Vehicle-mounted relay device, relay method, and relay program

Abstract

A vehicle-mounted relay device includes a relay section that relays frames transmitted and received between vehicle-mounted devices in a vehicle-mounted network; a calculation section that calculates a processing load of another vehicle-mounted device based on a plurality of the frames transmitted from the vehicle-mounted device to the other vehicle-mounted device and received by the relay section; and a determination section that performs a determination process that determines whether the frames transmitted to the other vehicle-mounted device should be relayed in the relay section based on the processing load calculated by the calculation section.

Description

Technical Field

[0001] This disclosure relates to vehicle-mounted relay devices, relay methods, and relay procedures.

[0002] This application claims priority based on Japanese Patent Application No. 2021-76437, filed on April 28, 2021, the entire disclosure of which is incorporated herein by reference. Background Technology

[0003] Japanese Patent Application Publication No. 2008-252221 (Patent Document 1) discloses a device for preventing DoS attacks. This device monitors data packets transmitted and received between a communication terminal and a server connected to the communication terminal via a network. The DoS attack prevention device includes: a receiving unit for receiving data packets; and a sending unit for determining whether the received data packets can be sent, and sending the data packets if possible. In this device, the rate of data packets, i.e., the number of data packets per unit time, is measured, and data packets are discarded if a preset threshold is exceeded.

[0004] Furthermore, Japanese Patent Publication No. 2019-523584 (Patent Document 2) discloses the following method: a network attack defense method comprising: a step of obtaining one or more statistical attributes of a set of protected websites by collecting statistical values ​​of one or more website attributes of a set of protected websites; a step of representing the operation mode of the protected website by the one or more website attributes of the set of protected websites; a step of determining, at least in part, based on one or more statistical attributes of the set, that the protected website will switch from a current operation mode to a target operation mode, wherein the current operation mode has a current defense strategy, the target operation mode has a target defense strategy, and the current defense strategy is different from the target defense strategy; and a step of switching from the current operation mode to the target operation mode according to the determination that the protected website will switch from the current operation mode to the target operation mode, and applying the target defense strategy to the protected website.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2008-252221

[0008] Patent Document 2: Japanese Patent Publication No. 2019-523584 Summary of the Invention

[0009] The vehicle-mounted relay device disclosed herein includes: a relay unit for relaying frames transmitted and received between vehicle-mounted devices in a vehicle network; a calculation unit for calculating the processing load of other vehicle-mounted devices based on a plurality of frames received by the relay unit from the vehicle-mounted devices and destined for other vehicle-mounted devices; and a determination unit for performing determination processing based on the processing load calculated by the calculation unit, the determination processing determining whether the frames destined for other vehicle-mounted devices should be relayed in the relay unit.

[0010] The relay method disclosed herein is a relay method in a vehicle-mounted relay device, the vehicle-mounted relay device having a relay unit that relays frames transmitted and received between vehicle-mounted devices in a vehicle network. The relay method includes the following steps: calculating the processing load of the other vehicle-mounted devices based on a plurality of frames received by the relay unit from the vehicle-mounted device and destined for other vehicle-mounted devices; and performing a judgment process based on the calculated processing load, the judgment process determining whether the frames destined for the other vehicle-mounted devices should be relayed in the relay unit.

[0011] The relay program disclosed herein is used in an in-vehicle relay device, wherein the relay program enables a computer to function as the following components: a relay unit for relaying frames transmitted and received between in-vehicle devices in an in-vehicle network; a calculation unit for calculating the processing load of the other in-vehicle devices based on a plurality of frames received by the relay unit from the in-vehicle devices and destined for other in-vehicle devices; and a judgment unit for performing a judgment process based on the processing load calculated by the calculation unit, the judgment process determining whether the frames destined for the other in-vehicle devices should be relayed in the relay unit.

[0012] One embodiment of this disclosure can be implemented not only as a vehicle-mounted relay device having such a characteristic processing unit, but also as a vehicle-mounted relay device comprising part or all of a semiconductor integrated circuit, or as a system including a vehicle-mounted relay device. Attached Figure Description

[0013] Figure 1 This is a diagram illustrating the structure of an in-vehicle system according to an embodiment of the present disclosure.

[0014] Figure 2 This is a diagram illustrating the structure of a vehicle-mounted relay device in a vehicle-mounted system according to an embodiment of the present disclosure.

[0015] Figure 3 This is a diagram illustrating an example of frame processing information in a vehicle-mounted relay device according to an embodiment of the present disclosure.

[0016] Figure 4This is a diagram illustrating an example of load information in a vehicle-mounted relay device according to an embodiment of the present disclosure.

[0017] Figure 5 This is a diagram illustrating an example of load information in a vehicle-mounted relay device according to an embodiment of the present disclosure.

[0018] Figure 6 This is a diagram illustrating an example of the processing of frame restriction in a vehicle-mounted relay device according to an embodiment of this disclosure.

[0019] Figure 7 This is a flowchart illustrating an example of determining the sequence of actions of a vehicle-mounted relay device receiving a frame according to an embodiment of this disclosure.

[0020] Figure 8 This is a flowchart illustrating an example of determining the sequence of actions when an on-board relay device updates load information according to an embodiment of this disclosure. Detailed Implementation

[0021] Previously, a technology was developed to improve security in in-vehicle networks.

[0022] [The problem this disclosure aims to solve]

[0023] In vehicular networks, the amount of data transmitted varies depending on the mode of transportation and the functions used. Assuming we have a statistical understanding of the data transmitted in vehicular networks, we need to explore various scenarios, differentiated by mode of transportation and by whether a function is present or not.

[0024] This disclosure was made to solve the above-mentioned problems, and its purpose is to provide a vehicle relay device, relay method and relay procedure that can easily improve the security of vehicle networks.

[0025] [The Effects of This Disclosure]

[0026] According to this disclosure, security in vehicle networks can be easily improved.

[0027] [Description of embodiments of this disclosure]

[0028] First, the contents of the embodiments of this disclosure will be listed for explanation.

[0029] (1) The vehicle relay device according to the embodiments of the present disclosure includes: a relay unit for relaying frames transmitted and received between vehicle devices in a vehicle network; a calculation unit for calculating the processing load of the other vehicle devices based on a plurality of frames received by the relay unit from the vehicle devices and sent to other vehicle devices; and a determination unit for performing determination processing based on the processing load calculated by the calculation unit, the determination processing determining whether the frames sent to the other vehicle devices should be relayed in the relay unit.

[0030] By calculating the processing load of a vehicle-mounted device based on multiple frames received at the relay device and destined for the same device, and using the calculation results to determine the correctness of the relay of frames sent to the vehicle-mounted device, attacks exploiting frame transmission to the vehicle-mounted device can be defended, for example, in vehicle-mounted networks where the amount of data transmitted in the network varies depending on the mode of travel and the function used. This avoids attempting various distinctions based on mode of travel or whether a function is present. Therefore, security in vehicle-mounted networks can be easily improved.

[0031] (2) The vehicle-mounted relay device may also include a storage unit that stores frame processing information, which represents the processing load of each type of frame in the vehicle-mounted device. The computing unit may also calculate the processing load based on the types of the plurality of frames and the frame processing information.

[0032] The processing load of the device when processing received data packets varies depending on the type of data packet. With the above structure, compared to structures that only use communication traffic such as the number of data packets per unit time as a judgment criterion, it is possible to make a judgment that takes into account the differences in processing load corresponding to the type of data packet. Therefore, for example, in the event of an attack that sends a small number of data packets requiring high processing load to a specific vehicle device, such attacks can be defended more reliably.

[0033] (3) The frame processing information may also represent the processing time required to process the frame in the vehicle-mounted device for each type of the frame. The computing unit may also update the processing load based on the elapsed time since receiving the frame from the relay unit or relaying the frame and the processing time corresponding to the frame.

[0034] This structure allows for appropriate judgments that take into account the differences in processing completion time corresponding to the types of data sets.

[0035] (4) The vehicle-mounted relay device may also include a storage unit that stores frame processing information, which represents the processing load of each vehicle-mounted device and the frame in the vehicle-mounted device. The calculation unit may also calculate the processing load based on the processing load corresponding to the other vehicle-mounted devices in the frame processing information.

[0036] The load on the device when processing the received data packets varies depending on the specifications of the vehicle-mounted device. With the above structure, compared to structures that only use communication traffic volume, such as the number of data packets per unit time, as a judgment criterion, appropriate judgments can be made that take into account the differences in processing load corresponding to the specifications of the vehicle-mounted device.

[0037] (5) The frame processing information may also represent the processing time required for each of the vehicle-mounted devices to process the frame in the vehicle-mounted device. The computing unit may also update the processing load based on the elapsed time since receiving the frame from the relay unit or relaying the frame and the processing time corresponding to the frame.

[0038] This structure allows for appropriate judgments that take into account differences in processing completion time related to the specifications of the vehicle-mounted device.

[0039] (6) The vehicle-mounted relay device may also include a storage unit that stores frame processing information, which represents a threshold of the processing load for each vehicle-mounted device. The judgment unit may also perform the judgment processing based on the comparison result between the processing load calculated by the calculation unit and the threshold corresponding to the other vehicle-mounted devices in the frame processing information.

[0040] The permissible processing load value in an on-board unit varies depending on the specifications of the on-board unit. The above structure allows for an appropriate judgment that takes into account the differences in permissible processing load values ​​corresponding to the specifications of the on-board unit.

[0041] (7) The judgment unit may also perform the judgment process based on the comparison result of the processing load and the threshold calculated by the calculation unit. The threshold may also be a value based on the measurement result of the frame transmission period in a vehicle with a specified network structure.

[0042] With such a structure, more appropriate thresholds can be set, for example in vehicular networks that perform best-effort communication and whose frequency band usage varies depending on the vehicle's condition.

[0043] (8) The vehicle-mounted relay device can also relay the frames sent and received between the vehicle-mounted devices in a star topology where communication is conducted via a peer-to-peer network.

[0044] By using a star topology in which the vehicle relay device relays frames in a peer-to-peer network communication configuration, the transmission of frames between vehicle devices can be easily limited compared to a configuration with a CAN (Controller Area Network) bus.

[0045] (9) The relay method involved in the embodiments of this disclosure is a relay method in a vehicle-mounted relay device, the vehicle-mounted relay device having a relay unit that relays frames sent and received between vehicle-mounted devices in a vehicle network, wherein the relay method includes the following steps: calculating the processing load of the other vehicle-mounted devices based on a plurality of frames received by the relay unit from the vehicle-mounted device and sent to other vehicle-mounted devices; and performing a judgment process based on the calculated processing load, the judgment process determining whether the frames sent to the other vehicle-mounted devices should be relayed in the relay unit.

[0046] By calculating the processing load of a vehicle-mounted device based on multiple frames received at the relay device and destined for the same device, and using the calculation results to determine the correctness of the relay of frames sent to the vehicle-mounted device, attacks exploiting frame transmission to the vehicle-mounted device can be defended against, for example, in vehicle-mounted networks where the amount of data transmitted varies depending on the mode of travel and the function used. This is achieved without attempting various scenarios differentiated by mode of travel or by whether a function is present. Therefore, security in vehicle-mounted networks can be easily improved.

[0047] (10) The relay program according to the embodiments of this disclosure is used in a vehicle relay device, wherein the relay program enables a computer to function as the following components: a relay unit that relays frames sent and received between vehicle devices in a vehicle network; a calculation unit that calculates the processing load of the other vehicle devices based on a plurality of frames received by the relay unit from the vehicle device and sent to the other vehicle devices; and a judgment unit that performs a judgment process based on the processing load calculated by the calculation unit, the judgment process determining whether the frames sent to the other vehicle devices should be relayed in the relay unit.

[0048] By calculating the processing load of a vehicle-mounted device based on multiple frames received at the relay device and destined for the same device, and using the calculation results to determine the correctness of the relay of frames sent to the vehicle-mounted device, attacks exploiting frame transmission to the vehicle-mounted device can be defended against, for example, in vehicle-mounted networks where the amount of data transmitted varies depending on the mode of travel and the function used. This is achieved without attempting various scenarios differentiated by mode of travel or by whether a function is present. Therefore, security in vehicle-mounted networks can be easily improved.

[0049] The embodiments of this disclosure will now be described using the accompanying drawings. Furthermore, the same or equivalent parts in the drawings will be given the same reference numerals, and their descriptions will not be repeated. Additionally, at least some of the embodiments described below may be arbitrarily combined.

[0050] [Structure and Basic Movements]

[0051] Figure 1 This is a diagram illustrating the structure of an in-vehicle system according to an embodiment of this disclosure. (Refer to...) Figure 1 The vehicle system 301 is mounted on the vehicle and includes a vehicle relay device 101 and multiple vehicle devices 202.

[0052] Furthermore, the vehicle system 301 can also be a structure that includes multiple vehicle relay devices 101. Figure 1 As an example, the vehicle system 301 is shown to have one vehicle relay device 101 and four vehicle ECUs (Electronic Control Units) 202.

[0053] The vehicle-mounted ECU 202 is an example of an in-vehicle device, such as a TCU (Telematics Control Unit), an autonomous driving ECU, an engine ECU, sensors, a navigation device, a human-machine interface, and a camera. The TCU communicates with external devices such as server 401 via a wireless base station (not shown). Furthermore, the in-vehicle device can also be a device brought into the vehicle by the user; for example, it could be a portable terminal such as a tablet or an electronic device such as a USB (Universal Serial Bus) memory.

[0054] The vehicle relay device 101 and the vehicle ECU 202 constitute the vehicle network 151. The vehicle ECU 202 and the vehicle relay device 101 are examples of vehicle devices in the vehicle network 151. The network structure of the vehicle network 151, such as the types of vehicle devices, their connection relationships, and communication protocols, is, for example, fixed. In addition, new vehicle devices or electronic devices can be added to the vehicle network 151.

[0055] The vehicle relay device 101 is capable of relaying information between multiple vehicle ECUs 202 in the vehicle network 151. More specifically, the vehicle relay device 101 can, for example, perform relay processing according to the second layer of the OSI (Open Systems Interconnection) reference model. Furthermore, the vehicle relay device 101 can also be configured to perform relay processing according to the third layer, which is a layer above the second layer.

[0056] In the vehicle network 151, the vehicle ECU 202 is connected to the vehicle relay device 101, for example, via an Ethernet (registered trademark) cable 91.

[0057] The vehicle-mounted relay device 101 performs Ethernet frame relay processing according to the Ethernet communication standard. Specifically, the vehicle-mounted relay device 101 relays, for example, Ethernet frames exchanged between vehicle-mounted ECUs 202. IP data groups are stored within the Ethernet frames.

[0058] Furthermore, in the vehicle system 301, the structure for relaying Ethernet frames is not limited to the Ethernet communication standard. For example, it may also be a structure for relaying data according to communication standards such as CAN (Controller Area Network) (registered trademark), CAN-FD (CAN with Flexible Data Rate), FlexRay (registered trademark), MOST (Media Oriented Systems Transport) (registered trademark), and LIN (Local Interconnect Network).

[0059] Figure 2 This is a diagram illustrating the structure of a vehicle-mounted relay device in a vehicle-mounted system according to an embodiment of this disclosure. (Refer to...) Figure 2 The vehicle-mounted relay device 101 includes four communication ports 21, a relay unit 22, a processing unit 24, and a storage unit 25. The processing unit 24 includes a calculation unit 1 and a judgment unit 2. Furthermore, the vehicle-mounted relay device 101 is not limited to having a structure with four communication ports 21, but may also have a structure with two, three, or five or more communication ports 21.

[0060] Communication port 21 is, for example, a terminal capable of connecting to Ethernet cable 91. Alternatively, communication port 21 can also be a terminal for an integrated circuit. The four communication ports 21 are connected to the vehicle ECU 202 via Ethernet cables 91.

[0061] The processing unit 24 is implemented, for example, by a processor such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor). The relay unit 22 is implemented, for example, by an L2 switch IC and a processor. The storage unit 25 is, for example, a non-volatile memory.

[0062] The relay unit 22 relays frames transmitted and received between vehicle ECUs 202 in the vehicle network 151. For example, the relay unit 22 can function as an L2 switch, relaying Ethernet frames transmitted between vehicle ECUs 202 connected to its own vehicle relay device 101. More specifically, if the relay unit 22 receives an Ethernet frame from a vehicle ECU 202 via the corresponding Ethernet cable 91, it sends the received Ethernet frame to the receiving vehicle ECU 202 via the corresponding Ethernet cable 91. Furthermore, the relay unit 22 can also function as an L3 switch, relaying Ethernet frames transmitted between vehicle ECUs 202 connected to different vehicle relay devices 101.

[0063] The relay unit 22 performs the above relay processing, for example, by referring to a table stored in the storage unit 25 that shows the correspondence between the recipient's MAC address and the communication port 21.

[0064] The calculation unit 1 calculates the processing load of the other vehicle ECU 202 (hereinafter also referred to as the receiving ECU) based on the multiple frames received by the relay unit 22 from the vehicle ECU 202 and sent to other vehicle ECU 202. That is, it calculates the estimated value of the processing load in the vehicle ECU 202.

[0065] The judgment unit 2 performs a judgment process based on the processing load calculated by the calculation unit 1, which determines whether the frames sent to the other vehicle ECU 202 should be relayed in the relay unit 22.

[0066] Figure 3 This is a diagram illustrating an example of frame processing information in a vehicle-mounted relay device according to an embodiment of the present disclosure.

[0067] The storage unit 25 stores frame processing information representing the processing load in the vehicle ECU 202 for each type of frame and each vehicle ECU 202. For example, the frame processing information also represents the processing time required to process the frame in the vehicle ECU 202 for each type of frame and each vehicle ECU 202.

[0068] In addition, the storage unit 25 stores frame processing information representing the threshold of the processing load for each vehicle ECU 202.

[0069] Specifically, refer to Figure 3 Frame processing information is information that represents the correspondence between the vehicle ECU, the frame being processed, the load rate, the processing time, and the threshold of the load rate.

[0070] For example, when vehicle ECU-A processes frame No. 1, the processor's processing load increases by a%, and the processing time required to complete the processing of that frame is w milliseconds. Similarly, when processing frame No. 2, the processor's processing load increases by b%, and the processing time required to complete the processing of that frame is x milliseconds. When vehicle ECU-B processes frame No. 1, the processor's processing load increases by c%, and the processing time required to complete the processing of that frame is y milliseconds. Furthermore, when processing frame No. 3, the processor's processing load increases by d%, and the processing time required to complete the processing of that frame is z milliseconds.

[0071] In addition, if the processing load rate of the processor of vehicle ECU-A exceeds M%, the judgment unit 2 determines that the relay of Ethernet frames sent to vehicle ECU-A should be stopped, and if the processing load rate of the processor of vehicle ECU-B exceeds N%, the judgment unit 2 determines that the relay of Ethernet frames sent to vehicle ECU-B should be stopped.

[0072] Figure 4 and Figure 5 This is a diagram illustrating an example of load information in a vehicle-mounted relay device according to an embodiment of the present disclosure.

[0073] Reference Figure 4 and Figure 5 The storage unit 25 stores load information representing the estimated current processing load rate of each vehicle ECU 202, the correspondence between frames being processed and the processing start time of frames.

[0074] For example in Figure 4 In the example shown, the vehicle ECU-A performs processing related to two frames No.1, with processing start times of t1 and t2 respectively, and the estimated current processing load rate is P%. Here, the processing start time is, for example, the time when the vehicle relay device 101 receives the frame or the time when it sends the frame to the vehicle ECU 202, which is the receiver.

[0075] In addition, the relay unit 22 receives Ethernet frames and notifies the processing unit 24 of information such as the recipient's MAC address and logical port number of the received Ethernet frames.

[0076] The processing unit 24 uses the information notified from the relay unit 22 to determine the recipient and type of the Ethernet frame.

[0077] After receiving the notification, the relay unit 22 relays the Ethernet frame to the vehicle ECU 202, which is the receiving end, if the processing unit 24 notifies the relay of the Ethernet frame as "allowed". If the relay is notified as "disallowed", the relay is not performed and the Ethernet frame is discarded.

[0078] Figure 6 This is a diagram illustrating an example of the processing of frame restriction in a vehicle-mounted relay device according to an embodiment of this disclosure.

[0079] The calculation unit 1 calculates the sum of the increased load rates corresponding to multiple frames as the processing load of other vehicle ECUs 202.

[0080] For example, the computing unit 1 calculates the processing load rate of the other vehicle ECU 202 based on the multiple frames received by the relay unit 22 from the vehicle ECU 202 and sent to other vehicle ECU 202, as well as the processing load corresponding to the other vehicle ECU 202 in the frame processing information.

[0081] In addition, for example, the calculation unit 1 calculates the processing load rate of the other vehicle ECU 202 based on the types and frame processing information of the aforementioned multiple frames.

[0082] The judgment unit 2 performs judgment processing based on the comparison results between the processing load rate calculated by the calculation unit 1 and the threshold corresponding to the other vehicle ECU 202 in the frame processing information.

[0083] Specifically, refer to Figure 6 This explains the situation where a large number of frames flow through vehicle ECU-Z, which is also vehicle ECU 202, in order to deplete the resources of vehicle ECU-A, which is vehicle ECU 202.

[0084] First, the vehicle ECU-Z sends frame No. 1 destined for vehicle ECU-A to the vehicle relay device 101. The calculation unit 1 adds a% to the processing load rate of vehicle ECU-A. Since the processing load rate after addition implemented by the calculation unit 1 does not exceed M%, the determination unit 2 registers the added processing load rate and the processing start time t1 of frame No. 1 in the load information, and notifies the relay unit 22 of the relay "allow" for that frame.

[0085] Next, the vehicle ECU-Z sends frame No. 1, intended for vehicle ECU-A, to the vehicle relay device 101. The calculation unit 1 adds a% to the processing load rate of vehicle ECU-A. The processing load rate becomes P%, which is less than M%. Since the added processing load rate implemented by the calculation unit 1 does not exceed M%, the judgment unit 2 registers the added processing load rate and the processing start time t2 of frame No. 1 in the load information, and notifies the relay unit 22 of relay "allow" for that frame. Figure 4 This status is displayed.

[0086] Next, the vehicle ECU-Z sends frame No.2, intended for vehicle ECU-A, to the vehicle relay unit 101. The calculation unit 1 adds b% to the processing load rate of vehicle ECU-A. The processing load rate becomes Q%, which is less than M%. Since the processing load rate after addition implemented by the calculation unit 1 does not exceed M%, the judgment unit 2 registers the added processing load rate and the processing start time t3 of frame No.2 in the load information, and notifies the relay unit 22 of the relay "allow" for this frame. Figure 5 This status is displayed.

[0087] Next, the No. 1 frame destined for the vehicle ECU-A is sent from the vehicle ECU-Z to the vehicle relay device 101. The calculation unit 1 adds a% to the processing load rate of the vehicle ECU-A. The processing load rate becomes R% which is greater than M%. Since the processing load rate after addition performed by the calculation unit 1 exceeds M%, the judgment unit 2 notifies the relay unit 22 of relay "disabled" for this frame. Load information is maintained, for example... Figure 5 The state shown.

[0088] Subsequently, the processing load rate is reduced until the processing load rate, including the increased load rate corresponding to the newly received frame, becomes below M%. At this point, the judgment unit 2 prohibits frame relay, and the relay unit 22 discards the received frame destined for the vehicle ECU-A. Thus, attacks that cause a large number of frames to flow from the vehicle ECU-Z to the vehicle ECU-A can be defended.

[0089] For example, the threshold used by the judgment unit 2 in comparing with the processing load calculated by the calculation unit 1 can also be a value based on the measurement result of the frame transmission period in a vehicle with a specified network structure.

[0090] Specifically, for example, the process involves parsing the logs of measurement results from a vehicle, calculating the communication cycle of the onboard ECU 202 (as the receiver) and each type of frame, calculating the variance of this communication cycle relative to the design value, and setting a lower threshold when the variance is large and a higher threshold when the variance is small. As an example, this log is obtained from other vehicles of the same model and type.

[0091] [Action Flow]

[0092] Each device in the vehicle-mounted system according to embodiments of this disclosure includes a computer containing a memory. An arithmetic processing unit such as a CPU (Central Processing Unit) in the computer reads a portion or all of a program containing the steps of the flowchart below from the memory and executes it. The programs for these multiple devices can be installed externally. The programs for these multiple devices are circulated in a state of being stored on a recording medium.

[0093] Figure 7 This is a flowchart illustrating an example of determining the sequence of actions of a vehicle-mounted relay device receiving a frame according to an embodiment of this disclosure.

[0094] Reference Figure 7 First, the vehicle relay device 101 waits for a frame from the vehicle ECU 202 to the receiving vehicle ECU 202 (hereinafter also referred to as the receiving ECU) (No in step S1). If a frame is received (Yes in step S1), the increased load rate corresponding to the frame is added to the processing load rate of the receiving ECU with reference to the frame processing information (step S2).

[0095] Next, if the summed processing load rate does not exceed the threshold corresponding to the receiving ECU ("No" in step S3), the vehicle relay device 101 determines that the relay of the frame should be allowed (step S4), and registers the summed processing load rate and the information of the frame in the load information. The vehicle relay device 101 then relays the frame to the receiving ECU (step S5).

[0096] On the other hand, if the summed processing load rate exceeds the threshold corresponding to the receiving ECU ("Yes" in step S3), the vehicle relay device 101 determines that the relay of the frame should be prohibited and the load information should not be updated. The vehicle relay device 101 discards the frame (step S6).

[0097] Figure 8 This is a flowchart illustrating an example of determining the sequence of actions when an on-board relay device updates load information according to an embodiment of this disclosure.

[0098] For example, the computing unit 1 updates the processing load of the receiving ECU based on the elapsed time since receiving a frame from the relay unit 22 or relaying a frame, and the processing time corresponding to that frame.

[0099] More specifically, the computing unit 1 monitors the elapsed time of each frame since the start of processing. If the corresponding processing time has elapsed since the start of processing of a certain frame, the corresponding increase in load rate is subtracted from the processing load rate in the load information, and the information of that frame is deleted from the load information.

[0100] Specifically, refer to Figure 8 First, the vehicle-mounted relay device 101 waits for the processing time corresponding to the frame to elapse from the start time of processing the relayed frame (in step S11, this is "No").

[0101] Next, when the corresponding processing time has elapsed since the start time of processing the relayed frame ("Yes" in step S11), the computing unit 1 in the vehicle relay device 101, referring to the frame processing information, subtracts the increase load rate corresponding to the frame from the processing load rate of the receiving ECU in the load information, deletes the information of the frame from the load information (step S12), and waits for the corresponding processing time to elapse since the start time of processing other relayed frames ("No" in step S11).

[0102] As described above, the processing load of the vehicle ECU 202 is calculated not only using the processing load of the frame to be received, but also using the cumulative value of the processing load of the previously received frames, assuming that the vehicle ECU 202, as the receiver, is processing the frame to be received before the relay, thereby enabling a more accurate prediction of the processing load of the vehicle ECU 202.

[0103] Furthermore, in the state of relaying a stopped frame, by continuing to update the processing load rate after processing previously relayed frames, it is also possible to appropriately determine whether to restart the relay. Additionally, it is also possible to appropriately determine whether to stop the relay again after it has restarted.

[0104] As mentioned above, in vehicular networks, the network structure, including the types of vehicular devices, their connection relationships, and communication protocols, is often fixed and easy to pre-register. Figure 3 The frame processing information shown makes the structure for performing the above-mentioned frame relay control in vehicular networks particularly effective.

[0105] Furthermore, the vehicle relay device 101 is not limited to the vehicle ECU 202 directly connected to itself, but can also receive frames transmitted via other vehicle relay devices and perform various processes such as the aforementioned judgment processing.

[0106] Furthermore, the vehicle relay device 101 is not limited to a structure that relays frames transmitted and received between vehicle ECUs 202 in a star topology where communication is conducted via a peer-to-peer network, such as Ethernet. When the vehicle system 301 has a CAN (Controller Area Network) bus, it can also be a structure that relays frames between vehicle devices connected to different CAN buses and performs various processing such as the aforementioned judgment processing on those frames. However, by using the structure described above where the vehicle relay device 101 relays frames in a star topology where communication is conducted via a peer-to-peer network, the transmission of frames transmitted and received between vehicle ECUs 202 can be easily limited.

[0107] Furthermore, in the vehicle-mounted system according to the embodiments of this disclosure, the vehicle-mounted relay device 101 is configured to use a processing load rate, but it is not limited thereto. For example, the vehicle-mounted relay device 101 may also be configured to use a processing load and a threshold of the processing load to perform frame relay control.

[0108] Furthermore, in the vehicle system according to the embodiments of this disclosure, the vehicle relay device 101 is configured to use frame processing information that registers information about each type of frame for each vehicle ECU 202, but is not limited thereto. The vehicle relay device 101 may be configured to use frame processing information that registers information common to each vehicle ECU 202 in the vehicle network 151, or it may be configured to use frame processing information that registers information common to various types of frames, or it may be configured to use frame processing information that registers information common to each vehicle ECU 202 and the type of frame in the vehicle network 151.

[0109] Furthermore, in the vehicle system according to the embodiments of this disclosure, the vehicle relay device 101 is configured to update the processing load rate based on the elapsed time since receiving a frame from the relay unit 22 or relaying a frame, but it is not limited to this. For example, the vehicle relay device 101 may also be configured such that, in the load information, the number of frames registered for one vehicle ECU 202 is limited to a predetermined value, new frames are received, and if the predetermined value is exceeded, the information of the oldest frame is deleted, and the corresponding increase in load rate is subtracted from the processing load rate.

[0110] It should be considered that the above embodiments are exemplary in all respects and not restrictive. The scope of the invention is defined not by the foregoing description but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0111] The above description includes the features noted below.

[0112] [Note 1]

[0113] A vehicle-mounted relay device, comprising:

[0114] The relay unit relays frames sent and received between vehicle-mounted devices in the vehicle network.

[0115] The computing unit calculates the processing load of the other vehicle-mounted devices based on the multiple frames received by the relay unit from the vehicle-mounted device and destined for other vehicle-mounted devices; and

[0116] The judgment unit performs a judgment process based on the processing load calculated by the calculation unit. This judgment process determines whether the frame destined for the other vehicle-mounted device should be relayed in the relay unit.

[0117] The computing unit calculates the sum of the processing loads corresponding to the plurality of frames as the processing load of the other vehicle-mounted devices.

[0118] Label Explanation

[0119] 1. Computing Department

[0120] 2 Judgment Department

[0121] 21 Communication Ports

[0122] 22 Relay Section

[0123] 24 Processing Department

[0124] 25 Storage Department

[0125] 91 Ethernet cable

[0126] 101 Vehicle-mounted relay device

[0127] 202 Vehicle-mounted devices

[0128] 301 Vehicle In-Vehicle System

[0129] 401 server

Claims

1. A vehicle-mounted relay device, comprising: The relay unit relays frames sent and received between vehicle-mounted devices in the vehicle network. The computing unit calculates the processing load of the other vehicle devices based on the multiple frames received by the relay unit from the vehicle device and sent to other vehicle devices. The judgment unit performs a judgment process based on the processing load calculated by the calculation unit, which determines whether the frame sent to the other vehicle-mounted device should be relayed in the relay unit. as well as The storage unit stores frame processing information, which represents the processing load of each type of frame in the on-board unit. The computing unit calculates the processing load based on the respective types of the multiple frames and the frame processing information. The frame processing information also indicates the processing time required for each type of frame to be processed in the vehicle-mounted device. The computing unit updates the processing load based on the elapsed time since receiving the frame from the relay unit or relaying the frame, and the processing time corresponding to the frame.

2. The vehicle-mounted relay device according to claim 1, wherein, The frame processing information also represents the threshold of the processing load for each of the vehicle-mounted devices. The judgment unit performs the judgment process based on the comparison result between the processing load calculated by the calculation unit and the threshold corresponding to the other vehicle-mounted device in the frame processing information.

3. The vehicle-mounted relay device according to claim 1, wherein, The judgment unit performs the judgment process based on the comparison result between the processing load calculated by the calculation unit and the threshold. The threshold is a value based on a measurement of the frame transmission period in a vehicle with a defined network structure.

4. The vehicle-mounted relay device according to claim 1, wherein, The vehicle-mounted relay device relays the frames sent and received between the vehicle-mounted devices in a star topology where communication is conducted via a peer-to-peer network.

5. A vehicle-mounted relay device, comprising: The relay unit relays frames sent and received between vehicle-mounted devices in the vehicle network. The computing unit calculates the processing load of the other vehicle devices based on the multiple frames received by the relay unit from the vehicle device and sent to other vehicle devices. The judgment unit performs a judgment process based on the processing load calculated by the calculation unit, which determines whether the frame sent to the other vehicle-mounted device should be relayed in the relay unit. as well as The storage unit stores frame processing information, which represents the processing load of each frame in the on-board unit. The computing unit calculates the processing load based on the processing load corresponding to the other vehicle-mounted devices in the frame processing information. The frame processing information also indicates the processing time required for each of the vehicle-mounted devices to process the frame within that device. The computing unit updates the processing load based on the elapsed time since receiving the frame from the relay unit or relaying the frame, and the processing time corresponding to the frame.

6. The vehicle-mounted relay device according to claim 5, wherein, The frame processing information also represents the threshold of the processing load for each of the vehicle-mounted devices. The judgment unit performs the judgment process based on the comparison result between the processing load calculated by the calculation unit and the threshold corresponding to the other vehicle-mounted device in the frame processing information.

7. The vehicle-mounted relay device according to claim 5, wherein, The judgment unit performs the judgment process based on the comparison result between the processing load calculated by the calculation unit and the threshold. The threshold is a value based on a measurement of the frame transmission period in a vehicle with a defined network structure.

8. The vehicle-mounted relay device according to claim 5, wherein, The vehicle-mounted relay device relays the frames sent and received between the vehicle-mounted devices in a star topology where communication is conducted via a peer-to-peer network.

9. A relay method, which is a relay method in a vehicle-mounted relay device, the vehicle-mounted relay device comprising a relay unit, the relay unit relaying frames transmitted and received between vehicle-mounted devices in a vehicle network, wherein, The relay method includes the following steps: Based on the multiple frames received by the relay unit from the vehicle-mounted device and sent to other vehicle-mounted devices, the processing load of the other vehicle-mounted devices is calculated. Based on the calculated processing load, a judgment process is performed to determine whether the frame destined for the other vehicle-mounted device should be relayed in the relay unit; and The storage includes frame processing information, which represents the processing load of each type of frame in the on-board unit. The step of calculating the processing load is based on the respective types of the multiple frames and the frame processing information, and calculates the processing load accordingly. The frame processing information also indicates the processing time required for each type of frame to be processed in the vehicle-mounted device. The step of calculating the processing load is based on the elapsed time since the frame was received from the relay unit or the frame was relayed, and the processing time corresponding to the frame, and updates the processing load.

10. A relay method, which is a relay method in a vehicle-mounted relay device, the vehicle-mounted relay device comprising a relay unit, the relay unit relaying frames transmitted and received between vehicle-mounted devices in a vehicle network, wherein, The relay method includes the following steps: Based on the multiple frames received by the relay unit from the vehicle-mounted device and sent to other vehicle-mounted devices, the processing load of the other vehicle-mounted devices is calculated. Based on the calculated processing load, a judgment process is performed to determine whether the frame destined for the other vehicle-mounted device should be relayed in the relay unit; and The storage frame processing information represents the processing load of each frame in the on-board unit. The step of calculating the processing load is based on the processing load corresponding to the other vehicle-mounted devices in the frame processing information, and the processing load is calculated accordingly. The frame processing information also indicates the processing time required for each of the vehicle-mounted devices to process the frame within that device. The step of calculating the processing load is based on the elapsed time since the frame was received from the relay unit or the frame was relayed, and the processing time corresponding to the frame, and updates the processing load.

11. A computer-readable recording medium storing a relay program for use in a vehicle-mounted relay device, wherein, The relay program enables the computer to function as the following components: The relay unit relays frames sent and received between vehicle-mounted devices in the vehicle network. The computing unit calculates the processing load of the other vehicle devices based on the multiple frames received by the relay unit from the vehicle device and sent to other vehicle devices. The judgment unit performs a judgment process based on the processing load calculated by the calculation unit, which determines whether the frame sent to the other vehicle-mounted device should be relayed in the relay unit. as well as The storage unit stores frame processing information, which represents the processing load of each type of frame in the on-board unit. The computing unit calculates the processing load based on the respective types of the multiple frames and the frame processing information. The frame processing information also indicates the processing time required for each type of frame to be processed in the vehicle-mounted device. The computing unit updates the processing load based on the elapsed time since receiving the frame from the relay unit or relaying the frame, and the processing time corresponding to the frame.

12. A computer-readable recording medium storing a relay program for use in a vehicle-mounted relay device, wherein, The relay program enables the computer to function as the following components: The relay unit relays frames sent and received between vehicle-mounted devices in the vehicle network. The computing unit calculates the processing load of the other vehicle devices based on the multiple frames received by the relay unit from the vehicle device and sent to other vehicle devices. The judgment unit performs a judgment process based on the processing load calculated by the calculation unit, which determines whether the frame sent to the other vehicle-mounted device should be relayed in the relay unit. as well as The storage unit stores frame processing information, which represents the processing load of each frame in the on-board unit. The computing unit calculates the processing load based on the processing load corresponding to the other vehicle-mounted devices in the frame processing information. The frame processing information also indicates the processing time required for each of the vehicle-mounted devices to process the frame within that device. The computing unit updates the processing load based on the elapsed time since receiving the frame from the relay unit or relaying the frame, and the processing time corresponding to the frame.

Images