JP2010206651A - Communication repeater, communication relay method, communication network, and electronic controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication repeater capable of transferring a signal from a transfer source of a transfer route to a transfer destination via an alternative route, even if any fault occurs in a signal transfer route within the communication repeater. <P>SOLUTION: The communication repeater includes plural transceivers, plural transfer routes, a routing control unit, and a communication fault detection unit. The transceiver unit is provided for each communication bus, and receives a signal from the communication bus to which the self transceiver unit is connected and recognizes the contents of the signal. While transferring the received signal to the other transceiver unit, the transceiver unit sends the signal transferred from the other transceiver unit to the communication bus to which the self transceiver unit is connected. The routing control unit controls a destination transceiver to which the signal received by the transceiver unit is to be transferred in accordance with the contents of the signal. When any communication fault of the transfer route is detected, the routing control unit switches the transfer route so that a signal to be transferred in a fault transfer route in which the communication fault is detected at the beginning may be transferred from the transfer source of the fault transfer route to the transfer destination via any transfer route other than the fault transfer route. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication relay device, a communication relay method, a communication network, and an electronic control device. More specifically, an abnormality occurs in a signal transfer path in the communication relay device, and a signal cannot be transferred via the transfer path. The present invention also relates to a communication relay device, a communication relay method, a communication network, and an electronic control device that cooperates with the communication relay device that can transfer a signal via a detour path.

  In recent years, the number of electronic control units (ECUs) constituting an in-vehicle network of an automobile has increased. FIG. 20 is a diagram illustrating an example of a conventional in-vehicle network. FIG. 21 is a diagram showing a communication relay device constituting the in-vehicle network shown in FIG.

  As shown in FIG. 20, a conventional in-vehicle network 260 includes a plurality of communication buses 262 to 264, a plurality of electronic control units (ECUs) A to F connected to the communication buses 262 to 264, and a communication bus 262. And a communication relay device (gateway) 265 that relays communication between the electronic control devices A to F connected to H.264. In recent years, communication relay apparatuses are often connected with three or more communication buses. Further, recent communication relay apparatuses often perform communication based on the CAN protocol. Hereinafter, a communication relay device 265 that relays CAN protocol communication between the electronic control devices A to F connected to the three communication buses 262 to 264 will be described as an example of the communication relay device.

  As illustrated in FIG. 21, the communication relay device 265 includes a plurality of transmission / reception units 266 to 268, a plurality of transfer paths 211 to 213, and a routing control unit 271.

  The transmission / reception unit 266 is provided for the communication bus 262, the transmission / reception unit 267 is provided for the communication bus 263, and the transmission / reception unit 268 is provided for the communication bus 264. Each of the transmission / reception units 266 to 268 receives a signal from the communication bus to which it is connected and recognizes the content of the signal. Each of the transmission / reception units 266 to 268 selectively transfers the signal to one of the other transmission / reception units based on an instruction from the routing control unit 271 corresponding to the content of the received signal. Each of the transmission / reception units 266 to 268 transmits a signal transferred from another transmission / reception unit to a communication bus to which the transmission / reception unit 266 to 268 is connected. Each of the transmission / reception units 266 to 268 includes a transceiver 269 and a CAN controller 270.

  The transceiver 269 converts the differential analog signal input from the communication bus 262 (263, 264), which is a twisted pair line, into a digital signal, and outputs the digital signal to the CAN controller 270. The transceiver 269 converts the digital signal output from the CAN controller 270 into a differential analog signal, and outputs the differential analog signal to the communication bus 262 (263, 264).

  The CAN controller 270 identifies the content of the digital signal input from the transceiver 269 and outputs the content to the routing control unit 271. The CAN controller 270 selectively transfers the digital signal input from the transceiver 269 to another transmission / reception unit based on an instruction from the routing control unit 271. Further, the CAN controller 270 outputs the digital signal transferred from the other CAN controller 270 to the transceiver 269 to which the CAN controller 270 is connected.

  The routing control unit 271 controls to which transmission / reception unit the signals received by the transmission / reception units 266 to 268 are transferred according to the content of the signal. Specifically, the routing control unit 271 instructs the transfer source CAN controller 270 to which CAN controller 270 the digital signal should be transferred according to the content of the digital signal input from the CAN controller 270.

  According to the communication relay device 260, the transfer source CAN controller 270 inputs a signal from the communication bus via the transceiver 269. The routing control unit 271 outputs a signal indicating the transfer destination to the transfer source CAN controller 270 according to the content of the signal input by the transfer source CAN controller 270. The CAN controller 270 that has received the transfer destination instruction transfers the signal to the transfer destination CAN controller 270. The transfer destination CAN controller 270 outputs the signal to the communication bus via the transceiver 269. Therefore, in the communication relay apparatus 260, appropriate routing according to the content of the signal is performed.

However, the above-described conventional communication relay device 260 has the following problems.
When an abnormality occurs in any of the transfer paths 211 to 213 between the transmission / reception units 266 to 268 and a signal cannot be transferred via the path, conventionally, the communication relay device 260 is reset. , Trying to restore the transfer path. However, if the transfer path does not return even after resetting, there is a problem that the signal cannot be transferred.

  Patent Document 1 discloses a communication relay device (gateway) that relays CAN protocol communication between electronic control devices respectively connected to three communication buses. However, the communication relay device described in Patent Document 1 is scheduled to transfer on the transfer route when an abnormality occurs in any of the transfer routes in the communication relay device and the transfer of the signal through the transfer route becomes impossible. The transmitted signal cannot be transferred, and communication between the electronic control units cannot be relayed.

Japanese Patent Laid-Open No. 2002-243591

  The present invention has been made in view of such circumstances, and even if an abnormality occurs in the signal transfer path in the communication relay device and the signal cannot be transferred via the transfer path, the present invention passes through the detour path. It is an object of the present invention to provide a communication relay device, a communication relay method, a communication network, and an electronic control device that cooperates with the communication relay device.

The first invention is
Three or more communication buses are connected, a communication relay device that relays communication between the electronic control devices connected to each of the communication buses,
A plurality of transceiver units;
Multiple transfer paths,
A routing controller;
A communication abnormality detection unit,
The transmission / reception unit is provided for each communication bus, receives a signal from the communication bus to which the communication bus is connected, recognizes the content of the signal, and transfers the received signal to the other transmission / reception unit, Send the signal transferred from the other transceiver unit to the communication bus to which it is connected,
The routing control unit controls which of the transmission / reception units the signal received by the transmission / reception unit is transferred according to the content of the signal,
The communication abnormality detection unit detects that a communication abnormality has occurred in the transfer path between the transmission and reception units,
When a communication abnormality is detected by the communication abnormality detection unit, the routing control unit initially transmits a signal that is scheduled to be transferred through the abnormal transfer path in which the communication abnormality is detected from the transfer source of the abnormal transfer path. A communication relay device that switches a transfer route so that a detour transfer is performed to the transfer destination via the transfer route other than the abnormal transfer route.

  According to the first invention, even if an abnormality occurs in the signal transfer path in the communication relay device and the signal cannot be transferred via the transfer path, the transfer source from the transfer path in which the abnormality has occurred is transferred to the transfer destination. Signals can be transferred via a detour path.

According to a second invention, in the first invention,
The transfer path includes a first transfer path, a second transfer path, and a third transfer path that are connected to each other through the transmission / reception unit.
The transmission / reception unit includes: a first transmission / reception unit that connects the first transfer path and the second transfer path; a second transmission / reception unit that connects the second transfer path and the third transfer path; A third transmission / reception unit connecting the third transfer path and the first transfer path,
The electronic control device has a reply function for returning a signal received from the communication bus to the communication bus,
When the communication abnormality detection unit detects a communication abnormality in the first transfer path,
(A) The first transmission / reception unit transmits a signal that was originally scheduled to be transferred from the first transmission / reception unit to the third transmission / reception unit via the first transfer path. Transfer to the second transmitter / receiver via the transfer path,
(B) The second transmission / reception unit transmits the signal transferred from the first transmission / reception unit to the communication bus to which the second transmission / reception unit is connected,
(C) When a signal having the same content as the signal transmitted by itself is replied from the electronic control unit, the second transmitting / receiving unit receives the replied signal, and receives the received signal as the third signal. It transfers to the said 3rd transmission / reception part via this transfer path | route, It is characterized by the above-mentioned.

  According to the second invention, while the transmission / reception unit (second transmission / reception unit) is transmitting a signal to the communication bus, the transmission / reception unit (second transmission / reception unit) outputs a signal having the same content as the signal being transmitted. Even if a communication protocol (for example, CAN protocol) that cannot be received and transferred to another transmission / reception unit (third transmission / reception unit) is used, the transmission / reception unit (second transmission / reception unit) has transmitted. A signal having the same content as the signal can be received from the electronic control unit and transferred to another transmitting / receiving unit (third transmitting / receiving unit). Therefore, according to the second invention, even if it becomes impossible to transfer a signal via the first transfer path due to a communication error, the signal is transmitted via the second transfer path and the third transfer path. Can be transferred.

According to a third invention, in the second invention,
When the communication abnormality detection unit detects a communication abnormality in the first transfer path, the second transmission / reception unit transmits an abnormality notification signal informing the communication abnormality to the communication bus to which the self is connected,
When the electronic control device receives the abnormality notification signal, the electronic control device returns a signal received thereafter to the communication bus.

  According to the third invention, the electronic control unit returns the received signal after receiving the abnormality notification signal. Therefore, compared with the case where the electronic control device always returns the received signal, the amount of the signal flowing through the communication bus is reduced, and the degree of collision of the signals can be reduced.

According to a fourth invention, in the first invention,
The transfer path includes a first transfer path, a second transfer path, and a third transfer path that are connected to each other through the transmission / reception unit.
The transmission / reception unit includes: a first transmission / reception unit that connects the first transfer path and the second transfer path; a second transmission / reception unit that connects the second transfer path and the third transfer path; A third transmission / reception unit connecting the third transfer path and the first transfer path,
When the communication abnormality detection unit detects a communication abnormality in the first transfer path,
(A) The first transmission / reception unit transmits a signal that was originally scheduled to be transferred from the first transmission / reception unit to the third transmission / reception unit via the first transfer path. Transfer to the second transmitter / receiver via the transfer path,
(B) The second transmission / reception unit transmits the signal transferred from the first transmission / reception unit to the communication bus to which the second transmission / reception unit is connected,
(C) The second transmission / reception unit receives a signal transmitted by the second transmission / reception unit, and transfers the received signal to the third transmission / reception unit via the third transfer path.

  According to the fourth aspect of the invention, the transmission / reception unit (second transmission / reception unit) can receive the signal transmitted to the communication bus from the communication bus and transfer it to another transmission / reception unit (third transmission / reception unit). it can. Therefore, according to the fourth invention, even if it becomes impossible to transfer a signal via the first transfer path due to a communication error, the signal is transmitted via the second transfer path and the third transfer path. Can be transferred.

A fifth invention is the fourth invention,
The second transmitting / receiving unit includes two transmitting / receiving units, and the other transmitting / receiving unit receives a signal transmitted from one of the two transmitting / receiving units to the communication bus.

  According to the fifth aspect, while the transmission / reception unit (second transmission / reception unit) is transmitting a signal to the communication bus, the transmission / reception unit (second transmission / reception unit) outputs a signal having the same content as the signal being transmitted. Even when a communication protocol (for example, CAN protocol) that cannot be received and transferred to another transmission / reception unit (third transmission / reception unit) is used, the transmission / reception unit (second transmission / reception unit) The transmitted signal can be received from the communication bus and transferred to another transmission / reception unit (third transmission / reception unit). Therefore, according to the fifth aspect of the present invention, even if the signal cannot be transferred via the first transfer path due to a communication error, the signal is transmitted via the second transfer path and the third transfer path. Can be transferred.

A sixth invention is the first to fifth inventions,
Communication is performed based on a CAN (Controller Area Network) protocol.

  According to the sixth invention, in a communication network using the CAN protocol, an abnormality occurs even if an abnormality occurs in the signal transfer path in the communication relay device and the signal cannot be transferred via the transfer path. A signal can be transferred from the transfer source of the transfer route to the transfer destination via the detour route.

According to a seventh invention, in the fourth invention,
The communication relay device draws a part of the communication bus inside,
The communication relay device further includes:
When the second transmitter / receiver receives a signal transmitted from the second transmitter / receiver to the communication bus, the transmitted signal does not go out of the communication relay device via the communication bus. And a switch for electrically disconnecting the drawn portion of the communication bus in the middle.

  According to the seventh invention, when the signal is transferred through the bypass route, the signal does not go out of the communication relay device through the communication bus connected to the bypass route. A collision can be made difficult to occur.

In an eighth aspect based on the fifth aspect,
The communication relay device draws a part of the communication bus inside,
The communication relay device further includes:
When the other transmitter / receiver receives a signal transmitted by one of the two transmitter / receivers to the communication bus, the transmitted signal does not go out of the communication relay device via the communication bus. And a switch for electrically disconnecting the drawn portion of the communication bus in the middle.

  According to the eighth invention, when the signal is transferred through the bypass route, the signal does not go out of the communication relay device through the communication bus connected to the bypass route. A collision can be made difficult to occur.

According to a ninth invention, in the fifth invention,
The communication bus is composed of a twisted pair line that includes a first communication line and a second communication line and transmits a differential signal,
The communication relay device draws a part of the twisted pair wire inside,
The communication relay device further includes:
A termination circuit that connects the first communication line and the second communication line so that the other transmission / reception unit can receive a signal transmitted from one of the two transmission / reception units to the first communication line;
When one of the two transmission / reception units receives a signal transmitted to the first communication line, the other transmission / reception unit receives the transmitted signal out of the communication relay device via the twisted pair line. And a switch for electrically disconnecting the portion where the twisted-pair wire is drawn in the middle.

  According to the ninth invention, when the signal is transferred through the detour path, the signal does not go out of the communication relay device through the communication bus (twisted pair line) connected to the detour path. It is possible to make it difficult for signal collisions to occur.

In a tenth aspect based on the first aspect,
The transfer path includes a first transfer path, a second transfer path, and a third transfer path that are connected to each other through the transmission / reception unit.
The transmission / reception unit includes: a first transmission / reception unit that connects the first transfer path and the second transfer path; a second transmission / reception unit that connects the second transfer path and the third transfer path; A third transmission / reception unit connecting the third transfer path and the first transfer path,
The communication relay device further includes:
A signal return unit that receives a signal transmitted from the second transmission / reception unit to the communication bus and returns a signal having the same content as the received signal to the second transmission / reception unit;
When the communication abnormality detection unit detects a communication abnormality in the first transfer path,
(A) The first transmission / reception unit transmits a signal that was originally scheduled to be transferred from the first transmission / reception unit to the third transmission / reception unit via the first transfer path. Transfer to the second transmitter / receiver via the transfer path,
(B) The second transmission / reception unit transmits the signal transferred from the first transmission / reception unit to the communication bus to which the second transmission / reception unit is connected,
(C) When a signal having the same content as the signal transmitted by itself is returned from the signal return unit, the second transmission / reception unit receives the returned signal, and receives the received signal as the third signal. It transfers to the said 3rd transmission / reception part via this transfer path | route, It is characterized by the above-mentioned.

  According to the tenth aspect, it is not necessary to provide a return function in the electronic control device connected to the communication bus.

The eleventh invention is
An electronic control device connected to a communication bus,
An electronic control device having a reply function for returning a signal received from the communication bus to the communication bus.

  According to the eleventh aspect, the electronic control unit returns the received signal. Here, a communication relay device is assumed in which three or more communication buses are connected and relays communication between electronic control devices connected to each communication bus. This communication relay apparatus has a transmission / reception unit for each communication bus, and signal relaying is performed by transferring signals between the transmission / reception units. In such a communication relay device, while the transmission / reception unit is transmitting a signal to the communication bus, the transmission / reception unit cannot receive a signal having the same content as the signal being transmitted and cannot be transferred to another transmission / reception unit. It is assumed that a protocol (for example, CAN protocol) is used. Even in such a case, the transmission / reception unit can receive a signal having the same content as the transmitted signal from the electronic control unit and transfer it to another transmission / reception unit. Therefore, according to the seventh invention, even if a communication abnormality occurs in a part of the transfer path in the communication relay apparatus and the signal cannot be transferred via the transfer path, the communication relay apparatus is the present invention. The signal can be transferred from the transfer source of the transfer path to the transfer destination via the detour path in cooperation with the electronic control device according to the above.

In a twelfth aspect based on the eleventh aspect,
When there is an abnormality in the communication relay device that relays communication between the electronic control devices, and the electronic control device receives an abnormality notification signal transmitted by the communication relay device through the communication bus, the electronic control device The received signal is returned to the communication bus.

  According to the twelfth aspect of the invention, the electronic control device may return the received signal after receiving the abnormality notification signal. Therefore, compared with the case where the electronic control device always returns the received signal, the amount of the signal flowing through the communication bus is reduced, and the degree of collision of the signals can be reduced.

The thirteenth invention
A communication network comprising three or more communication buses, a communication relay device that relays communication between the electronic control devices connected to each of the communication buses, and each of the electronic control devices,
The electronic control device
While transmitting a signal to the communication bus to which it is connected, receiving a signal from the communication bus,
The communication relay device is
A plurality of transceiver units;
A routing controller;
A communication abnormality detection unit,
The transmission / reception unit is provided for each communication bus, receives a signal from the communication bus to which the communication bus is connected, recognizes the content of the signal, and transfers the received signal to the other transmission / reception unit, Send the signal transferred from the other transceiver unit to the communication bus to which it is connected,
The routing control unit controls which of the transmission / reception units the signal received by the transmission / reception unit is transferred according to the content of the signal,
The communication abnormality detection unit detects that a communication abnormality has occurred in the transfer path between the transmission and reception units,
When a communication abnormality is detected by the communication abnormality detection unit, the routing control unit initially transmits a signal that is scheduled to be transferred through the abnormal transfer path in which the communication abnormality is detected from the transfer source of the abnormal transfer path. A communication network characterized in that a transfer route is switched so that a detour transfer is made to a transfer destination via the transfer route other than the abnormal transfer route.

  According to the thirteenth aspect, even if an abnormality occurs in the signal transfer path in the communication relay device and the signal cannot be transferred via the transfer path, the transfer source from the transfer path in which the abnormality has occurred is transferred to the transfer destination. Signals can be transferred via a detour path.

The fourteenth invention is
A communication relay method for relaying communication between electronic control devices respectively connected to three or more communication buses,
Sending and receiving steps;
A routing control step;
A communication abnormality detection step,
The transmission / reception step is executed by a transmission / reception unit provided for each communication bus. Each of the transmission / reception units receives a signal from the communication bus, recognizes the content of the signal, and transmits the received signal to another transmission / reception unit. While transmitting the signal transferred from the other transceiver unit to the communication bus to which it is connected,
The routing control step controls which of the transmission / reception units the signal received by the transmission / reception unit is transferred according to the content of the signal,
The communication abnormality detection step detects that a communication abnormality has occurred in the transfer path between the transmission and reception units,
In the routing control step, when a communication error is detected in the communication error detection step, a signal that was originally scheduled to be transferred through the abnormal transfer path in which the communication error was detected is transferred from the transfer source of the abnormal transfer path. A communication relay method characterized in that a transfer route is switched so that a detour transfer is made to the transfer destination via the transfer route other than the abnormal transfer route.

  According to the fourteenth aspect, even if an abnormality occurs in the signal transfer path in the communication relay device and the signal cannot be transferred through the transfer path, the transfer source from the transfer path in which the error has occurred is transferred to the transfer destination. Signals can be transferred via a detour path.

  According to the present invention, even if an abnormality occurs in the signal transfer path in the communication relay device and the signal cannot be transferred via the transfer path, the detour path from the transfer source of the transfer path in which the error has occurred to the transfer destination The signal can be transferred via

The figure which shows the communication network which concerns on 1st Embodiment of this invention. The figure which shows the communication relay apparatus which comprises the communication network shown by FIG. The figure which shows the transmission path | route initially planned of the flame | frame A in the communication network shown by FIG. The figure which shows a mode that communication abnormality has arisen in the transmission path | route initially planned of the flame | frame A in the communication network shown by FIG. The figure which shows a mode that the transfer route of the flame | frame A is switched and transferred in the communication network shown by FIG. The figure which shows a mode that the transfer path | route of the flame | frame A is switched and transferred in the communication relay apparatus shown by FIG. The flowchart which shows the transfer operation | movement of the flame | frame A in 1st Embodiment. The flowchart which shows the transfer operation | movement of the flame | frame A in 1st Embodiment. The figure which shows the communication network which concerns on 2nd Embodiment of this invention. The figure which shows the communication relay apparatus which comprises the communication network shown by FIG. The figure which shows the transmission route initially planned of the frame A in the communication network shown by FIG. The figure which shows a mode that communication abnormality has arisen in the transmission path | route initially planned of the flame | frame A in the communication network shown by FIG. The figure which shows a mode that the transfer path | route of the flame | frame A is switched and transferred in the communication network shown by FIG. The figure which shows a mode that the transfer path of the flame | frame A is switched and it transfers in the communication relay apparatus shown by FIG. Flowchart showing transfer operation of frame A in the second embodiment It is a figure which extracts and shows a part of communication network which concerns on 3rd Embodiment of this invention, and shows a mode that a switch is turned on It is a figure which extracts and shows a part of communication network which concerns on 3rd Embodiment of this invention, and shows a mode that a switch is turned off The figure which shows the communication network (corresponding to 2nd Embodiment) for contrast with the communication network which concerns on 3rd Embodiment of this invention. The figure which extracts and shows a part of communication network which concerns on 4th Embodiment of this invention. Diagram showing an example of a conventional in-vehicle network The figure which shows the communication relay equipment which constitutes the conventional in-vehicle network

(First embodiment)
A first embodiment of a communication system according to the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a communication network according to the first embodiment. FIG. 2 is a diagram showing a communication relay device that constitutes the communication network shown in FIG.

  As shown in FIGS. 1 and 2, a communication network 1 according to the first embodiment includes a plurality of electronic control units (ECUs) A, B, C, D, E, and F, and a plurality of communication buses 2 and 3. , 4 and a communication relay device 5.

  The communication network 1 is an in-vehicle network mounted on a car, for example. In the communication network 1, for example, communication based on a CAN (controller area network) protocol is performed.

  The electronic control devices A, B, C, D, E, and F transmit signals to the communication buses 2, 3, and 4 to which they are connected, and receive signals from the communication buses 2, 3, and 4. In the example shown in FIG. 1, the electronic control devices A and B are connected to the communication bus 2, the electronic control devices C and D are connected to the communication bus 3, and the electronic control devices E and F are connected to the communication bus 3. Yes. The electronic control devices A, B, C, D, E, and F control various devices that are installed in automobiles and the like. For example, the electronic control devices A and B control the engine system devices, the electronic control devices C and D control the brake system devices, and the electronic control devices E and F control the steering system devices.

  For each of the communication buses 2, 3, and 4, at least one electronic control device has a reply function for returning a signal received from the communication bus to the communication bus. In the example shown in FIG. 1, the electronic control devices A, C, and E have a reply function.

  The communication relay device 5 is connected to three or more communication buses 2, 3, 4 (three in the example shown in FIG. 1). The communication relay device 5 includes electronic control devices A and B connected to the communication bus 2, electronic control devices C and D connected to the communication bus 3, and electronic control devices E and F connected to the communication bus 4. Relay communication between them.

  The communication relay device 5 includes a first transmission / reception unit 6, a second transmission / reception unit 7, a third transmission / reception unit 8, a first transfer path 11, a second transfer path 12, a third transfer path 13, A routing control unit 9 and a communication abnormality detection unit 10 are provided.

  The first transmission / reception unit 6 is provided for the communication bus 2, the second transmission / reception unit 7 is provided for the communication bus 3, and the third transmission / reception unit 8 is provided for the communication bus 4.

  The first transmission / reception unit 6 receives a signal from the communication bus 2 to which the first transmission / reception unit 6 is connected, and recognizes the content of the signal. The first transmission / reception unit 6 inputs a transfer instruction according to the content of the received signal from the routing control unit 9. The first transmission / reception unit 6 selectively transfers the signal to either the second transmission / reception unit 7 or the third transmission / reception unit 8 based on the transfer instruction. The first transmission / reception unit 6 transmits the signals transferred from the second transmission / reception unit 7 and the third transmission / reception unit 8 to the communication bus 2 to which the first transmission / reception unit 6 is connected.

  As shown in FIG. 2, the first transmission / reception unit 6 includes a transceiver 20, a CAN controller 23, and a buffer 26. The transceiver 20 converts the differential analog signal input from the communication bus 2 that is a twisted pair line into a digital signal, and outputs the digital signal to the CAN controller 23 via the signal line Rx. Further, the transceiver 20 converts the digital signal output from the CAN controller 23 into a differential analog signal and outputs the differential analog signal to the communication bus 2.

  The CAN controller 23 identifies the content of the digital signal input from the transceiver 20 and does not output the signal to the buffer 26 if the content is the same as the content of the signal being transmitted. The CAN controller 23 outputs the input signal to the buffer 26 when the content of the digital signal input from the transceiver 20 is different from the content of the signal being transmitted or when the signal is not being transmitted. The routing control unit 9 transfers the digital signal to another transmission / reception unit via the buffer 26 according to the content of the digital signal output to the buffer 26. Further, the CAN controller 23 outputs the digital signal transferred from the other transmitting / receiving unit to the transceiver 20 to which the CAN controller 23 is connected via the signal line Tx.

  When the communication abnormality detection unit 10 detects a communication abnormality in the third transfer path 13, the first transmission / reception unit 6 transmits an abnormality notification signal informing the communication abnormality to the communication bus 2 to which it is connected. When receiving the abnormality notification signal, the electronic control unit A returns the received signal to the communication bus 2.

  The second transmitting / receiving unit 7 receives a signal from the communication bus 3 to which the second transmitting / receiving unit 7 is connected, and recognizes the content of the signal. The second transmission / reception unit 7 inputs a transfer instruction according to the content of the received signal from the routing control unit 9. Based on the transfer instruction, the second transmission / reception unit 7 selectively transfers the signal to either the first transmission / reception unit 6 or the third transmission / reception unit 8. The second transmitting / receiving unit 7 transmits the signals transferred from the first transmitting / receiving unit 6 and the third transmitting / receiving unit 8 to the communication bus 3 to which the second transmitting / receiving unit 7 is connected.

  The second transmission / reception unit 7 includes a transceiver 21, a CAN controller 24, and a buffer 27. The transceiver 21 converts the differential analog signal input from the communication bus 3 that is a twisted pair line into a digital signal, and outputs the digital signal to the CAN controller 24 via the signal line Rx. The transceiver 21 converts the digital signal output from the CAN controller 24 into a differential analog signal and outputs the differential analog signal to the communication bus 3.

  The CAN controller 24 identifies the content of the digital signal input from the transceiver 21 and does not output the signal to the buffer 27 when the content is the same as the content of the signal being transmitted. The CAN controller 24 outputs the input signal to the buffer 27 when the content of the digital signal input from the transceiver 21 is different from the content of the signal being transmitted or when the signal is not being transmitted. The routing control unit 9 transfers the digital signal to another transmission / reception unit via the buffer 27 according to the contents of the digital signal output to the buffer 27. Further, the CAN controller 24 outputs the digital signal transferred from the other transmitting / receiving unit to the transceiver 21 to which the CAN controller 24 is connected via the signal line Tx.

  When the communication abnormality detection unit 10 detects a communication abnormality in the first transfer path 11, the second transmission / reception unit 7 transmits an abnormality notification signal informing the communication abnormality to the communication bus 3 to which it is connected. When receiving the abnormality notification signal, the electronic control unit C returns the received signal to the communication bus 3.

  The third transmission / reception unit 8 receives a signal from the communication bus 4 to which the third transmission / reception unit 8 is connected, and recognizes the content of the signal. The third transmission / reception unit 8 inputs a transfer instruction according to the content of the received signal from the routing control unit 9. The third transmitter / receiver 8 selectively transfers the signal to either the first transmitter / receiver 6 or the second transmitter / receiver 7 based on the transfer instruction. The third transmitter / receiver 8 transmits the signals transferred from the first transmitter / receiver 6 and the second transmitter / receiver 7 to the communication bus 4 to which the third transmitter / receiver 8 is connected.

  The third transmission / reception unit 8 includes a transceiver 22, a CAN controller 25, and a buffer 28. The transceiver 22 converts the differential analog signal input from the communication bus 4 that is a twisted pair line into a digital signal, and outputs the digital signal to the CAN controller 25 via the signal line Rx. The transceiver 22 converts the digital signal output from the CAN controller 25 into a differential analog signal, and outputs the differential analog signal to the communication bus 4.

  The CAN controller 25 identifies the content of the digital signal input from the transceiver 22 and does not output the signal to the buffer 28 when the content is the same as the content of the signal being transmitted. The CAN controller 25 outputs the input signal to the buffer 28 when the content of the digital signal input from the transceiver 22 is different from the content of the signal being transmitted or when the signal is not being transmitted. The routing control unit 9 transfers the digital signal to another transmission / reception unit via the buffer 28 according to the contents of the digital signal output to the buffer 28. Further, the CAN controller 25 outputs a digital signal transferred from another transmitting / receiving unit to the transceiver 22 to which the CAN controller 25 is connected via the signal line Tx.

  When the communication abnormality detection unit 10 detects a communication abnormality in the second transfer path 12, the third transmission / reception unit 8 transmits an abnormality notification signal informing the communication abnormality to the communication bus 4 to which it is connected. When receiving the abnormality notification signal, the electronic control unit E returns the received signal to the communication bus 4.

  The first transfer path 11, the second transfer path 12, and the third transfer path 13 are mutually connected so as to make a round through the first transmission / reception unit 6, the second transmission / reception unit 7, and the third transmission / reception unit 8. It is connected to the.

  The first transfer path 11 is a path that connects the first transmission / reception unit 6 and the third transmission / reception unit 8 and transfers a signal between the first transmission / reception unit 6 and the third transmission / reception unit 8. The second transfer path 12 is a path that connects the first transmission / reception unit 6 and the second transmission / reception unit 7 and transfers a signal between the first transmission / reception unit 6 and the second transmission / reception unit 7. The third transfer path 13 is a path that connects the second transmission / reception unit 7 and the third transmission / reception unit 8 and transfers a signal between the second transmission / reception unit 7 and the third transmission / reception unit 8.

  The routing control unit 9 controls which of the other transmission / reception units 7 and 8 the signal received by the first transmission / reception unit 6 is transferred according to the content of the signal. The routing control unit 9 controls which of the other transmission / reception units 6 and 8 transfers the signal received by the second transmission / reception unit 7 in accordance with the content of the signal. Further, the routing control unit 9 controls which of the other transmission / reception units 6 and 7 the signal received by the third transmission / reception unit 8 is transferred according to the content of the signal. Routing information indicating which transfer path the signals received from the communication bus by the first transmitter / receiver 6, the second transmitter / receiver 7, and the third transmitter / receiver 8 are routed in advance according to the contents of the signals. It is set in the control unit 9. However, when a communication abnormality occurs in a part of the transfer routes and transfer on the transfer route becomes impossible, the routing control unit 9 switches the transfer route so that the transfer is performed via another transfer route.

  The communication abnormality detection unit 10 includes a first transfer path 11 that connects the first transmission / reception unit 6 and the third transmission / reception unit 8, and a second transfer that connects the first transmission / reception unit 6 and the second transmission / reception unit 7. It is detected that a communication error has occurred in the third transfer path 13 connecting the path 12, the second transmitting / receiving unit 7 and the third transmitting / receiving unit 8, and that the signal cannot be transferred through the transfer path.

  FIG. 3 is a diagram showing an initially scheduled transfer path of frame A in the communication network shown in FIG. FIG. 4 is a diagram showing a state in which a communication abnormality has occurred in the transfer path initially scheduled for frame A in the communication network shown in FIG. FIG. 5 is a diagram illustrating a state in which transfer is performed by switching the transfer path of the frame A in the communication network illustrated in FIG. FIG. 6 is a diagram illustrating a state in which the transfer is performed by switching the transfer path of the frame A in the communication relay device illustrated in FIG.

  When the communication abnormality detection unit 10 detects a communication abnormality in the transfer path, the routing control unit 9 initially detects the abnormal transfer path in which the communication abnormality is detected (in the example illustrated in FIGS. 3 and 4, the first transfer path 11). ) Is transferred from the transfer source (the first transmitting / receiving unit 6 in the example shown in FIGS. 3 and 4) of the abnormal transfer path to the transfer destination (shown in FIGS. 3 and 4). In the example, the transfer path is switched to the third transmission / reception unit 8) so that detour transfer is performed via transfer paths other than the abnormal transfer path (transfer paths 12 and 13 in the examples shown in FIGS. 5 and 6).

  For example, as illustrated in FIG. 4, when the communication abnormality detection unit 10 detects a communication abnormality in the first transfer path 11, the transfer path is specifically switched as follows by the routing control unit 9. That is, the first transmission / reception unit 6 was originally scheduled to be transferred from the first transmission / reception unit 6 to the third transmission / reception unit 8 via the first transfer path 11 as shown in FIG. The signal (frame A) is transferred to the second transmitter / receiver 7 via the second transfer path 12 as shown in FIGS. As shown in FIGS. 5 and 6, the second transmission / reception unit 7 transmits the signal transferred from the first transmission / reception unit 6 to the communication bus 3 to which the second transmission / reception unit 7 is connected. As shown in FIGS. 5 and 6, when the second transmitter / receiver 7 returns a signal having the same content as the signal transmitted by itself from the electronic control device C, the second transmitter / receiver 7 receives the returned signal. The received signal is transferred to the third transmission / reception unit 8 via the third transfer path 13.

  Next, the operation of the communication network 1 will be described with reference to the flowcharts of FIGS. Hereinafter, a case where a signal (frame A) is sent from the electronic control unit A to the electronic control unit E will be described as an example.

  First, the electronic control unit A transmits a signal to the first transmission / reception unit 6 via the communication bus 2 (step S1). Next, the communication abnormality detection unit 10 determines whether or not there is a communication abnormality in the transfer path 11 (step S2). When the communication abnormality detection unit 10 determines that there is no communication abnormality in the transfer path 11, the routing control unit 9 performs the third transmission / reception with respect to the first transmission / reception unit 6 via the first transfer path 11. An instruction is given to transfer the signal to the unit 8 (step S3). Next, the first transmission / reception unit 6 transfers the signal to the third transmission / reception unit 8 via the first transfer path 11 (step S4). Next, the third transmission / reception unit 8 transmits a signal to the third communication bus 4 (step S5). Next, the electronic control unit E receives a signal from the third communication bus 4 (step S6) and ends the process.

  On the other hand, if the communication abnormality detection unit 10 determines that there is a communication abnormality in the first transfer path 11 and the signal cannot be transferred via the first transfer path 11, the communication abnormality detection unit 10 Then, the second transmission / reception unit 7 is instructed to transmit an abnormality notification signal indicating that a communication abnormality has occurred in the first transfer path 11 to the second communication bus 3 (step S7). Next, the second transmission / reception unit 7 transmits an abnormality notification signal indicating that a communication abnormality has occurred in the first transfer path 11 to the second communication bus 3 (step S8). Next, the electronic control unit C receives the abnormality notification signal from the second communication bus 3 and recognizes that a communication abnormality has occurred in the first transfer path 12 (step S9).

  Next, the routing control unit 9 instructs the first transmission / reception unit 6 to transfer the signal to the second transmission / reception unit 7 via the second transfer path 12 (step S10). Next, the first transmission / reception unit 6 transfers the signal to the second transmission / reception unit 7 via the second transfer path 12 (step S11). Next, the second transmission / reception unit 7 transmits a signal to the second communication bus 3 (step S12).

  Next, the electronic control unit C receives a signal from the second communication bus 3 (step S13). Next, the electronic control unit C returns the received signal to the second communication bus 3 (step S14). Next, the second transmission / reception unit 7 receives the signal returned from the electronic control device C (step S15).

  Next, the routing controller 9 instructs the second transmitter / receiver 7 to transfer the signal to the third transmitter / receiver 8 via the third transfer path 13 (step S16). Next, the second transmission / reception unit 7 transfers the signal to the third transmission / reception unit 8 via the third transfer path 13 (step S17). Next, the third transmission / reception unit 8 transmits a signal to the third communication bus 3 (step S18). Next, the electronic control unit E receives a signal from the third communication bus 4 (step S19). The above is the operation of the communication network 1.

  Due to the communication protocol (for example, CAN protocol), the communication network 1 transmits and receives the signal while the transmission / reception unit (for example, the second transmission / reception unit 7) transmits a signal to the communication bus (for example, the second communication bus 3). The unit (for example, second transmission / reception unit 7) cannot receive a signal having the same content as the signal being transmitted and cannot transfer it to another transmission / reception unit (for example, third transmission / reception unit 8). However, in the communication network 1, the transmission / reception unit (for example, the second transmission / reception unit 7) receives a signal having the same content as the transmitted signal from the electronic control device (for example, the electronic control device C) and receives other transmission / reception units (for example, the third transmission / reception unit). To the transmitting / receiving unit 8). This is because when the electronic control device (for example, the electronic control device C) returns a signal having the same content as the received signal, the transmission timing of the transmission / reception unit (for example, the second transmission / reception unit 7) and the electronic control device (for example, the electronic control device C). This is because the transmission / reception unit (for example, the second transmission / reception unit 7) can receive a signal having the same content as the transmitted signal. According to the communication network 1, even if a signal cannot be transferred via a part of transfer paths (for example, the first transfer path 11) due to a communication error, another transfer path (for example, the second transfer path) 12 and the third transfer path 13).

  Further, according to the communication network 1, the electronic control device C may return the received signal after receiving the abnormality notification signal. Therefore, compared with the case where the electronic control unit C always returns the received signal, the amount of the signal flowing through the communication bus 2 is reduced, and the degree of collision of the signals can be reduced.

Next, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 9 is a diagram illustrating a communication network according to the second embodiment. FIG. 10 is a diagram showing a communication relay apparatus that constitutes the communication network shown in FIG. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The communication network 100 according to the second embodiment is different from the first embodiment in that a communication relay device 50 is provided instead of the communication relay device 5. Specific differences are as follows. The first difference is that instead of the first transmission / reception unit 6, the second transmission / reception unit 7, and the third transmission / reception unit 8, a first transmission / reception unit 60, a second transmission / reception unit 70, and a third transmission / reception unit. 80 is provided. The second difference is that instead of the first transfer path 11, the second transfer path 12, and the third transfer path 13, a first transfer path 110, a second transfer path 120, and a third transfer path are used. 130 is provided. The third difference is that a routing control unit 90 is provided instead of the routing control unit 9. Regarding other configurations, the second embodiment is the same as the second embodiment.

  The first transmission / reception unit 60 receives a signal from the communication bus 2 to which the first transmission / reception unit 60 is connected, and recognizes the content of the signal. The first transmission / reception unit 60 inputs a transfer instruction according to the content of the received signal from the routing control unit 90. The first transmitter / receiver 60 selectively transfers the signal to either the second transmitter / receiver 70 or the third transmitter / receiver 80 based on the transfer instruction. The first transmission / reception unit 60 transmits the signal transferred from the second transmission / reception unit 70 and the third transmission / reception unit 80 to the communication bus 2 to which the first transmission / reception unit 60 is connected.

  The first transmission / reception unit 60 includes two transmission / reception units 600 and 601, and a signal transmitted from one of the two transmission / reception units 600 and 601 (600 in the example shown in FIG. 10) to the communication bus 2 is transmitted and received by the other transmission / reception unit. Unit (601 in the example shown in FIG. 10) receives.

  Specifically, the first transmission / reception unit 60 includes one transceiver 30, two CAN controllers 33 and 34, and two sets of buffers 39 and 40. The transceiver 30 converts the differential analog signal input from the communication bus 2 which is a twisted pair line into a digital signal, and outputs the digital signal to both CAN controllers 33 and 34 via the signal line Rx. In addition, the transceiver 30 converts the digital signal output from one CAN controller 33 into a differential analog signal, and outputs the differential analog signal to the communication bus 2. The transmission / reception unit 600 described above includes one transceiver 30, one CAN controller 33, and one set of buffers 39. The transmission / reception unit 601 described above includes one transceiver 30, one CAN controller 34, and one set of buffer 40.

  The other CAN controller 34 transmits the signal flowing through the first communication bus 2 via the transceiver 30 while the one CAN controller 33 transmits the signal to the first communication bus 2 via the transceiver 30. Enter. The CAN controller 34 identifies the contents of the digital signal input from the transceiver 30. The routing control unit 90 transfers the digital signal to another transmission / reception unit via the buffer 40 in accordance with the contents of the digital signal.

  One CAN controller 33 outputs the digital signal transferred from the other transmitting / receiving unit to the transceiver 30 to which the CAN controller 33 is connected via the signal line Tx. The CAN controller 33 identifies the content of the digital signal input from the transceiver 30 and does not output the signal to the buffer 39 when the content is the same as the content of the signal being transmitted. The CAN controller 33 outputs the input signal to the buffer 39 when the content of the digital signal input from the transceiver 30 is different from the content of the signal being transmitted or when the signal is not being transmitted. The routing control unit 90 transfers the digital signal to another transmission / reception unit via the buffer 39 according to the contents of the digital signal output to the buffer 39.

  The second transmission / reception unit 70 receives a signal from the communication bus 3 to which the second transmission / reception unit 70 is connected, and recognizes the content of the signal. The second transmission / reception unit 70 inputs a transfer instruction according to the content of the received signal from the routing control unit 90. The second transmission / reception unit 70 selectively transfers the signal to either the first transmission / reception unit 60 or the third transmission / reception unit 80 based on the transfer instruction. The second transmitting / receiving unit 70 transmits the signals transferred from the first transmitting / receiving unit 60 and the third transmitting / receiving unit 80 to the communication bus 3 to which the second transmitting / receiving unit 70 is connected.

  The second transmission / reception unit 70 includes two transmission / reception units 700 and 701. A signal transmitted from one of the two transmission / reception units 700 and 701 (700 in the example illustrated in FIG. 10) to the communication bus 3 is transmitted / received to the other transmission / reception unit. Unit (701 in the example shown in FIG. 10) receives.

  Specifically, the second transmission / reception unit 70 includes one transceiver 31, two CAN controllers 35 and 36, and two sets of buffers 41 and 42. The transceiver 31 converts the differential analog signal input from the communication bus 3 that is a twisted pair line into a digital signal, and outputs the digital signal to both CAN controllers 35 and 36 via the signal line Rx. The transceiver 31 converts the digital signal output from one CAN controller 35 into a differential analog signal and outputs the differential analog signal to the communication bus 3. The transmission / reception unit 700 described above includes one transceiver 31, one CAN controller 35, and one set of buffers 41. The transmission / reception unit 701 described above includes one transceiver 31, one CAN controller 36, and one set of buffer 42.

  The other CAN controller 36 transmits the signal flowing through the second communication bus 3 via the transceiver 31 while the one CAN controller 35 transmits the signal to the second communication bus 3 via the transceiver 30. Enter. The CAN controller 36 identifies the contents of the digital signal input from the transceiver 31. The routing control unit 90 transfers the digital signal to another transmission / reception unit via the buffer 42 according to the content of the digital signal.

  One CAN controller 35 outputs the digital signal transferred from the other transmission / reception unit to the transceiver 31 to which the CAN controller 35 is connected via the signal line Tx. Further, the CAN controller 35 identifies the content of the digital signal input from the transceiver 31 and does not output the signal to the buffer 41 when the content is the same as the content of the signal being transmitted. The CAN controller 35 outputs the input signal to the buffer 41 when the content of the digital signal input from the transceiver 31 is different from the content of the signal being transmitted or when the signal is not being transmitted. The routing control unit 90 transfers the digital signal to another transmission / reception unit via the buffer 41 according to the contents of the digital signal output to the buffer 41.

  The third transmission / reception unit 80 receives a signal from the communication bus 4 to which the third transmission / reception unit 80 is connected, and recognizes the content of the signal. The third transmission / reception unit 80 inputs a transfer instruction according to the content of the received signal from the routing control unit 90. The third transmission / reception unit 80 selectively transfers the signal to either the first transmission / reception unit 60 or the second transmission / reception unit 70 based on the transfer instruction. Further, the third transmission / reception unit 80 transmits the signals transferred from the first transmission / reception unit 60 and the second transmission / reception unit 70 to the communication bus 4 to which the third transmission / reception unit 80 is connected.

  The third transmission / reception unit 80 includes two transmission / reception units 800 and 801, and a signal transmitted from one of the two transmission / reception units 800 and 801 (800 in the example shown in FIG. 10) to the communication bus 4 is transmitted and received by the other transmission / reception unit. Unit (801 in the example shown in FIG. 10) receives.

  Specifically, the third transmission / reception unit 80 includes one transceiver 32, two CAN controllers 37 and 38, and two sets of buffers 43 and 44. The transceiver 32 converts the differential analog signal input from the communication bus 4 which is a twisted pair line into a digital signal, and outputs the digital signal to both CAN controllers 37 and 38 via the signal line Rx. The transceiver 32 converts the digital signal output from the one CAN controller 37 into a differential analog signal, and outputs the differential analog signal to the communication bus 4. The transmission / reception unit 800 described above includes one transceiver 32, one CAN controller 37, and a set of buffers 43. The transmission / reception unit 701 described above includes one transceiver 32, one CAN controller 38, and one set of buffers 44.

  The other CAN controller 38 transmits the signal flowing through the third communication bus 4 via the transceiver 32 while the one CAN controller 37 transmits the signal to the third communication bus 4 via the transceiver 32. Enter. The CAN controller 38 identifies the contents of the digital signal input from the transceiver 32. The routing control unit 90 transfers the digital signal to another transmission / reception unit via the buffer 44 according to the contents of the digital signal.

  One CAN controller 37 outputs the digital signal transferred from the other transmitting / receiving unit to the transceiver 32 to which the CAN controller 37 is connected via the signal line Tx. Further, the CAN controller 37 identifies the content of the digital signal input from the transceiver 32 and does not output the signal to the buffer 43 when the content is the same as the content of the signal being transmitted. The CAN controller 37 outputs the input signal to the buffer 43 when the content of the digital signal input from the transceiver 32 is different from the content of the signal being transmitted or when the signal is not being transmitted. The routing control unit 90 transfers the digital signal to another transmission / reception unit via the buffer 43 according to the contents of the digital signal output to the buffer 43.

  The first transfer path 110, the second transfer path 120, and the third transfer path 130 are mutually connected so as to make a round through the first transmission / reception unit 60, the second transmission / reception unit 70, and the third transmission / reception unit 80. It is connected to the.

  The first transfer path 110 is a path that connects the first transmission / reception unit 60 and the third transmission / reception unit 80 and transfers signals between the first transmission / reception unit 60 and the third transmission / reception unit 80. The second transfer path 120 is a path that connects the first transmission / reception unit 60 and the second transmission / reception unit 70 and transfers signals between the first transmission / reception unit 60 and the second transmission / reception unit 70. The third transfer path 130 is a path that connects the second transmission / reception unit 70 and the third transmission / reception unit 80 and transfers a signal between the second transmission / reception unit 70 and the third transmission / reception unit 80.

  FIG. 11 is a diagram showing a transfer path initially scheduled for frame A in the communication network shown in FIG. FIG. 12 is a diagram showing a state in which a communication abnormality has occurred in the transfer path initially scheduled for frame A in the communication network shown in FIG. FIG. 13 is a diagram illustrating a state in which transfer is performed by switching the transfer path of the frame A in the communication network illustrated in FIG. 9. FIG. 14 is a diagram illustrating a state in which the transfer is performed by switching the transfer path of the frame A in the communication relay device illustrated in FIG. 10.

  When the communication abnormality detection unit 10 detects a communication abnormality in the transfer path, the routing control unit 90 initially detects the abnormal transfer path in which the communication abnormality is detected (the first transfer path 110 in the example shown in FIGS. 11 and 12). ) Is transferred from the transfer source (first transmission / reception unit 60 in the example shown in FIGS. 11 and 12) of the abnormal transfer path to the transfer destination (shown in FIGS. 11 and 12). In the example, the third transmission / reception unit 80) switches the transfer path so that the transfer is bypassed via a transfer path other than the abnormal transfer path (transfer paths 120 and 130 in the examples shown in FIGS. 13 and 14). Specifically, the routing control unit 90 switches the transfer path as described below, and performs signal transfer.

  When the communication abnormality detection unit 10 detects a communication abnormality in the first transfer path 110, the first transmission / reception unit 60 initially transmits the third transmission line from the first transmission / reception unit 60 via the first transfer path 110. The signal (frame) scheduled to be transferred to the transmission / reception unit 80 is transferred to the second transmission / reception unit 70 via the second transfer path 120. Next, the second transmitting / receiving unit 70 transmits the signal transferred from the first transmitting / receiving unit 60 to the communication bus 3 to which the second transmitting / receiving unit 70 is connected. Next, the second transmission / reception unit 70 receives the signal transmitted by itself, and transfers the received signal to the third transmission / reception unit 80 via the third transfer path 130. The third transmission / reception unit 80 transmits the received signal to the third communication bus 4.

  When the communication abnormality detection unit 10 detects a communication abnormality in the first transfer path 110, the third transmission / reception unit 80 initially transmits the first transfer path 110 from the third transmission / reception unit 80 via the first transfer path 110. The signal (frame) scheduled to be transferred to the transmission / reception unit 60 is transferred to the second transmission / reception unit 70 via the third transfer path 130. Next, the second transmission / reception unit 70 transmits the signal transferred from the third transmission / reception unit 80 to the communication bus 3 to which the second transmission / reception unit 70 is connected. Next, the second transmission / reception unit 70 receives the signal transmitted by itself, and transfers the received signal to the first transmission / reception unit 60 via the second transfer path 120. The first transmission / reception unit 60 transmits the received signal to the first communication bus 2.

  In addition, when the communication abnormality detection unit 10 detects a communication abnormality in the second transfer path 120, the first transmission / reception unit 60 initially starts from the first transmission / reception unit 60 via the second transfer path 120. The signal that was scheduled to be transferred to the second transmitter / receiver 70 is transferred to the third transmitter / receiver 80 via the first transfer path 110. Next, the third transmission / reception unit 80 transmits the signal transferred from the first transmission / reception unit 60 to the communication bus 4 to which the third transmission / reception unit 80 is connected. Next, the third transmission / reception unit 80 receives the signal transmitted by itself, and transfers the received signal to the second transmission / reception unit 70 via the third transfer path 130. The second transmission / reception unit 70 transmits the received signal to the second communication bus 3.

  In addition, when the communication abnormality detection unit 10 detects a communication abnormality in the second transfer path 120, the second transmission / reception unit 70 initially starts from the second transmission / reception unit 70 via the second transfer path 120. The signal that was scheduled to be transferred to one transmitter / receiver 60 is transferred to the third transmitter / receiver 80 via the third transfer path 130. Next, the third transmission / reception unit 80 transmits the signal transferred from the second transmission / reception unit 70 to the communication bus 4 to which the third transmission / reception unit 80 is connected. Next, the third transmission / reception unit 80 receives the signal transmitted by itself, and transfers the received signal to the first transmission / reception unit 60 via the first transfer path 110. The first transmission / reception unit 60 transmits the received signal to the first communication bus 2.

  When the communication abnormality detection unit 10 detects a communication abnormality in the third transfer path 130, the second transmission / reception unit 70 initially starts from the second transmission / reception unit 70 via the third transfer path 130. 3 is transferred to the first transmission / reception unit 60 via the second transfer path 120. Next, the first transmission / reception unit 60 transmits the signal transferred from the second transmission / reception unit 70 to the communication bus 2 to which the first transmission / reception unit 60 is connected. Next, the first transmission / reception unit 60 receives the signal transmitted by itself, and transfers the received signal to the third transmission / reception unit 80 via the first transfer path 110. The third transmission / reception unit 80 transmits the received signal to the third communication bus 4.

  In addition, when the communication abnormality detection unit 10 detects a communication abnormality in the third transfer path 130, the third transmission / reception unit 80 initially starts from the third transmission / reception unit 80 via the third transfer path 130. The signal that was scheduled to be transferred to the second transmitter / receiver 70 is transferred to the first transmitter / receiver 60 via the first transfer path 110. Next, the first transmission / reception unit 60 transmits the signal transferred from the third transmission / reception unit 80 to the communication bus 2 to which the first transmission / reception unit 60 is connected. Next, the first transmission / reception unit 60 receives the signal transmitted by itself, and transfers the received signal to the second transmission / reception unit 70 via the second transfer path 120. The second transmission / reception unit 70 transmits the received signal to the second communication bus 3.

  Next, the operation of the communication network 100 will be described with reference to the flowcharts of FIGS. 14 and 15. Hereinafter, a case where a signal (frame A) is sent from the electronic control unit A to the electronic control unit E will be described as an example.

  First, the electronic control unit A transmits a signal to the first transmission / reception unit 60 via the communication bus 2 (step S1). Next, the communication abnormality detection unit 10 determines whether there is a communication abnormality in the transfer path 110 (step S2). When the communication abnormality detection unit 10 determines that there is no communication abnormality in the transfer path 110, the routing control unit 90 performs the third transmission / reception with respect to the first transmission / reception unit 60 via the first transfer path 110. An instruction is given to transfer the signal to the unit 80 (step S3). Next, the first transmission / reception unit 60 transfers the signal to the third transmission / reception unit 80 via the first transfer path 110 (step S4). In step S4, specifically, one of the two transmission / reception units 600 and 601 (transmission / reception unit 600) constituting the first transmission / reception unit 60 receives a signal from the first communication bus 2, and the transmission / reception unit 600 transfers the received signal to one transmitting / receiving unit 800 constituting the third transmitting / receiving unit 80. Next, the third transmission / reception unit 80 transmits a signal to the third communication bus 4 (step S5). In step S <b> 5, specifically, one transmitting / receiving unit 800 transmits a signal to the third communication bus 4. Next, the electronic control unit E receives a signal from the third communication bus 4 (step S6).

  On the other hand, when the communication abnormality detection unit 10 determines that there is a communication abnormality in the first transfer path 110 and the signal cannot be transferred via the first transfer path 110, the routing control unit 90 The first transmitter / receiver 60 is instructed to transfer a signal to the second transmitter / receiver 70 via the second transfer path 120 (step S7). Next, the first transmission / reception unit 60 transfers the signal to the second transmission / reception unit 70 via the second transfer path 120 (step S8). In step S <b> 8, specifically, one transmission / reception unit 600 configuring the first transmission / reception unit 60 transfers the received signal to one transmission / reception unit 700 configuring the second transmission / reception unit 70. Next, the second transmission / reception unit 70 transmits a signal to the second communication bus 3 (step S9). In step S <b> 9, specifically, one transmitting / receiving unit 700 transmits a signal to the second communication bus 3.

  Next, the second transmission / reception unit 70 receives a signal from the second communication bus 3 (step S10). In step S 10, specifically, the other transmission / reception unit 701 receives a signal from the second communication bus 3. Next, the routing control unit 90 instructs the second transmission / reception unit 70 to transfer the signal to the third transmission / reception unit 80 via the third transfer path 130 (step S11). Next, the second transmission / reception unit 70 transfers the signal to the third transmission / reception unit 80 via the third transfer path 130 (step S12). Specifically, in step S <b> 12, the other transmitting / receiving unit 701 transfers a signal to one transmitting / receiving unit 800 of the third transmitting / receiving unit 8. Next, the third transmission / reception unit 80 transmits a signal to the third communication bus 4 (step S13). Specifically, in step S <b> 13, one transmission / reception unit 800 transmits a signal to the third communication bus 4. Next, the electronic control unit E receives a signal from the third communication bus 4 (step S14). The above is the operation of the communication network 100.

  According to the communication network 100, the transmission / reception unit (for example, the second transmission / reception unit 70) receives the signal transmitted to the communication bus (for example, the second communication bus 3) from the communication bus and receives another transmission / reception unit (for example, the third transmission / reception unit) To the transmission / reception unit 80). Therefore, according to the communication network 100, even if it becomes impossible to transfer a signal via a certain transfer path (for example, the first transfer path 110) due to a communication abnormality, another transfer path (for example, the second transfer path) Signals can be transferred via path 120 and third transfer path 130).

  Further, the communication network 1 has a relationship between a communication protocol (for example, the CAN protocol) and while the transmission / reception unit (for example, the second transmission / reception unit 70) transmits a signal to the communication bus (for example, the second communication bus 3). The transmission / reception unit (for example, the second transmission / reception unit 70) cannot receive a signal having the same content as the signal being transmitted and cannot transfer the signal to another transmission / reception unit (for example, the third transmission / reception unit 80). However, in the communication network 100, the transmission / reception unit (for example, the second transmission / reception unit 70) receives the transmitted signal from the communication bus (for example, the second communication bus 3) and receives other transmission / reception units (for example, the third transmission / reception unit 80). ). Therefore, according to the communication network 100, even if it becomes impossible to transfer a signal via a certain transfer path (for example, the first transfer path 110) due to a communication abnormality, another transfer path (for example, the second transfer path) Signals can be transferred via path 120 and third transfer path 130).

Next, a third embodiment of the present invention will be described with reference to the drawings.
FIG. 16 is a diagram illustrating a part of the communication network according to the third embodiment, and illustrates a state in which the switch is turned on. FIG. 17 is a diagram illustrating a part of the communication network according to the third embodiment, and illustrates a state where the switch is turned off. FIG. 18 is a diagram (corresponding to the second embodiment) showing a configuration of a communication network for comparison with the communication network shown in FIG. In addition, about the structure similar to 2nd Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The third embodiment is different from the second embodiment in that a communication relay device 51 is provided instead of the communication relay device 50. In addition to the configuration of the communication relay device 50, the communication relay device 51 includes a switch 52, a termination circuit 53, and a switch control line 54. 16 and 17, only the second transmission / reception unit 70 is illustrated and the other transmission / reception units are not illustrated for the sake of simplicity. Similarly, the switch 52, the termination circuit 53, and the switch control line 54 are connected to the other transmission / reception units.

  The switch 52 shown in FIG. 16 has a signal error via the second transfer path 120 and the third transfer path 130 in FIGS. 13 and 14 because a communication abnormality has occurred in the first transfer path 110 in FIG. In order to prevent transfer, the signal transmitted from the second transmitter / receiver 70 in FIGS. 13 and 14 to the second communication bus 3 via the transceiver 31 does not go out of the communication relay device 51. belongs to. The switch 52 can be configured by a relay, for example.

The communication bus that is a twisted pair line includes a first communication line 350 and a second communication line 351.
The termination circuit 53 generates a potential difference for signal generation on a communication bus (in the example shown in FIG. 16, the first communication line 350 and the second communication line 351) that are twisted pair lines. Termination circuit 53 includes a resistor and a capacitor. The termination circuit 53 may not have a capacitor.

  The switch control line 54 is a communication line for controlling on / off of the switch 52. A signal for controlling on / off of the switch 52 is output from the microcomputer 300 including the CAN controllers 35 and 36.

  A part of the actual communication bus 3 is drawn into the communication relay device 51. The switch 52 is provided in the portion where the communication bus 3 is drawn. When each transfer path is normal, the switch 52 is turned on (conductive state) as shown in FIG. On the other hand, because an abnormality has occurred in the first transfer path 110, the second transmission / reception unit 70 in the detour path transmits a signal as in the second embodiment, and the transmission / reception unit 70 receives the transmitted signal. In this case, the switch 52 is turned off (non-conducting state) as shown in FIG. As a result, when a signal is transferred through the detour path, the signal does not go out of the communication relay device 51 through the communication bus 3 connected to the detour path. It can be made difficult to occur. Further, since the termination circuit 53 is provided in the communication relay device 51, communication can be established even when the switch 52 is turned off.

  On the other hand, when there is no switch 52 as shown in FIG. 18, when the signal is transferred through the bypass route, the signal goes out of the communication relay device 50 through the communication bus of the bypass route. Signal collision is likely to occur on the communication bus.

Next, a fourth embodiment of the present invention will be described with reference to the drawings.
FIG. 19 is a diagram illustrating an extracted part of the communication network according to the fourth embodiment. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

The fourth embodiment is different from the first embodiment in that a function for returning a signal is provided in the communication relay device 52. In the example shown in FIG. 19, a signal return unit 55 is connected to the vicinity of the transceiver 21 of the communication bus 3. The signal reply unit 55 receives the signal output from the transceiver 21 and returns a signal having the same content as the signal to the transceiver 21. The signal is returned after the transceiver 21 finishes transmitting the signal having the same content as the signal. As a result, the transceiver 21 can receive a signal having the same content as the signal transmitted by itself and transfer it to another CAN controller.
In the example shown in FIG. 19, the signal reply unit 55 is provided only in the communication bus 3, but the signal reply unit may be provided in each of the communication buses 2, 3, and 4.

  According to the fourth embodiment, it is not necessary to provide a return function in the electronic control device connected to each communication bus.

  The present invention can be used for a communication relay device of an in-vehicle communication network.

DESCRIPTION OF SYMBOLS 1,100 Communication network 2 1st communication bus 3 2nd communication bus 4 3rd communication bus 5, 50, 51, 52 Communication relay apparatus 6 1st transmission / reception part 7 2nd transmission / reception part 8 3rd transmission / reception Unit 9 routing control unit 10 communication abnormality detection unit 11, 110 first transfer route 12, 120 second transfer route 13, 130 third transfer route 20, 21, 22, 30, 31, 32 transceivers 23, 24, 25, 33, 34, 35, 36, 37, 38 CAN controller 26, 27, 28, 39, 40, 41, 42, 43, 44 Buffer 52 Switch 53 Termination circuit 54 Switch control line 55 Signal return section

Claims (14)

Three or more communication buses are connected, and a communication relay device relays communication between the electronic control devices connected to each of the communication buses,
A plurality of transceiver units;
Multiple transfer paths,
A routing controller;
A communication abnormality detection unit,
The transmission / reception unit is provided for each communication bus, receives a signal from the communication bus to which the communication bus is connected, recognizes the content of the signal, and transfers the received signal to the other transmission / reception unit, Sending the signal transferred from the other transceiver unit to the communication bus to which it is connected,
The routing control unit controls which of the transmission / reception units the signal received by the transmission / reception unit is transferred according to the content of the signal,
The communication abnormality detection unit detects that a communication abnormality has occurred in the transfer path between the transmission and reception units,
When a communication abnormality is detected by the communication abnormality detection unit, the routing control unit initially transmits a signal that is scheduled to be transferred through the abnormal transfer path in which the communication abnormality is detected from the transfer source of the abnormal transfer path. A communication relay device that switches a transfer path so that a detour transfer is performed to the transfer destination via the transfer path other than the abnormal transfer path. The transfer path includes a first transfer path, a second transfer path, and a third transfer path that are connected to each other so as to make a round through the transceiver.
The transmission / reception unit includes: a first transmission / reception unit that connects the first transfer path and the second transfer path; a second transmission / reception unit that connects the second transfer path and the third transfer path; A third transmission / reception unit that connects the third transfer path and the first transfer path,
The electronic control unit has a reply function for returning a signal received from the communication bus to the communication bus;
When the communication abnormality detection unit detects a communication abnormality in the first transfer path,
(A) The first transmission / reception unit transmits a signal that was originally scheduled to be transferred from the first transmission / reception unit to the third transmission / reception unit via the first transfer path. Transfer to the second transmitter / receiver via a transfer path;
(B) The second transmitting / receiving unit transmits the signal transferred from the first transmitting / receiving unit to the communication bus to which the second transmitting / receiving unit is connected.
(C) When a signal having the same content as the signal transmitted by itself is returned from the electronic control unit, the second transmission / reception unit receives the returned signal, and receives the received signal as the third signal. The communication relay device according to claim 1, wherein the transfer is transferred to the third transmission / reception unit via a transfer path. When the communication abnormality detection unit detects a communication abnormality in the first transfer path, the second transmission / reception unit transmits an abnormality notification signal informing the communication abnormality to the communication bus to which the self is connected,
3. The communication relay device according to claim 2, wherein, when receiving the abnormality notification signal, the electronic control device returns a signal received thereafter to the communication bus. The transfer path includes a first transfer path, a second transfer path, and a third transfer path that are connected to each other so as to make a round through the transceiver.
The transmission / reception unit includes: a first transmission / reception unit that connects the first transfer path and the second transfer path; a second transmission / reception unit that connects the second transfer path and the third transfer path; A third transmission / reception unit that connects the third transfer path and the first transfer path,
When the communication abnormality detection unit detects a communication abnormality in the first transfer path,
(A) The first transmission / reception unit transmits a signal that was originally scheduled to be transferred from the first transmission / reception unit to the third transmission / reception unit via the first transfer path. Transfer to the second transmitter / receiver via a transfer path;
(B) The second transmitting / receiving unit transmits the signal transferred from the first transmitting / receiving unit to the communication bus to which the second transmitting / receiving unit is connected.
(C) The second transmission / reception unit receives a signal transmitted by the second transmission / reception unit, and transfers the received signal to the third transmission / reception unit via the third transfer path. The communication relay device according to 1.   The communication according to claim 4, wherein the second transmission / reception unit includes two transmission / reception units, and the other transmission / reception unit receives a signal transmitted from one of the two transmission / reception units to the communication bus. Relay device.   6. The communication relay device according to claim 1, wherein communication is performed based on a CAN (Controller Area Network) protocol. The communication relay device draws a part of the communication bus therein,
The communication relay device further includes:
When the second transmitter / receiver receives a signal transmitted from the second transmitter / receiver to the communication bus, the transmitted signal does not go out of the communication relay device via the communication bus. The communication relay device according to claim 4, further comprising: a switch that electrically disconnects the portion where the communication bus is drawn in midway. The communication relay device draws a part of the communication bus therein,
The communication relay device further includes:
When the other transmitter / receiver receives a signal transmitted by one of the two transmitter / receivers to the communication bus, the transmitted signal does not go out of the communication relay device via the communication bus. The communication relay device according to claim 5, further comprising: a switch that electrically disconnects a portion where the communication bus is drawn in midway. The communication bus is composed of a twisted pair line that includes a first communication line and a second communication line and transmits a differential signal,
The communication relay device draws a part of the twisted pair wire therein,
The communication relay device further includes:
A termination circuit connecting the first communication line and the second communication line so that the other transmission / reception unit can receive a signal transmitted from one of the two transmission / reception units to the first communication line;
When the other transmitting / receiving unit receives a signal transmitted from one of the two transmitting / receiving units to the first communication line, the transmitted signal goes out of the communication relay device via the twisted pair line. The communication relay device according to claim 5, further comprising: a switch that electrically disconnects the portion where the twisted-pair wire is drawn in midway so as not to exist. The transfer path includes a first transfer path, a second transfer path, and a third transfer path that are connected to each other so as to make a round through the transceiver.
The transmission / reception unit includes: a first transmission / reception unit that connects the first transfer path and the second transfer path; a second transmission / reception unit that connects the second transfer path and the third transfer path; A third transmission / reception unit that connects the third transfer path and the first transfer path,
The communication relay device further includes:
A signal return unit that receives a signal transmitted from the second transmission / reception unit to the communication bus and returns a signal having the same content as the received signal to the second transmission / reception unit;
When the communication abnormality detection unit detects a communication abnormality in the first transfer path,
(A) The first transmission / reception unit transmits a signal that was originally scheduled to be transferred from the first transmission / reception unit to the third transmission / reception unit via the first transfer path. Transfer to the second transmitter / receiver via a transfer path;
(B) The second transmitting / receiving unit transmits the signal transferred from the first transmitting / receiving unit to the communication bus to which the second transmitting / receiving unit is connected,
(C) When a signal having the same content as the signal transmitted by itself is returned from the signal return unit, the second transmission / reception unit receives the returned signal, and receives the received signal as the third signal. The communication relay device according to claim 1, wherein the transfer is transferred to the third transmission / reception unit via a transfer path. An electronic control device connected to a communication bus,
An electronic control device having a reply function for returning a signal received from the communication bus to the communication bus.   When there is an abnormality in the communication relay device that relays communication between the electronic control devices, and the electronic control device receives an abnormality notification signal transmitted by the communication relay device through the communication bus, the electronic control device The electronic control device according to claim 11, wherein the received signal is returned to the communication bus. A communication network comprising three or more communication buses, a communication relay device that relays communication between the electronic control devices connected to each of the communication buses, and each of the electronic control devices,
The electronic control device
While transmitting a signal to the communication bus to which it is connected, receiving a signal from the communication bus,
The communication relay device is:
A plurality of transceiver units;
A routing controller;
A communication abnormality detection unit,
The transmission / reception unit is provided for each communication bus, receives a signal from the communication bus to which the communication bus is connected, recognizes the content of the signal, and transfers the received signal to the other transmission / reception unit, Sending the signal transferred from the other transceiver unit to the communication bus to which it is connected,
The routing control unit controls which of the transmission / reception units the signal received by the transmission / reception unit is transferred according to the content of the signal,
The communication abnormality detection unit detects that a communication abnormality has occurred in the transfer path between the transmission and reception units,
When a communication abnormality is detected by the communication abnormality detection unit, the routing control unit initially transmits a signal that is scheduled to be transferred through the abnormal transfer path in which the communication abnormality is detected from the transfer source of the abnormal transfer path. A communication network, wherein a transfer path is switched so that a detour transfer is performed to the transfer destination via the transfer path other than the abnormal transfer path. A communication relay method for relaying communication between electronic control devices respectively connected to three or more communication buses,
Sending and receiving steps;
A routing control step;
A communication abnormality detection step,
The transmission / reception step is executed by a transmission / reception unit provided for each communication bus. Each of the transmission / reception units receives a signal from the communication bus, recognizes the content of the signal, and transmits the received signal to another transmission / reception unit. While transmitting the signal transferred from the other transceiver unit to the communication bus to which it is connected,
The routing control step controls which of the transmission / reception units the signal received by the transmission / reception unit is transferred according to the content of the signal,
The communication abnormality detection step detects that a communication abnormality has occurred in the transfer path between the transmission and reception units,
In the routing control step, when a communication error is detected in the communication error detection step, a signal that was originally scheduled to be transferred on the abnormal transfer path in which the communication error was detected is transferred from the transfer source of the abnormal transfer path. A communication relay method, wherein a transfer path is switched so that a detour transfer is performed to the transfer destination via the transfer path other than the abnormal transfer path.

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