Electronic control unit and communication system

Abstract

To properly execute control processing after recovery of communication when a failure occurs on a two-wire communication line connected to an electronic control apparatus.SOLUTION: An electronic control apparatus having terminal resistors equipped at both ends to perform two-wire communication, connected to another electronic control apparatus over a network, having a communication interface which establishes a communication over the network, and configured to execute control processing while communicating with the another electronic control apparatus, includes recovery information including control information associated with failure location information identifying a location of a failure which may occur on the network and device information identifying the another electronic control apparatus. When receiving a notification on the failure location information identifying a location of a failure detected on the network, the electronic control apparatus refers to the recovery information, acquires the control information associated with failure location information and the device information from the recovery information, and establishes a communication with the another electronic control apparatus on the basis of the control information in control processing after recovery of the network.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electronic control unit and a communication system. [Background technology]

[0002] CAN (Controller Area Network) is one of the communication protocols used for communication between electronic control devices. As an example of a technology related to communication using CAN, a technology has been proposed in which, in a communication device having multiple communication stations via a two-wire communication line, when an abnormality is detected in the two-wire communication line, communication is restored by controlling a resistor connectable to the two-wire communication line. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-83471 Summary of the Invention [Problem to be solved by the invention]

[0004] In this conventional technology, when a failure occurs in a two-wire communication line, it is possible to physically restore communication. However, after the network is restored in this way, it may be desirable to perform control processing using data different from normal processing depending on the system state after the restoration. However, the above-mentioned conventional technology does not mention how to perform control processing after the restoration, and there is a possibility that appropriate control processing cannot be realized.

[0005] Therefore, one aspect of the present invention aims to enable appropriate control processing to be performed after communication is restored in the event of a failure in a two-wire communication line to which an electronic control device is connected. [Means for solving the problem]

[0006] In one aspect of the present invention, in an electronic control device that is connected to other electronic control devices via a network that performs two-wire communication with termination resistors at both ends, and that has a processor, memory, and a communication interface that enables communication via the network, and that performs control processing while communicating with the other electronic control devices, the memory stores recovery information including failure location information that identifies a failure location that may occur in the network and control information that is associated with device information that identifies the other electronic control devices, and when the processor receives notification of failure location information that identifies a failure location detected in the network, it refers to the recovery information and obtains from the recovery information the control information that is associated with the failure location information and the device information, and in control processing after the network is restored, communicates with the other electronic control devices based on the control information. [Effects of the Invention]

[0007] According to one aspect of the present invention, when a failure occurs in a two-wire communication line to which an electronic control device is connected, appropriate control processing can be performed after communication is restored. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram illustrating an example of a control system according to an embodiment of the present invention. [Figure 2] 2 is a block diagram showing the functional configuration and data configuration of an ECU (other than the main ECU) according to an embodiment of the present invention. FIG. [Figure 3] 2 is a block diagram showing the functional configuration and data configuration of an ECU (main) according to an embodiment of the present invention. FIG. [Figure 4] FIG. 10 is an explanatory diagram illustrating an example of a recovery information matrix according to an embodiment of the present invention. [Figure 5] 5 is a flowchart showing an example of a process for identifying and recovering a broken wire location by an ECU (main) according to an embodiment of the present invention. [Figure 6]10 is a flowchart illustrating an example of selection of control information when recovering from a disconnection and control processing based on the control information according to an embodiment of the present invention. [Figure 7] 10A and 10B are explanatory diagrams showing specific examples of fault locations and termination resistors when a recovery process is executed in one embodiment of the present invention. [Figure 8] 10A and 10B are explanatory diagrams showing specific examples of fault locations and termination resistors when a recovery process is executed in one embodiment of the present invention. [Figure 9] 1A and 1B are explanatory diagrams showing examples of sub-tables of a recovery information matrix in an embodiment of the present invention, where (A) shows a control group table and (B) shows a control information table. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described in this specification, and different embodiments and their modifications can be combined as appropriate.

[0010] [Overall configuration of the control system] FIG. 1 shows an example of a control system 10 according to this embodiment. The control system 10 is mounted on a vehicle such as an automobile and controls various devices related to the vehicle's running. Depending on the type of on-board device to be controlled, the control system 10 can be classified into a powertrain control system such as an engine control system, a vehicle control system such as an electric power steering system or a brake control system, a body control system such as an airbag or perimeter monitoring system, and an information system such as a navigation system or a global positioning system (GPS). The control system 10 includes ECUs (Electronic Control Units) 20 (first ECU 20A, second ECU 20B, third ECU 20C, fourth ECU 20D, and fifth ECU 20E) that control the on-board devices. In the following description, the first ECU 20A to fifth ECU 20E will be referred to as ECU 20 when describing all of them in common or when describing any one or more of them, and the first ECU 20A to fifth ECU 20E will be referred to individually. The same applies to other components. The control system 10 includes a network 30 that is connected to each of these ECUs 20 and transmits and receives signals using the CAN protocol. The network 30 includes buses CAN_H 31 and CAN_L 32 that configure two-wire communication.

[0011] The ECU 20 includes a CPU (Central Processing Unit) 21 (21A to 21E) constituting a microcomputer, and a communication interface 22 (22A to 22E). The ECU 20 also includes a switch 41 (41A to 41E) connected to the CAN_H 31 and the CAN_L 32, and a resistor 42 (42A to 42E) that can serve as a termination resistor for two-wire communication by the CAN_H 31 and the CAN_L 32.

[0012] The CPU 21 loads and executes programs stored in a memory (not shown in FIG. 1) to perform control processing of the in-vehicle devices that are to be controlled by the ECU 20. The CPU 21 also performs communication control processing for communicating with other ECUs 20 via the CAN_H 31 and CAN_L 32.

[0013] The communication interface 22 is configured by, for example, a CAN (Controller Area Network) transceiver, and generates and adjusts the voltage to be transmitted to the bus, ensures the operating current, and provides the function of connecting to the network 30. The communication interface 22 transmits signals (differential signals) of different voltages to CAN_H31 and CAN_L32 according to the value of data transmitted from the CPU 21. Furthermore, when the communication interface 22 receives signals from CAN_H31 and CAN_L32, it identifies the value of the data indicated by the received signals based on the voltage difference between the signals at CAN_H31 and CAN_L32.

[0014] The switch 41 is made of a semiconductor element such as a transistor, and is turned on / off under the control of the CPU 21. When the switch 41 is turned on, the resistor 42 is connected to the CAN_H 31 and the CAN_L 32 and functions as a termination resistor (for example, a resistance value of 120 Ω) in the network 30. In the system example shown in Fig. 1, the switch 41A included in the first ECU 20A and the switch 41E included in the fifth ECU 20E are turned on. Therefore, the resistor 42A included in the first ECU 20A and the resistor 42E included in the fifth ECU 20E serve as termination resistors for the two-wire communication in the CAN_H 31 and the CAN_L 32, respectively.

[0015] 1, of the first ECU 20A to the fifth ECU 20E, the fifth ECU 20E has a communication management function (main function) in the network 30. In other words, a CPU 21E included in the fifth ECU 20E functions as a main CPU in the network 30. Below, the functional configuration and data configuration of each of the first ECU 20A to the fourth ECU 20D and the fifth ECU 20E having the communication management function will be described separately. The fifth ECU 20E is a specific example of a first electronic control unit, and the first ECU 20A to the fourth ECU 20D are specific examples of second electronic control units.

[0016] [ECU functional configuration and data configuration] 2 is a block diagram showing the functional configuration and data configuration of each of the first ECU 20A to the fourth ECU 20D. Each of the first ECU 20A to the fourth ECU 20D includes a signal transmission unit 51 and a control processing unit 52 as a control unit 50, the functions of which are realized by a CPU 21 constituting a microcomputer executing a program. Each of the microcomputers of the first ECU 20A to the fourth ECU 20D also includes a memory 60, which stores a recovery information matrix 61. Note that the memory 60 also stores data used for normal control processing in the first ECU 20A to the fourth ECU 20D, but this is not shown or described in the present embodiment.

[0017] The signal transmitting unit 51 transmits a heartbeat signal indicating that the device itself is operating normally to the fifth ECU 20E having a communication management function at predetermined time intervals. The control processing unit 52 performs normal control processing for the in-vehicle devices. When the control processing unit 52 receives a failure location code indicating a failure location in the network 30 from a failure location notifying unit 55 of the fifth ECU 20E having a communication management function, the control processing unit 52 refers to the recovery information matrix 61 stored in the memory 60 and acquires control information associated with the failure location code and device information identifying each of the ECUs 20 with which communication is performed during the control processing. Then, the control processing unit 52 performs control processing after the network 30 is restored based on the control information.

[0018] 3 is a block diagram showing the functional and data configurations of a fifth ECU 20E having a communication management function. Like the first to fourth ECUs 20A to 20D, the fifth ECU 20E includes a control processing unit 52 in a control unit 50 and a recovery information matrix 61 in a memory 60. Furthermore, the fifth ECU 20E further includes a fault detection unit 53, a termination control unit 54, and a fault location notification unit 55 instead of the signal transmission unit 51 in the first to fourth ECUs 20A to 20D.

[0019] The failure detection unit 53 identifies the location of a failure in the network 30. Specifically, when the failure detection unit 53 detects that the heartbeat signals from the first ECU 20A to the fourth ECU 20D have been interrupted, the failure detection unit 53 performs broadband transmission to the first ECU 20A to the fourth ECU 20D. Then, the failure detection unit 53 identifies the location of the failure based on the presence or absence of a response signal from the first ECU 20A to the fourth ECU 20D in response to the broadband transmission.

[0020] The termination control unit 54 turns on the switch 41 provided in any one of the first ECU 20A to fourth ECU 20D according to the identified fault location in the network 30, and connects the resistor 42 to the network 30. This makes it possible to change the position of the termination resistor in the two-wire communication of the network 30, and physically restore the network 30.

[0021] The fault location notification unit 55 notifies the control processing unit 52 of the first to fifth ECUs 20A to 20E of a fault location code that identifies the detected fault location in the network 30. This fault location code can be set in advance in any correspondence with each fault location that may occur in the network 30, for example, between binary codes "00000000" to "11111111." The control processing unit 52 of the control unit 50 and the recovery information matrix 61 of the memory 60 are similar to those of the first ECU 20A to the fourth ECU 20D, and therefore a description thereof will be omitted. The fifth ECU 20E may be configured to include only components related to the communication management function, without including the control processing unit 52 and the recovery information matrix 61.

[0022] [Configuration of recovery information matrix] An example of the recovery information matrix 61 provided in each ECU 20 is shown in Fig. 4. The recovery information matrix 61 is a table showing control information associated with a failure location code (failure location information) that identifies a failure location that may occur in the network 30, and device information that identifies the ECU 20 that will be the other party to communicate in the control process. For example, Fig. 4 shows a specific example of the recovery information matrix 61 held by the fourth ECU 20D. In the recovery information matrix 61, the control information associated with the failure location code "1 (00000001 in binary code)" and the third ECU 20C that will be the other party to communicate is the "abnormal setting value." This indicates that when the control processing unit 52 of the fourth ECU 20D including the recovery information matrix 61 receives a notification of the failure location code "1" from the failure location notification unit 55 of the fifth ECU 20E, i.e., when a failure occurs between the first ECU 20A and the second ECU 20B on the network 30, the control processing unit 52 performs control using a predetermined "abnormal setting value" in communication with the third ECU 20C. On the other hand, in communication with the fifth ECU 20E, the control is continued using the "previous value" transmitted and received before the failure occurred. Note that it is assumed that the "previous value" is stored in the memory 60 of each ECU 20. Note that, among the data examples shown in the recovery information matrix 61, the "transmitted and received value" indicates that the value of data that can be transmitted and received after recovery is used as is (i.e., normal processing is performed). Note that the "abnormal setting value," "previous value," "transmitted and received value," etc. are merely examples of control information.

[0023] [Recovery process by each ECU when a failure occurs] Next, the processing executed by the ECU 20 will be described in detail. First, the processing executed by the failure detection unit 53, the termination control unit 54, and the failure location notification unit 55 of the fifth ECU 20E having a communication management function will be described with reference to the flowchart shown in FIG.

[0024] In step 101 (shown as S101 in the figure, and the same applies below), the failure detection unit 53 determines whether or not a heartbeat signal has been received from any of the ECUs 20A to 20D within a predetermined period of time. If a heartbeat signal has been received, the process of step 101 continues (Yes); if not, the process proceeds to step 102 (No). In step 102, the termination control unit 54 turns on the switch 41E included in its own device (the fifth ECU 20E) and connects the resistor 42E to the network 30. In step 103, the failure detection unit 53 performs broadband transmission to request a response signal from the first ECU 20A to the fourth ECU 20D.

[0025] In step 104, the failure detection unit 53 determines whether or not a response signal has been received from the fourth ECU 20D. If not received, the process proceeds to step 105 (No), and if received, the process proceeds to step 107 (Yes). In step 105, the failure detection unit 53 identifies that the failure location in the network 30 is between the fourth ECU 20D and the fifth ECU 20E. At this time, the failure detection unit 53 sets the failure location code to "4 (00000100)". In step 106, the failure detection unit 53 determines whether or not a response signal has been received from the third ECU 20C. If not received, the process proceeds to step 107 (No), and if received, the process proceeds to step 108 (Yes). In step 107, the failure detection unit 53 identifies that the failure location in the network 30 is between the third ECU 20C and the fourth ECU 20D. At this time, the failure detection unit 53 sets the failure location code to "3 (00000011)".

[0026] In step 108, the failure detection unit 53 determines whether or not a response signal has been received from the second ECU 20B. If not received, the process proceeds to step 109 (No), and if received, the process proceeds to step 110 (Yes). In step 109, the failure detection unit 53 identifies that the failure location of the network 30 is between the second ECU 20B and the third ECU 20C. At this time, the failure detection unit 53 sets the failure location code to "2 (00000010)". In step 110, the failure detection unit 53 determines whether or not a response signal has been received from the first ECU 20A. If not received, the process proceeds to step 111 (No), and if received, the process proceeds to step 112 (Yes). In step 111, the failure detection unit 53 identifies that the failure location of the network 30 is between the first ECU 20A and the second ECU 20B. At this time, the failure detection unit 53 sets the failure location code to "1 (00000001)".

[0027] In step 112, the failure detection unit 53 determines that the cause of the heartbeat signal interruption is not a wire breakage or the like because response signals have been received from all of the first ECU 20A to the fourth ECU 20D. Specifically, the failure detection unit 53 determines that the heartbeat signal interruption is due to a software reset in an ECU 20 having a termination resistor, unstable operation of the termination resistor, or the like. At this time, the failure detection unit 53 sets the failure location code to "0 (00000000)".

[0028] In step 113, the termination control unit 54 connects the resistor 42 of any one of the first ECU 20A to the fifth ECU 20E to the network 30 according to the location of the failure identified by the failure detection unit 53, thereby changing the location of the termination resistor. As a specific example in the case of the control system 10 shown in FIG. 1, if the location of the failure in the network 30 is between the second ECU 20B and the third ECU 20C, the termination control unit 54 sends an instruction to the third ECU 20C to connect the resistor 42C to the network 30. In response to this, the third ECU 20C turns on the switch 41C to connect the resistor 42C to the network 30. As a result, the resistor 42C of the third ECU 20C becomes the termination resistor of the network 30, and communication can be restored at least among the third ECU 20C to the fifth ECU 20E. In step 114, the termination control unit 54 turns off the switch 41E included in its own device (the fifth ECU 20E) and releases the connection of the resistor 42E to the network 30.

[0029] In step 115, as a result of the network 30 being physically restored by the processing of step 112, the failure location notification unit 55 notifies the currently communicable ECUs 20 of the failure location code determined by the processing of step 105, 107, 109, 111 or 112. Specifically, the failure location notification unit 55 transmits the failure location code to the control processing unit 52 of the communicable ECU 20 among the first ECU 20A to the fourth ECU 20D via the network 30. The failure location notification unit 55 also transfers the failure location code to the control processing unit 52 in the fifth ECU 20E, which is its own device.

[0030] Next, the processing executed by the control processing unit 52 of the first to fifth ECUs 20A to 20E will be described with reference to the flowchart shown in FIG. In step 211, the control processing unit 52 determines whether or not a failure location code has been notified from the failure location notifying unit 55 of the fifth ECU 20E. If a notification has been received, the process proceeds to step 212 (Yes), and if no notification has been received, the process of step 211 continues (No). In step 212, the control processing unit 52 determines whether the received failure location code is “1 (00000001),” “2 (00000010),” “3 (00000011),” “4 (00000100),” or “0 (00000000).” Then, in steps 213 to 217, the control processing unit 52 performs processing according to each failure location code.

[0031] In step 213, the control processing unit 52 refers to the recovery information matrix 61 and acquires the control information associated with the failure location code "1" and each of the ECUs 20 with which it communicates in the control processing. In step 214, the control processing unit 52 refers to the recovery information matrix 61 and acquires the control information associated with the failure location code "2" and each of the ECUs 20 that are the other parties with which the control processing is to communicate. In step 215, the control processing unit 52 refers to the recovery information matrix 61 and acquires the control information associated with the failure location code "3" and each of the ECUs 20 with which it communicates in the control processing. In step 216, the control processing unit 52 refers to the recovery information matrix 61 and acquires the control information associated with the failure location code "4" and each of the ECUs 20 with which it communicates in the control processing. In step 217, the control processing unit 52 refers to the recovery information matrix 61 and acquires the control information associated with the failure location code "0" and each of the ECUs 20 that are the other parties with which the control processing is to communicate.

[0032] In step 218, the control processing unit 52 determines data to be used for control with each of the ECUs 20 with which it communicates in the control processing, based on the control information acquired in any of steps 213 to 217, and performs the control processing using the determined data.

[0033] Next, a specific example of such recovery processing will be described with reference to FIGS. 7 and 8. FIG. 7 illustrates a state in which a disconnection fault occurs between the first ECU 20A and the second ECU 20B. In this case, the fault detection unit 53 of the fifth ECU 20E, which has a communication management function, performs broadband transmission to the first ECU 20A, the second ECU 20B, the third ECU 20C, and the fourth ECU 20D. As a result, the fault detection unit 53 of the fifth ECU 20E cannot receive a response signal from the first ECU 20A, and therefore determines that a disconnection fault has occurred between the first ECU 20A and the second ECU 20B. Then, the termination control unit 54 of the fifth ECU 20E transmits an instruction to the second ECU 20B to connect the resistor 42B to the network 30. In response to this instruction, the second ECU 20B turns on the switch 41B to connect the resistor 42B to the network 30. As a result, the resistor 42B of the second ECU 20B becomes a terminating resistor of the network 30, and communication can be restored at least between the second ECU 20B to the fifth ECU 20E enclosed by the dashed lines in FIG.

[0034] Then, the failure location notification unit 55 of the fifth ECU 20E notifies the control processing unit 52 of each of the second ECU 20B to the fifth ECU 20E of a failure location code "1 (00000001)" that identifies the failure location. Meanwhile, upon receiving the notification of the failure location code "1," the control processing unit 52 of each of the second ECU 20B to the fifth ECU 20E refers to the recovery information matrix 61, acquires control information associated with the failure location code "1," and performs control based on the control information. For example, if the fourth ECU 20D holds the example of the recovery information matrix 61 shown in FIG. 4, the control processing unit 52 of the fourth ECU 20D sets the data to be exchanged with the third ECU 20C after recovery to a preset "abnormal setting value." Meanwhile, the data to be exchanged with the fifth ECU 20E is set to a "previous value," which is a value used in processing immediately before the failure occurred.

[0035] FIG. 8 further illustrates a state in which a disconnection fault occurs between the second ECU 20B and the third ECU 20C. In this case, the fifth ECU 20E, which has a communication management function, performs broadband transmission and is unable to receive a response signal from the second ECU 20B. As a result, the fault detection unit 53 of the fifth ECU 20E determines that a disconnection fault has occurred between the second ECU 20B and the third ECU 20C. The termination control unit 54 of the fifth ECU 20E then sends an instruction to the third ECU 20C to connect the resistor 42C to the network 30. In response to this, the third ECU 20C turns on the switch 41C to connect the resistor 42C to the network 30. As a result, the resistor 42C of the third ECU 20C serves as a termination resistor for the network 30, and communication can be restored at least between the third ECU 20C and the fifth ECU 20E, which are enclosed by dashed lines in FIG. 8.

[0036] Then, the failure location notification unit 55 of the ECU 20E notifies the control processing units 52 of the third to fifth ECUs 20C to 20E of a failure location code "2 (00000010)" that identifies the failure location. Meanwhile, upon receiving the failure location code "2," the control processing units 52 of the third to fifth ECUs 20C to 20E refer to the recovery information matrix 61, acquire control information associated with the failure location code "2," and perform communication based on the control information. For example, if the example of the recovery information matrix 61 shown in FIG. 4 is held by the fourth ECU 20D, the data exchanged with the third ECU 20C will be the "previous value," which is the value used in the process immediately before the failure occurred, while the data exchanged with the fifth ECU 20E will be the predetermined "abnormal setting value." In this way, a change in the failure location may also change the value of the data used in communication in the control process after recovery.

[0037] [Effects of this embodiment] The present embodiment, with the above-described configuration, provides the following advantages when a failure such as a broken wire occurs in a two-wire CAN network. Specifically, according to the present embodiment, a recovery information matrix is ​​provided in advance, in which control information after communication recovery is stored in association with the failure location and each of the ECUs communicating with the control process. By referencing the control information in the recovery information matrix, control processing can be performed while transmitting and receiving data corresponding to the failure location with each of the ECUs communicating with the control process after communication recovery. Therefore, not only can communication be physically restored, but post-recovery control processing can be performed more appropriately. Furthermore, even when multiple such failures occur in stages, the failure location can be identified each time, and control processing can be performed using data corresponding to the most recent failure location.

[0038] [Modification of this embodiment] Here, a modified example of this embodiment will be described. In this modified example, each of the ECUs 20 described above has, in addition to the recovery information matrix 61, a control group table 61A and a control information table 61B, which are sub-tables, in the memory 60.

[0039] 9A shows a control group table 61A, which includes information on CAN_IDs and control groups. CAN_IDs are control identifiers assigned according to the control processes executed by each ECU 20, and data transmitted and received during the control processes includes the control identifiers. Meanwhile, control groups indicate predetermined classifications according to the content of the control processes (functions or types, for example, the safety level required for the control content, etc.). 9(B) is a control information table 61B, which includes information on control groups and control information. The control groups correspond to the control groups stored in the control group table 61A described above. The control information indicates the control information associated with each control group.

[0040] These control group tables 61A and control information tables 61B may be provided separately to correspond to the failure location and the counterpart ECU 20 with which communication occurs during control processing, or, for example, a common control group table 61A and control information table 61B may be provided for multiple counterpart ECUs 20.

[0041] In this modification, when the control processing unit 52 of the ECU 20 refers to the recovery information matrix 61 in the processing of steps 213 to 217 described above, the control processing unit 52 identifies the ECU 20 with which to communicate in the control processing and the CAN_ID assigned according to the control processing. Then, the control processing unit 52 refers to the control group table 61A to identify the control group associated with the CAN_ID. Furthermore, the control processing unit 52 refers to the control information table 61B to acquire the control information associated with the identified control group. For example, in the specific example of data shown in FIG. 9 , when the control group table 61A is referenced, if the CAN_ID of the control processing is "0x222," the control group is "B." Therefore, the control processing unit 52 refers to the control information table 61B to acquire the "abnormal setting value" as control information, and performs control processing based on the control information.

[0042] According to this modification, in the control process after the CAN network is restored, it is possible to obtain control information according to more specific control content in addition to the fault location and the ECU of the communication partner, so that after the CAN network is restored, the control process can be performed using more appropriate data according to the control content.

[0043] [others] In this embodiment, an example of application to a vehicle control system has been described, but CAN networks are also used in many fields, such as industrial facilities and medical equipment, and the systems to which the present invention is applicable are not limited to vehicle control systems. The ECU in this embodiment is merely an example of an electronic control unit that performs various controls. Furthermore, the embodiments of the present invention described above are merely some of the possible implementations within the technical scope of the present invention, and are disclosed as examples of the present invention, and do not limit the technical scope of the present invention. Furthermore, the functional configurations and physical configurations in each embodiment are not limited to the above-mentioned aspects, and for example, each function or physical resource can be integrated and implemented, or conversely, implemented in a more distributed manner, and further, some configurations can be added, deleted, or replaced with other configurations. [Explanation of symbols]

[0044] 10...control system, 20...ECU, 21...CPU, 22...communication interface, 30...network, 41...switch, 42...resistor, 51...signal transmission unit, 52...control processing unit, 53...fault detection unit, 54...termination control unit, 55...fault location notification unit, 61...restoration information matrix

Claims

1. An electronic control device that is connected to another electronic control device via a network that performs two-wire communication with a termination resistor at both ends, and that is equipped with a processor, a memory, and a communication interface that realizes communication via the network, and performs control processing while communicating with the other electronic control device, the memory includes recovery information including failure location information for identifying a failure location that may occur in the network and control information associated with device information for identifying the other electronic control device, the processor: When receiving notification of failure location information identifying a failure location detected in the network, refer to the recovery information, acquire the control information associated with the failure location information and the device information from the recovery information, and communicate with the other electronic control unit based on the control information in a control process after the network is restored. Electronic control unit.

2. An electronic control device that is connected to another electronic control device via a network that performs two-wire communication with termination resistors at both ends, and that is equipped with a processor, memory, and a communication interface that realizes communication via the network, and that performs control processing while communicating with the other electronic control device, the memory includes information in which control identifiers are classified according to the control content of the control process and control information associated with the classification; The processor: When receiving notification of failure location information identifying a failure location detected in the network, the other electronic control device with which the control processing is to be performed after the network is restored is identified, and the control identifier corresponding to the control processing is identified, the control information associated with the classification to which the control identifier belongs is acquired, and communication with the other electronic control device is performed based on the control information during the control processing after the network is restored. Electronic control unit.

3. The electronic control device according to claim 1 or 2, wherein the control information is information indicating that communication with the other electronic control device will be performed using a previous value or a predetermined abnormality setting value used in communication with the other electronic control device before a failure occurs in the control process.

4. A communication system in which a plurality of electronic control devices are connected via a network that performs two-wire communication with termination resistors at both ends, each of the plurality of electronic control devices having a processor, a memory, and a communication interface that realizes communication via the network, and performs control processing while communicating with each other, When a fault occurs in the network, a first electronic control device among the plurality of electronic control devices detects the fault location, changes the position of the termination resistor to restore communication on the network, and notifies a second electronic control device of fault location information that identifies the fault location; When the second electronic control unit receives the notification of the fault location information, the second electronic control unit refers to recovery information stored in the memory, the recovery information including control information associated with fault location information identifying a fault location that may occur in the network and device information identifying other electronic control units, acquires the control information associated with the fault location information and the device information from the recovery information, and communicates with the other electronic control units based on the control information. Communication system.

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