JP2017092566A - On-vehicle network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle network system that enables a communication node connected to an Ethernet network to grasp a communication node of which the communication state changes, in real time.SOLUTION: An intermediate node detects that a communication with a neighboring low-order node is interrupted or that the communication is recovered, and notifies a highest-order node of a detection content. The highest-order node also detects that a communication with a neighboring low-order node is interrupted or that the communication is recovered. Based on information about the low-order node reported from the intermediate node or detected by the highest-order node itself and hierarchical constitution information indicating a hierarchical connection constitution of a plurality of network-connected communication nodes, the highest-order node identifies a communication node of which the communication with the highest-order node is interrupted or the communication is recovered, and sends information about the identified communication node to an Ethernet network.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an in-vehicle network system in which a plurality of communication nodes are connected via a network.

  Many communication nodes are connected to the in-vehicle network system via a network such as a communication bus. The communication node is, for example, an electronic control unit (ECU), a sensor, or a camera.

  In this in-vehicle network system, when an abnormality such as communication interruption occurs in a communication node connected to the network, various techniques for detecting the communication node in which the abnormality has occurred and taking countermeasures have been developed. For example, Patent Document 1 discloses a method for detecting a communication node in which an abnormality has occurred in a ring network.

JP 2014-078771 A

  In an Ethernet (registered trademark) network in which a plurality of communication nodes are connected by a communication bus via a switch, when communication interruption occurs at an arbitrary location on the communication bus, a link-down detection function defined in IEEE 802.3 Can be used to detect the location where communication is interrupted and the nearest communication node. However, this link-down detection function cannot detect a communication node connected further ahead of the latest communication node.

  With respect to a communication node connected further ahead of the latest communication node, it is possible to grasp that communication has been interrupted by a detection method in which a response request (Ping) is transmitted at regular intervals and a response to the request is confirmed. However, with this conventional detection method, a communication node that has lost communication cannot be recognized in real time by another communication node connected to the network. In addition, this conventional detection method consumes network resources and places a load on the network. For this reason, there is a possibility that a plurality of communication nodes connected to the network cannot perform fail-safe control at the same timing.

  The present invention has been made in view of the above problems, and an in-vehicle network system in which a communication node connected to an Ethernet network can grasp in real time a communication node whose communication state has changed (communication interruption or communication return). The purpose is to provide.

  In order to solve the above problem, the present invention provides an in-vehicle network system in which a top node, an intermediate node having a relay function, and a terminal node not having a relay function are connected in a hierarchical manner via an Ethernet network. The intermediate node includes a first detection unit that detects that communication with an adjacent lower node has been interrupted or has returned, and a lower level in which communication interruption or communication recovery has been detected by the first detection unit. A notification unit for notifying the highest node of the node, the highest node being a second detection unit for detecting that communication with the adjacent lower node has been interrupted or returned to communication, and the highest node, intermediate A node that holds the hierarchical configuration information indicating the hierarchical connection configuration of the node and the end node, and a communication interruption or communication recovery at the second detection unit notified from the intermediate node or the second node. Based on the lower-level node where the node is detected and the hierarchical configuration information, the identification unit for identifying the node where communication with the highest node is interrupted or the communication is restored, and the node information identified by the identification unit And a sending unit for sending to the device.

  In this in-vehicle network system of the present invention, the highest node holds in advance hierarchical configuration information representing the hierarchical connection structure of each node (the highest node, intermediate node, and end node) connected to the Ethernet network. ing. The intermediate node detects the communication interruption or communication return with the adjacent lower node, and notifies the highest node. Further, also in the uppermost node, a communication interruption or communication return with an adjacent lower node is detected. When the uppermost node recognizes a lower node whose communication has been interrupted or returned due to notification from the intermediate node or its own detection, communication with the uppermost node has been interrupted based on the recognized lower node and the hierarchy configuration information. Identify the node to which communication has returned. Then, the highest node 10 sends information on the identified node to the Ethernet network.

  In this way, information on nodes whose communication status has changed due to communication interruption or communication recovery is broadcasted over the Ethernet network, so that intermediate nodes and terminal nodes that have received information from the highest node are nodes that have lost communication or communication recovery. Can be easily grasped.

  In particular, in this in-vehicle network system, when communication interruption or communication recovery occurs in a lower node, information on the lower node is immediately notified to the highest node. Therefore, the communication node connected by the Ethernet network can grasp the node in which the communication state has changed in real time as compared with the conventional detection method described above. Therefore, a plurality of communication nodes connected to the Ethernet network can perform fail-safe control at the same timing.

  In this in-vehicle network system, notification is performed only when communication is interrupted or communication is returned to a lower node. Therefore, the load on the Ethernet network can be minimized as compared with the conventional detection method described above. Thereby, generation | occurrence | production of the malfunction resulting from a communication delay can be suppressed.

  As described above, according to the in-vehicle network system of the present invention, a communication node connected to the Ethernet network can grasp a communication node whose communication state has changed due to communication interruption or communication return in real time.

The figure which shows the structural example of the vehicle-mounted network system which concerns on one Embodiment of this invention. (A) The figure explaining the connection structure of the communication node in the vehicle-mounted network system shown in FIG. 1, (b) The figure which shows an example of the hierarchy structure information hold | maintained at the highest node The figure which shows an example of the information which the highest node sends out to the Ethernet network The flowchart which shows the procedure of the communication interruption / recovery detection process which an intermediate node performs The flowchart which shows the procedure of the communication interruption / restoration node specific process which a highest node performs The figure explaining the example in which communication between communication nodes was interrupted The figure which shows the specific example of the highest-level network system using the communication node mounted in a vehicle

[Overview]
The present invention is an in-vehicle network system in which a plurality of child nodes are hierarchically connected to a parent node. In this system, a parent node grasps in advance a hierarchical connection configuration of a plurality of child nodes. When each child node detects a change in the connection status (communication interruption or communication return) with an adjacent lower node, the child node notifies the detected content to the parent node. The parent node identifies the node whose communication state has changed based on the notified contents and the connection configuration, and broadcasts the identified information to the network. Therefore, the child node receiving this information can grasp the node whose communication state has changed in real time.

[Description of this embodiment]
Hereinafter, an in-vehicle network system provided by the present invention will be described in detail with reference to the drawings.

1. Configuration Example of In-vehicle Network System FIG. 1 is a diagram illustrating a configuration example of an in-vehicle network system 1 according to an embodiment of the present invention. An in-vehicle network system 1 shown in FIG. 1 is an Ethernet network system mounted on a vehicle configured based on an Ethernet communication protocol, and includes a top node 10, a plurality of intermediate nodes 20, and a plurality of end nodes 30. Included. In this in-vehicle network system 1, a plurality of intermediate nodes 20 and a plurality of end nodes 30 are hierarchically connected to the highest node 10 via a plurality of communication buses 50 that are networks.

  In the in-vehicle network system 1 of FIG. 1, a configuration example in which a third child node 40 is further connected to the highest node 10 via a communication bus 60 based on a communication protocol other than Ethernet is shown. Yes.

1-1. The highest node The highest node 10 is a so-called communication node such as an electronic control unit (ECU), for example, a multi-protocol gateway device (GW). The highest node 10 is the highest communication node (parent node) in the Ethernet network hierarchy, and manages the states of the intermediate node 20 and the end node 30 connected by the Ethernet network. Further, the highest node 10 relays data communication with another communication node 40 connected to another network (for example, CAN (Controller Area Network)) having a communication protocol different from that of the Ethernet network.

  As shown in FIG. 1, the highest node 10 includes a switch 11, an information transmission unit 12, a communication interruption / recovery detection unit 13, a communication node identification unit 14, and a network information holding unit 15.

  The switch 11 is a network device having a switch function for connecting the highest node 10 to a predetermined communication node. The switch 11 stores, for example, the MAC address of the connected communication node, and transmits (switches) data only to the connection port to which the destination MAC address belongs. For example, in FIG. 1, the parent node (top node 10) is connected to the child node_1 (terminal node 30) and the child node_2 (intermediate node 20) via the communication bus 50 by the switch 11.

  The network information holding unit 15 holds information representing the hierarchical connection structure of communication nodes in the Ethernet network, that is, the highest node 10, the intermediate node 20, and the terminal node 30 (hereinafter referred to as “hierarchical configuration information”). The Ethernet network shown in FIG. 1 can be represented by the connection configuration shown in FIG. Therefore, the network information holding unit 15 holds this connection configuration as, for example, information in a table format shown in FIG. In the table of FIG. 2 (b), the communication nodes are arranged in the order in which the connection configuration shown in FIG. 2 (a) is vertically searched from the parent node which is the highest node 10, and the lower side connected to the communication node is arranged. It is described in ascending order according to the number of all communication nodes. For example, since the number of lower node connections of the child node_2 is “2”, it can be understood that the child node_2 is connected to the child node_3 and the child node_4 corresponding to the lower two on the table.

  The communication interruption / return detection unit 13 determines whether or not the change in the connection status between the uppermost node 10 and the adjacent lower node via the switch 11, that is, whether or not the communication between the lower node and the lower node has been interrupted. It is detected whether or not it has returned. Hereinafter, a lower node in which communication has been interrupted (also expressed as “communication loss”) or communication that has been lost (also referred to as “communication return”) is referred to as a “target node”. For example, in FIG. 1, the communication interruption / recovery detection unit 13 determines whether or not the communication between the parent node (the highest node 10) and the child node_1 (the end node 30) has been lost or has returned. Whether the communication between the highest node 10 and the child node_2 (intermediate node 20) is interrupted or communication is recovered is detected. Then, the communication interruption / recovery detection unit 13 notifies the communication node specifying unit 14 of information for identifying the target node and information indicating communication interruption or communication recovery for the detected target node.

  The communication node specifying unit 14 receives the notification of the target node that detected the communication interruption or the communication return from the communication interruption / recovery detection unit 13 and the notification of the target node that has lost or returned the communication from the intermediate node 20. In the case (described later), it is recognized that the connection status has changed in the target node. Then, the communication node specifying unit 14 specifies the communication node whose communication state has changed based on the recognized target node and the hierarchical configuration information held by the network information holding unit 15. That is, the communication node specifying unit 14 specifies a communication node in which communication with the highest node 10 is interrupted or communication that has been interrupted is restored.

If the hierarchical configuration information is described in ascending order according to the number of communication nodes as shown in FIG. 2B, the communication node specifying unit 14 uses the binary search algorithm to reduce the calculation amount O (log ₂ n ), It is possible to specify a communication node in which communication with the highest node 10 is interrupted or communication that has been interrupted is restored from among the n pieces of data.

  The information sending unit 12 sends information indicating the communication node whose communication state specified by the communication node specifying unit 14 has changed to the communication bus 50, and broadcasts the information to the communication nodes connected to the Ethernet network. For example, the information sending unit 12 broadcasts a message frame as shown in FIG. In the example of FIG. 3, information indicating whether the communication node to be notified has “disconnected” or “communication return” and information indicating a plurality of communication nodes to be targeted are stored in one message frame.

  Note that the information sending unit 12 may send information that tells the communication node whose communication state specified by the communication node specifying unit 14 has changed to the communication bus 60 based on a communication protocol other than Ethernet.

1-2. The intermediate node intermediate node 20 is a so-called communication node such as an electronic control unit (ECU). The intermediate node 20 is a communication node located in the middle of the Ethernet network hierarchical configuration, and has a relay function for relaying adjacent upper notes and lower nodes. As shown in FIG. 1, the intermediate node 20 includes a switch 21, a notification unit 22, and a communication interruption / recovery detection unit 23.

  The switch 21 is a network device having a switch function for connecting the intermediate node 20 to a predetermined communication node. The switch 21 transmits (switches) data only to the connection port to which the destination MAC address belongs in the same manner as the switch 11 described above. For example, in FIG. 1, the child node_2 (intermediate node 20) is connected to the parent node (top node 10) and the child node_3 (intermediate node 20) via the communication bus 50 by the switch 21. The child node_3 (intermediate node 20) is connected to the child node_2 (intermediate node 20) and the child node_4 (terminal node 30) via the communication bus 50 by the switch 21.

  The communication interruption / recovery detection unit 23 changes the connection status between the intermediate node 20 and the adjacent lower node via the switch 21, that is, whether or not the communication with the lower node is interrupted, or the communication that has been interrupted is recovered. Detect whether or not. For example, in FIG. 1, the communication interruption / recovery detection unit 23 of the child node_2 (intermediate node 20) performs communication interruption or communication recovery between the child node_2 (intermediate node 20) and the child node_3 (intermediate node 20). To detect. Further, the communication interruption / recovery detection unit 23 of the child node_3 (intermediate node 20) detects communication interruption or communication return between the child node_3 (intermediate node 20) and the child node_4 (terminal node 30).

  When the communication interruption / recovery detection unit 23 detects a subordinate node (target node) that has lost or returned communication, the notification unit 22 identifies information for identifying the target node and communication interruption or communication for the detected target node. Information indicating the return is notified to the highest node 10.

1-3. The terminal node The terminal node 30 is a so-called communication node such as an electronic control unit (ECU), a sensor, or a camera. The end node 30 is the lowest communication node in the Ethernet network hierarchy. Therefore, since the end node 30 does not have a relay function for relaying adjacent upper notes and lower nodes, the intermediate node 20 does not have a switch, a notification unit, and a communication interruption / recovery detection unit included in the configuration.

  Note that the top node 10, the plurality of intermediate nodes 20, and the plurality of end nodes 30 described above typically include a central processing unit (CPU), a memory, and an input / output interface. Various functions are realized by the CPU reading and interpreting and executing the program stored in the memory.

2. Processing Performed in In-vehicle Network System Processing performed in the intermediate node 20 and the highest node 10 in the in-vehicle network system 1 according to one embodiment of the present invention will be described with reference to FIG. FIG. 4 is a flowchart showing a procedure of communication interruption / recovery detection processing executed by the intermediate node 20. FIG. 5 is a flowchart showing the procedure of the communication interruption / recovery node identification process executed by the highest node 10. FIG. 6 is a diagram for explaining the flow of information using a specific example in which communication between the child node_2 (intermediate node 20) and the child node_3 (intermediate node 20) is interrupted.

2-1. Process Performed by Intermediate Node Refer to FIG. When the communication interruption / recovery detection process is started, time measurement by a fixed-cycle timer based on a predetermined cycle is first started (step S401). When timing is started, one connection port to which a lower communication node is connected via the communication bus 50 in the system configuration is selected in the switch 21 of the intermediate node 20 (step S402). In the example of FIG. 6, the connection port to which the child node_3 is connected is selected in the child node_2.

  Then, in the communication interruption / recovery detection unit 23 of the intermediate node 20, “link down” in which communication with an adjacent lower node is impossible or communication with a lower node is possible for the selected connection port. Any link status of “up” is acquired (step S403). In the example of FIG. 6, the link state of “link down” is acquired (FIG. 6 (1)).

  When the acquired link state is “link down” (step S404, Yes), the communication interruption / recovery detection unit 23 determines that the link state is the same even in the communication interruption / recovery detection process performed previously for the same connection port. It is determined whether or not it is “link down” (step S405). If the link state is not “link down” in the previous process (step S405, No), it is determined that communication with the lower node connected to the connection port has been interrupted in this process, and the intermediate node The notification unit 22 of 20 notifies the highest node 10 of information identifying the lower node (target node) and information indicating that communication has been interrupted (step S407). On the other hand, if the link state is “link down” in the previous process (step S405, Yes), information indicating that the lower-level node has lost communication by the previous process has already been notified to the highest node 10. Therefore, the notification unit 22 does not notify again. In the example of FIG. 6, since the link state was not “link down” in the previous process, information indicating that communication with the child node_3 was interrupted is notified to the highest node 10 (FIG. 6 (2)). .

  In addition, when the acquired link state is not “link down”, that is, “link up” (No in step S404), the communication interruption / recovery detection unit 23 performs the same connection port last time. Whether or not the link state is “link down” is also determined in the communication interruption / recovery detection process (step S406). If the link state is “link down” in the previous process (step S406, Yes), it is determined that the communication that has been interrupted with the lower node connected to the connection port in this process has been restored. Then, the notification unit 22 notifies the highest-level node 10 of information for identifying the lower node (target node) and information indicating that communication has been restored (step S408). On the other hand, if the link state is not “link down” in the previous process (step S406, No), information indicating that the lower-level node has returned to the communication by the previous process has already been notified to the highest node 10. Therefore, the notification unit 22 does not notify again.

  The processes in steps S402 to S408 described above are repeatedly executed for all connection ports of the intermediate node 20 (step S409). Then, when the processing of steps S402 to S408 is completed for all the connection ports, the communication interruption / recovery detection processing in the intermediate node 20 is completed after the completion of the timing by the fixed cycle timer (step S410).

  In FIG. 4, the procedure of the communication interruption / recovery detection process executed by the intermediate node 20 has been described, but this communication interruption / recovery detection process is also executed by the highest node 10. When the uppermost node 10 performs communication interruption / recovery detection processing, “the information identifying the target node by the notification unit 22 of the intermediate node 20 and the fact that communication has been interrupted” is executed in step S407 of the flowchart shown in FIG. “Information is notified to the highest-level node 10” is read as “communication interruption / recovery detection unit 13 notifies communication node identification unit 14 of information identifying the target node and information indicating that communication has been interrupted”. . Also, “communication interruption / recovery detection unit is notified by the notification unit 22 of the intermediate node 20 that the information identifying the target node and the information indicating that communication has been restored is notified by the notification unit 22 of the intermediate node 20” executed in step S408. 13 is notified to the communication node specifying unit 14 of information for identifying the target node and information indicating that communication has been restored.

  As described above, in order to use the link state in the previous communication interruption / recovery detection process, the link state acquired in step S403 is stored in the memory of the highest node 10 and the intermediate node 20 or the like. (Not shown) may be stored.

2-2. Processing performed by the highest node Referring to FIG. When the communication interruption / recovery node identification process is started, time measurement by a fixed-cycle timer based on a predetermined cycle is first started (step S501). When the timing is started, whether or not the communication node specifying unit 14 of the highest node 10 has received a notification about the target node that has lost or returned communication from either the intermediate node 20 or the communication interruption / recovery detection unit 13. Is determined (step S502). In the example of FIG. 6, the highest node 10 has received a notification about the target node from the child node_2 (FIG. 6 (2)).

  When the communication node identification unit 14 receives a notification about a target node that has lost or returned communication from the intermediate node 20 or the communication interruption / recovery detection unit 13, the communication node identification unit 14 and the hierarchical configuration information held in the information holding unit 15 Based on, a communication node whose communication state has changed is identified (step S503). In other words, a communication node (intermediate node 20 and / or end node 30) to which communication with the highest node 10 has been interrupted or communication that has been interrupted has been restored is identified. In the example of FIG. 6, based on the hierarchical configuration information of the Ethernet network (FIG. 6 (3)), the child node_3 and the child node_4 are identified as child nodes whose communication state has changed (FIG. 6 (4)). .

  When the communication node whose communication state has changed is specified, the communication node specifying unit 14 determines whether or not the notified link state of the target node is “link down” (step S504). If the link status is “link down” in this determination (step S504, Yes), the information sending unit 12 of the highest node 10 shows information indicating that communication with the identified communication node has been interrupted. The information is broadcast to the communication nodes connected to the network (step S505). On the other hand, if the link state is not “link down” in the above determination (step S504, No), the information sending unit 12 of the highest node 10 indicates that the communication that has been interrupted with the identified communication node has been restored. Information is transmitted to the Ethernet network, and the information is broadcast to the communication nodes connected to the network (step S506).

  Note that the information indicating that the specified communication node described above has lost communication or has returned to communication is not limited to the Ethernet network, and may be broadcast to other communication protocol networks. In the example of FIG. 6, information indicating that communication with the child node_3 and the child node_4 has been interrupted is notified to the child node_1 and the child node_2 (FIG. 6 (5)), and also to the child node_5. Notification is made (FIG. 6 (6)).

  The processes in steps S502 to S506 described above are repeatedly executed for all target nodes that receive the notification from the intermediate node 20 or the communication interruption / recovery detection unit 13 (step S507). Then, when the processing of steps S502 to S506 is completed for all the target nodes that have received the notification, the communication disruption / recovery node identification processing at the highest node 10 ends after the completion of the time measurement by the fixed cycle timer (step S508) ).

3. Specific Example of In-Vehicle Network System FIG. 7 illustrates the uppermost node 10, the plurality of intermediate nodes 20, and the plurality of end nodes 30 constituting the in-vehicle network system 1 using specific communication nodes mounted on the vehicle. It is a figure to do.

  The in-vehicle network system 1 shown in FIG. 7 includes a gateway ECU that functions as the highest node 10, an advanced safety ECU and switch ECU that function as the intermediate node 20, sensors 1 to 4 that function as the end node 30, a front camera, The configuration includes a display ECU, an engine ECU, and a brake ECU.

  Consider a case where communication interruption occurs between the advanced safety ECU and the switch ECU (FIG. 7 (1)). When the communication interruption occurs, the advanced safety ECU detects that it cannot communicate with the lower switch ECU connected via the switch 1 (FIG. 7 (2)), and communication with the switch ECU (target node) is interrupted. This is notified to the gateway ECU (FIG. 7 (3)). When the gateway ECU receives a notification of communication interruption with the switch ECU (target node) from the advanced safety ECU, the gateway ECU is connected to the switch ECU (target node) based on the switch ECU (target node) and the hierarchical configuration information. The sensor 3, the sensor 4, and the front camera are specified as communication nodes that have lost communication (FIG. 7 (4)). When the gateway ECU identifies the sensor 3, the sensor 4, and the front camera as communication nodes that have lost communication, the gateway ECU broadcasts the information to the network.

  The display ECU that has received the notification of information from the gateway ECU displays a failure occurrence on the display unit to warn the driver and stops the display function of the front camera (FIG. 7 (5)). Further, the advanced safety ECU that has received the notification of information from the gateway ECU continues the recognition processing around the vehicle using only the sensor 1 and the sensor 2 (FIG. 7 (6)). For example, the advanced safety ECU executes the processing by excluding the reception of the target data from the sensor 3, the sensor 4, and the front camera by timeout and stopping the synthesis process of the target data. Further, the engine ECU and the brake ECU that have received the notification of information from the gateway ECU execute a fail-safe process (FIG. 7 (7)).

  As in this example, even if communication interruption occurs in any part of the in-vehicle network system 1, it is possible to confirm the communication node where communication is interrupted in real time. Therefore, it is possible to quickly execute a system stop or degeneration operation within a predetermined time. This predetermined time can be set to 1 second, for example. When driving on an expressway at 100 km / h, the vehicle moves about 30 m per second. Considering that the travel distance after sudden braking is about 60 m and that the general inter-vehicle distance at high speed is 50 to 100 m, in order for the driver to respond to sudden braking of the vehicle ahead, It is desirable to notify the driver of the failure within one second from the occurrence of the communication interruption.

[Operations and effects of the embodiment]
As described above, according to the in-vehicle network system 1 according to the embodiment of the present invention, the highest node 10 has a hierarchical connection structure of the highest node 10, the intermediate node 20, and the end node 30 in the Ethernet network. The represented hierarchical configuration information is held in advance. The intermediate node 20 detects a change in connection status with adjacent lower nodes (communication interruption or communication return) and notifies the highest node 10. In addition, the uppermost node 10 also detects a change in connection status with adjacent lower nodes (communication interruption or communication return). When the highest node 10 receives a notification from the intermediate node 20 or the lower node (target node) whose connection status has changed from itself, the communication state has changed based on the notified target node and the hierarchical configuration information. A communication node in which communication with the highest node 10 is interrupted or communication is restored is specified. Then, the highest node 10 broadcasts the specified information to the network.

  Thereby, the intermediate node 20 and the end node 30 that have received information from the highest node 10 by broadcast can easily grasp the communication node whose communication state changes, that is, the communication node that has lost communication or has returned from communication.

  In particular, in the in-vehicle network system 1 according to the present embodiment, when communication is interrupted or communication is restored, information on the target node is immediately notified to the highest node 10. Therefore, a communication node connected in a network transmits a response request (Ping) at a fixed interval described in the background to check a communication node whose communication state has changed in real time, compared with a conventional detection method. I can grasp it. Therefore, a plurality of communication nodes connected to the network can perform fail-safe control at the same timing.

  In the in-vehicle network system 1 according to the present embodiment, notification is performed only when communication is interrupted or communication is restored. Also, the broadcast transmission performed by the highest node 10 is performed by including information of a plurality of communication nodes whose communication states have changed in one message frame as shown in FIG. 3, for example, thereby suppressing consumption of network resources. Can do. Therefore, the load on the network can be minimized as compared with the conventional detection method. Thereby, generation | occurrence | production of the malfunction resulting from a communication delay can be suppressed.

  In the above embodiment, the in-vehicle network system using the Ethernet network has been described. However, even in an in-vehicle network system using other than Ethernet, a network system having a hierarchical structure in which a plurality of child nodes (intermediate node 20 and terminal node 30) are hierarchically connected to a parent node (top node 10) If so, the communication interruption / recovery detection process and the communication interruption / recovery node identification process of the present invention can be applied.

  The in-vehicle network system according to the present invention can be used for an Ethernet network system in which a plurality of child nodes are hierarchically connected to a parent node, and in particular, a communication node whose communication state has changed due to communication interruption or communication recovery can be used as a network. This is useful when you want the connected communication node to know in real time.

DESCRIPTION OF SYMBOLS 1 In-vehicle network system 10 Top node 11, 21 Switch 12 Information transmission part 13, 23 Communication interruption / recovery detection part 14 Communication node specific | specification part 15 Network information holding | maintenance part 20 Intermediate | middle node 22 Notification part 30 Terminal node 40 Other communication nodes 50 , 60 Communication bus

Claims (1)

An in-vehicle network system in which an uppermost node, an intermediate node having a relay function, and a terminal node not having a relay function are hierarchically connected via an Ethernet network,
The intermediate node is
A first detection unit for detecting that communication with an adjacent lower node is interrupted or communication is restored;
A notification unit for notifying the uppermost node of the lower-order node in which communication interruption or communication return is detected by the first detection unit;
The top node is
A second detection unit for detecting that communication with an adjacent lower node is interrupted or communication is restored;
A holding unit that holds hierarchical configuration information indicating a hierarchical connection configuration of the top node, the intermediate node, and the end node;
Communication with the highest node is interrupted or communicated based on the subordinate node notified from the intermediate node or the communication detection or communication recovery detected by the second detection unit and the hierarchical configuration information. A specific part that identifies the node that has returned,
A sending unit that sends information of the node specified by the specifying unit to the Ethernet network;
In-vehicle network system.