication data containing the diagnostic data request based on the aforementioned transmission data and transmits the generated communication data to the second communication lines 4a, 4b, and 4c.

[0101] The diagnostic communication unit 82 receives communication data containing diagnostic data from the vehicle control ECU and sends the diagnostic data contained in the received communication data to the vehicle diagnostic device 40 via the first communication line 3 using the fifth communication device 74.

[0102] The second communication management unit 83 manages the communication in the central ECU2 via the first communication bus 41 and the second communication bus 42. Specifically, the second communication management unit 83 sends communication data received from one of the second communication lines 4a, 4b, and 4c via the third communication device 72 or the fourth communication device 73, along with receiving line information indicating which second communication line the communication data was received from, to the relay unit 80.

[0103] Furthermore, when the second communication management unit 83 receives communication data from one of the second communication lines 4a, 4b, and 4c via the third communication device 72 or the fourth communication device 73, it extracts a category code representing the content category from the ID of the communication data. Referring to the second receive code list 78 stored in the memory 71, if the extracted category code is included in the second receive code list 78, the second communication management unit 83 sends the received communication data to the OTA management unit 81 or the diagnostic communication unit 82 according to the transmission destination corresponding to the category code indicated in the second receive code list 78.

[0104] Furthermore, when the second communication management unit 83 receives transmission data from the OTA management unit 81 or the diagnostic communication unit 82, it refers to the second transmission code list 77 and generates an ID that includes a category code assigned to the transmission data, and a priority and identification code corresponding to that category code. Then, the second communication management unit 83 generates communication data that includes the received transmission data and the generated ID.

[0105] Furthermore, the second communication management unit 83 determines whether the generated communication data is control data or non-control data based on the identification code contained in the ID of the generated communication data. Then, if the generated communication data is control data, the second communication management unit 83 transmits the communication data to the first communication bus 41 or the second communication bus 42 via the third communication device 72 or the fourth communication device 73, respectively. If the generated communication data is non-control data, the second communication management unit 83 transmits the communication data to the second communication bus 42 via the fourth communication device 73.

[0106] Furthermore, when the second communication management unit 83 receives the received communication data and receiving line information from the relay unit 80, it determines whether the communication data is control data or non-control data based on the ID contained in the received communication data. Then, if the received communication data is control data, the second communication management unit 83 transmits the communication data via the third communication device 72 or the fourth communication device 73 to the first communication bus 41 or the second communication bus 42 of the second communication line 4 other than the second communication line 4 indicated by the received line information. Furthermore, if the received communication data is non-control data, the second communication management unit 83 transmits the communication data via the fourth communication device 73 to the second communication bus 42 of the second communication line 4 other than the second communication line 4 indicated by the received line information.

[0107] Specifically, the second communication management unit 83 determines the redundancy of transmission operations for each of the three transceivers 721, 722, and 723 of the third communication device 72, which are respectively connected to the second communication lines 4a, 4b, and 4c. Then, when the communication data to be transmitted (i.e., the generated communication data or the communication data received from the relay unit 80) is control data and the transmission operations of the transceivers 721, 722, and 723 are all redundant, the second communication management unit 83 transmits the communication data to be transmitted to the three transceivers 721, 722, and 723 of the third communication device 72.

[0108] On the other hand, when the communication data to be transmitted is control data and any of the transceivers 721, 722, and 723 has no spare transmission operation, the transceiver 731, 732, or 733, which has no spare transmission operation, is used instead of the transceiver with no spare transmission operation to transmit the aforementioned communication data to a transceiver 731, 732, or 733 connected to a fourth communication device 73 via a second communication line, which is the same as the second communication line 4a, 4b, or 4c to which the transceiver is connected. That is, for example, when the transceiver 721 connected to the first communication bus 41a of the second communication line 4a has no spare transmission operation, the second communication management unit 83 transmits the communication data to be transmitted to a transceiver 731 connected to the second communication bus 42a of the same second communication line 4a.

[0109] Furthermore, in the above, when the communication data to be transmitted is communication data received from the relay unit 80 as a relay object, the second communication management unit 83 excludes transceivers 721, 722, or 723 and transceivers 731, 732, or 733 connected to the second communication lines 4a, 4b, or 4c indicated by the receiving line information of the communication data from the above-mentioned redundancy judgment objects and the transmission destination of the communication data to be transmitted.

[0110] That is, for example, when receiving line information indicating the second communication line 4b, the second communication management unit 83 excludes the transceiver 722 connected to the first communication bus 41b of the second communication line 4b from the objects of the redundancy judgment of the transmission operation, and excludes the transceivers 722 and 732 connected to the first communication bus 41b and the second communication bus 42b of the second communication line 4b, respectively, from the transmission destinations of communication data that are relay objects.

[0111] Here, the redundancy of the transmission actions of transceivers 721, 722, 723, 731, 732, and 733 can be determined based on the average dwell time of communication data within the most recent specified time period in the transmission buffer of each transceiver. The second communication management unit 83, for example, compares the aforementioned average dwell time of each transceiver with a specified threshold. If the average dwell time is above the threshold, it is determined that the corresponding transceiver's transmission action has no redundancy.

[0112] Furthermore, on the other hand, when the communication data to be transmitted is non-control data, the second communication management unit 83 transmits the communication data to the second communication bus 42 of each of the second communication lines 4a, 4b, and 4c via transceivers 731, 732, and 733 of the fourth communication device 73. In this case, for each of the second communication lines 4a, 4b, and 4c, when there is no control data to be transmitted via the second communication bus 42, the second communication management unit 83 can perform non-control data communication via the second communication bus 42. Specifically, for each of the second communication lines 4a, 4b, and 4c, when there is no communication data as control data stored in the transmit buffers of transceivers 731, 732, and 733 connected to the second communication bus 42, the second communication management unit 83 transmits communication data as non-control data to transceivers 731, 732, and 733.

[0113] Furthermore, when it is determined that control data that should be transmitted via the second communication bus 42 exists for each of the second communication lines 4a, 4b, and 4c, the second communication management unit 83 does not perform communication of non-control data via the second communication bus 42. Specifically, for each of the second communication lines 4a, 4b, and 4c, the second communication management unit 83 determines whether communication data as control data is stored in the transmit buffer of the transceiver 731, 732, or 733 connected to the second communication bus 42. If control data is stored in the transmit buffer of any of these transceivers, communication data as non-control data is not transmitted to that transceiver.

[0114] In addition, the second communication management unit 83 determines whether control data has been received from the second communication bus 42 by transceivers 731, 732 or 733 within the most recent specified time. When control data is received by any of these transceivers within the most recent specified time, communication data as non-control data is not sent to that transceiver.

[0115] Alternatively, if any of the transceivers 731, 732, and 733 connected to the second communication bus 42 stores communication data as non-control data in its transmit buffer, when transmitting communication data as control data to that transceiver, the second communication management unit 83 instructs that transceiver to discard the communication data as non-control data in its transmit buffer. The second communication management unit 83 can temporarily store the non-control data in advance and then retry transmitting the discarded non-control data.

[0116] In the above, the third communication device 72 can measure the average dwell time of each of the transceivers 721, 722, and 723, and send the measurement result to the second communication management unit 83. Furthermore, the fourth communication device 73 can send a list of IDs of communication data stored in the transmission buffers of each of the transceivers 731, 732, and 733, upon request from the second communication management unit 83. Therefore, the second communication management unit 83 can determine, based on the ID list, whether communication data as non-control data and / or communication data as control data is stored in the transmission buffers of the transceivers 731, 732, and 733.

[0117] The priority management unit 84 manages the allocation of priorities for non-control data. In this embodiment, when the vehicle is parked, the priority management unit 84 assigns a higher priority to non-control data compared to when the vehicle is not parked. Specifically, when the vehicle is parked, the priority management unit 84 generates transmission data containing a priority change indication. Then, the priority management unit 84 sends the generated transmission data along with a category code indicating the content category of the transmission data to the second communication management unit 83. The second communication management unit 83 generates communication data containing a priority change indication based on the aforementioned transmission data and sends the generated communication data to all second communication lines 4. The communication data containing the priority change indication is non-control data. Upon receiving the communication data containing the priority change indication, the vehicle control ECU, such as the second area ECU 20b, uses the first communication management unit 60 to increase the priority of the non-control data listed in the first transmission code list 55 by a predetermined level.

[0118] Furthermore, when the vehicle has already stopped, the priority management unit 84 will increase the priority of the non-control data listed in the second transmission code list 77 stored in the memory 71 by a predetermined level. Also, when the vehicle has already stopped, the priority management unit 84 will change the ID list 76 stored in the memory 71 to match the priority of the non-control data that has been changed in the vehicle control ECU according to the aforementioned priority change instruction.

[0119] Furthermore, when the vehicle begins to move, the priority management unit 84 sets the priority of non-control data to an initial value. Specifically, when the vehicle begins to move, the priority management unit 84 generates transmission data containing an initialization instruction. Then, the priority management unit 84 sends the generated transmission data along with a category code indicating the content category of the transmission data to the second communication management unit 83. The second communication management unit 83 generates communication data containing an initialization instruction based on the aforementioned transmission data and sends the generated communication data to the second communication line 4. The communication data containing the initialization instruction is non-control data. Upon receiving the communication data containing the initialization instruction, the vehicle control ECU, such as the second area ECU 20b, sets the priority of the non-control data listed in the first transmission code list 55 to a predetermined initial value via the first communication management unit 60.

[0120] Furthermore, when the vehicle starts moving, the priority management unit 84 sets the priority of the non-control data listed in the second transmission code list 77 stored in the memory 71 to a predetermined initial value. Also, when the vehicle starts moving, the priority management unit 84 changes the ID list 76 stored in the memory 71 to match the priority of the non-control data that was set to the initial value in the vehicle control ECU according to the aforementioned initialization instruction.

[0121] In the above, the priority management unit 84 can determine whether the vehicle is in a parked state and whether the vehicle has started to move based on the vehicle speed detected by the vehicle speed sensor (not shown) equipped with the vehicle.

[0122] Furthermore, when the vehicle diagnostic device 40 is connected to the central ECU 2 via the DLC 19, the priority management unit 84 assigns a higher priority to non-control data compared to when the vehicle diagnostic device 40 is not connected. Additionally, when the vehicle diagnostic device 40 is disconnected from the DLC 19, the priority management unit 84 sets the priority of the non-control data to its initial value. Here, priority changes and initial value settings can be performed in the same manner as described above. Furthermore, along with these priority changes or initial value settings, the priority management unit 84 changes the priority of the non-control data listed in the second transmission code list 77 stored in the memory 71 or sets that priority to its initial value, and changes the ID list 76 stored in the memory 71 to match the priority of the non-control data that has been changed or set to its initial value in the vehicle control ECU.

[0123] Here, when the diagnostic communication unit 82 receives a diagnostic data request from the vehicle diagnostic device 40, the priority management unit 84 can detect that the vehicle diagnostic device 40 is connected to the DLC 19. Furthermore, for example, when the diagnostic communication unit 82 receives a diagnostic completion notification from the vehicle diagnostic device 40, the priority management unit 84 can determine that the vehicle diagnostic device 40 has been disconnected from the DLC 19.

[0124] [4. Processing steps in the vehicle communication system]

[0125] Next, the communication processing steps between the vehicle control ECU and the relay device in the control system 1, which is the vehicle communication system, will be explained.

[0126] Figure 4 This is a flowchart illustrating the steps of communication processing performed by the first communication management unit 60 in the second area ECU20b, which is a vehicle control ECU. This processing is repeatedly performed by the first communication management unit 60.

[0127] When processing begins, the first communication management unit 60 determines whether a priority change instruction has been received from the central ECU 2 (S100). Then, if a priority change instruction is received (S100, yes), the first communication management unit 60 assigns a higher priority to the non-control data represented by the first transmission code list 55 stored in the memory 51 (S102), and then ends the processing.

[0128] On the other hand, if no priority change instruction is received in step S100 (S100, No), the first communication management unit 60 determines whether an initialization instruction sent from the central ECU2 has been received (S104). Then, if an initialization instruction is received (S104, Yes), the first communication management unit 60 sets the priority of the non-control data represented by the first transmission code list 55 stored in the memory 51 to a predetermined initial value (S106), and then ends the process.

[0129] On the other hand, if no initialization instruction is received in step S104 (S104, No), the first communication management unit 60 determines whether transmission data has been received from the control unit 57, update unit 58, or diagnostic unit 59 (S108). Then, if no transmission data is received (S108, No), the first communication management unit 60 returns to step S100 and repeats the process. On the other hand, if transmission data is received (S108, Yes), the first communication management unit 60 generates communication data containing the received transmission data (S110).

[0130] Next, the first communication management unit 60 determines whether the generated communication data is control data (S112). Then, if the generated communication data is control data (S112, yes), the first communication management unit 60 determines whether the transmission operation of the first communication device 52 has surplus capacity (S114). Then, if the transmission operation of the first communication device 52 has surplus capacity (S114, yes), the first communication management unit 60 transmits the control data, which is the aforementioned communication data, via the first communication device 52 through the first communication bus 41b (S116), and ends this process.

[0131] On the other hand, in step S114, when the transmission operation of the first communication device 52 is not sufficient (S114, No), the first communication management unit 60 transmits control data, which is the aforementioned communication data, via the second communication device 53 through the second communication bus 42b (S118), and ends this process.

[0132] Furthermore, on the other hand, in step S112, if the communication data generated in step S110 is not control data, i.e., non-control data (S112, No), the first communication management unit 60 determines whether there is control data that should be transmitted via the second communication bus (S120). Then, if there is control data that should be transmitted via the second communication bus 42b (S120, Yes), the first communication management unit 60 discards the generated communication data, i.e., non-control data (S122), and ends the process.

[0133] On the other hand, if there is no control data to be sent via the second communication bus 42b in step S120 (S120, No), the first communication management unit 60 sends the generated communication data, i.e., non-control data, via the second communication device 53 via the second communication bus 42b (S124), and ends the process.

[0134] Figure 5 This is a flowchart illustrating the steps of communication processing performed by the second communication management unit 83 in the central ECU2, which acts as a relay device. This processing is repeatedly performed by the second communication management unit 83.

[0135] When processing begins, the second communication management unit 83 first determines whether the communication data to be relayed has been received from the relay unit 80 (S200). Then, if the communication data to be relayed has not been received (S200, no), the second communication management unit 83 determines whether the transmission data has been received from the OTA management unit 81, the diagnostic communication unit 82, or the priority management unit 84 (S202).

[0136] Then, if no data for transmission is received (S202, No), the second communication management unit 83 returns to step S200 and repeats the process until the communication data to be relayed or the data for transmission is received.

[0137] On the other hand, when the transmission data is received in step S202 (S202, Yes), the second communication management unit 83 generates communication data containing the received transmission data (S204), and the second communication management unit 83 transfers the processing to step S206.

[0138] Furthermore, on the other hand, in step S200, when the communication data to be relayed is received (S200, Yes), the second communication management unit 83 transfers the processing to step S206.

[0139] In step S206, the second communication management unit 83 determines whether the communication data to be relayed or the aforementioned communication data (hereinafter referred to as the communication data to be sent) is control data. Then, if the communication data to be sent is control data (S206, Yes), the second communication management unit 83 transfers the processing to step S208.

[0140] Hereinafter, the transceivers 721, 722, and 723 of the third communication device 72 will be treated as processing objects, and the processing steps S208 to S210 will be performed individually. Hereinafter, the transceivers 721, 722, or 723 treated as processing objects will be referred to as "the object transceivers of the third communication device 72".

[0141] In step S208, the second communication management unit 83 determines whether there is sufficient transmission capacity in the target transceiver of the third communication device 72. Then, if there is sufficient transmission capacity in the target transceiver of the third communication device 72 (S208, Yes), the second communication management unit 83 transmits the aforementioned communication data, i.e., control data, which is the target of transmission, via the first communication bus 41 through the target transceiver of the third communication device 72 (S210), thus ending this process.

[0142] On the other hand, in step S208, if the transmission operation of the target transceiver of the third communication device 72 is insufficient (S208, No), the second communication management unit 83 transmits the aforementioned communication data, i.e., control data, which is the transmission target, via the second communication bus 42 through the transceiver of the fourth communication device 73 corresponding to the target transceiver of the third communication device 72 (S212), thus ending this process. Here, "the transceiver of the fourth communication device 73 corresponding to the target transceiver of the third communication device 72" refers to the transceiver of the fourth communication device 73 connected to the second communication bus 42, which corresponds to the first communication bus 41 connected to the target transceiver of the third communication device 72. That is, the transceivers of the fourth communication device 73 corresponding to the transceivers 721, 722, and 723 of the third communication device 72 are transceivers 731, 732, and 733, respectively.

[0143] On the other hand, when the communication data to be sent in step S206 is not control data, that is, when it is non-control data (S206, No), the second communication management unit 83 transfers the processing to step S214.

[0144] Hereinafter, the transceivers 731, 732, and 733 of the fourth communication device 73 will be treated as processing objects, and the processing steps S214 to S218 will be performed individually. Hereinafter, the transceivers 731, 732, or 733 treated as processing objects will be referred to as "the object transceivers of the fourth communication device 73".

[0145] In step S214, the second communication management unit 83 determines whether there is control data to be transmitted via the second communication bus 42 connected to the target transceiver of the fourth communication device 73. Then, if there is control data to be transmitted via the second communication bus 42 connected to the target transceiver of the fourth communication device 73 (S214, Yes), the second communication management unit 83 discards the aforementioned communication data to be transmitted, i.e., non-control data (S216), and ends the process.

[0146] On the other hand, in step S214, if there is no control data to be sent via the second communication bus 42 connected to the target transceiver of the fourth communication device 73 (S214, No), the aforementioned communication data, i.e. non-control data, which is the target of the transmission, is sent via the second communication bus 42 connected to the target transceiver of the fourth communication device 73 (S218), and this process ends.

[0147] In addition, Figure 4 S108, S110 or Figure 5 In S202 and S204, the configuration is to generate communication data after receiving the data to be transmitted, but it is not limited to this. If the configuration is to initially include the data to be transmitted, the category code, the identification code, the ID, etc., as communication data for transmission, then the generation step can be omitted.

[0148] In addition, Figure 4 S122 or Figure 5 S216 describes a structure for discarding non-control data, but it is not limited to this. It can also be configured to pre-reserve non-control data and then send the non-control data when it is possible to send it.

[0149] [5. Other Implementation Methods]

[0150] Furthermore, the present invention is not limited to the structure of the embodiments described above, and can be implemented in various ways without departing from its spirit.

[0151] For example, in the above embodiment, the communication between the central ECU2, which acts as a relay device, and the second area ECU20b, which acts as a vehicle control ECU, follows the CAN communication standard. However, as long as the priority of the communication data can be defined, communication can be performed according to any communication standard or communication method. For example, the relay device and the vehicle control ECU can also communicate via Ethernet (registered trademark) or USB.

[0152] Furthermore, in the above embodiment, when there is no redundancy in the transmission operation of the first communication device 52 connected to the first communication bus 41b, the first communication management unit 60 transmits control data via the second communication device 53 through the second communication bus 42b. Not limited to this, the first communication management unit 60 may also redundancy control data communication via the first communication bus 41b and the second communication bus 42b. For example, for specific control data, the first communication management unit 60 may simultaneously transmit the same specific control data via both the first communication device 52 and the second communication device 53 through the first communication bus 41b and the second communication bus 42b.

[0153] [6. Structure supported by the above embodiments]

[0154] The above implementation supports the following structure.

[0155] (Structure 1) A vehicle communication system, comprising: a relay device for relaying data communication between a plurality of vehicle control ECUs mounted in a vehicle; and two communication buses connecting the relay device to each of the vehicle control ECUs, wherein the relay device and the vehicle control ECUs use a first communication bus, which is one of the two communication buses, to communicate control data related to the control actions of the vehicle, and the relay device and the vehicle control ECUs use a second communication bus, which is the other of the two communication buses, to communicate the control data and / or non-control data other than data related to the control actions of the vehicle.

[0156] According to the vehicle communication system of Structure 1, good communication of non-control data such as diagnostic data can be ensured without setting up a dedicated communication line for transmitting diagnostic data, and the communication volume of control data required for vehicle movement control can be increased and / or redundant.

[0157] (Structure 2) Based on the vehicle communication system described in Structure 1, the data used for communication between the relay device and the vehicle control ECU is prioritized. The relay device and the vehicle control ECU communicate with data that has been assigned a higher priority than other data. The control data is assigned a higher priority than the non-control data.

[0158] According to the vehicle communication system of Structure 2, it is possible to prevent the communication speed of control data from decreasing due to the generation of non-control data, and to ensure good responsiveness of vehicle control actions performed collaboratively by multiple vehicle control ECUs.

[0159] (Structure 3) Based on the vehicle communication system described in Structure 2, the relay device has a priority management unit that manages the allocation of priority for the non-control data. When the vehicle is in a parked state, the priority management unit allocates a higher priority to the non-control data compared to when the vehicle is not parked.

[0160] According to the vehicle communication system of structure 3, during the period when the vehicle is in a parked state and vehicle control is not required, the communication speed of non-control data can be improved, thus enabling, for example, the update program of the vehicle control ECU to be executed quickly.

[0161] (Structure 4) Based on the vehicle communication system described in Structure 2 or 3, the relay device has a priority management unit that manages the allocation of priority for the non-control data, which includes diagnostic data that is communicated between a vehicle diagnostic device and the vehicle control ECU. The vehicle diagnostic device is connected to the relay device from outside the vehicle. When the vehicle diagnostic device is connected to the relay device, the priority management unit assigns a higher priority to the non-control data compared to when the vehicle diagnostic device is not connected.

[0162] Connecting the vehicle diagnostic device from the outside of the vehicle is limited to when the vehicle is parked. Therefore, according to the vehicle communication system of structure 4, the speed of diagnosis including the communication of diagnostic data can be ensured without affecting the speed of control of the vehicle while it is in motion.

[0163] (Structure 5) Based on the vehicle communication system described in any one of Structures 1 to 4, the communication bandwidth of the communication between the relay device and the vehicle control ECU via the second communication bus is narrower than the communication bandwidth of the communication via the first communication bus.

[0164] According to the vehicle communication system of structure 5, the communication bandwidth of the second communication bus for communicating non-control data at a speed slower than that of control data is reduced. Therefore, the cost of communication devices using the second communication bus can be reduced without affecting the traffic volume of communication data.

[0165] (Structure 6) Based on the vehicle communication system described in any one of Structures 1 to 5, the relay device includes a first communication management unit that manages communication via the second communication bus, and the vehicle control ECU includes a second communication management unit that manages communication via the second communication bus. When there is no control data to be transmitted via the second communication bus, the first communication management unit and the second communication management unit communicate the non-control data via the second communication bus.

[0166] According to the vehicle communication system of structure 6, it is possible to prevent the communication speed of control data from decreasing due to the generation of non-control data in the second communication bus, and to ensure good responsiveness of vehicle control actions performed collaboratively by multiple vehicle control ECUs.

[0167] (Structure 7) Based on the vehicle communication system described in any one of Structures 1 to 6, the relay device includes a first communication management unit that manages communication via the second communication bus, and the vehicle control ECU includes a second communication management unit that manages communication via the second communication bus. When there is control data that should be sent via the second communication bus, the first communication management unit and the second communication management unit do not communicate the non-control data via the second communication bus.

[0168] According to the vehicle communication system of structure 7, in the second communication bus, when control data communication is required during non-control data communication, the non-control data communication can be stopped, and the control data communication speed can be maintained at a high level.

Claims

1. A vehicle communication system, wherein, The vehicle communication system includes: A relay device that relays data communication between multiple vehicle control ECUs mounted in the vehicle; and Two communication buses connect the relay device to one of the plurality of vehicle control ECUs. The relay device and the vehicle control ECU each have a first communication management unit and a second communication management unit for managing communication. The relay device and the vehicle control ECU use the first communication bus, which is one of the two communication buses, to communicate control data related to the vehicle's control actions. The relay device and the vehicle control ECU use a second communication bus, which is the other of the two communication buses, to communicate the control data and / or non-control data other than data related to the vehicle's control actions. When the first communication management unit and the second communication management unit communicate the control data, if there is sufficient margin for transmission based on the first communication bus, they communicate the control data via the first communication bus; if there is no margin for transmission based on the first communication bus, they communicate the control data via the second communication bus. The redundancy is determined based on the retention status of the control data in the transmit buffer used in transmission based on the first communication bus. The latency status refers to the average latency of the control data in the transmission buffer. The condition that is determined to have the aforementioned margin of safety includes the condition that the average residence time is less than a predetermined threshold.

2. The vehicle communication system according to claim 1, wherein, The data allocation for communication between the relay device and the vehicle control ECU is prioritized. The relay device and the vehicle control ECU will communicate with data assigned a higher priority than other data. The control data is assigned a higher priority than the non-control data.

3. The vehicle communication system according to claim 2, wherein, The relay device includes a priority management unit that manages the allocation of priorities for the non-control data. When the vehicle is parked, the priority management unit assigns a higher priority to the non-control data compared to when the vehicle is not parked.

4. The vehicle communication system according to claim 2, wherein, The relay device includes a priority management unit that manages the allocation of priorities for the non-control data. The non-control data includes diagnostic data used in communication between the vehicle diagnostic device and the vehicle control ECU, the vehicle diagnostic device being connected to the relay device from outside the vehicle. When the vehicle diagnostic device is connected to the relay device, the priority management unit assigns a higher priority to the non-control data compared to when the vehicle diagnostic device is not connected.

5. The vehicle communication system according to claim 1, wherein, The communication bandwidth of the communication between the relay device and the vehicle control ECU via the second communication bus is narrower than that of the communication via the first communication bus.

6. The vehicle communication system according to claim 1, wherein, When there is no control data that should be transmitted via the second communication bus, the first communication management unit and the second communication management unit communicate the non-control data via the second communication bus.

7. The vehicle communication system according to any one of claims 1 to 6, wherein, When there is control data that should be transmitted via the second communication bus, the first communication management unit and the second communication management unit do not communicate the non-control data via the second communication bus.

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