JP5949538B2 - Relay device, communication system, and communication method - Google Patents

Description

  The present invention relates to a communication system.

  In many cases, a vehicle-mounted network is configured in a vehicle to perform various controls in the vehicle. The in-vehicle network is realized by connecting many electronic control units (ECUs), sensors, actuators, and the like to the LAN. Hereinafter, electronic control units, sensors, actuators, and the like connected to the in-vehicle network are referred to as communication nodes. The communication node is installed at various positions in the vehicle. Communication nodes are connected by communication lines or electric wires.

  For example, an in-vehicle network is configured by connecting a plurality of communication nodes to a data bus. The in-vehicle network includes CAN (Controller Area Network) and LIN (Local Interconnect Network). Further, the in-vehicle network may include one that performs communication according to FlexRay (registered trademark).

  A connector (DLC: Data Link Connector) for connecting a device from the outside is mounted on the vehicle. By connecting various tools to this connector, the tool and the in-vehicle network can be connected. A communication node included in the in-vehicle network has a plurality of operation modes. The operation mode includes a normal mode and a low voltage mode. In the normal mode, the communication node can communicate with other communication nodes. In the low voltage mode, the communication node cannot communicate with other communication nodes, but can transition to the normal mode by a predetermined event.

  When communication is started by the tool, the communication node having the gateway function changes the communication node from the low voltage mode to the normal mode.

  If it is determined that the request frequency for the in-vehicle LAN is out of the normal request frequency or the request interval for the in-vehicle LAN is out of the normal request interval, and it is determined that the request is non-regular, battery protection A technique for setting the mode is known (see, for example, Patent Document 1).

JP 2006-315585 A

  There are various tools from high quality to low quality tools. When a low quality tool is connected to the data link connector, noise may be input from the tool to a communication node having a gateway function. A communication node having a gateway function may erroneously determine noise as a signal and cause the communication node to transition from the low voltage mode to the normal mode. However, since it is actually noise, the communication node often transitions from the normal mode to the low voltage mode after a while.

  However, when an instruction to shift from the low voltage mode to the normal mode is repeatedly executed from the communication node having the gateway function to the communication node, the communication node cannot shift to the low voltage mode. Since the communication node cannot shift to the low voltage mode, the power consumption increases and the battery is increased.

  Accordingly, an object of the present invention is to reduce erroneous transition of the electronic control unit from the low voltage mode to the normal mode.

A relay device according to an embodiment of the disclosure is:
A relay device that relays communication between a tool outside the vehicle and the electronic control unit,
State determination for detecting the potential of a bus connected to the tool outside the vehicle and determining whether the state of the tool outside the vehicle is abnormal based on the number of changes in the potential of the bus during a predetermined time And
An operation mode control unit for controlling an operation mode of the electronic control unit,
The operation mode control unit, when the state of the vehicle outside of the tool is determined to be abnormal by said state determination unit, stops the control for shifting the electronic control unit to a state capable of the communication.

The disclosed communication system is:
A communication system having an electronic control unit and a relay device that relays communication between the electronic control unit and a tool outside the vehicle,
The relay device is
State determination for detecting the potential of a bus connected to the tool outside the vehicle and determining whether the state of the tool outside the vehicle is abnormal based on the number of changes in the potential of the bus during a predetermined time And
A first operation mode control unit for controlling an operation mode of the electronic control unit;
Said first operation mode control unit, when by the state determination unit is a state of the vehicle outside of the tool is determined to be abnormal, and stops the control for shifting the electronic control unit to a state that can the communication ,
The electronic control unit is
A second operation mode control unit configured to control an operation mode of the electronic control unit in accordance with control by the first operation mode control unit;

The communication control method disclosed is
A communication control method in a relay device that relays communication between a tool outside a vehicle and an electronic control unit,
Detecting the potential of the bus connected to the tool outside the vehicle, and determining whether the state of the tool outside the vehicle is abnormal based on the number of changes in the potential of the bus in a predetermined time ;
In controlling an operation mode of the electronic control unit, when the state of the vehicle outside of the tool is abnormal, it stops the control for shifting the electronic control unit to a state capable of the communication.

The communication control method disclosed is
A communication control method in a communication system having an electronic control unit and a relay device that relays communication between the electronic control unit and a tool outside the vehicle,
The relay device is
Detecting the potential of the bus connected to the tool outside the vehicle, and determining whether the state of the tool outside the vehicle is abnormal based on the number of changes in the potential of the bus in a predetermined time ;
In controlling an operation mode of the electronic control unit, when the state of the vehicle outside of the tool is determined to be abnormal, and stops the control for shifting the electronic control unit to a state capable of the communication,
The electronic control unit is
The operation mode of the electronic control unit is controlled according to the control by the relay device.

  According to the disclosed embodiment, it is possible to reduce erroneous transition of the electronic control unit from the low voltage mode to the normal mode.

It is a figure which shows one Example of a communication system. It is a figure which shows one Example of a 1st communication node. It is a functional block diagram which shows one Example of a 1st communication node. It is a figure which shows one Example of the electric potential detected at the time of a communication start. It is a figure which shows one Example of a 2nd communication node. It is a functional block diagram which shows one Example of a 2nd communication node. It is a flowchart which shows one Example of operation | movement of a communication system. It is a flowchart which shows one Example of operation | movement of a communication system.

Next, the form for implementing this invention is demonstrated, referring drawings based on the following Examples.
In all the drawings for explaining the embodiments, the same reference numerals are used for those having the same function, and repeated explanation is omitted.

<Example>
<Communication system>
FIG. 1 shows an embodiment of a communication system.

The communication system includes a first communication node 100 and a second communication node 200 _n (n is an integer where n> 0). FIG. 1 shows an example where n = 6. The value of n can be changed as appropriate. The first communication node 100 and the second communication node 200 _n are mounted on a moving body such as a vehicle. In one embodiment of the communication system, the first communication node 100 and the second communication node 200 _n are mounted on a vehicle and constitute an in-vehicle LAN. The in-vehicle LAN includes LIN (Local Interconnect Network), CAN (Controller Area Network), FlexRay, and Ethernet (registered trademark). The first communication node 100 may function as a master node, and the second communication node 200 _n may function as a slave node.

  In addition, an external device connecting connector 500 is mounted on the vehicle. The external device connection connector 500 includes a data link connector (DLC).

Between the first communication node 100 and the second communication node 200 _n and between the first communication node 100 and the external device connection connector 500, a bus 300 _m (m is an integer of m> 0). Wired connection. FIG. 1 shows a case where m = 4 as an example. The value of m, the number of the external device connecting connector 500 can be appropriately changed depending on the number of the second communication node 200 _n.

The first communication node 100 is preferably realized by an electronic control unit or the like. In addition, the first communication node 100 may include a sensor, an actuator, and the like. The second communication node 200 _n may be realized by an electronic control unit, or may be realized by a sensor, an actuator, or the like. For example, the first communication node 100 may include an air conditioner control function, and the second communication node 200 _n may include a temperature sensor or the like.

  In some cases, the first communication node 100 includes a plurality of systems. For example, the first communication node 100 may communicate with another first communication node (not shown). Further, the first communication node 100 may execute control of the system.

In the example shown in FIG. 1, the first communication node 100 is connected to the second communication node 200 ₁ and 200 ₂ via the bus 300 _1. The first communication node 100 is connected to the second communication node 200 ₃ and 200 ₄ via the bus 300 _2. The first communication node 100 is connected to the second communication node 200 ₅ and 200 ₆ via the bus 300 _3.

The first communication node 100 is connected to an external device connecting connector 500 via a bus 300 _4.

  Various tools such as a diagnostic machine 400 are connected to the external device connecting connector 500 from the outside of the vehicle. The diagnostic machine 400 includes, for example, a failure location detection device. The failure location detection device may be configured by a failure determination tool outside the vehicle. The failure determination tool includes a diagnosis tool of the service unit.

  In one embodiment of the communication system, a case where the diagnostic device 400 is connected to the external device connection connector 500 will be described. The same applies when a tool other than the diagnostic machine 400 is connected.

  One embodiment of the diagnostic machine 400 is connected to the communication system via the external device connection connector 500. The diagnostic machine 400 includes an interface (I / F) 402 and a CPU 404.

The interface 402 receives data from the first communication node 100. For example, the interface 402 receives data stored in the first communication node 100. Further, the interface 402 receives data stored in the second communication node 200 _n via the first communication node 100. The interface 402 inputs the received data to the CPU 404.

  The CPU 404 is connected to the interface 402. The CPU 404 performs predetermined processing on data from the interface 402. The CPU 404 may execute processing for outputting data from the interface 402.

The first communication node 100 has a function as a gateway (GW) that relays communication between the second communication node 200 _n and the diagnostic device 400. The first communication node 100 may be called a relay device.

The first communication node 100 determines whether or not the diagnostic device 400 connected via the external device connection connector 500 is normal. If the first communication node 100 determines that the diagnostic device 400 is normal, the first communication node 100 shifts the second communication node 200 _n from the power saving mode to the normal mode. If the first communication node 100 determines that the diagnostic device 400 is not normal, that is, is abnormal, the first communication node 100 does not shift the second communication node 200 _n to the normal mode.

After the second communication node 200 _n transitions to the normal mode, communication is started between the first communication node 100 and the diagnostic machine 400.

  The first communication node 100 preferably determines that an abnormality has occurred in the diagnostic machine 400 when data from the diagnostic machine 400 is not received after detecting the start of communication with the diagnostic machine 400. For example, the first communication node 100 determines that an abnormality has occurred in the diagnostic device 400 when data from the diagnostic device 400 is not received even after a certain period of time has elapsed after detecting the start of communication. It is preferable to do this. This is because the diagnostic machine 400 is often set to transmit data within a certain time after communication is started. The first communication node 100 receives data from the diagnostic machine 400 within a certain time after detecting the start of communication.

  Further, after detecting the start of communication, the first communication node 100 has detected an abnormality in the diagnostic device 400 when the data has not been received from the diagnostic device 400 for a predetermined number of times even after a predetermined time has elapsed. It is preferable to judge that. In this case, the first communication device 100 has a counter (hereinafter referred to as “abnormality detection counter”) that counts the number of times data has not been received from the diagnostic device 400 even after a predetermined time has elapsed since the start of communication. Is preferred. If the first communication node 100 determines that the value of the abnormality detection counter is equal to or greater than the abnormality detection threshold, the first communication node 100 determines that the state of the diagnostic machine 400 is abnormal. The abnormality detection threshold is preferably set in advance. As described above, by determining that an abnormality has occurred when data has not been received for a predetermined number of times, the influence of erroneous detection can be reduced, so that reliability can be improved.

  In addition, it is not preferable that the state in which the diagnostic device 400 is determined to be abnormal by the first communication device 100 continues. For this reason, it is preferable to return to a state before the diagnosis device 400 is determined to be abnormal by using some event as a trigger. For example, when a vehicle equipped with a communication system starts traveling and power supply to the battery is started, the vehicle may be returned.

<First communication node 100>
FIG. 2 shows an embodiment of the first communication node 100. FIG. 2 mainly shows the hardware configuration of the first communication node 100.

  The first communication node 100 includes a microcontroller (Micro-Control Unit) 102, a first transceiver 112, a second transceiver 114, a third transceiver 116, and a fourth transceiver 118.

  The first communication node 100 may have 2-3 transceivers, or may have 5 or more transceivers. The reason why the number is two or more is that a transceiver connected to the external device connection connector 500 and a transceiver connected to one second communication node are necessary.

  Further, the first communication node 100 may include two or more microcontrollers.

  The microcontroller 102 includes a first communication device 104, a second communication device 106, a third communication device 108, and a fourth communication device 110.

The first communication device 104 is connected to the first transceiver 112 via a reception (RxD) bus and a transmission (TxD) bus. The first transceiver 112 is connected to the second communication device 200 ₁ and 200 ₂ and via the bus 300 _1. The first communication device 104 transmits and receives data via the first transceiver 112. The first communication device 104 may perform serial communication. As an example of the first communication device 104, CAN is applied.

The second communication device 106 is connected to the second transceiver 114 via a reception (RxD) bus and a transmission (TxD) bus. The second transceiver 114 is connected to the second communication apparatus 200 ₃ and 200 ₄ via the bus 300 _2. The second communication device 106 transmits and receives data via the second transceiver 114. The second communication device 106 may execute serial communication. As an example of the second communication device 106, CAN is applied.

The third communication device 108 is connected to the third transceiver 116 via a reception (RxD) bus and a transmission (TxD) bus. The third transceiver 116 is connected to the second communication apparatus 200 ₅ and 200 ₆ via the bus 300 _3. The third communication device 108 transmits and receives data via the third transceiver 116. The third communication device 108 may execute serial communication. As an example of the third communication device 108, CAN is applied.

The fourth communication device 110 is connected to the fourth transceiver 118 via a reception (RxD) bus and a transmission (TxD) bus. The fourth transceiver 118 is connected to an external device connecting connector 500 via a bus 300 _4. The fourth communication device 110 transmits and receives data via the fourth transceiver 118. The fourth communication device 110 may perform serial communication. As an example of the fourth communication device 118, CAN is applied.

The microcontroller 102 determines whether or not the diagnostic machine 400 connected to the external device connection connector 500 is normal. If the microcontroller 102 determines that the diagnostic device 400 is normal, the microcontroller 102 transitions the second communication node 200 _n from the power saving mode to the normal mode. If the microcontroller 102 determines that the diagnostic machine 400 is not normal, the microcontroller 102 stops the control for transitioning the second communication node 200 _n from the power saving mode to the normal mode. That is, if the microcontroller 102 determines that the diagnostic device 400 is not normal, the microcontroller 102 does not transition the second communication node 200 _n from the power saving mode to the normal mode.

<Function of First Communication Device 100>
FIG. 3 is a functional block diagram illustrating an embodiment of the first communication device 100. The functions represented by the functional block diagram of FIG. 3 are mainly executed by the microcontroller 102. That is, the microcontroller 102 functions as a state determination unit 302, an operation mode control unit 304, and an abnormality detection counter 306.

  It is preferable that the function as the state determination unit 302, the operation mode control unit 304, and the abnormality detection counter 306 is executed by the microcontroller 102 in accordance with an application (firmware) stored in the microcontroller 102. Further, the functions as the state determination unit 302, the operation mode control unit 304, and the abnormality detection counter 306 may be executed by the microcontroller 102 according to the application stored in the storage unit (not shown).

The state determination unit 302 determines the state of the diagnostic machine 400 connected to the external device connection connector 500. For example, state determination unit 302, based on the change in the potential of the bus 300 _4, preferably to determine the status of the diagnostic device 400. For example, the voltage on the bus 300 ₄ is applied by the diagnostic device 400, the voltage from the fourth transceiver 118, via the bus for receiving (RxD), it is transmitted to the fourth communication device 110.

State determining unit 302 detects the fourth transmission potentials of the bus 300 ₄ to the communication device 110. The state determination unit 302 determines the state of the diagnostic machine 400 based on the change in the potential. State determining unit 302 determines that when the potential of the bus 300 ₄ is substantially constant, the diagnostic device 400 is normal. State determining unit 302, the number of changes of the potential of the bus 300 ₄ in a predetermined time threshold (hereinafter, "number of changes threshold" hereinafter) is equal to or greater than, determines that the diagnostic apparatus 400 is not normal. The state determination unit 302, if the number of changes in the potential of the path 300 ₄ at a given time is less than the number of changes the threshold, determines that the diagnostic apparatus 400 is normal. For example, it is preferable that a threshold value for potential fluctuation is set in advance, and the state determination unit 302 determines that the potential has been changed when the change in potential exceeds the threshold value.

Figure 4 illustrates one embodiment of a potential detected from the bus 300 ₄ When the communication is started between the diagnostic device 400.

If the communication is initiated by the diagnostic apparatus 400, the potential of the bus 300 ₄ becomes the predetermined time substantially constant. State determining unit 302, when the potential of time after detecting that the communication has started a predetermined bus 300 ₄ detects that a substantially constant, the operation mode control unit 304, communication is started Notify that.

On the other hand, and if the diagnosis unit 400 has failed, when the noise is generated, the potential of the bus 300 ₄ varies predetermined time. State determining unit 302, when the potential of the predetermined since it is detected that the communication has started time bus 300 ₄ fluctuates, the operation mode control unit 304 does not notify that communication has started. In other words, the state determining unit 302, when the potential of time after detecting that the communication has started a predetermined bus 300 ₄ fluctuates waits.

In addition, the state determination unit 302 does not receive data from the diagnostic device 400 even after the second communication node 200 _n has been _switched to the normal mode, even after a certain period of time has elapsed since the start of communication. Then, the value of the abnormality detection counter 306 is counted up. The state determination unit 302 preferably determines that the state of the diagnostic device 400 has become abnormal when the value of the abnormality detection counter 306 is equal to or greater than the abnormality detection threshold. When it is determined that the state of the diagnostic machine 400 has become abnormal, the state determination unit 302 preferably notifies the operation mode control unit 304 that an abnormal state has occurred.

In addition, information indicating the vehicle state (hereinafter referred to as “vehicle state information”) is input to the state determination unit 302. The vehicle state information includes a traveling state, a stopped state, that the ACC is turned on, and the like. The state determination unit 302 resets the determination result of the diagnosis device 400 when vehicle state information indicating that the diagnosis device 400 is in a traveling state is input after determining that the diagnosis device 400 is abnormal. Also, the value of the abnormality detection counter 306 is reset. By doing in this way, the diagnostic result of the diagnostic machine 400 is maintained, and it can be prevented that the second communication node 200 _n is continuously maintained in the low voltage mode.

  The abnormality detection counter 306 is connected to the state determination unit 302. The abnormality detection counter 306 counts the number of times that data from the diagnostic device 400 is not received even after a predetermined time has elapsed since the start of communication.

The operation mode control unit 304 is connected to the state determination unit 302. The operation mode control unit 304 transitions the second communication node 200 _n to the normal mode when notified from the state determination unit 302 that communication has started. Operation mode control unit 304, the first communication device 104, the second communication device 106, the third communication device 108, it is preferable to transmit the potential of the bus 300 _4.

The potential of the bus 300 ₄ is transmitted through the transmission (TxD) bus from the first communication device 104 to the first transceiver 112. Furthermore, the potential of the bus 300 ₄ is transmitted from the first transceiver 112 bus 300 ₁ to the second communication node 200 ₁ and 200 ₂ via the.

The potential of the bus 300 ₄ is transmitted from the second communication device 106 to the second transceiver 114 via a transmission (TxD) bus. Furthermore, the potential of the bus 300 ₄ is transmitted from the second transceiver 114 via the bus 300 ₂ to the second communication node 200 ₃ and 200 _4.

The potential of the bus 300 ₄ is transmitted through the transmission (TxD) bus from the third communication device 108 to the second transceiver 116. Furthermore, the potential of the bus 300 ₄ is transmitted from the third transceiver 116 via the bus 300 ₃ to the second communication node 200 ₅ and 200 _6.

The second communication nodes 200 ₁ and 200 ₂ detect the potential of the bus 300 ₁ and make a transition from the low voltage mode to the normal mode based on the potential. The second communication node 200 ₃ and 200 ₄ detects the potential of the bus 300 _2, based on said potential transitions from a low voltage mode to the normal mode. The second communication node 200 ₅ and 200 ₆ detects the potential of the bus 300 _3, based on said potential transitions from a low voltage mode to the normal mode.

Further, the operation mode control unit 304 transitions the second communication node 200 _n from the normal mode to the low voltage mode when notified from the state determination unit 302 that an abnormal state has occurred. It is preferable that the operation mode control unit 304 transmits a command to make a transition to the low voltage mode to the first communication device 104, the second communication device 106, and the third communication device 108.

The command to transition to the low voltage mode is transmitted from the first communication device 104 to the first transceiver 112 via a transmission (TxD) bus. Further, instructions to transition to the low voltage mode is transmitted from the first transceiver 112 bus 300 ₁ to the second communication node 200 ₁ and 200 ₂ via the.

The command to transition to the low voltage mode is transmitted from the second communication device 106 to the second transceiver 114 via a transmission (TxD) bus. Further, instructions to transition to the low voltage mode is transmitted from the second transceiver 114 via the bus 300 ₂ to the second communication node 200 ₃ and 200 _4.

The command to transition to the low voltage mode is transmitted from the third communication device 108 to the second transceiver 116 via the transmission (TxD) bus. Further, instructions to transition to the low voltage mode is transmitted from the third transceiver 116 via the bus 300 ₃ to the second communication node 200 ₅ and 200 _6.

The second communication node 200 ₁ and 200 ₂ detects an instruction to transition to the low-voltage mode, based on the instruction to transition to the low voltage mode, the transition from the normal mode to the low-voltage mode. The second communication nodes 200 ₃ and 200 ₄ detect an instruction to transition to the low voltage mode, and transition from the normal mode to the low voltage mode based on the instruction to transition to the low voltage mode. The second communication nodes 200 ₅ and 200 ₆ detect an instruction to transition to the low voltage mode, and transition from the normal mode to the low voltage mode based on the instruction to transition to the low voltage mode.

<Second communication node 200 _n >
Figure 5 shows an example of a second communication node 200 _n. FIG. 2 mainly shows the hardware configuration of the second communication node 200 _n .

The second communication node 200 _n includes a microcontroller 202 and a transceiver 206.

The microcontroller 202 has a communication device 204. The microcontroller 202 is connected to the bus 300 _m via the transceiver 206. The microcontroller 202 controls the state of the second communication node 200 _n itself. In addition, the microcontroller 202 executes control for transmitting and receiving data.

  The communication device 204 transmits and receives data via the transceiver 206. The communication device 204 may execute serial communication. As an example of the communication device 204, CAN is applied.

The transceiver 206 is connected to the communication device 204 via a transmission (TxD) bus and a reception (RxD) bus. The transceiver 206 transmits a transmission request and data from the communication device 204 to the bus 300 _m . In addition, the transceiver 206 detects the potential of the bus 300 _m and notifies the communication device 204 of it. The transceiver 206 receives data from the first communication device 100 and inputs the data to the communication device 204.

<Second communication node 200 _n functions>
An example of the function of the second communication node 200 _n will be described.

FIG. 6 is a functional block diagram showing an example of the function of the second communication node 200 _n . The functions represented by this functional block diagram are mainly executed by the microcontroller 202. For example, the microcontroller 202 may be executed by operating according to a program such as firmware.

  The microcontroller 202 functions as the operation mode control unit 602.

The operation mode control unit 602 is connected to the communication device 204. The operation mode control unit 602 controls the operation mode of the second communication node 200 _n . The operation mode includes a normal mode and a low voltage mode. The operation mode control unit 602 is notified of the potential of the bus 300 _m detected by the transceiver 206 from the communication device 204. The operation mode control unit 602 controls the operation mode from the low voltage mode to the normal mode based on the potential of the bus 300 _m .

  Further, the operation mode control unit 602 controls the operation mode from the normal mode to the low voltage mode based on a command for transition to the low voltage mode.

<Operation of communication system (1)>
FIG. 7 shows an embodiment of the operation of the communication system. FIG. 7 mainly shows the operation of the first communication node 100.

FIG. 7 shows an operation when determining whether or not the diagnostic machine 400 is in an abnormal state.
In one embodiment of the operation of the communication system, the first communication node 100 and the second communication node 200 _n are in the low voltage mode.

  In step S <b> 702, the first communication node 100 determines whether or not the diagnostic machine 400 detects that communication has started. When it is determined that the diagnosis machine 400 does not detect that communication has started, the process returns to step S702.

  In step S704, when the first communication node 100 detects that communication is started by the diagnostic machine 400, the first communication node 100 determines whether the state of the diagnostic machine 400 is normal. If it is determined that the state of the diagnostic machine 400 is not normal, the process ends.

In step S706, when it is determined that the state of the diagnostic machine 400 is normal, the first communication node 100 shifts the communication system to the normal mode. That is, the first communication node 100 shifts the second communication node 200 _n from the low voltage mode to the normal mode. From the low voltage mode to the normal mode, by shifting the second communication node 200 _n, the second communication node 200 _n may perform the communication.

  In step S708, the first communication node 100 determines whether data has been received from the diagnostic machine 400.

  In step S710, when it is determined that data is not received from the diagnostic machine 400, the first communication node 100 determines whether or not a certain time has elapsed since the start of communication. If it is determined that a certain time has not elapsed since the start of communication, the process returns to step S708.

  In step S712, when it is determined in step S710 that a certain time has elapsed from the start of communication, the first communication node 100 increases the count of the abnormality detection counter 306.

  In step S714, the first communication node 100 determines whether or not the abnormality detection counter 306 is greater than or equal to the abnormality detection threshold. If the abnormality detection counter 306 determines that it is not greater than or equal to the abnormality detection threshold, the process ends.

  In step S716, when it is determined in step S714 that the abnormality detection counter 306 is greater than or equal to the abnormality detection threshold, the first communication node 100 determines that the diagnostic machine 400 is in an abnormal state.

  In step S718, if it is determined in step S708 that data has been received from the diagnostic machine 400, the first communication node 100 clears the abnormality detection counter 306 and ends.

<Operation of communication system (2)>
FIG. 8 shows an embodiment of the operation of the communication system. FIG. 8 mainly shows the operation of the first communication node 100.

  FIG. 7 shows an operation when the state in which the diagnostic machine 400 is determined to be in an abnormal state is returned to the initial state.

  In step S802, the first communication node 100 determines whether or not the vehicle is traveling. If it is not determined that the vehicle is traveling, the process returns to step S802.

  In step S804, when it is determined in step S802 that the vehicle is traveling, the first communication node 100 clears the abnormality detection counter 306.

  In step S806, the state where diagnostic device 400 is determined to be in an abnormal state is returned to a normal state.

  In the flowchart shown in FIG. 8, the process in step S804 and the process in step S806 may be interchanged.

According to one embodiment of the communication system, even if it is detected that the communication is started, when a change in the potential of the bus 300 ₄ is detected during from the start of communication of the predetermined time, the operation mode control unit for 304 to communication that has been started is not notified, the second communication node ₂₀₀ 1 -200 ₆ are not transition to the normal mode. Therefore, even if it is erroneously detected that communication has been started due to a failure of the diagnostic machine 400 or noise, it can be determined whether or not communication has actually started from the diagnostic machine 400 based on the subsequent potential change. . For this reason, it is possible to reduce the erroneous transition of the communication node from the low voltage mode to the normal mode. Since it is possible to reduce the erroneous transition of the communication node to the normal mode, it is possible to reduce the battery exhaustion caused by the cause.

Furthermore, even after transitions the communication node from the low voltage mode to the normal mode, if the diagnostic device 400 is abnormal shifts the second communication node 200 ₁ -200 ₆ to the low voltage mode. The second communication node ₂₀₀ 1 -200 ₆ can reduce the power consumption by transitioning to a low voltage mode. For this reason, it is possible to reduce battery exhaustion caused by this.

  Although the present invention has been described above with reference to specific embodiments and modifications, each embodiment and modification is merely illustrative, and those skilled in the art will recognize various modifications, modifications, alternatives, and substitutions. You will understand examples. For convenience of explanation, an apparatus according to an embodiment of the present invention has been described using a functional block diagram, but such an apparatus may be implemented in hardware, software, or a combination thereof. The present invention is not limited to the above-described embodiments, and various variations, modifications, alternatives, substitutions, and the like are included without departing from the spirit of the present invention.

100 First communication node 200 _n (n is an integer of n> 1) Second communication node 300 _m (m is an integer of n> 1) Bus 400 Diagnostic machine 500 Connector for connecting external device

Claims (8)

A relay device that relays communication between a tool outside the vehicle and the electronic control unit,
State determination for detecting the potential of a bus connected to the tool outside the vehicle and determining whether the state of the tool outside the vehicle is abnormal based on the number of changes in the potential of the bus during a predetermined time And
An operation mode control unit for controlling an operation mode of the electronic control unit,
The operation mode control unit, when the state of the vehicle outside of the tool is determined to be abnormal by said state determination unit, stops the control for shifting the electronic control unit to a state capable of the communication relay apparatus . The relay device according to claim 1, wherein the operation mode control unit determines that the state of the tool outside the vehicle is abnormal when the number of changes of the bus in the predetermined time is equal to or greater than a threshold value . The operation mode control unit, when the state of the vehicle outside of the tool is determined to be normal by the status determination unit shifts the electronic control unit to a state capable of the communication, to claim 1 or 2 The relay device described. The state determination unit is configured by the operation mode control unit the electronic control unit is a control run for shifting to a state where it is the communication, the communication is started between the vehicle external tool and said electronic control unit The determination of whether or not the state of the tool outside the vehicle is abnormal based on the number of times that data from the tool outside the vehicle is not received even after a predetermined time has elapsed Relay device.   The relay according to any one of claims 1 to 4, wherein the state determination unit determines whether or not to clear a determination result of a state of the tool outside the vehicle based on information indicating a state of the vehicle. apparatus. A communication system having an electronic control unit and a relay device that relays communication between the electronic control unit and a tool outside the vehicle,
The relay device is
State determination for detecting the potential of a bus connected to the tool outside the vehicle and determining whether the state of the tool outside the vehicle is abnormal based on the number of changes in the potential of the bus during a predetermined time And
A first operation mode control unit for controlling an operation mode of the electronic control unit;
Said first operation mode control unit, when by the state determination unit is a state of the vehicle outside of the tool is determined to be abnormal, and stops the control for shifting the electronic control unit to a state that can the communication ,
The electronic control unit is
A communication system comprising: a second operation mode control unit that controls an operation mode of the electronic control unit according to control by the first operation mode control unit. A communication control method in a relay device that relays communication between a tool outside a vehicle and an electronic control unit,
Detecting the potential of the bus connected to the tool outside the vehicle, and determining whether the state of the tool outside the vehicle is abnormal based on the number of changes in the potential of the bus in a predetermined time ;
In controlling an operation mode of the electronic control unit, wherein when the state of the vehicle external tool is abnormal, stops the control for shifting the electronic control unit to a state capable of the communication, communication control Method. A communication control method in a communication system having an electronic control unit and a relay device that relays communication between the electronic control unit and a tool outside the vehicle,
The relay device is
Detecting the potential of the bus connected to the tool outside the vehicle, and determining whether the state of the tool outside the vehicle is abnormal based on the number of changes in the potential of the bus in a predetermined time ;
In controlling an operation mode of the electronic control unit, when the state of the vehicle outside of the tool is determined to be abnormal, and stops the control for shifting the electronic control unit to a state capable of the communication,
The electronic control unit is
A communication control method for controlling an operation mode of the electronic control unit according to control by the relay device.

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