Vehicular fault diagnosis system

Abstract

To enable a system connecting a plurality of ECUs by a bus to easily estimate the location of an abnormality in more detail, when the abnormality occurs.SOLUTION: A vehicular fault diagnosis system includes target ECUs such as a first ECU 30, a second ECU 40, and a third ECU 50, a fault diagnosis device 10 connected to the first ECU 30 via a diagnostic I / F 20, and buses A and B that connect the target ECUs in a bus configuration, the fault diagnosis device 10 includes an information receiving unit that receives ECU-related information output from the target ECU, and a diagnosis unit that diagnoses an abnormality in a communication system 2 including the target ECU and the buses A and B by using a reception status of the ECU-related information at the information receiving unit, and the buses A and B are provided in parallel for each of a plurality of target ECUs including the first ECU 30.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a fault diagnosis system for a vehicle. [Background technology]

[0002] Patent Document 1 discloses a technique for identifying an abnormality in communication. In Patent Document 1, a plurality of connector connection parts are provided on a communication path between a first ECU and a plurality of second ECUs. In Patent Document 1, each of the plurality of connector connection parts has a first connector part on the first ECU side on the communication path and a second connector part on the second ECU side. In Patent Document 1, each ECU is connected by a communication line such as a single-wire bus. In Patent Document 1, when a communication abnormality occurs, it is determined that the abnormality exists among the connector connection parts having an abnormality in communication with all the second ECUs connected to the second connector part side. In Patent Document 1, it is determined that the abnormality exists in the connector connection part with the largest number of second ECUs connected among the connector connection parts. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-14039 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology disclosed in Patent Document 1, the bus connecting the ECUs is a single line, so if an abnormality occurs on the bus, it is not possible to check the abnormality via communication. For example, if a break occurs on the bus, it is not possible to check whether the abnormality is in the ECU or the bus.

[0005] One object of this disclosure is to provide a vehicle fault diagnosis system that makes it easier to estimate the location of an abnormality in more detail when an abnormality occurs in a system in which multiple ECUs are connected via a bus. [Means for solving the problem]

[0006] The above object is achieved by the combination of features recited in the independent claims, and the subclaims define further advantageous embodiments of the disclosure. The reference characters in parentheses in the claims indicate a correspondence with specific means described in the following embodiment as one aspect, and do not limit the technical scope of the present disclosure.

[0007] In order to achieve the above object, a vehicle fault diagnosis system according to the present disclosure is a vehicle fault diagnosis system (1, 1a, 1b, 1c, 1d) that can be used in a vehicle, and includes at least two or more ECUs (30, 30a, 30b, 30d, 40, 40b, 50, 50a, 50b, 50d, 53c, 54c) as ECUs that are electronic control units, a fault diagnosis device (10, 10a) that is connected to some of the ECUs via an interface (20), and buses (A, B, C, I) that are communication lines that connect the ECUs in a bus configuration. The fault diagnosis device includes an information receiving unit (102) that receives ECU-related information, which is information output from an ECU, when the ECU-related information is transmitted via the interface, and a diagnosis unit (103) that diagnoses an abnormality in a communication system (2) including the ECU and a bus by using a reception state of the ECU-related information at the information receiving unit, and at least two buses are provided in parallel for each of a plurality of ECUs including boundary ECUs (30, 30a, 30b) that are ECUs connected to the fault diagnosis device via the interface.

[0008] According to the above configuration, at least two or more buses that connect multiple ECUs including the boundary ECU in a bus-like configuration are provided in parallel for each of the multiple ECUs. Therefore, even if a break occurs in any of the buses, the diagnostic unit can diagnose an abnormality in the communication system by communication using the other bus that is not broken. Therefore, even if an abnormality occurs in any of the buses, it is easy to check whether the abnormality is in the ECU or the bus. As a result, when an abnormality occurs in a system in which multiple ECUs are connected by a bus, it is possible to more easily estimate the location of the abnormality in more detail. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing an example of a schematic configuration of a vehicle fault diagnosis system; [Diagram 2] FIG. 1 is a diagram illustrating an example of a schematic configuration of a fault diagnosis device. [Diagram 3] FIG. 2 is a diagram illustrating an example of a schematic configuration of a first ECU. [Figure 4] FIG. 2 is a diagram illustrating an example of a schematic configuration of a second ECU. [Diagram 5] FIG. 2 is a diagram illustrating an example of a schematic configuration of a third ECU. [Figure 6] 4 is a sequence diagram for explaining an overall flow of fault diagnosis in the vehicle fault diagnosis system. FIG. [Figure 7] FIG. 1 is a diagram for explaining diagnosis of an abnormality in a communication system. [Figure 8] FIG. 1 is a diagram for explaining diagnosis of an abnormality in a communication system. [Figure 9] FIG. 1 is a diagram for explaining diagnosis of an abnormality in a communication system. [Figure 10] FIG. 1 is a diagram for explaining diagnosis of an abnormality in a communication system. [Figure 11] FIG. 1 is a diagram for explaining diagnosis of an abnormality in a communication system. [Figure 12] 10 is a flowchart showing an example of a diagnosis process in a diagnosis unit. [Figure 13]1 is a diagram showing an example of a schematic configuration of a vehicle fault diagnosis system; [Figure 14] FIG. 11 is a diagram for explaining a diagnostic process in a diagnostic unit in the second embodiment. [Figure 15] 1 is a diagram showing an example of a schematic configuration of a vehicle fault diagnosis system; [Figure 16] 1 is a diagram showing an example of a schematic configuration of a vehicle fault diagnosis system; [Figure 17] 1 is a diagram showing an example of a schematic configuration of a vehicle fault diagnosis system; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A number of embodiments for disclosure will be described with reference to the drawings. For convenience of description, in a number of embodiments, parts having the same functions as parts shown in the drawings used in the previous description may be given the same reference numerals and their description may be omitted. For parts given the same reference numerals, the description in other embodiments may be referred to.

[0011] (Embodiment 1) <Outline of vehicle fault diagnosis system 1> A first embodiment of the present disclosure will be described below with reference to the drawings. A vehicle fault diagnosis system 1 shown in FIG. 1 can be used in a vehicle. As shown in FIG. 1, the vehicle fault diagnosis system 1 includes a fault diagnosis device 10, a diagnostic interface (I / F) 20, a bus X, and a communication system 2. The communication system 2 includes a first ECU 30, a second ECU 40, a third ECU 50, a bus A, and a bus B. Although the vehicle using the vehicle fault diagnosis system 1 is not necessarily limited to an automobile, the following description will be given taking the case of use in an automobile as an example.

[0012] The fault diagnosis device 10 is mainly constituted by a computer including, for example, a processor, a volatile memory, a non-volatile memory, an I / O, and a bus connecting these. The fault diagnosis device 10 executes various processes related to diagnosing anomalies in the communication system 2 by executing a control program stored in the non-volatile memory. The details of the fault diagnosis device 10 will be described later.

[0013] The diagnostic I / F 20 is an interface that connects the fault diagnosis device 10 and the communication system 2. The connection between the fault diagnosis device 10 and the diagnostic I / F 20 may be a wired connection or a wireless connection. When the fault diagnosis device 10 and the diagnostic I / F 20 are connected by a wired connection, the diagnostic I / F 20 may be a physical connector. When the fault diagnosis device 10 and the diagnostic I / F 20 are connected by a wireless connection, the diagnostic I / F 20 may be a wireless communication device. When the diagnostic I / F 20 is a wireless communication device, the fault diagnosis device 10 may be configured to include a wireless communication module. When the diagnostic I / F 20 is a wireless communication device, the fault diagnosis device 10 may not be configured to include a wireless communication module. In this case, the fault diagnosis device 10 may be provided in a server, and wireless communication may be performed between the wireless communication device connected to the server and the wireless communication device serving as the diagnostic I / F 20.

[0014] The bus X is a communication line that connects the diagnostic I / F 20 and the communication system 2. In this embodiment, the bus X is connected to the first ECU 30 of the communication system 2. It is preferable to use a diagnostic communication protocol as the communication protocol used in the bus X. Note that the communication protocol used in the bus X may be any communication protocol. For example, CAN (registered trademark), Ethernet (registered trademark), SerDes, LIN, CXPI, etc. may be used.

[0015] The first ECU 30, the second ECU 40, and the third ECU 50 are electronic control units. The first ECU 30, the second ECU 40, and the third ECU 50 are equipped with an arithmetic processing device as a circuit element that executes arithmetic processing. The arithmetic processing device has a processor and a memory. The memory may be configured to be provided outside the arithmetic processing device. The arithmetic processing device may be, for example, an MCU (Micro Controller Unit) or an SoC (System on a Chip). This arithmetic processing device corresponds to an electronic component that performs control. In this embodiment, the first ECU 30, the second ECU 40, and the third ECU 50 are described below with reference to an example in which the arithmetic processing device is equipped with an MCU.

[0016] The first ECU 30 includes a communication circuit for communicating via each of the buses X, A, and B. The second ECU 40 and the third ECU 50 include a communication circuit for communicating via each of the buses A and B. The first ECU 30 is connected to the diagnostic I / F 20 via the bus X. That is, the first ECU 30 is connected to the fault diagnosis device 10 via the diagnostic I / F 20. This first ECU 30 corresponds to a boundary ECU.

[0017] The first ECU 30 is connected to the second ECU 40 and the third ECU 50 via a bus A. The second ECU 40 is connected to the first ECU 30 and the third ECU 50 via a bus A. The third ECU 50 is connected to the first ECU 30 and the second ECU 40 via a bus A. The bus A is a communication line that connects the first ECU 30, the second ECU 40, and the third ECU 50 in a bus-type configuration. The bus-type connection means that all terminals are connected to one common communication path. The first ECU 30, the second ECU 40, and the third ECU 50 communicate with each other via the bus A, which is a common communication path.

[0018] The first ECU 30 is connected to the second ECU 40 and the third ECU 50 via a bus B. The second ECU 40 is connected to the first ECU 30 and the third ECU 50 via a bus B. The third ECU 50 is connected to the first ECU 30 and the second ECU 40 via a bus B. The bus B is a communication line that connects the first ECU 30, the second ECU 40, and the third ECU 50 in a bus-type configuration. The first ECU 30, the second ECU 40, and the third ECU 50 communicate with each other through the bus B, which is a common communication path. Details of the first ECU 30, the second ECU 40, and the third ECU 50 will be described later. In the following, when the first ECU 30, the second ECU 40, and the third ECU 50 are collectively referred to without distinction, they are called target ECUs.

[0019] In the vehicle fault diagnosis system 1, two buses, bus A and bus B, are provided in parallel for each of the first ECU 30, the second ECU 40, and the third ECU 50. The buses A and B are in a redundant line relationship. Any communication protocol may be used for the buses A and B. For example, CAN, Ethernet (registered trademark), SerDes, LIN, CXPI, DoCAN, etc. may be used. When the bus X uses a different communication protocol from the buses A and B, the first ECU 30 may be configured to convert the protocol or the format.

[0020] <General Configuration of Fault Diagnosis Device 10> Next, the schematic configuration of the fault diagnosis device 10 will be described with reference to Fig. 2. As shown in Fig. 2, the fault diagnosis device 10 includes a request sending unit 101, an information receiving unit 102, and a diagnosis unit 103 as functional blocks. Note that some or all of the functions executed by the fault diagnosis device 10 may be configured as hardware using one or more ICs or the like. Also, some or all of the functional blocks included in the fault diagnosis device 10 may be realized by a combination of software execution by a processor and hardware members.

[0021] The request transmission unit 101 transmits a message requesting ECU-related information to each target ECU via the diagnostic I / F 20. The message requesting ECU-related information is hereinafter referred to as a request message. The ECU-related information is information output from the target ECU. The ECU-related information may be identification information such as an ID for identifying the target ECU. The ECU-related information is preferably information on the state of the target ECU. This makes it possible to further improve the accuracy of diagnosis by the diagnostic unit 103 described later. Examples of the state of the target ECU include the state of the target ECU itself and the state of communication between the target ECUs. The request transmission unit 101 preferably transmits the request message by broadcast. This is because the processing time can be reduced compared to the case where the request message is transmitted by unicast. The request transmission unit 101 may transmit the request message by unicast. In the following, the description will be continued by taking the case where the request transmission unit 101 transmits the request message by broadcast as an example. The request transmission unit 101 may transmit the request message by broadcast to each target ECU for each bus A and bus B.

[0022] The information receiving unit 102 receives the ECU-related information output from the target ECU when the ECU-related information is transmitted via the diagnostic I / F 20. The diagnosis unit 103 diagnoses an abnormality in the communication system 2 using the reception status of the ECU-related information at the information receiving unit 102. The diagnosis unit 103 then notifies the user of the diagnosis result. The notification to the user may be performed, for example, by displaying on a display device. The reception status of the ECU-related information may include a status of whether or not the ECU-related information was received from which target ECU and via which bus. The reception status of the ECU-related information may also include a status of what content of the ECU-related information was received. Details of the diagnosis by the diagnosis unit 103 will be described later.

[0023] <General Configuration of First ECU 30> Next, a schematic configuration of the first ECU 30 will be described with reference to Fig. 3. The first ECU 30 includes an MCU 301, a TRX_X 302, a TRX_A 303, and a TRX_B 304, as shown in Fig. 3.

[0024] The MCU 301 controls the first ECU 30. This MCU 301 corresponds to an electronic component that controls the first ECU 30. TRX_X 302, TRX_A 303, and TRX_B 304 are transceivers. TRX_X 302 is used for transmission and reception via bus X. TRX_A 303 is used for transmission and reception via bus A. TRX_B 304 is used for transmission and reception via bus B. TRX_X 302, TRX_A 303, and TRX_B 304 each correspond to a communication circuit. Note that the communication circuit may include communication circuit elements such as ICs that function as part of the communication circuit other than TRX_X 302, TRX_A 303, and TRX_B 304.

[0025] The MCU 301 has an abnormality detection function for communication with other ECUs other than its own ECU. In this embodiment, the MCU 301 judges the communication state between the first ECU 30 and the second ECU 40 and the third ECU 50. The MCU 301 then detects whether or not there is an abnormality in the communication state. Examples of the abnormality include a CRC error, a reception timeout, and a transmission timeout. The MCU 301 records a history of such communication abnormalities (hereinafter, communication diagnosing information) in a memory. The communication diagnosing information may include no abnormality in the history. The communication diagnosing information is information for each bus. That is, it is assumed that there is a history of abnormalities in communication between the target ECUs via the bus A and a history of abnormalities in communication between the target ECUs via the bus B. Hereinafter, the history of abnormalities in communication between the target ECUs via the bus A is referred to as communication diagnosing information on the bus A side. Hereinafter, the history of abnormalities in communication between the target ECUs via the bus B is referred to as communication diagnosing information on the bus B side.

[0026] The MCU 301 receives a request message for each target ECU via the TRX_X 302. The MCU 301 responds to the request message for the first ECU 30 with a message including ECU-related information according to the request. A message that responds to a request message is hereinafter referred to as a response message. The MCU 301 transmits this response message to the fault diagnosis device 10 via the TRX_X 302 and the diagnostic I / F 20. For example, if the request message requests communication diagnostic information, the MCU 301 may transmit a response message including the communication diagnostic information as the ECU-related information. For example, if the request message requests the ID of the ECU itself, the MCU 301 may transmit a response message including the ID of the ECU itself as the ECU-related information. It is preferable that the response message includes the communication diagnostic information. This is because the diagnostic unit 103 can diagnose abnormalities in more detail.

[0027] The MCU 301 relays a request message for the second ECU 40 to the second ECU 40 via TRX_A 303 and bus A. Then, when the MCU 301 receives a response message to the request message from the second ECU 40, the MCU 301 relays this response message to the fault diagnosis device 10. That is, the MCU 301 transmits this response message to the fault diagnosis device 10 via TRX_X 302 and the diagnostic I / F 20. The MCU 301 relays a request message for the third ECU 50 to the third ECU 50 via TRX_B 304 and bus B. Then, when the MCU 301 receives a response message to the request message from the third ECU 50, the MCU 301 relays this response message to the fault diagnosis device 10.

[0028] <General Configuration of Second ECU 40> Next, a schematic configuration of the second ECU 40 will be described with reference to Fig. 4. The second ECU 40 includes an MCU 401, a TRX_A 402, and a TRX_B 403, as shown in Fig. 4.

[0029] The MCU 401 controls the second ECU 40. This MCU 401 corresponds to an electronic component that controls the second ECU 40. TRX_A 402 and TRX_B 403 are transceivers. TRX_A 402 is used for transmission and reception via bus A. TRX_B 403 is used for transmission and reception via bus B. TRX_A 402 and TRX_B 403 each correspond to a communication circuit. Note that the communication circuit may include communication circuit elements such as ICs that function as part of the communication circuit other than TRX_A 402 and TRX_B 403.

[0030] The MCU 401 has an abnormality detection function similar to that of the MCU 301. In this embodiment, the MCU 401 detects abnormalities in the communication between the second ECU 40 and the first ECU 30 and the third ECU 50. Examples of abnormalities are the same as those described in the description of the MCU 301. The MCU 401 also records communication diagnostic information in a memory.

[0031] The MCU 401 receives a request message for the second ECU 40 relayed by the first ECU 30 via the TRX_A 402 and the TRX_B 403. The MCU 401 responds to the request message for the second ECU 40 with a response message including ECU-related information according to the request, similar to the MCU 301. The MCU 401 transmits this response message to the first ECU 30. As a result, this response message is relayed by the first ECU 30 and sent to the fault diagnosis device 10.

[0032] When the second ECU 40 receives a request message via bus A and bus B, the second ECU 40 may do the following. The second ECU 40 may transmit a response message to the request message using a bus different from the bus used to receive the request message. Specifically, a response message to a request message received via bus A is transmitted via bus B. On the other hand, a response message to a request message received via bus B is transmitted via bus A. In this way, even if communication is interrupted on either bus side, information that can narrow down the cause of the interruption can be transmitted via the bus that is not interrupted.

[0033] It is more preferable that the second ECU 40 should be configured as follows so that the cause of the interruption can be narrowed down more easily. The second ECU 40 should preferably transmit, as a response message, communication diagnostic information for a bus other than the bus targeted by the transmitted request message, among the messages transmitted for each bus. With this configuration, when communication on one of the buses is interrupted, information capable of narrowing down the cause of the interruption can be transmitted by the bus that is not interrupted. Specifically, among the request messages for each bus A and bus B, the response message to the request message targeted for bus A includes communication diagnostic information for bus B. A request message that is not received by the first ECU 30 via bus A but is transmitted to other target ECUs via bus A by broadcast is hereinafter collectively referred to as a request message for bus A. On the other hand, the response message to the request message targeted for bus B includes communication diagnostic information for bus A. A request message that is not received by the first ECU 30 via bus B but is transmitted to other target ECUs via bus B is hereinafter collectively referred to as a request message for bus B.

[0034] <General Configuration of Third ECU 50> Next, a schematic configuration of the third ECU 50 will be described with reference to Fig. 5. The third ECU 50 includes an MCU 501, a TRX_A 502, and a TRX_B 503, as shown in Fig. 5.

[0035] The MCU 501 controls the third ECU 50. This MCU 501 corresponds to an electronic component that controls the third ECU 50. TRX_A 502 and TRX_B 503 are transceivers. TRX_A 502 is used for transmission and reception via bus A. TRX_B 503 is used for transmission and reception via bus B. TRX_A 502 and TRX_B 503 each correspond to a communication circuit. Note that the communication circuit may include communication circuit elements such as ICs that function as part of the communication circuit other than TRX_A 502 and TRX_B 503.

[0036] The MCU 501 has an abnormality detection function similar to that of the MCU 301. In this embodiment, the MCU 501 detects an abnormality in the communication between the 3rd ECU 50 and the 1st ECU 30 and the 2nd ECU 40. Examples of the abnormality are the same as those described in the description of the MCU 301. The MCU 501 also records communication diagnostic information in a memory.

[0037] The MCU 501 receives a request message for the third ECU 50 relayed by the first ECU 30 via the TRX_A 502 and the TRX_B 503. The MCU 501 responds to the request message for the third ECU 50 with a response message including ECU-related information according to the request, similar to the MCU 301. The MCU 501 transmits this response message to the first ECU 30. As a result, this response message is relayed by the first ECU 30 and sent to the fault diagnosis device 10.

[0038] When the third ECU 50 receives a request message via bus A or bus B, the third ECU 50 may do the following for the same reason as the second ECU 40. The third ECU 50 may transmit a response message to the request message using a bus different from the bus used to receive the request message. The third ECU 50 may transmit, as the response message, communication diagnostic information about a bus different from the bus used to receive the request message.

[0039] <Overall flow of fault diagnosis> Next, the overall flow of fault diagnosis in the vehicle fault diagnosis system 1 will be described with reference to the sequence diagram of Fig. 6. In the example of Fig. 6, a case where no communication interruption occurs on either side of bus A or bus B will be described as an example.

[0040] First, at t1, the fault diagnosis device 10 broadcasts a request message to each target ECU on bus A. For the first ECU 30, this request message is sent via the diagnosis I / F 20 and bus X. For the second ECU 40 and the third ECU 50, this request message is sent via the diagnosis I / F 20, bus X, the first ECU 30, and bus A.

[0041] At t2, the target ECU receives a request message targeted for bus A. The first ECU 30 receives this request message via bus X, not via bus A, since there is no need for the message to go through bus A. The second ECU 40 and the third ECU 50 receive this request message via bus X, the first ECU 30, and bus A.

[0042] At t3, the fault diagnosis device 10 broadcasts a request message to each target ECU on bus B. For the first ECU 30, this request message is sent via the diagnosis I / F 20 and bus X. For the second ECU 40 and the third ECU 50, this request message is sent via the diagnosis I / F 20, bus X, the first ECU 30, and bus B.

[0043] At t4, the target ECU receives a request message targeted for bus B. Since the first ECU 30 does not need to transmit the request message via bus B, it transmits the request message via bus X without via bus B. The second ECU 40 and the third ECU 50 receive the request message via bus X, the first ECU 30, and bus B.

[0044] At t5, the target ECU judges the communication state with other ECUs other than its own ECU. Then, the target ECU detects whether there is an abnormality in the communication state with the other ECUs. At t6, the target ECU transmits communication diagnosing information on the bus B side. The first ECU 30 transmits the communication diagnosing information on the bus B side to the fault diagnosis device 10 via the bus X and the diagnostic I / F 20. The second ECU 40 and the third ECU 50 transmit the communication diagnosing information on the bus B side to the fault diagnosis device 10 via the bus A, the first ECU 30, the bus X, and the diagnostic I / F 20. At t7, the fault diagnosis device 10 receives the communication diagnosing information on the bus B side from the target ECU.

[0045] At t8, the target ECU transmits communication diagnostic information on the bus A side. The first ECU 30 transmits the communication diagnostic information on the bus A side to the fault diagnosis device 10 via the bus X and the diagnostic I / F 20. The second ECU 40 and the third ECU 50 transmit the communication diagnostic information on the bus A side to the fault diagnosis device 10 via the bus B, the first ECU 30, the bus X, and the diagnostic I / F 20. At t9, the fault diagnosis device 10 receives the communication diagnostic information on the bus A side from the target ECU.

[0046] At t10, the diagnosis unit 103 of the fault diagnosis device 10 performs a diagnosis process to diagnose an abnormality in the communication system 2. The details of the diagnosis process will be described later. At t11, the diagnosis unit 103 displays the diagnosis result.

[0047] Although a configuration in which a request message is transmitted via both bus A and bus B has been shown here, this is not necessarily limited to this. For example, a request message may be transmitted via only one of bus A and bus B. In this case, a response message may be transmitted via both bus A and bus B. In particular, communication diagnostic information on the bus B side may be transmitted via bus A, and communication diagnostic information on the bus A side may be transmitted via bus B.

[0048] <Diagnosis process> Next, the diagnosis process in the diagnosis unit 103 will be described. The diagnosis unit 103 estimates the abnormality location of the communication system 2 by using the reception status of the ECU-related information from each target ECU in the information receiving unit 102. The diagnosis unit 103 may perform a diagnosis to estimate the abnormality location of the communication system 2 from the communication path through which the ECU-related information can be received. This makes it easier to estimate the abnormality location of the communication system 2 in more detail, as described later. The communication path through which the ECU-related information can be received corresponds to the above-mentioned reception status. The diagnosis unit 103 may perform a diagnosis to estimate the abnormality location of the communication system 2 from the history indicated by the communication diagnosis information received by the information receiving unit 102. The history indicated by the communication diagnosis information received by the information receiving unit 102 corresponds to the above-mentioned reception status. This makes it easier to estimate the abnormality location of the communication system 2 in more detail, as described later.

[0049] If the diagnosis unit 103 is able to receive both the bus A side communication diagnostic information and the bus B side communication diagnostic information from all target ECUs and none of the communication diagnostic information indicates an abnormality, the diagnosis unit 103 may diagnose that there is no abnormality in the communication system 2. On the other hand, if there is a target ECU from which the diagnosis unit 103 is unable to receive either the bus A side communication diagnostic information or the bus B side communication diagnostic information, the diagnosis unit 103 may diagnose that there is an abnormality in the communication system 2. There are five patterns for diagnosing that there is an abnormality. These five patterns will be explained below.

[0050] The first pattern is a case where ECU-related information cannot be received from all the target ECUs for any of the multiple buses. In the example of this embodiment, this is a pattern where ECU-related information cannot be received from all the target ECUs for any of the buses A and B. In the first pattern, the diagnosis unit 103 performs a diagnosis to estimate an abnormality in the first ECU 30. Here, the first pattern will be described using the table of FIG. 7. In the table of FIG. 7, a response result to a request message transmitted via the bus A and the bus B is associated with each target ECU. In addition, if the response result is a response and the communication diagnostic information indicates an abnormality, the abnormality content is associated. The response indicates that the communication diagnostic information has been received. The response result in the row of the bus "A" in the table of FIG. 7 indicates a response result to a request message for the bus A. The response result in the row of the bus "B" in the table of FIG. 7 indicates a response result to a request message for the bus B. The above contents are the same for FIG. 8 to FIG. 11.

[0051] The reception status in the example of FIG. 7 is as follows: Communication diagnostic information for bus B in response to the request message for bus A is not received from the first ECU 30. Communication diagnostic information for bus A in response to the request message for bus B is also not received from the first ECU 30. Communication diagnostic information for bus B in response to the request message for bus A is not received from the second ECU 40. Communication diagnostic information for bus A in response to the request message for bus B is also not received from the second ECU 40. Communication diagnostic information for bus B in response to the request message for bus A is not received from the third ECU 50. Communication diagnostic information for bus A in response to the request message for bus B is also not received from the third ECU 50.

[0052] In the first pattern shown in FIG. 7 as an example, the following may be considered. Since the first ECU 30 is not operating, it may be considered that the request message has not reached the second ECU 40 and the third ECU 50 regardless of the bus A or the bus B. Also, since the request message has not reached the second ECU 40 and the third ECU 50, it may be considered that the response from the second ECU 40 and the third ECU 50 has not been returned. Therefore, in the first pattern, a diagnosis may be performed to estimate an abnormality in the first ECU 30. In the example of FIG. 7, the possibility of a failure of the MCU 301 may be considered. Note that the failure of the arithmetic processing device of the first ECU 30 includes a failure in which the failure diagnosis device 10 and the first ECU 30 cannot be linked up.

[0053] The first pattern diagnosis can be performed even if the ECU-related information does not include communication diagnostic information. For example, even if the ECU-related information does not include communication diagnostic information, the first pattern diagnosis can be performed depending on whether there is a response from the ECU-related information. Specifically, the first pattern diagnosis can be performed when there is neither a response to the request message for bus A nor a response to the request message for bus B. With the above configuration, it is possible to estimate the abnormality by narrowing it down to a failure of the first ECU 30.

[0054] The second pattern is a case where ECU-related information cannot be received from all target ECUs for a specific bus among the multiple buses, and the history indicated by the communication diagnostic information received via a bus other than the specific bus among the multiple buses indicates an abnormality in communication with the first ECU 30. Here, a pattern where communication diagnostic information cannot be received from all target ECUs via bus B, and the history indicated by the communication diagnostic information received via bus A indicates an abnormality in communication with the first ECU 30 will be described as an example. In the second pattern, the diagnosis unit 103 performs a diagnosis to estimate an abnormality in the first ECU 30.

[0055] The reception status in the example of FIG. 8 is as follows. The communication diagnostic information of the bus B side in response to the request message of the bus A was received from the first ECU 30, but the communication diagnostic information indicates an abnormality. The abnormality is a communication interruption between the first ECU 30 and the second ECU 40 and between the first ECU 30 and the third ECU 50. On the other hand, the communication diagnostic information of the bus A side in response to the request message of the bus B was not received from the first ECU 30. The communication diagnostic information of the bus B side in response to the request message of the bus A was received from the second ECU 40, but the communication diagnostic information indicates an abnormality. The abnormality is a communication interruption between the second ECU 40 and the first ECU 30. On the other hand, the communication diagnostic information of the bus A side in response to the request message of the bus B was not received from the second ECU 40. The communication diagnostic information of the bus B side in response to the request message of the bus A was received from the third ECU 50, but the communication diagnostic information indicates an abnormality. The abnormality is a breakdown in communication between the third ECU 50 and the first ECU 30. On the other hand, communication diagnostic information on the bus A side cannot be received from the third ECU 50 as a response to the request message for the bus B.

[0056] In the second pattern shown in FIG. 8 as an example, the following can be considered. Since the first ECU 30 is disconnected from the bus B, it can be seen that communication with the first ECU 30 is interrupted only on the bus B side of the buses A and B. Therefore, in the second pattern, a diagnosis can be performed to estimate an abnormality in the first ECU 30. In the example of FIG. 8, a failure in the open mode in the communication circuit on the bus B side of the first ECU 30 can be considered. Note that the second pattern also includes a case in which the reception statuses of the buses A and B in FIG. 8 are swapped. Even in the example in which the reception statuses of the buses A and B in FIG. 8 are swapped, a diagnosis can be performed to estimate an abnormality. With the above configuration, it is possible to narrow down the abnormality to a failure of the first ECU 30.

[0057] The third pattern is a case where ECU-related information cannot be received from all target ECUs for a specific bus among the multiple buses, and the history indicated by the communication diagnostic information received via a bus other than the specific bus among the multiple buses indicates an abnormality in communication between all target ECUs. Here, an example is described in which the communication diagnostic information cannot be received from all target ECUs via bus B, and the history indicated by the communication diagnostic information received via bus A indicates an abnormality in communication between all target ECUs. In the third pattern, the diagnosis unit 103 performs a diagnosis to estimate an abnormality in the specific bus or an abnormality in any of the target ECUs.

[0058] The reception status in the example of FIG. 9 is as follows. The communication diagnostic information of the bus B side in response to the request message for the bus A was received from the first ECU 30, but the communication diagnostic information indicates an abnormality. The abnormality is a communication interruption between the first ECU 30 and the second ECU 40, and a communication interruption between the first ECU 30 and the third ECU 50. On the other hand, the communication diagnostic information of the bus A side in response to the request message for the bus B was not received from the first ECU 30. The communication diagnostic information of the bus B side in response to the request message for the bus A was received from the second ECU 40, but the communication diagnostic information indicates an abnormality. The abnormality is a communication interruption between the second ECU 40 and the first ECU 30, and a communication interruption between the second ECU 40 and the third ECU 50. On the other hand, the communication diagnostic information of the bus A side in response to the request message for the bus B was not received from the second ECU 40. Although communication diagnostic information on the bus B side was received from the 3rd ECU 50 in response to the request message for the bus A, the communication diagnostic information indicates an abnormality. The abnormality is a communication interruption between the 3rd ECU 50 and the 1st ECU 30, and a communication interruption between the 3rd ECU 50 and the 2nd ECU 40. On the other hand, communication diagnostic information on the bus A side was not received from the 3rd ECU 50 in response to the request message for the bus B.

[0059] In the third pattern shown in FIG. 9 as an example, the following can be considered. In the third pattern, there is a response via bus A, but there is no response via bus B. It is considered that such a situation occurs when an abnormality occurs in bus B. However, the same situation may occur even when there is no abnormality in bus B. Specifically, the same situation occurs when an abnormality in short mode occurs in the communication circuit on the bus B side of any of the target ECUs. Therefore, in the third pattern, a diagnosis may be performed to estimate an abnormality in a specific bus or an abnormality in any of the target ECUs. In the example of FIG. 9, there is a possibility of an abnormality in bus B or a failure in short mode in the communication circuit on the bus B side of any of the target ECUs. Note that the third pattern also includes a case in which the reception statuses of bus A and bus B in FIG. 9 are swapped. In the example in FIG. 9 in which the reception statuses of bus A and bus B are swapped, a diagnosis may be performed to estimate an abnormality in bus A or a failure in any of the target ECUs. According to the above configuration, it is possible to narrow down the abnormality to an abnormality in a specific bus or a failure in any of the target ECUs.

[0060] The fourth pattern is a case where ECU-related information cannot be received only from a specific target ECU for any of the multiple buses, and the history indicated by the received communication diagnostic information for any of the multiple buses indicates an abnormality in communication with the specific target ECU. Here, an example will be described in which ECU-related information cannot be received only from the second ECU 40 for any of the buses A and B, and the history indicated by the communication diagnostic information for any of the buses A and B indicates an abnormality in communication with the second ECU 40. In the fourth pattern, the diagnosis unit 103 performs a diagnosis to estimate an abnormality in the specific target ECU.

[0061] The reception status in the example of FIG. 10 is as follows. The communication diagnostic information of the bus B side as a response to the request message of the bus A was received from the first ECU 30, but the communication diagnostic information indicates an abnormality. The abnormality is a communication interruption between the first ECU 30 and the second ECU 40. The communication diagnostic information of the bus A side as a response to the request message of the bus B was also received from the first ECU 30, but the communication diagnostic information indicates an abnormality. The abnormality is a communication interruption between the first ECU 30 and the second ECU 40. The communication diagnostic information of the bus B side as a response to the request message of the bus A was not received from the second ECU 40. The communication diagnostic information of the bus A side as a response to the request message of the bus B was also not received from the second ECU 40. The communication diagnostic information of the bus B side as a response to the request message of the bus A was received from the third ECU 50, but the communication diagnostic information indicates an abnormality. The abnormality is a communication interruption between the third ECU 50 and the second ECU 40. The communication diagnostic information on the bus A side in response to the request message for the bus B has been received from the third ECU 50, and the communication diagnostic information indicates an abnormality. The abnormality is a breakdown in communication between the third ECU 50 and the second ECU 40.

[0062] In the fourth pattern shown in FIG. 10 as an example, the following can be considered. Since the second ECU 40 is not operating, it can be considered that the request message has not arrived at the second ECU 40 or the third ECU 50 regardless of the bus A or the bus B. Also, since the request message has not arrived at the second ECU 40, it can be considered that the response from the second ECU 40 has not been returned. Therefore, in the fourth pattern, a diagnosis for estimating an abnormality in a specific target ECU can be performed. In the example of FIG. 10, a diagnosis for estimating an abnormality in the second ECU 40 can be performed. Note that, in the example of FIG. 10, the possibility of a failure of the MCU 401 can be considered. Note that the fourth pattern also includes a case where the receiving conditions of the second ECU 40 and the third ECU 50 in FIG. 10 are swapped. In the example of FIG. 10 where the receiving conditions of the second ECU 40 and the third ECU 50 are swapped, a diagnosis for estimating an abnormality in the third ECU 50 can be performed. According to the above configuration, it is possible to narrow down the abnormality to a failure of a specific target ECU and estimate the abnormality.

[0063] The fifth pattern is a case where ECU-related information cannot be received only from a specific target ECU for a specific bus among the multiple buses, and the history indicated by the communication diagnostic information received via a bus other than the specific bus among the multiple buses indicates an abnormality in communication with the specific target ECU. Here, a pattern where ECU-related information cannot be received only from the second ECU 40 for the bus B, and the communication diagnostic information received via the bus A indicates an abnormality in communication with the second ECU 40 will be described as an example. In the fifth pattern, the diagnosis unit 103 performs a diagnosis to estimate an abnormality in the specific target ECU.

[0064] The reception status in the example of FIG. 11 is as follows. The communication diagnostic information of the bus B side in response to the request message of the bus A was received from the first ECU 30, but the communication diagnostic information indicates an abnormality. The abnormality is a communication interruption between the first ECU 30 and the second ECU 40. On the other hand, the communication diagnostic information of the bus A side in response to the request message of the bus B was received from the first ECU 30, and the communication diagnostic information does not indicate an abnormality. The communication diagnostic information of the bus B side in response to the request message of the bus A was received from the second ECU 40, but the communication diagnostic information indicates an abnormality. The abnormality is a communication interruption between the second ECU 40 and the first ECU 30, and between the second ECU 40 and the third ECU 50. On the other hand, the communication diagnostic information of the bus A side in response to the request message of the bus B was not received from the second ECU 40. Communication diagnostic information on bus B in response to the request message for bus A was received from the third ECU 50, but the communication diagnostic information indicates an abnormality. The abnormality is a breakdown in communication between the third ECU 50 and the second ECU 40. On the other hand, communication diagnostic information on bus A in response to the request message for bus B was received from the third ECU 50, and the communication diagnostic information does not indicate an abnormality.

[0065] In the fifth pattern shown in FIG. 11 as an example, the following may be considered. Since the second ECU 40 is disconnected from the bus B, it is understood that communication with the second ECU 40 is interrupted only on the bus B side of the bus A and bus B. Therefore, in the fifth pattern, a diagnosis may be performed to estimate an abnormality in a specific target ECU. This specific target ECU may exclude the first ECU 30, which is a boundary ECU. In the example of FIG. 11, the diagnosis unit 103 may perform a diagnosis to estimate an abnormality in the second ECU 40. In the example of FIG. 11, a failure in an open mode in the communication circuit on the bus B side of the second ECU 40 may be considered. Note that the fifth pattern also includes a case in which the reception statuses of the bus A and bus B in FIG. 11 are swapped, and a case in which the reception statuses of the second ECU 40 and the third ECU 50 are swapped. In the example of FIG. 11 in which the reception statuses of the bus A and bus B are swapped, a diagnosis may be performed to estimate an abnormality in the second ECU 40. In the example in which the receiving conditions of the second ECU 40 and the third ECU 50 in Fig. 11 are switched, a diagnosis may be performed to estimate an abnormality in the third ECU 50. In the example in which the receiving conditions of the buses A and B and the receiving conditions of the second ECU 40 and the third ECU 50 in Fig. 11 are switched, a diagnosis may be performed to estimate an abnormality in the third ECU 50. With the above configuration, it is possible to estimate an abnormality by narrowing down to a failure of a specific target ECU.

[0066] As described above, according to the configuration of this embodiment, a plurality of buses A and B that connect the target ECUs in a bus-type configuration are provided in parallel for each target ECU. Therefore, even if a break occurs in any of the buses, the diagnosis unit 103 can diagnose an abnormality in the communication system 2 by communication using the other bus that is not broken. Therefore, even if an abnormality occurs in any of the buses, it is easy to check whether the abnormality is in the target ECU or in the bus. As a result, when an abnormality occurs in the communication system 2, it is possible to more easily estimate the location of the abnormality in more detail.

[0067] The communication diagnostic information is information that indicates which target ECU the abnormality detection function is applicable to in a message sent to it or received from it. Therefore, by using the communication diagnostic information, it becomes easier to narrow down which target ECU has an abnormality in the communication between them, as shown in the second to fifth patterns. In addition, by using the communication diagnostic information, it becomes possible to check the location of the abnormality by comparing the diagnosis result by the diagnosis unit 103 with the communication diagnostic information. For example, when an abnormality occurs in the short mode, a receive timeout and a transmit timeout may occur, but a CRC error may not occur. Therefore, by utilizing this, it becomes possible to check whether the diagnosis of the abnormality in the short mode is correct or not.

[0068] Here, an example of the flow of diagnosis processing in diagnosis unit 103 will be described with reference to the flowchart in Fig. 12. In Fig. 12, CDI indicates communication diagnostic information. The flowchart in Fig. 12 may be configured to start when a request message for bus A and a request message for bus B are transmitted.

[0069] First, in step S1, if no response to the request message for either bus A or bus B has been received from any of the target ECUs (YES in S1), the process proceeds to step S2. In other words, if there has been no response from all buses and all ECUs, the process proceeds to S2. On the other hand, if there has not been no response from all (NO in S1), the process proceeds to step S3. Regarding the response to the request message, if no response is received within a specified time from the transmission of the request message, the diagnosis unit 103 may determine that no response has been received. In step S2, the diagnosis unit 103 performs the diagnosis of the first pattern described above, and ends the diagnosis process.

[0070] In step S3, if ECU-related information could not be received from all target ECUs for a specific bus among the multiple buses (YES in S3), the process proceeds to step S4. In other words, if there is no response from all ECUs for only the specific bus, the process proceeds to S4. In this case, ECU-related information could be received from the target ECU for buses other than the specific bus. On the other hand, if ECU-related information could be received from any of the target ECUs for the above-mentioned specific bus (NO in S3), the process proceeds to step S9.

[0071] In step S4, if the history indicated by the communication diagnosing information included in the received ECU-related information indicates an abnormality in communication between all of the target ECUs (YES in S4), the process proceeds to step S5. On the other hand, if the history indicated by the communication diagnosing information indicates an abnormality in communication between some of the target ECUs (NO in S4), the process proceeds to step S6. In step S5, the diagnosis unit 103 performs the diagnosis of the third pattern described above, and ends the diagnosis process.

[0072] In step S6, if the history indicated by the communication diag information included in the received ECU-related information indicates the disconnection of only the first ECU 30 (YES in S6), the process proceeds to step S7. Disconnection of only the first ECU 30 refers to the interruption of communication only with the first ECU 30 among all the target ECUs. On the other hand, if the history indicated by the communication diag information included in the received ECU-related information indicates the disconnection of target ECUs other than the first ECU 30 (NO in S6), the process proceeds to step S8. In step S7, the diagnosis unit 103 performs the diagnosis of the second pattern described above, and ends the diagnosis process. In step S8, the diagnosis unit 103 performs the diagnosis of the fourth pattern described above, and ends the diagnosis process.

[0073] In step S9, if ECU-related information could not be received from only a specific target ECU for any of the multiple buses (YES in S9), the process proceeds to step S8. In other words, if there is no response from all buses for only a specific target ECU, the process proceeds to S8. On the other hand, if there is no target ECU from which ECU-related information could not be received for any of the multiple buses for any of the target ECUs (NO in S9), the process proceeds to step S10.

[0074] In step S10, if the history indicated by the communication diagnosing information included in the received ECU-related information includes normality (YES in S10), the process proceeds to step S11. Normal here means that there is no abnormality in the communication with the target ECU. On the other hand, if the history indicated by the communication diagnosing information included in the received ECU-related information does not include normality (NO in S10), the process proceeds to step S12. In step S11, the diagnosis unit 103 performs a diagnosis of the fifth pattern described above and ends the diagnosis process. In step S12, the diagnosis unit 103 determines that the above-mentioned five patterns do not apply and ends the diagnosis process. In S12, the diagnosis process ends without narrowing down the location of the failure in the communication system 2.

[0075] In the first embodiment, the communication system 2 includes three target ECUs, but this is not necessarily limited to this. The communication system 2 may include two or more target ECUs, for example, may include two target ECUs. Even in this case, according to the configuration of the first embodiment, when an abnormality occurs in the communication system 2, it becomes possible to more easily estimate the location of the abnormality in more detail.

[0076] (Embodiment 2) In the first embodiment, a configuration in which two buses are provided in parallel for each target ECU has been described as an example, but this is not necessarily limited to this. A configuration in which three or more buses are provided in parallel for each target ECU (hereinafter, referred to as the second embodiment) may also be used. An example of the configuration of the second embodiment will be described below with reference to the drawings.

[0077] A second embodiment of the present disclosure will be described below with reference to the drawings. As shown in Fig. 13, the vehicle fault diagnosis system 1a includes a fault diagnosis device 10a, a diagnostic I / F 20, a bus X, and a communication system 2a. The communication system 2a includes a first ECU 30a, a second ECU 40, a third ECU 50a, a bus A, a bus B, and a bus C. The vehicle fault diagnosis system 1a is similar to the vehicle fault diagnosis system 1 except for the points described below as differences from the vehicle fault diagnosis system 1.

[0078] The fault diagnosis device 10a is similar to the fault diagnosis device 10 of the first embodiment, except for some differences in the processing in the diagnosis unit 103. The bus C is a bus that connects the first ECU 30a and the third ECU 50a in a bus-type configuration. In the example of FIG. 13, the bus C is not connected to the second ECU 40. In this way, some of the multiple buses do not need to be in a redundant line relationship with some of all the target ECUs. It is also possible that all of the three or more buses are in a redundant line relationship with all the target ECUs.

[0079] The first ECU 30a and the third ECU 50a are similar to the first ECU 30 and the third ECU 50 of the first embodiment, except that they are provided with a communication circuit for communicating via the bus C. The first ECU 30a and the third ECU 50a are provided with a transceiver used for transmitting and receiving via the bus C. In the vehicle fault diagnosis system 1a shown in FIG. 13, three buses, a bus A, a bus B, and a bus C, are provided in parallel with the first ECU 30a and the third ECU 50a, respectively. The buses A, B, and C are in a redundant line relationship for the communication between the first ECU 30a and the third ECU 50a. The buses A and B are provided in parallel with the first ECU 30a, the second ECU 40, and the third ECU 50a, respectively. The buses A and B are in a redundant line relationship for the communication between the first ECU 30a, the second ECU 40, and the third ECU 50a.

[0080] Even if the number of buses in the bus-type connection of the target ECU is three or more, it is preferable that the target ECU transmits, as a response message, communication diagnostic information for a bus other than the bus used to receive the request message. In this case, it is assumed that communication diagnostic information for each bus used for communication by the target ECU is transmitted. In other words, it is assumed that they have a mutually complementary relationship. As a specific example, in the example of FIG. 13, it is assumed that the following. The first ECU 30a transmits communication diagnostic information for the bus C side in response to a request message for the bus A. The first ECU 30a transmits communication diagnostic information for the bus A side in response to a request message for the bus B. The first ECU 30a transmits communication diagnostic information for the bus B side in response to a request message for the bus C. The second ECU 40 transmits communication diagnostic information for the bus B side in response to a request message for the bus A. The second ECU 40 transmits communication diagnostic information for the bus A side in response to a request message for the bus B. The third ECU 50a transmits communication diagnostic information for the bus C in response to the request message for the bus A. The third ECU 50a transmits communication diagnostic information for the bus A in response to the request message for the bus B. The third ECU 50a transmits communication diagnostic information for the bus B in response to the request message for the bus C.

[0081] Next, the diagnosis process in the diagnosis unit 103 in the second embodiment will be described. According to the configuration of the second embodiment, the diagnosis unit 103 can diagnose even overlapping failures in multiple buses or communication circuits on the multiple bus sides of the target ECU. An example will be described with reference to Fig. 14. Fig. 14 shows an example in which an abnormality occurs in bus B and bus C, or a failure in a short mode occurs in the communication circuits on the bus B and bus C sides of the target ECU.

[0082] The reception status in the example of FIG. 14 is as follows. The communication diagnostic information of the bus C side as a response to the request message for the bus A was received from the first ECU 30a, but the communication diagnostic information indicates an abnormality. The abnormality is a communication interruption between the first ECU 30a and the third ECU 50a. On the other hand, the communication diagnostic information of the bus A side as a response to the request message for the bus B was not received from the first ECU 30a. The communication diagnostic information of the bus B side as a response to the request message for the bus C was also not received from the first ECU 30a. In addition, the communication diagnostic information of the bus B side as a response to the request message for the bus A was received from the second ECU 40, but the communication diagnostic information indicates an abnormality. The abnormality is a communication interruption between the second ECU 40 and the first ECU 30a, and between the second ECU 40 and the third ECU 50a. On the other hand, the communication diagnostic information of the bus A side as a response to the request message for the bus B was not received from the second ECU 40. Also, communication diagnostic information on the bus C side in response to the request message for bus A was received from the third ECU 50a, but the communication diagnostic information indicates an abnormality. The abnormality is a breakdown in communication between the third ECU 50a and the first ECU 30a. On the other hand, communication diagnostic information on the bus A side in response to the request message for bus B was not received from the third ECU 50a. Communication diagnostic information on the bus B side in response to the request message for bus C was also not received from the third ECU 50a.

[0083] In the reception status shown in FIG. 14, there is a response via bus A, but no response via bus B or bus C, so it is possible to narrow down the abnormality to the following faults and estimate the abnormality. From the reception status shown in FIG. 14, the diagnosis unit 103 performs a diagnosis to estimate an abnormality in bus B or bus C, or an abnormality in any of the target ECUs. As described above, according to the configuration of the second embodiment, it is possible to diagnose even overlapping faults. Furthermore, even for faults other than overlapping faults, it is possible to improve the accuracy of diagnosis by increasing the number of bus routes that receive responses to communication diagnosis information.

[0084] 13, the communication system 2a includes three target ECUs, but the present invention is not limited to this example, and the communication system 2a may include four or more target ECUs.

[0085] (Embodiment 3) The configuration is not limited to the above-described embodiment, and may be such that the target ECU functions as a domain controller (hereinafter, referred to as embodiment 3). An example of the configuration of embodiment 3 will be described below with reference to the drawings.

[0086] Hereinafter, a third embodiment of the present disclosure will be described with reference to the drawings. As shown in FIG. 15, a vehicle fault diagnosis system 1b includes a fault diagnosis device 10, a diagnostic I / F 20, a bus X, and a communication system 2b. The vehicle fault diagnosis system 1b is similar to the vehicle fault diagnosis system 1 except that the vehicle fault diagnosis system 1b includes a communication system 2b instead of the communication system 2. The communication system 2b includes a first ECU 30b, a second ECU 40b, a third ECU 50b, a first subordinate ECU 31-34, a second subordinate ECU 41-44, a third subordinate ECU 51-54, a bus A, a bus B, a bus D, a bus E, a bus F, a bus G, a bus H, and a bus I.

[0087] The first ECU 30b, the second ECU 40b, and the third ECU 50b function as domain controllers. Except for this, they are the same as the first ECU 30, the second ECU 40, and the third ECU 50 of the first embodiment. The first ECU 30b has a function of determining the communication state of the subordinate ECUs 31 to 34. The subordinate ECUs 31 to 34 are the subordinate ECU 31, the subordinate ECU 32, the subordinate ECU 33, and the subordinate ECU 34. The second ECU 40b has a function of determining the communication state of the subordinate ECUs 41 to 44. The subordinate ECUs 41 to 44 are the subordinate ECU 41, the subordinate ECU 42, the subordinate ECU 43, and the subordinate ECU 44. The third ECU 50b has a function of determining the communication state of the subordinate ECUs 51 to 54. The subordinate ECUs 51 to 54 are the subordinate ECU 51, the subordinate ECU 52, the subordinate ECU 53, and the subordinate ECU 54.

[0088] The subordinate ECUs 31 to 34 are connected in a star topology to the first ECU 30b, with the first ECU 30b as a central device. The first ECU 30b is connected to the subordinate ECUs 31 and 32 via a bus D. The first ECU 30b is connected to the subordinate ECUs 31 and 32 in a bus topology via the bus D. The first ECU 30b is connected to the subordinate ECUs 33 and 34 via a bus E. The first ECU 30b is connected to the subordinate ECUs 33 and 34 in a bus topology via the bus E.

[0089] The subordinate ECUs 41 to 44 are connected to the second ECU 40b in a star topology, with the second ECU 40b as a central device. The second ECU 40b is connected to the subordinate ECUs 41 and 42 via a bus F. The second ECU 40b is connected to the subordinate ECUs 41 and 42 in a bus topology via the bus F. The second ECU 40b is connected to the subordinate ECUs 43 and 44 via a bus G. The second ECU 40b is connected to the subordinate ECUs 43 and 44 in a bus topology via the bus G.

[0090] The subordinate ECUs 51 to 54 are connected in a star topology to the third ECU 50b, with the third ECU 50b as a central device. The third ECU 50b is connected to the subordinate ECUs 51 and 52 via a bus H. The third ECU 50b is connected to the subordinate ECUs 51 and 52 in a bus topology via the bus H. The third ECU 50b is connected to the subordinate ECUs 53 and 54 via a bus I. The third ECU 50b is connected to the subordinate ECUs 53 and 54 in a bus topology via the bus I.

[0091] 15 shows an example in which all the target ECUs included in the communication system 2b function as domain controllers, but this is not necessarily limited to this. For example, only some of the target ECUs included in the communication system 2b may function as domain controllers.

[0092] In the configuration of the third embodiment, the first ECU 30b, the second ECU 40b, and the third ECU 50b may include the determined communication states of the subordinate ECUs in the ECU-related information and transmit the information to the fault diagnosis device 10. This allows the fault diagnosis device 10 to diagnose communication abnormalities related to the subordinate ECUs of the first ECU 30b, the second ECU 40b, and the third ECU 50b as well.

[0093] (Embodiment 4) The configuration is not limited to that of the third embodiment described above, and the subordinate ECUs may also be configured to have multiple buses in parallel (hereinafter, referred to as a fourth embodiment). An example of the configuration of the fourth embodiment will be described below with reference to the drawings.

[0094] Hereinafter, a fourth embodiment of the present disclosure will be described with reference to the drawings. As shown in FIG. 16, a vehicle fault diagnosis system 1c includes a fault diagnosis device 10, a diagnostic I / F 20, a bus X, and a communication system 2c. The vehicle fault diagnosis system 1c is similar to the vehicle fault diagnosis system 1 except that the vehicle fault diagnosis system 1c includes the communication system 2c instead of the communication system 2. The communication system 2c includes a first ECU 30b, a second ECU 40b, a third ECU 50c, a first subordinate ECU 31-34, a second subordinate ECU 41-44, a third subordinate ECU 51-52, 53c, 54c, a bus A, a bus B, a bus D, a bus E, a bus F, a bus G, a bus H, and a bus I.

[0095] The subordinate ECUs 53c, 54c are similar to the subordinate ECUs 53, 54 of the third embodiment, except that the subordinate ECUs 53c, 54c are connected to the bus B in addition to the bus I. The bus I and the bus B are provided in parallel for the subordinate ECUs 53c, 54c. The bus I and the bus B are in a redundant line relationship for the subordinate ECUs 53c, 54c. The communication state of the subordinate ECUs 53c, 54c can be determined by the third ECU 50c. For example, the fault diagnosis device 10 may receive the determination results via the bus A and the bus B, and perform diagnosis by comparing the results. For example, the subordinate ECU that is found to be the fault location in the comparison of the determination results may be diagnosed as being abnormal.

[0096] According to the configuration of the fourth embodiment, it is possible to perform a diagnosis of abnormalities of the target ECU and the bus described in the first embodiment for the subordinate ECU and the bus to which the subordinate ECU is connected, in the same manner. Therefore, it is possible to easily estimate the abnormality location in more detail for the subordinate ECU and the bus to which the subordinate ECU is connected.

[0097] (Embodiment 5) Moreover, a configuration (hereinafter, referred to as embodiment 5) may be formed by combining the configuration of embodiment 4 with the configuration of embodiment 2. An example of the configuration of embodiment 5 will be described below with reference to the drawings.

[0098] Hereinafter, a fifth embodiment of the present disclosure will be described with reference to the drawings. As shown in FIG. 17, a vehicle fault diagnosis system 1d includes a fault diagnosis device 10, a diagnostic I / F 20, a bus X, and a communication system 2d. The vehicle fault diagnosis system 1d is similar to the vehicle fault diagnosis system 1 except that the vehicle fault diagnosis system 1d includes the communication system 2d instead of the communication system 2. The communication system 2d includes a first ECU 30d, a second ECU 40b, a third ECU 50d, a first subordinate ECU 31-34, a second subordinate ECU 41-44, a third subordinate ECU 51-52, 53c, 54c, a bus A, a bus B, a bus C, a bus D, a bus E, a bus F, a bus G, a bus H, and a bus I.

[0099] The first ECU 30d and the third ECU 50d are similar to the first ECU 30b and the third ECU 50b of the fourth embodiment, except that the first ECU 30d and the third ECU 50d are provided with a communication circuit for communication via the bus C. The first ECU 30d and the third ECU 50d are provided with a transceiver used for transmission and reception via the bus C. In the vehicle fault diagnosis system 1d shown in FIG. 17, three buses, a bus A, a bus B, and a bus C, are provided in parallel for each of the first ECU 30d and the third ECU 50d. The buses A, B, and C are in a redundant line relationship for the communication between the first ECU 30d and the third ECU 50d. The buses A and B are provided in parallel for each of the first ECU 30d, the second ECU 40b, and the third ECU 50d. The buses A and B are provided in parallel for each of the first ECU 30d, the second ECU 40b, and the third ECU 50d. The buses A and B are in a redundant line relationship for the communication between the first ECU 30d, the second ECU 40b, and the third ECU 50d.

[0100] The present disclosure is not limited to the above-described embodiment, and various modifications are possible within the scope of the claims. The embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also included in the technical scope of the present disclosure. The control unit and the method described in the present disclosure may be realized by a dedicated computer constituting a processor programmed to execute one or more functions embodied by a computer program. Alternatively, the device and the method described in the present disclosure may be realized by a dedicated hardware logic circuit. Alternatively, the device and the method described in the present disclosure may be realized by one or more dedicated computers configured by a combination of a processor that executes a computer program and one or more hardware logic circuits. The computer program may be stored in a computer-readable non-transient tangible recording medium as instructions executed by the computer. [Explanation of symbols]

[0101] 1, 1a, 1b, 1c, 1d vehicle fault diagnosis system, 10, 10a fault diagnosis device, 20 diagnostic I / F (interface), 30, 30a, 30b, 30d first ECU (boundary ECU), 40 second ECU, 50, 50a, 50b, 50d third ECU, 101 request transmission unit, 102 information reception unit, 103 diagnosis unit, A bus, B bus, C bus, I bus

Claims

1. A vehicle fault diagnosis system (1, 1a, 1b, 1c, 1d) that can be used in a vehicle, At least two ECUs (30, 30a, 30b, 30d, 40, 40b, 50, 50a, 50b, 50d, 53c, 54c) as ECUs that are electronic control units; a fault diagnosis device (10, 10a) connected to some of the ECUs via an interface (20); A bus (A, B, C, I) is a communication line that connects the ECUs in a bus configuration, The fault diagnosis device includes: an information receiving unit (102) for receiving ECU-related information, which is information output from the ECU, when the ECU-related information is transmitted via the interface; a diagnosis unit (103) that diagnoses an abnormality in a communication system (2) including the ECU and the bus by using a reception status of the ECU-related information by the information receiving unit, A vehicle fault diagnosis system in which at least two buses are provided in parallel for each of a plurality of ECUs, including a boundary ECU (30, 30a, 30b) which is the ECU connected to the fault diagnosis device via the interface.

2. 2. A vehicle fault diagnosis system according to claim 1, The fault diagnosis system for a vehicle includes a request sending unit (101) that broadcasts a message requesting the ECU-related information to each ECU included in the communication system via the interface.

3. 3. A vehicle fault diagnosis system according to claim 2, the request transmission unit causes the transmission of the message by broadcast to each ECU included in the communication system to be performed for each of the plurality of buses provided in parallel for each of the plurality of ECUs; The ECU records communication diagnostic information which is a history of abnormalities in communication with other ECUs, which are ECUs other than the ECU itself, via the bus, among the plurality of ECUs, and The ECU-related information includes the communication diagnostic information, When the ECU receives the message intended for itself, the ECU transmits, as a response message to the message, the communication diagnostic information for a bus other than the bus to which the message was sent, among the messages sent for each bus.This is a fault diagnosis system for a vehicle.

4. 3. A vehicle fault diagnosis system according to claim 2, the request transmission unit causes the transmission of the message by broadcast to each ECU included in the communication system to be performed for each of the plurality of buses provided in parallel for each of the plurality of ECUs; A vehicle fault diagnosis system in which, when the ECUs other than the boundary ECU receive the message via the bus, they transmit the ECU-related information to the fault diagnosis device as a response message to the message using a bus among the multiple buses that is different from the bus used to receive the message.

5. 2. A vehicle fault diagnosis system according to claim 1, The ECU includes at least three ECUs (30a, 40, 50a), In the vehicle fault diagnosis system, at least three buses are provided in parallel for each of the plurality of ECUs including the boundary ECU.

6. 6. A vehicle fault diagnosis system according to claim 5, At least one ECU (30b, 40b, 50b) of the plurality of ECUs is connected in a star configuration with a subordinate ECU (31, 32, 33, 34, 41, 42, 43, 44, 51, 52, 53, 54) that is an ECU other than the ECUs connected in a bus configuration, with the ECU serving as a central device, and the vehicle fault diagnosis system has a function of determining the communication state with the subordinate ECU.

7. A vehicle fault diagnosis system according to any one of claims 1 to 6, The diagnostic unit performs a diagnosis to estimate an abnormality in the communication system using a reception state of the ECU-related information from each ECU included in the communication system by the information receiving unit.

8. 8. A vehicle fault diagnosis system according to claim 7, The diagnostic unit performs diagnosis to estimate an abnormality in the communication system from a communication path through which the ECU-related information can be received as the reception status at the information receiving unit.

9. 8. A vehicle fault diagnosis system according to claim 7, The ECU records communication diagnostic information which is a history of abnormalities in communication with other ECUs, which are ECUs other than the ECU itself, via the bus, among the plurality of ECUs, and The ECU-related information includes the communication diagnostic information, The diagnostic unit performs a diagnosis to estimate an abnormality in the communication system from at least one of the communication path through which the ECU-related information was received as the reception status at the information receiving unit and the history indicated by the communication diagnostic information received by the information receiving unit.

10. 10. The vehicle fault diagnosis system according to claim 9, The diagnosis unit performs a diagnosis to estimate an abnormality in the communication system based on at least a communication path history through which the ECU-related information can be received, A vehicle fault diagnosis system in which the diagnosis unit performs a diagnosis to estimate an abnormality in the boundary ECU when the ECU-related information cannot be received from all of the ECUs included in the communication system for any of the multiple buses.

11. 10. The vehicle fault diagnosis system according to claim 9, The diagnosis unit performs a diagnosis to estimate an abnormality in the communication system based on the communication path through which the ECU-related information can be received and the history indicated by the communication diagnosis information received by the information receiving unit, The diagnostic unit is a vehicle fault diagnosis system that performs a diagnosis to estimate an abnormality in the border ECU when the diagnostic unit is unable to receive ECU-related information from all of the ECUs included in the communication system for a specific bus among the multiple buses and the history indicated by the communication diagnostic information received via a bus other than the specific bus among the multiple buses indicates an abnormality in communication with the border ECU.

12. 10. The vehicle fault diagnosis system according to claim 9, The diagnosis unit performs a diagnosis to estimate an abnormality in the communication system based on the communication path through which the ECU-related information can be received and the history indicated by the communication diagnosis information received by the information receiving unit, The diagnostic unit performs a diagnosis to estimate an abnormality in a specific bus or an abnormality in any of the ECUs included in the communication system when, for a specific bus among the multiple buses, it is unable to receive the ECU-related information from all of the ECUs included in the communication system and the history indicated by the communication diagnosing information received via a bus other than the specific bus among the multiple buses indicates an abnormality in communication between all of the ECUs included in the communication system.

13. 10. The vehicle fault diagnosis system according to claim 9, The diagnosis unit performs a diagnosis to estimate an abnormality in the communication system based on the communication path through which the ECU-related information can be received and the history indicated by the communication diagnosis information received by the information receiving unit, A vehicle fault diagnosis system in which the diagnostic unit performs a diagnosis to presume an abnormality in a specific ECU when, for any of the multiple buses, the ECU-related information cannot be received only from a specific ECU included in the communication system, and when, for any of the multiple buses, the history indicated by the received communication diagnostic information indicates an abnormality in communication with the specific ECU.

14. 10. The vehicle fault diagnosis system according to claim 9, The diagnosis unit performs a diagnosis to estimate an abnormality in the communication system based on the communication path through which the ECU-related information can be received and the history indicated by the communication diagnosis information received by the information receiving unit, The diagnostic unit performs a diagnosis to estimate an abnormality in a specific ECU included in the communication system when the diagnostic unit is unable to receive the ECU-related information from only a specific ECU included in the communication system for a specific bus among the multiple buses, and when the history indicated by the communication diagnosing information received via a bus other than the specific bus among the multiple buses indicates an abnormality in communication with the specific ECU included in the communication system.

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