Gateway device

Abstract

SOLUTION: The gateway device 20 according to the present disclosure is a gateway device that relays communication between the transmission paths 14 different from each other, and includes the reception processing unit 34 that performs reception processing of the frame FR, and the transfer control unit 36 that performs control to transfer the frame, and when the activation frame FRW is received by the reception processing unit and the idle node is connected to the transfer destination transmission path, the transfer control unit transfers the activation frame to the transfer destination transmission path in preference to the non-activation frame.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a gateway device. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2018-46509 discloses an in-vehicle network and a gateway device that constitutes part of the in-vehicle network. The gateway device is a network control device that connects multiple transmission paths. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-46509 Summary of the Invention [Problem to be solved by the invention]

[0004] Recently, there is a demand for better gateway devices.

[0005] The present disclosure aims to solve the above-mentioned problems. [Means for solving the problem]

[0006] One aspect of the present disclosure is a gateway device that, when a startup frame is received, which is a frame that starts up a dormant node that is a node in a dormant state, and the dormant node is connected to a destination transmission path, which is a transmission path to which the startup frame is forwarded, forwards the startup frame to the destination transmission path in priority over a non-startup frame, which is a frame that is not the startup frame. [Effects of the Invention]

[0007] According to the present disclosure, a better gateway device is provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a vehicle according to an embodiment and a communication system provided in the vehicle. [Figure 2] Figure 2A is a diagram illustrating a forwarding table, and Figure 2B is a diagram illustrating a portion of a communication system. [Figure 3] Fig. 3A is a table illustrating a forwarding table after the change process, and Fig. 3B is a diagram illustrating a part of a communication system. [Figure 4] Figure 4A is a diagram illustrating an example of a forwarding table, and Figure 4B is a diagram illustrating a portion of a communication system. [Figure 5] 10 is a flowchart of a transfer control method by a gateway device. [Figure 6] Fig. 6A is a diagram showing a part of a communication system according to Modification 1. Fig. 6B is a diagram showing a part of a communication system according to Modification 1. Fig. 6C is a diagram showing a part of a communication system according to Modification 1. DETAILED DESCRIPTION OF THE INVENTION

[0009] When a conventional gateway device simultaneously receives multiple communication data (frames) with the same destination transmission path, it determines which frame to transfer first based on the priority of each of the multiple frames (see also JP 2018-46509 A). Priorities are determined in advance based on, for example, the real-time performance and urgency required of the frame. For example, the priority of a state change frame is set relatively low. A state change frame is a frame for changing the state of a node such as an ECU (Electronic Control Unit) connected to the gateway device via a transmission path. The state change frame may be an NM frame, which is a frame for Network Management (NM). In response to receiving a state change frame, an ECU can transition from one of a normal state (e.g., wake-up mode) and a dormant state (e.g., sleep mode) to the other state. Compared to such state change frames, the priority of a control frame is set relatively high. A control frame is a frame for real-time control of an ECU. Control performed based on a control frame includes control other than changing the state of an ECU based on a state change frame.

[0010] According to the above-described network design, when the gateway device simultaneously receives an activation frame addressed to one ECU and a control frame addressed to another ECU in a dormant state, the gateway device prioritizes forwarding the control frame. This allows the one ECU to quickly execute control in accordance with the control frame. As a result, rapid vehicle control is achieved. However, there may be cases where the ECU addressed by the control frame is in a dormant state. A dormant ECU does not respond to the control frame. The gateway device continues to retransmit the control frame until it receives a response from the ECU or the control frame transfer process times out. In this case, the control frames continually retransmitted from the gateway device occupy the transmission path, effectively disrupting communication through the communication system. This has resulted in a problem of adversely affecting the responsiveness of the communication system.

[0011] Based on the above preliminary explanation, one embodiment will be described below.

[0012] Note that the programs in the following description are computer programs (computer software). Computer programs are also called computer program products. Computer program products are not limited to computer programs recorded on recording media, but also include computer programs transmitted, distributed, or downloaded via a network such as the Internet.

[0013] (One embodiment) FIG. 1 is a schematic diagram showing a vehicle 10 according to an embodiment and a communication system 12 provided in the vehicle 10. As shown in FIG.

[0014] As shown in FIG. 1, a vehicle 10 includes a communication system 12. The vehicle 10 is, for example, a four-wheeled automobile, but is not limited to this. The communication system 12 includes a plurality of transmission paths 14 and a plurality of nodes 16. Three or more transmission paths 14 may be included in the communication system 12. For example, four transmission paths 14 (141 to 144) are shown in FIG. 1. Each of the plurality of transmission paths 14 includes, for example, a serial bus for performing serial communication. The plurality of nodes 16 includes a plurality of ECUs 18 and a gateway device 20.

[0015] Each of the plurality of ECUs 18 is a control device (electronic control device) provided in the vehicle 10. At least some of the ECUs 18 may be realized by a relatively small computer such as a microcontroller.

[0016] The ECU 18 is connected to the gateway device 20 via a transmission path 14. One or more ECUs 18 may be connected to each of the multiple transmission paths 14. Multiple ECUs 18 may be connected to at least one of the multiple transmission paths 14.

[0017] The ECU 18 controls various devices (not shown) provided in the vehicle 10. The various devices include, but are not limited to, a prime mover, a brake system, an air conditioner, etc. The prime mover may include a heat engine such as an internal combustion engine, or may include an electric motor.

[0018] The ECU 18 includes a transmitter / receiver 22 and a controller 24 .

[0019] The transmitting / receiving unit 22 includes, for example, a communication module (not shown) connected to the transmission path 14. This communication module includes, for example, a transceiver connected to the transmission path 14. The transmitting / receiving unit 22 transmits communication data (frames FR) to other nodes 16 via the transmission path 14. The transmitting / receiving unit 22 also receives frames FR transmitted from other nodes 16 via the transmission path 14.

[0020] The frame FR transmitted and received by the transmitting / receiving unit 22 has a bit string consisting of a plurality of bits. The frame FR is composed of, for example, a predetermined number of bits. Each of the predetermined number of bits belongs to either a dominant signal (binary: 0) or a recessive signal (binary: 1). Identification information is set in advance in the frame FR. The identification information is represented by a part of the bit string described above. In other words, the identification information is represented by an appropriate combination of dominant signals and recessive signals.

[0021] The identification information of a frame FR is set based on the node 16 (ECU 18) that is the destination of the frame FR, the priority of the frame FR, etc. The priority of a frame FR is determined in advance according to the real-time characteristics and urgency required of the frame FR, while also taking into consideration communication arbitration, etc., which will be described later. In this case, the higher the priority of a frame FR, the smaller the value indicated by the identification information (bit string) of the frame FR may be set (see also FIG. 2A). In this embodiment, a case will be described in which the priority of a status change frame is lower than the priority of a control frame FRC. A status change frame is a frame FR for changing the status of the node 16. A control frame FRC is a frame FR for controlling the ECU 18 in real time.

[0022] The control unit 24 includes the above-mentioned transmitting / receiving unit 22 and a processing circuit (not shown) that controls various devices, etc. This processing circuit includes, for example, a memory that stores programs and a processor that controls various devices based on the programs. The processing circuit of the control unit 24 includes, for example, one or more processors. The one or more processors include, for example, a CPU (Central Processing Unit).

[0023] The control unit 24 can switch the state of the ECU 18. More specifically, the control unit 24 can switch the state of the ECU 18 from one of a normal state (e.g., a wake-up mode) and a halt state (e.g., a sleep mode) to the other. When a state change frame is received by the transceiver unit 22, the control unit 24 changes the state of the ECU 18 based on the state change frame. The state change frame functions as either an activation frame FRW or a halt request frame FRS. The activation frame FRW is a frame that requests the ECU 18 to transition from the halt state to the normal state. The halt request frame FRS is a frame that requests the ECU 18 to transition from the normal state to the halt state.

[0024] As described above, the frame FR is set with identification information corresponding to the destination node 16 (ECU 18). When the transmitter / receiver 22 receives a state change frame in which identification information corresponding to the ECU 18 that includes the control unit 24 is set, the control unit 24 changes the state of the ECU 18.

[0025] When the ECU 18 is in a normal state, the control unit 24 of the ECU 18 may monitor the state of the transmission path 14 to which the transceiver unit 22 is connected. The control unit 24 may determine whether the state of the transmission path 14 is idle by monitoring the state of the transmission path 14 (bus idle detection). When the state of the transmission path 14 to which the transceiver unit 22 is connected is idle, the control unit 24 may execute a transfer process of the frame FR.

[0026] When multiple ECUs 18 are connected to the same transmission path 14, each of the multiple ECUs 18 may start the transfer process of a frame FR based on the result of bus idle detection. However, in this case, two or more ECUs 18 connected to the same transmission path 14 may simultaneously start the transfer process of a frame FR. As a result, two or more frames FR may collide on the transmission path 14. In consideration of this, each of the multiple transmission paths 14 is configured to transmit a dominant signal when a dominant signal and a recessive signal are input simultaneously. The control unit 24 determines whether the frame FR transmitted from the transmission / reception unit 22 has collided with another frame FR based on a comparison between the identification information of the frame FR transmitted from the transmission / reception unit 22 and the identification information of the frame FR detected from the transmission path 14. More specifically, when the control unit 24 detects a dominant signal from the transmission path 14 despite transmitting a recessive signal as part of the frame FR (identification information) to the transmission path 14, the control unit 24 determines that the frame FR transmitted to the transmission path 14 has collided with another frame FR. Note that the function of detecting collisions of multiple frames FR may be provided in the transmitting / receiving unit 22 (transceiver).

[0027] The control unit 24, which has determined that the frame FR transmitted to the transmission path 14 has collided with another frame FR, executes communication arbitration. Communication arbitration includes, for example, a process of canceling (postponing) the transfer process of the frame FR. By canceling (postponing) the transfer process of frames FR other than the frame FR with the highest priority among the multiple frames FR that collided on the transmission path 14, the collision of the multiple frames FR is resolved. Furthermore, the transfer process of the frame FR with the highest priority among the multiple frames FR that collided on the transmission path 14 continues without being hindered by the other frames FR.

[0028] For example, two ECUs 18 (18C, 18D) connected to the transmission path 142 are shown in FIG. 1 . A control frame FRC may be input from the ECU 18C to the transmission path 142, and at the same time, a pause request frame FRS may be input from the ECU 18D to the transmission path 142. In this case, the control frame FRC and the pause request frame FRS collide with each other because they are simultaneously output to the transmission path 142. However, the priority of the pause request frame FRS, which is a status change frame, is lower than the priority of the control frame FRC. The ECU 18D can detect that the pause request frame FRS has collided with another frame FR (control frame FRC) by comparing the identification information of the pause request frame FRS with the identification information detected from the transmission path 142. Having detected that the pause request frame FRS has collided with another frame FR, the ECU 18D cancels the transmission process of the pause request frame FRS. This resolves the collision between the control frame FRC and the pause request frame FRS. Meanwhile, the ECU 18C continues the transmission process of the control frame FRC, and can complete the transmission process of the control frame FRC without being hindered by the other ECU 18 (ECU 18D).

[0029] When an ECU 18 is in a normal state, the control unit 24 of that ECU 18 controls the corresponding device based on the frame FR (control frame FRC) received via the transceiver 22. As described above, the frame FR is set with identification information corresponding to the destination node 16 (ECU 18). When the transceiver 22 receives a control frame FRC in which identification information corresponding to the ECU 18 that includes that control unit 24 is set, the control unit 24 controls the corresponding various devices based on the control frame FRC.

[0030] Furthermore, when an ECU 18 is in a normal state, the control unit 24 of the ECU 18 also executes a response process for the frame FR when the control unit 24 receives the frame FR via the transceiver unit 22. The response process includes, for example, outputting a dominant signal to the transmission path 14 via the transceiver unit 22. The control unit 24 determines whether to execute the response process based on the identification information set in the frame FR received by the transceiver unit 22. For example, the control unit 24 executes the response process for a frame FR set with identification information corresponding to the ECU 18 that includes the control unit 24. On the other hand, the control unit 24 does not execute the response process for a frame FR set with identification information that does not correspond to the ECU 18 that includes the control unit 24.

[0031] When an ECU 18 in a normal state receives a pause request frame FRS, the ECU 18 transitions to a pause state. That is, when an ECU 18 in a normal state receives a pause request frame FRS, the control unit 24 of the ECU 18 restricts some of the functions in the normal state. More specifically, the control unit 24 restricts at least some of the functions except for the function for transitioning the ECU 18 from the pause state to the normal state in response to the activation frame FRW. By transitioning to the pause state, the ECU 18 reduces power consumption.

[0032] At least one of the plurality of ECUs 18 may transition to a paused state in conjunction with the transition of the vehicle 10 to a stopped state. In this case, the stopped state may include a temporary stop state of the vehicle 10.

[0033] The ECU 18 in the inactive state transitions to the normal state in response to receiving the activation frame FRW addressed to the ECU 18. The control unit 24 of the ECU 18 also executes a response process to the received activation frame FRW.

[0034] The state change frame may be transmitted from at least one ECU 18 among the plurality of ECUs 18 to the other ECUs 18 when the vehicle 10 in the stopped state described above satisfies a predetermined activation condition. The predetermined activation condition may be, for example, a predetermined operation being performed on the vehicle 10 in the stopped state described above. For example, as described above, at least one of the plurality of ECUs 18 transitions to a hibernation state in conjunction with the transition of the vehicle 10 to a stopped state. If a predetermined operation is subsequently performed on the vehicle 10 in the stopped state, a startup frame FRW may be transmitted from a predetermined ECU 18 to transition the ECU 18 corresponding to the predetermined operation from the hibernation state to a normal state. In this way, when the predetermined operation is performed, the ECU 18 in the hibernation state corresponding to the predetermined operation can be quickly transitioned to the normal state.

[0035] The predetermined operation may be, for example, but is not limited to, an operation to open or close a door provided on the vehicle 10, an operation to charge a battery provided on the vehicle 10, etc. The vehicle 10 may be appropriately provided with a sensor (not shown) for detecting the predetermined operation.

[0036] All ECUs 18 connected to one of the multiple transmission paths 14 may transition to the hibernation state in conjunction with the transition of the vehicle 10 to the stopped state. In this case, at least one ECU 18 connected to another transmission path 14 may transmit an activation frame FRW for transitioning the ECU 18 connected to the one transmission path 14 to the normal state based on a predetermined operation being performed on the vehicle 10 that is in the stopped state. At least one ECU 18 connected to another transmission path 14 may transmit one or more activation frames FRW for transitioning all ECUs 18 connected to the one transmission path 14 to the normal state.

[0037] The gateway device 20 is a device (network control device) that relays communications between different transmission paths 14. The multiple transmission paths 14 are connected via the gateway device 20. As shown in FIG. 1, the gateway device 20 includes a transfer circuit unit 26 and a transfer control device 28. The gateway device 20 may include a microcontroller. In that case, at least a part of the transfer circuit unit 26 and the transfer control device 28 described below may be realized by the microcontroller.

[0038] The transfer circuit unit 26 includes a communication circuit (not shown) connected to the multiple transmission paths 14. The communication circuit may have a transceiver. A frame FR transmitted from a node 16 (ECU 18) connected to one of the multiple transmission paths 14 is relayed by the transfer circuit unit 26 and transferred to a node 16 connected to another of the multiple transmission paths 14. Since the transfer circuit unit 26 is connected to the multiple transmission paths 14, it can receive a frame FR from each of the multiple transmission paths 14.

[0039] The transfer control device 28 is a control device for the transfer circuit unit 26. The transfer control device 28 includes a storage unit 30 and an arithmetic unit 32.

[0040] The storage unit 30 includes a memory (one or more memories). The storage unit 30 may include multiple memories. A memory is a non-transitory recording medium that stores information. The one or more memories (multiple memories) may include a non-volatile memory. For example, the storage unit 30 may include a ROM (Read Only Memory), a flash memory, etc. The non-volatile memory stores, for example, programs, tables, maps, etc. The one or more memories (multiple memories) may further include a volatile memory. For example, the storage unit 30 may include a RAM (Random Access Memory). At least a part of the storage unit 30 may be realized by a portable recording medium such as a USB flash memory (USB: Universal Serial Bus), a memory card, or an optical disc.

[0041] The arithmetic unit 32 includes a processing circuit capable of executing arithmetic processing. At least a part of the processing circuit may be a processor. The processing circuit of the arithmetic unit 32 may be provided with multiple processors (one or more processors). At least a part of the processing circuit of the arithmetic unit 32 may be an IC (Integrated Circuit). This IC may be an MPU (Micro Processing Unit) that functions as a processor such as a CPU, or may be an ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), or the like. The processing circuit of the arithmetic unit 32 may include a discrete device, or the like.

[0042] The calculation unit 32 includes a reception processing unit 34 and a transfer control unit 36. The reception processing unit 34 and the transfer control unit 36 ​​are realized by the calculation unit 32 (processing circuit). For example, the reception processing unit 34 and the transfer control unit 36 ​​may be realized by one or more processors of the calculation unit 32 executing a program stored in the memory of the storage unit 30. An IC, a discrete device, or the like included in the calculation unit 32 may realize at least a part of the reception processing unit 34 and the transfer control unit 36.

[0043] The reception processing unit 34 performs reception processing of the frame FR input from the transmission path 14 to the transfer circuit unit 26. More specifically, the reception processing unit 34 includes an identification information acquisition unit 38 and a transfer table creation unit 40, which will be described below.

[0044] When a frame FR is received by the transfer circuit unit 26, the identification information acquisition unit 38 acquires the identification information set in the frame FR.

[0045] The forwarding table creation unit 40 creates the forwarding table TB based on the identification information acquired by the identification information acquisition unit 38. The forwarding table TB is a table for relaying communications by the forwarding circuit unit 26. The forwarding table TB is stored in the storage unit 30, for example.

[0046] FIG. 2A is a table illustrating the forwarding table TB.

[0047] The forwarding table TB may store identification information acquired by the identification information acquisition unit 38. For illustrative purposes, FIG. 2A shows a plurality of pieces of identification information expressed in binary, such as "identification information: 0001" (decimal number: 1), "identification information: 0101" (decimal number: 5), and "identification information: 0110" (decimal number: 6). Note that the number of bits constituting the identification information is not limited to 4 bits. Furthermore, as shown in FIG. 2A, forwarding destination information, type information, and forwarding order information may be stored in the forwarding table TB.

[0048] The destination information is information indicating the destination transmission path of the frame FR. The destination transmission path is the transmission path 14 that is the destination of the frame FR input from the transmission path 14 to the transfer circuit unit 26. In other words, the destination transmission path is the transmission path 14 that connects the transfer circuit unit 26 and the node 16 specified as the destination of the frame FR. For illustration, FIG. 2A shows a case where the destination transmission path of all frames FR input to the transfer circuit unit 26 is the transmission path 141.

[0049] The type information is information indicating the type of the frame FR input to the transfer circuit unit 26. For example, if the frame FR input to the transfer circuit unit 26 is a control frame FRC, type information indicating that the frame FR is a control frame FRC is stored in the transfer table TB. Also, if the frame FR input to the transfer circuit unit 26 is an enable frame FRW, type information indicating that the frame FR is an enable frame FRW is stored in the transfer table TB. Although not shown in FIG. 2A, if the frame FR input to the transfer circuit unit 26 is a pause request frame FRS, type information indicating that the frame FR is a pause request frame FRS is stored in the transfer table TB.

[0050] The transfer order information is information indicating the transfer order. The transfer order is the processing priority when a plurality of frames FR having the same transmission path 14 as the transfer destination (transfer destination transmission path) are input to the transfer circuit unit 26. The transfer order may also be the processing priority when a plurality of frames FR having the same transmission path 14 as the transfer destination (transfer destination transmission path) are simultaneously input to the transfer circuit unit 26. The transfer table creation unit 40 may set the transfer order for each group of frames FR having the same transfer destination transmission path.

[0051] The forwarding table creation unit 40 may determine the forwarding order based on identification information (priority) previously set in the frame FR. In this case, the forwarding order follows the arrangement order of the multiple frames FR according to the priority. However, when the startup priority control described later is executed, the forwarding order is changed regardless of the identification information (priority). The startup priority control will be described in more detail later.

[0052] The transfer control unit 36 ​​executes transfer control of the frame FR received by the reception processing unit 34. More specifically, the transfer control unit 36 ​​includes a transmission processing unit 42, an error detection unit 44, an error counter control unit 46, a dormant node determination unit 48, a transfer table modification unit 50, and a startup success / failure determination unit 52, which will be described below.

[0053] The transmission processing unit 42 of the transfer control unit 36 ​​performs transfer processing. This transfer processing includes transmitting (outputting) the frame FR received by the reception processing unit 34 via the transfer circuit unit 26 to the transfer destination transmission path corresponding to that frame FR. As a result, the frame FR is transferred to the transfer destination transmission path via the transfer circuit unit 26.

[0054] Fig. 2B is a diagram showing a portion of the communication system 12. Fig. 2B shows a forwarding process performed based on the forwarding table TB of Fig. 2A. The multi-digit binary number attached to each of the multiple frames FR of Fig. 2B corresponds to the identification information shown in Fig. 2A.

[0055] When multiple frames FR with the same destination transmission path are input to the transfer circuit unit 26, the transmission processing unit 42 determines which frame FR to transmit preferentially to the destination transmission path based on the transfer priority indicated by the transfer table TB. For example, the transmission processing unit 42 transfers the frame FR with the highest transfer priority to the destination transmission path with the highest priority. For example, according to FIG. 2A, the control frame FRC with "identification information: 0001" has the highest transfer priority. Therefore, the transmission processing unit 42 transfers this control frame FRC with the highest priority to the transmission path 141, which is the destination transmission path (FIG. 2B).

[0056] As described above, the transfer order indicated by the transfer table TB may be determined based on identification information (priority) preset for each of the multiple frames FR. The process of determining the frame FR to be preferentially transmitted to the destination transmission path based on the priority preset for each of the multiple frames FR is also referred to as normal control in the following description. In other words, the transfer control unit 36 ​​(transmission processing unit 42) can execute normal control based on the transfer table TB.

[0057] The transmission processing unit 42 may also perform communication arbitration, similar to the ECU 18. For example, the transmission processing unit 42 performs communication arbitration when detecting a collision between a frame FR transferred to a destination transmission path and another frame FR having a higher priority than the frame FR.

[0058] The error detection unit 44 detects an error in the destination transmission line. For example, the error detection unit 44 detects a transmission error (transfer error) based on the fact that a response to a frame FR transferred to the destination transmission line by the transmission processing unit 42 cannot be detected from the transmission processing unit 42. When a transfer error is detected by the error detection unit 44, the above-mentioned transmission processing unit 42 retransmits the frame FR to the destination transmission line.

[0059] When a transfer error is detected by the error detection unit 44, the error counter control unit 46 performs an increment process on the error counter corresponding to the transfer destination transmission line. When a response to a frame FR transferred to the transfer destination transmission line by the transmission processing unit 42 is detected, the error counter control unit 46 performs a decrement process on the error counter corresponding to the transfer destination transmission line. In this case, the error counter indicates the frequency of transfer errors in the transmission line 14 corresponding to the error counter. Note that the error counter is realized, for example, by a counter circuit (not shown) provided in the gateway device 20. In this case, the processing circuit (described above) of the calculation unit 32 may have the counter circuit.

[0060] The dormant node determination unit 48 determines whether or not a dormant node is connected to the destination transmission path to which the activation frame FRW is transferred. A dormant node is a node 16 in a dormant state. For example, the ECU 18 in sleep mode corresponds to a dormant node. The dormant node determination unit 48 can determine whether or not a dormant node is connected to the destination transmission path of the activation frame FRW based on the transfer result (transfer progress) of a non-activation frame that is transferred prior to the activation frame FRW to the same transmission path 14 as the transfer destination of the activation frame FRW. A non-activation frame is a frame FR that is not an activation frame FRW. For example, the above-mentioned control frame FRC, pause request frame FRS, etc. correspond to non-activation frames.

[0061] As described above, the priority of the control frame FRC is higher than the priority of the activation frame FRW. Therefore, when a control frame FRC and an activation frame FRW, both of which have the same transmission path 14 as their destination transmission path, are input to the transfer circuit unit 26, the control frame FRC is transferred with priority over the activation frame FRW based on the normal control described above (FIG. 2B). In this case, the control frame FRC is a non-activation frame that precedes the activation frame FRW.

[0062] However, a dormant node does not execute a response process to a non-activation frame. Therefore, if the node 16 that is the destination of the non-activation frame is a dormant node, a transmission error is detected by the error detection unit 44 described above. The number of transmission errors CE (error frequency), which is the number of transmission errors in the destination transmission path, increases as the transmission processing unit 42 repeatedly retransmits the non-activation frame. Based on this, the dormant node determination unit 48 determines that a dormant node is connected to the destination transmission path when the number of transmission errors CE becomes equal to or exceeds a predetermined threshold TH.

[0063] If the inactive node determination unit 48 determines that an inactive node is connected to the destination transmission line, the transfer control unit 36 ​​restricts the normal control described above and starts activation priority control. The activation priority control includes a change process.

[0064] FIG. 3A is a table illustrating the forwarding table TB after the change process.

[0065] The change process is a process of changing the transfer order of the activation frame FRW to be higher than the transfer order of frames FR other than the activation frame FRW. The change process is executed by the forwarding table change unit 50. For example, by executing the change process, the forwarding table change unit 50 sets the transfer order of the activation frame FRW to the highest order regardless of the identification information (priority) of the activation frame FRW. Note that when multiple activation frames FRW with the same destination transmission path are set in the forwarding table TB, the forwarding table change unit 50 may perform the change process based on the identification information (priority) of each of the multiple activation frames FRW. Even in this case, the transfer order of the multiple activation frames FRW may be changed to be higher than the transfer order of non-activation frames.

[0066] Fig. 3B is a diagram showing a part of the communication system 12. Fig. 3B shows a forwarding process (startup priority control) performed based on the forwarding table TB of Fig. 3A. The four-digit number written in each of the multiple frames FR of Fig. 3B corresponds to the identification information shown in Fig. 3A.

[0067] When the change process is performed by the forwarding table change unit 50, the transmission processing unit 42 transmits the start-up frame FRW based on the transfer order changed by the change process described above. As a result, the start-up frame FRW is transferred to the destination transmission path with priority over the non-start-up frame. In this case, the transfer process of the non-start-up frame that was transferred (retransmitted) prior to the start-up frame FRW to the transmission path 14 that is the transfer destination of the start-up frame FRW is restricted. The transmission processing unit 42 may restrict the transfer process of the non-start-up frame by discarding the non-start-up frame. The forwarding table change unit 50 may delete information about the discarded non-start-up frame from the forwarding table TB (see also FIG. 4A).

[0068] The activation success / failure determination unit 52 determines whether or not the activation of the dormant node by the activation frame FRW has been successful when the activation frame FRW has been preferentially transferred under activation priority control.

[0069] For example, the activation success / failure determination unit 52 may determine that activation of a dormant node by the activation frame FRW has not been successful based on the fact that the activation priority control has timed out. In this case, the activation success / failure determination unit 52 may use a timer to determine whether the activation priority control has timed out. The timer is implemented, for example, by the calculation unit 32 (processor, etc.). The activation success / failure determination unit 52 determines whether a transmission error (transmission error) in the destination transmission path continues to be detected for a predetermined time after the activation frame FRW starts to be preferentially transferred by the activation priority control. In other words, the activation success / failure determination unit 52 determines whether a response to the activation frame FRW is detected within a predetermined time after the activation frame FRW starts to be preferentially transferred. The activation success / failure determination unit 52 measures the elapsed time after the activation frame FRW starts to be preferentially transferred using a timer. If no response to the activation frame FRW is detected before the predetermined time has elapsed, the activation success / failure determination unit 52 determines that the activation priority control has timed out.

[0070] Fig. 4A is a table illustrating a forwarding table TB. Fig. 4A shows the forwarding table TB in the case where it is determined that the activation frame FRW (identification information: 0101), which was ranked first in the forwarding order in the forwarding table TB of Fig. 3A, did not succeed in activating the dormant node.

[0071] If the activation success / failure determination unit 52 determines that activation of the dormant node by the activation frame FRW was unsuccessful, the transfer control unit 36 ​​restricts the transfer of the activation frame FRW. For example, the transfer control unit 36 ​​(forwarding table change unit 50) may restrict the transfer of the activation frame FRW by changing the transfer order of the activation frame FRW that was unsuccessful in activating the dormant node to the lowest. The transfer control unit 36 ​​may discard the activation frame FRW that was unsuccessful in activating the dormant node.

[0072] Fig. 4B is a diagram showing a part of the communication system 12. Fig. 4B shows a forwarding process (startup priority control) performed based on the forwarding table TB of Fig. 4A. The four-digit number written in each of the multiple frames FR of Fig. 4B corresponds to the identification information shown in Fig. 4A.

[0073] After restricting the forwarding of the startup frame FRW that did not successfully start up the dormant node, the forwarding control unit 36 ​​(transmission processing unit 42) may forward another startup frame FRW. In this case, the other startup frame FRW is determined based on the forwarding priority set in the forwarding table TB changed by the change process.

[0074] The transmission processing unit 42 may forward another startup frame FRW even when the startup success / failure determination unit 52 determines that the startup of the dormant node was successful using the forwarded startup frame FRW. In this case, the other startup frame FRW is also determined based on the forwarding priority set in the forwarding table TB changed by the change process. As a result, when the startup priority control is executed, all startup frames FRW set in the forwarding table TB are forwarded to the destination transmission path with priority over non-startup frames. Note that the startup success / failure determination unit 52 determines that the startup of the dormant node using the startup frame FRW was successful when, for example, a response to the startup frame FRW is detected before a timeout occurs. Also, as described above, the startup priority control is initiated when the error frequency indicated by the error counter becomes equal to or greater than a predetermined threshold value TH. Thereafter, when a response to the startup frame FRW is detected, the error counter control unit 46 executes a subtraction process on the error counter. As a result of this subtraction process, the error frequency becomes less than the threshold value TH. In light of this, the activation success / failure determination unit 52 may determine that the activation of the dormant node by the activation frame FRW has been successful based on the fact that the error frequency has become less than the threshold value TH.

[0075] When all the startup frames FRW set in the forwarding table TB changed by the change process have been forwarded to the destination transmission path in priority to non-activation frames, the transmission processing unit 42 may end the activation priority process. In other words, when the activation success / failure determination unit 52 determines whether or not the activation of the dormant node has been successful for all the startup frames FRW set in the forwarding table TB changed by the change process, the transmission processing unit 42 may end the activation priority process. After ending the activation priority control, the transfer control unit 36 ​​may resume normal control.

[0076] FIG. 5 is a flowchart of a transfer control method performed by the gateway device 20.

[0077] The gateway device 20 (transfer control device 28) can execute the transfer control method shown in Fig. 5. As shown in Fig. 5, the transfer control method includes a reception processing step S1 and a transfer control step S2.

[0078] The receiving process step S1 is executed by the receiving processor 34. As shown in Fig. 5, the receiving process step S1 includes an identification information acquisition step S11 and a forwarding table creation step S12.

[0079] In identification information acquisition step S11, identification information acquisition unit 38 acquires identification information of frame FR input to forwarding circuit unit 26 of gateway device 20. In forwarding table creation step S12, forwarding table creation unit 40 creates a forwarding table TB based on the identification information acquired in identification information acquisition step S11.

[0080] When a plurality of frames FR having the same destination transmission path are input to the transfer circuit unit 26 at the same time, the transfer order of the plurality of frames FR is set in the transfer table TB in the transfer table creation step S12. In the following explanation, a case will be explained in which a non-activation frame and an activation frame FRW having the same destination transmission path are input to the transfer circuit unit 26 at the same time.

[0081] The transfer control step S2 is executed by the transfer control unit 36. As shown in Fig. 5, the transfer control step S2 includes a transfer processing step (normal transfer processing step) S21, an error detection step S22, an error counter control step S23, an inactive node determination step S24, and an activation priority control step S25.

[0082] In the normal transfer processing step S21, normal control is executed. That is, in the normal transfer processing step S21, the transmission processing unit 42 of the transfer control unit 36 ​​transfers the frame FR based on the transfer table TB created in the transfer table creation step S12. In the normal transfer processing step S21, based on the transfer priority set in the transfer table TB, the non-activation frame out of the non-activation frame and the activation frame FRW is preferentially transferred to the destination transmission path.

[0083] In error detection step S22, the error detection unit 44 detects an error (transfer error) in the destination transmission path. If no transfer error is detected (S22: NO), the transfer control method in Fig. 5 ends. That is, if a response to the frame FR transferred in normal transfer processing step S21 is input to the transfer circuit unit 26, the transfer control device 28 ends the transfer control method in Fig. 5.

[0084] If a transfer error is detected in the error detection step S22 (S22: YES), an error counter control step S23 is started. In the error counter control step S23, the error counter control unit 46 performs an increment process on an error counter (not shown) based on the fact that a transfer error has been detected in the error detection step S22. Although not shown in FIG. 5, if a response to the frame FR transferred in the normal transfer processing step S21 is input to the transfer circuit unit 26, the error counter control unit 46 performs a decrement process on the error counter.

[0085] In the inactive node determination step S24, the inactive node determination unit 48 determines whether or not an inactive node is connected to the destination transmission line. The inactive node determination unit 48 can determine whether or not an inactive node is connected to the destination transmission line based on the number of transfer errors CE (error frequency) on the destination transmission line. For example, the inactive node determination unit 48 determines whether or not the number of transfer errors CE on the destination transmission line is equal to or greater than a predetermined threshold TH (CE≧TH?).

[0086] If the number of transfer errors CE in the destination transmission line is less than the predetermined threshold TH (S24: NO), normal control continues. That is, if the number of transfer errors CE in the destination transmission line is less than the predetermined threshold TH, the normal transfer processing step S21 is executed again, and the non-activation frame is retransmitted to the destination transmission line.

[0087] On the other hand, if the number of transfer errors CE in the destination transmission path is equal to or greater than the predetermined threshold value TH (S24: YES), the startup priority control step S25 is started.

[0088] In the activation priority control step S25, the transfer control unit 36 ​​executes activation priority control. More specifically, as shown in Fig. 5, the activation priority control step S25 includes a transfer table change step S25A and a transfer processing step (priority transfer processing step) S25B. The activation priority control step S25 also includes an activation success / failure determination step S25C, an activation frame restriction step S25D, and an untransferred frame confirmation step S25E.

[0089] In the forwarding table changing step S25A, the forwarding table changing unit 50 executes a change process to change the forwarding table TB. As a result, the forwarding priority of the start-up frame FRW is set higher than the forwarding priority of the non-start-up frame. In the forwarding table changing step S25A, information about the non-start-up frame may be deleted from the forwarding table TB.

[0090] In the priority transfer processing step S25B, the transmission processing unit 42 transfers the frame FR to the destination transmission line based on the transfer priority set in the transfer table TB. Since the transfer priority has been changed in the transfer table change step S25A, in the priority transfer processing step S25B, the activation frame FRW is transferred to the destination transmission line with priority over the non-activation frame.

[0091] In the startup success / failure determination step S25C, the startup success / failure determination unit 52 determines whether or not the startup of the dormant node by the startup frame FRW has been successful. In the startup success / failure determination step S25C, for example, it is determined whether or not the forwarding process of the startup frame FRW has timed out. If the forwarding process has timed out, it is determined that the startup of the dormant node by the startup frame FRW has not been successful.

[0092] If the startup of the dormant node by the startup frame FRW is not successful (S25C: NO), the startup frame restriction step S25D is started. In the startup frame restriction step S25D, the forwarding control unit 36 ​​(transmission processing unit 42) restricts the forwarding of the startup frame FRW that did not succeed in starting the dormant node. In the startup frame restriction step S25D, the forwarding table changing unit 50 may set the forwarding priority of the startup frame FRW that did not succeed in starting the dormant node to the lowest.

[0093] The untransferred frame confirmation step S25E is started when the activation of the dormant node by the activation frame FRW is successful (S25C: YES). The untransferred frame confirmation step S25E is also started after the activation frame restriction step S25D is executed. In the untransferred frame confirmation step S25E, the transfer control unit 36 ​​(transmission processing unit 42) determines whether or not there is an untransferred activation frame FRW based on the transfer table TB.

[0094] If there is an untransferred startup frame FRW (S25E: YES), the priority transfer processing step S25B is executed again. The transfer control device 28 can sequentially repeat the priority transfer processing step S25B to the untransferred frame confirmation step S25E until the transfer processing of all the startup frames FRW set in the transfer table TB has been executed.

[0095] If the transfer process of all the enable frames FRW has been completed (S25E: NO), the transfer control device 28 ends the transfer control method of FIG.

[0096] The above gateway device 20 provides the following advantageous effects, for example.

[0097] The gateway device 20 relays communications between different transmission paths 14. The gateway device 20 includes a reception processing unit 34 and a transfer control unit 36. The reception processing unit 34 performs reception processing of the frame FR. The transfer control unit 36 ​​performs activation priority control when an activation frame FRW is received by the reception processing unit 34 and a dormant node is connected to the destination transmission path. By performing activation priority control, the activation frame FRW is transferred to the destination transmission path with priority over non-activation frames. This solves the problem of non-activation frames (e.g., control frames FRC) occupying the transmission path 14, which effectively stagnates communications by the communication system 12.

[0098] The destination transmission path is one of the multiple transmission paths 14 (first transmission path). For example, the transmission path 141 in FIG. 1 may be interpreted as the first transmission path. In this case, the non-activation frame is transmitted from the node 16 connected to the gateway device 20 via another transmission path 14 (second transmission path) other than the first transmission path among the multiple transmission paths 14. For example, the transmission path 142 in FIG. 1 may be interpreted as the second transmission path. Furthermore, the activation frame FRW is transmitted from the node 16 connected to the gateway device 20 via yet another transmission path 14 (third transmission path) among the multiple transmission paths 14. For example, the transmission path 143 in FIG. 1 may be interpreted as the third transmission path.

[0099] The transfer control unit 36 ​​determines that a dormant node is connected to the destination transmission path based on the fact that the number of transfer errors CE of a non-activation frame transferred to the destination transmission path prior to the activation frame FRW has reached a predetermined threshold TH or greater. This allows the transfer control unit 36 ​​to determine that a node 16 that does not respond to a non-activation frame is a dormant node. Furthermore, retransmission of a frame FR is promptly performed if no response to the frame FR is detected. Therefore, if a non-activation frame is repeatedly retransmitted to a dormant node, the number of transfer errors CE increases relatively quickly. Furthermore, because the determination criterion is whether or not there is a response to the non-activation frame, the transfer control unit 36 ​​can accurately determine whether or not a dormant node is connected to the destination transmission path, compared to when, for example, the elapse of time measured by a timer is used as the determination criterion. In other words, according to this embodiment, the transfer control unit 36 ​​can relatively quickly and accurately determine whether or not a dormant node is connected to the destination transmission path.

[0100] The transfer control unit 36 ​​terminates the activation priority control based on the successful activation of the dormant node. As a result, if the activation of the dormant node is successful, the transfer control unit 36 ​​can resume normal control. As a result, the transfer control unit 36 ​​can again preferentially transfer non-activation frames such as the control frame FRC necessary for real-time control of the vehicle 10.

[0101] In the activation priority control, the transfer control unit 36 ​​restricts the transfer of non-activation frames received by the reception processing unit 34. This allows the transfer control unit 36 ​​to transfer activation frames FRW to the destination transmission line.

[0102] The transfer control unit 36 ​​may limit the transfer of non-activation frames by discarding the non-activation frames received by the reception processing unit 34. This at least temporarily excludes the non-activation frames from the processing targets of the gateway device 20 (transfer control device 28), thereby reducing the processing load on the gateway device 20.

[0103] In normal control, the transfer control unit 36 ​​transfers frames FR based on a predetermined priority. In this case, the priority of a startup frame FRW in normal control is lower than the priority of a non-startup frame in normal control. As a result, when a startup frame FRW and a non-startup frame with the same destination transmission path are input to the gateway device 20, the non-startup frame is transferred before the startup frame FRW in normal control. By transferring the non-startup frame before the startup frame FRW, the transfer control unit 36 ​​can determine whether a dormant node is connected to the destination transmission path. Furthermore, by using normal control, which prioritizes non-startup frames such as control frames FRC over startup frames FRW, as the basic control operation, real-time control of the vehicle 10 is effectively achieved.

[0104] The activation frame FRW for activating a dormant node connected to the first transmission path (transmission path 141) may be issued from a node 16 connected to the gateway device 20 via a third transmission path (transmission path 143) when a stopped vehicle 10 satisfies a predetermined activation condition. The predetermined activation condition is, for example, that a predetermined operation is performed on the stopped vehicle 10. As a result, when the predetermined operation is performed on the stopped vehicle 10, the dormant node is activated by the activation frame FRW.

[0105] If it is determined that activation of the dormant node by the activation frame FRW has failed, the transfer control unit 36 ​​terminates the activation priority control. For example, if the activation priority control has timed out, the transfer control unit 36 ​​determines that activation of the dormant node by the activation frame FRW has failed. By terminating the activation priority control when activation of the dormant node by the activation frame FRW has failed, the transfer control unit 36 ​​can resume normal control. This eliminates the occupancy of the destination transmission path by the activation frame FRW that failed to activate the dormant node. In other words, the problem of communication by the communication system 12 being substantially stalled by the activation frame FRW is resolved.

[0106] There may be cases where a startup frame FRW transferred to a destination transmission path does not successfully activate a dormant node. In such cases, the receiving processor 34 may receive another startup frame FRW with the same destination transmission path as its destination. In such cases, the transfer controller 36 transfers the other startup frame FRW to the destination transmission path. This allows the transfer controller 36 to sequentially transfer all of the startup frames FRW with the same destination transmission path to the destination transmission path. By performing startup priority control, the transfer controller 36 can sequentially transfer all of the startup frames FRW with the same destination transmission path to the destination transmission path. This allows the transfer controller 36 to increase the number of nodes 16 in a normal state connected to the destination transmission path while preventing the destination transmission path from being continuously occupied by a startup frame FRW that failed to activate a dormant node.

[0107] In this embodiment, it is not necessarily required that the node 16 determined to be a dormant node by the transfer control unit 36 ​​and the node 16 that is the destination of the activation frame FRW that is preferentially transferred by activation priority control are the same. Explaining this in accordance with the examples of Figures 2A to 4B, for example, if the destination of the non-activation frame (identification information: 0001) is ECU 18A, the destinations of the two activation frames FRW (identification information: 0101; 0110) may be ECU 18A or ECU 18B.

[0108] This is because, by transferring the activation frame FRW when no response to the non-activation frame is received, the state in which the transmission path 14 is occupied by the non-activation frame is at least resolved. In this case, the state in which the transmission path 14 is occupied by the non-activation frame is resolved regardless of whether the node 16 determined to be a dormant node by the transfer control unit 36 ​​is the same as the node 16 that is the destination of the activation frame FRW that is preferentially transferred by the activation priority control. Furthermore, by preferentially transferring the activation frame FRW, the number of nodes 16 in the normal state connected to the destination transmission path increases. As a result, the risk of the communication system 12 stagnating due to the non-activation frame that is subsequently transferred to the destination transmission path is reduced.

[0109] The embodiment may be modified as in the modified examples described below. Note that the description that overlaps with the embodiment will be omitted as appropriate. Of the elements described below, the same elements as those already described in the embodiment will be assigned the same reference numerals as in the embodiment.

[0110] (Variation 1) There may be cases where a dormant node connected to one destination transmission line is not activated by one activation frame FRW transferred to the one destination transmission line (see also one embodiment). While the retransmission process of the one activation frame FRW is being repeated, there may be cases where another activation frame FRW having the one destination transmission line as its destination is received by the reception processing unit 34. In such cases, the transfer control unit 36 ​​(transmission processing unit 42) may restrict the retransmission of the one activation frame FRW and transfer the other activation frame FRW. In this modified example, the node 16 that is the destination of one activation frame FRW and the node 16 that is the destination of the other activation frame FRW may be the same or different.

[0111] Fig. 6A is a diagram showing a part of a communication system 12 according to Modification 1. Normal control executed by a transfer control device 28 according to Modification 1 is shown in Fig. 6A.

[0112] For example, as shown in Fig. 6A, two frames FR are input to the gateway device 20. More specifically, a control frame FRC (identification information: 0001) which is a non-activation frame and an activation frame FRW (identification information: 0101) are simultaneously input to the transfer circuit unit 26 (see also Fig. 1) of the gateway device 20. A case will be described in which the destination transmission path of both of these two frames FR is the transmission path 141. The transfer control unit 36 ​​executes normal control to transfer the control frame FRC which is a non-activation frame to the destination transmission path first (see also one embodiment).

[0113] 6B is a diagram showing a part of the communication system 12 according to Modification 1. The startup priority control executed by the transfer control device 28 according to Modification 1 is shown in FIG.

[0114] Based on the transfer result (progress) of the control frame FRC, which is a non-activation frame shown in Fig. 6A, the dormant node determination unit 48 determines whether or not a dormant node is connected to the transmission path 141 (see one embodiment). If the dormant node determination unit 48 determines that a dormant node is connected to the transmission path 141, activation priority control is started. As a result, the activation frame FRW (identification information: 0101), which was input to the gateway device 20 simultaneously with the above-mentioned non-activation frame, is transferred to the transmission path 141.

[0115] There may be a case where a dormant node does not start up in response to the startup frame FRW (identification information: 0101) transferred by the startup priority control. In that case, a retransmission process of the startup frame FRW (identification information: 0101) is executed. Furthermore, while the retransmission process is being repeated, there may be a case where another startup frame FRW (identification information: 0110) whose destination transmission path is the transmission path 141 of the startup frame FRW (identification information: 0101) is further input to the gateway device 20.

[0116] 6C is a diagram showing a part of the communication system 12 according to Modification 1. The startup priority control executed by the transfer control device 28 according to Modification 1 is shown in FIG.

[0117] If another startup frame FRW (identification information: 0110) is input to the gateway device 20 while the retransmission process of the startup frame FRW (identification information: 0101) is being repeated, the transfer control unit 36 ​​transfers the startup frame FRW (identification information: 0110). In other words, if another startup frame FRW (identification information: 0110) is input to the gateway device 20 under circumstances in which a dormant node does not start up in response to the startup frame FRW (identification information: 0101), the transfer control unit 36 ​​transfers the other startup frame FRW. In this case, the retransmission process of the startup frame FRW (identification information: 0101) is restricted.

[0118] According to this modification, if a dormant node does not start up in response to one startup frame FRW that is preferentially transferred by the startup priority control, an attempt is made to start up the dormant node using another startup frame FRW. This reduces the risk of the communication system 12 stagnating due to repeated retransmission processing of the startup frame FRW that cannot start up the dormant node.

[0119] (Variation 2) The configuration of the forwarding table TB may be modified as appropriate. For example, if the type of the frame FR is self-evident based on the identification information, the type information column of the forwarding table TB (FIG. 2A, etc.) may be omitted.

[0120] (Combination of multiple modifications) The above-described multiple modifications may be combined as appropriate within a range that does not contradict each other.

[0121] The following additional notes are provided regarding the above-described embodiment.

[0122] (Appendix 1) The gateway device according to the present disclosure is a gateway device (20) that relays communications between different transmission paths (14), and includes a reception processing unit (34) that performs reception processing of frames (FR), and a transfer control unit (36) that controls the transfer of the frames received by the reception processing unit, wherein, when an activation frame (FRW) that activates a dormant node that is a dormant node (16) is received by the reception processing unit and the dormant node is connected to a destination transmission path that is a transmission path to which the activation frame is to be transferred, the transfer control unit performs activation priority control that transfers the activation frame to the destination transmission path with priority over non-activation frames that are frames that are not the activation frame. This solves the problem of communications in a communication system being stagnate due to non-activation frames.

[0123] (Appendix 2) The gateway device according to Supplementary Note 1 may be such that the destination transmission path is a first transmission path of the plurality of transmission paths, the non-activation frame is transmitted from a node connected to the gateway device via a second transmission path of the plurality of transmission paths, and the activation frame is transmitted from a node connected to the gateway device via a third transmission path of the plurality of transmission paths.

[0124] (Appendix 3) In the gateway device according to Supplementary Note 1 or 2, the forwarding control unit may determine that the dormant node is connected to the destination transmission path based on the fact that the number of forwarding errors (CE) of the non-activation frame forwarded to the destination transmission path prior to the activation frame becomes equal to or greater than a predetermined threshold (TH). This allows the forwarding control unit to determine that a node that does not respond to the non-activation frame is a dormant node.

[0125] (Appendix 4) In the gateway device according to Supplementary Note 3, the forwarding control unit may terminate the activation priority control based on successful activation of the dormant node. This allows the forwarding control unit to again preferentially forward non-activation frames.

[0126] (Appendix 5) In the gateway device according to Supplementary Note 1 or 2, in the activation priority control, the transfer control unit may limit transfer of the non-activation frame received by the reception processing unit, thereby allowing the transfer control unit to transfer the activation frame to the destination transmission path.

[0127] (Appendix 6) In the gateway device according to Supplementary Note 5, the forwarding control unit may be configured to discard the non-activation frame received by the reception processing unit, thereby restricting forwarding of the non-activation frame. This reduces the processing load on the gateway device.

[0128] (Appendix 7) The gateway device may be one as described in Supplementary Note 1 or 2, wherein when the dormant node connected to a destination transmission line is not started by a startup frame (FRW) transferred to the destination transmission line, and another startup frame (FRW) having the destination transmission line as its destination is received by the receiving processing unit, the transfer control unit restricts re-transfer of the one startup frame and transfers the other startup frame.

[0129] (Appendix 8) In the gateway device according to Supplementary Note 1 or 2, in normal control that is not the activation priority control, the forwarding control unit may forward the frames based on a predetermined priority. By using normal control, in which non-activation frames such as control frames are prioritized over activation frames, as a basic control operation, real-time control is effectively achieved.

[0130] (Appendix 9) The gateway device according to Supplementary Note 8 may be configured such that the priority of the startup frame under normal control is lower than the priority of the non-startup frame under normal control. Thus, when a startup frame and a non-startup frame having the same destination transmission path are input to the gateway device, the non-startup frame is transferred prior to the startup frame.

[0131] (Appendix 10) The gateway device according to Supplementary Note 2 may be a gateway device that is provided in a vehicle (10) and that starts activation of the dormant node when the vehicle in a stopped state satisfies a predetermined activation condition. As a result, even if the vehicle is in a stopped state, if the predetermined activation condition is satisfied, the dormant node is activated by an activation frame.

[0132] (Appendix 11) In the gateway device according to Supplementary Note 1 or 2, if it is determined that activation of the dormant node by the activation frame has failed, the forwarding control unit may terminate the activation priority control. This eliminates the state in which the destination transmission path is occupied by the activation frame that has failed to activate the dormant node.

[0133] (Appendix 12) In the gateway device according to Supplementary Note 11, the forwarding control unit may determine that the startup of the dormant node by the startup frame has failed when the startup priority control has reached a timeout. This eliminates the state in which the destination transmission path is occupied by the startup frame that has failed to start the dormant node.

[0134] (Appendix 13) In the gateway device according to Supplementary Note 1 or 2, when the startup of the dormant node by one startup frame (FRW) transferred to one destination transmission line is not successful and another startup frame (FRW) having the one destination transmission line as its destination is received by the reception processing unit, the transfer control unit may transfer the other startup frame to the one destination transmission line. This allows the transfer control unit to transfer all of a plurality of startup frames having the same destination transmission line to the destination transmission line in order.

[0135] The present disclosure is not limited to the above disclosure, and various configurations may be adopted without departing from the gist of the present disclosure. [Explanation of symbols]

[0136] 10...Vehicle 14...Transmission path 16...Node 20...Gateway device 34...Reception processing unit 36...Transmission control unit CE...Number of transmission errors FR...Frame FRW...Start frame TH...Threshold

Claims

1. A gateway device that relays communications between different transmission paths, a reception processing unit that performs reception processing of frames; a transfer control unit that controls transfer of the frame received by the reception processing unit; Equipped with A gateway device in which, when a startup frame, which is a frame that starts up a dormant node, which is a node in a dormant state, is received by the receiving processing unit, and the dormant node is connected to a destination transmission path, which is the transmission path to which the startup frame is forwarded, the forwarding control unit performs startup priority control, which is control to forward the startup frame to the destination transmission path in priority over a non-startup frame, which is a frame that is not the startup frame.

2. 2. The gateway device according to claim 1, the destination transmission path is a first transmission path among the plurality of transmission paths, the non-activation frame is transmitted from a node connected to the gateway device via a second transmission path among the plurality of transmission paths; The gateway device, wherein the activation frame is transmitted from a node connected to the gateway device via a third transmission path among the plurality of transmission paths.

3. 3. The gateway device according to claim 1, A gateway device, wherein the transfer control unit determines that the dormant node is connected to the destination transmission path based on the number of transfer errors of the non-startup frame transferred to the destination transmission path prior to the startup frame becoming greater than or equal to a predetermined threshold.

4. 4. The gateway device according to claim 3, The gateway device, wherein the transfer control unit terminates the activation priority control based on successful activation of the inactive node.

5. 3. The gateway device according to claim 1, In the activation priority control, the transfer control unit restricts transfer of the non-activation frame received by the reception processing unit.

6. 6. The gateway device according to claim 5, The gateway device, wherein the transfer control unit limits transfer of the non-activation frame by discarding the non-activation frame received by the reception processing unit.

7. 3. The gateway device according to claim 1, A gateway device in which, when the dormant node connected to a destination transmission path is not activated by a startup frame transferred to the destination transmission path, and another startup frame having the destination transmission path as its destination is received by the receiving processing unit, the transfer control unit restricts re-transfer of the one startup frame and transfers the other startup frame.

8. 3. The gateway device according to claim 1, In normal control other than the startup priority control, the transfer control unit transfers the frame based on a predetermined priority.

9. 9. The gateway device according to claim 8, The priority of the startup frame in the normal control is lower than the priority of the non-startup frame in the normal control.

10. 3. The gateway device according to claim 2, the gateway device is provided in a vehicle; When the vehicle in a stopped state satisfies a predetermined activation condition, activation of the dormant node is initiated.

11. 3. The gateway device according to claim 1, When it is determined that the startup of the dormant node by the startup frame has failed, the transfer control unit terminates the startup priority control.

12. The gateway device according to claim 11, The gateway device, wherein the transfer control unit determines that activation of the dormant node by the activation frame has failed when the activation priority control reaches a timeout.

13. 3. The gateway device according to claim 1, A gateway device in which, when a startup frame transferred to a destination transmission path does not successfully start up the dormant node, and another startup frame having the destination transmission path as its destination is received by the receiving processing unit, the transfer control unit transfers the other startup frame to the destination transmission path.

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