JP4698632B2 - Gateway device and control method thereof - Google Patents

Description

  The present invention relates to a gateway device that relays data communication between a plurality of network buses and a control method therefor, and in particular, a plurality of driver circuits that are provided for each network bus and perform data transmission / reception with the network buses connected thereto. And a control method for relaying data transmission / reception between the network buses via the driver circuit and a control method therefor.

  2. Description of the Related Art In recent years, vehicles such as automobiles are equipped with various sensors and electronic control units (ECUs) for electronically controlling the operation of the vehicle. These electronic devices are connected by an in-vehicle LAN (Local Area Network) to transmit / receive data such as a vehicle state and a control amount to each other, and cooperate to control operations of various actuators.

  Such an in-vehicle LAN has various systems for each control target, and various sensors and ECUs are connected to a network bus for each system. For example, an engine control ECU, a transmission ECU, and the like are connected to a powertrain network bus. The body network bus is connected to an air conditioner, a power window, a door security ECU, and the like. Furthermore, a follow-up travel control ECU, an airbag control ECU, and the like are connected to the safety network bus. The network bus for each system employs a communication protocol suitable for the specifications required for each control. Therefore, between the network buses of different systems, the gateway device relays data communication so that data is shared with each other. FIG. 1 is a diagram illustrating a general configuration of such a gateway device.

  FIG. 1 shows, as an example, a gateway device 1 having driver circuits 16, 18, and 20 that are connected to different network buses and perform data communication with each network bus. The data communication between the network buses is relayed by the control unit 14 via the driver circuit. The power consumed by the driver circuits 16 to 20 and the control unit 14 is supplied by the regulator circuit 12. The regulator circuit 12 is configured to be supplied with power from the battery 2 through the constant power line S1. Thus, the regulator circuit 12 can supply the power necessary for data communication to the control unit 14 and the driver circuits 16 to 20 at a constant voltage.

  In addition, the control unit 14 acquires an on / off signal of the ignition switch 3 via the signal line S2, and enters the sleep state in order to prevent the battery 2 from being consumed when the ignition switch 3 is off. When the data communication relay is necessary during the sleep, the control unit 14 is activated by a wake-up signal from the driver circuits 16 to 20 and relays the data communication. When the ignition switch 3 is turned on, the control unit 14 is activated to enter a standby state for data communication relay, and relays the data communication every time data communication occurs between the network buses.

  By the way, the gateway device 1 that is indispensable for data communication between the network buses must have a fail-safe function when power supply is abnormal. As an example of a system having a fail-safe function when power supply is abnormal, a system that has a plurality of power supply lines and uses a sub power supply line when an abnormality occurs in the main power supply line is disclosed in Patent Document 1 (for example, paragraph 0027). It is described in.

In this regard, in the conventional gateway device 1, the provision of a backup power supply line that can supply power to the regulator circuit 12 when the power supply line S1 is disconnected leads to an increase in circuit scale and high cost. Therefore, a proposal has been made to draw the signal line S2 for obtaining the on / off signal of the ignition switch 3 into the regulator circuit 12 as a power supply line. Thus, the regulator circuit 12 can receive power from the power supply line S1 when the ignition switch 3 is off, and from both the power supply lines S1 and S2 when the ignition switch 3 is on. When the power supply line S1 is disconnected, the signal line S2 functions as the backup power supply line S2 by turning on the ignition switch 3.
Special table 2003-527804

  However, the conventional gateway device 1 configured as described above has the following problems. In recent years, the number of electronic devices mounted on vehicles has increased, and as a result, the number of network buses relayed by gateway devices tends to increase. For this reason, the number of driver circuits provided in the gateway device 1, that is, the electrical load on the regulator circuit 12 tends to increase.

  Here, in the gateway device 1, a diode D <b> 1 is provided in the power supply line S <b> 1 so that a current does not flow backward when the battery 2 is reversely connected, and the same purpose diode D <b> 2 is provided in the power supply line S <b> 2. Further, a diode D3 is provided between the power supply lines S1 and S2 for preventing a current from flowing backward from the power supply line S1 side to the control unit. Then, when the power supply line S1 is disconnected while the electrical load of the regulator circuit 12 is increased, power is supplied to the regulator circuit 12 from the power supply line S2, so that the current flowing through the power supply line S2 increases. That is, since the current flowing through the diodes D2 and D3 increases, a diode having a large rated current that can withstand the load is required. However, by doing so, the circuit scale is increased and the cost is increased.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a gateway device that can secure a backup power supply line without increasing the circuit scale even when the number of network buses to be connected increases, and a control method thereof. There is.

  In order to achieve the above object, according to a first aspect of the present invention, in a gateway device that relays data communication between a plurality of network buses mounted on a vehicle, each gateway is provided for each network bus. A plurality of driver circuits that transmit or receive data to and from the network bus, and data that is transmitted between the network buses is received from the driver circuit that is connected to the network bus that is the data transmission source, and the data is transmitted A control unit that causes the driver circuit connected to the previous network bus to transmit the data, a first power line connected to a power source regardless of whether the vehicle ignition is on or off, or when the ignition is on A driver that receives power from a second power line connected to a power source and performs the data transmission. A regulator circuit that supplies power to the circuit, and the control unit transmits data of at least one driver circuit when the first power supply line cannot supply power and the ignition is on. Is prohibited.

  According to a preferred embodiment of the above aspect, the control unit prohibits data transmission of a first driver circuit that performs first data transmission, and second data transmission having a higher priority than the first data transmission. The data transmission of the second driver circuit that performs is permitted.

  According to another preferred embodiment of the above aspect, the control unit includes a second driver circuit that is prohibited from transmitting data after the first driver circuit that is not prohibited from transmitting data starts the first data transmission. When the second data transmission having a higher priority than the first data transmission is to be performed, the first data transmission is interrupted and the second driver circuit is caused to execute the second data transmission. It is characterized by that.

  According to the above aspect, when the first power supply line cannot supply power and the ignition is on, data transmission of at least one of the driver circuits is prohibited. Current can be suppressed. Therefore, even when a large number of network buses are connected, the gateway device can operate by supplying power from the backup power supply line without increasing the circuit scale.

  According to the above preferred embodiment, the second driver that prohibits data transmission of the first driver circuit that performs the first data transmission and performs the second data transmission having a higher priority than the first data transmission. Since circuit data transmission is permitted, high-priority functions such as evacuation for vehicle safety and diagnostic data collection for fault recovery are realized even when current consumption for data transmission is reduced. Data communication for the purpose can be surely executed.

  According to another preferred embodiment of the present invention, after the first driver circuit that is not prohibited from transmitting data starts the first data transmission, the second driver circuit that is prohibited from transmitting data receives the first data. When the second data transmission having a higher priority than the transmission is to be performed, the first data transmission is interrupted and the second driver circuit is caused to execute the second data transmission. Data communication for realizing a high-priority function can be reliably executed while limiting the number of driver circuits to be performed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to these embodiments, but extends to the matters described in the claims and equivalents thereof.

  FIG. 2 is a diagram illustrating a configuration example of the gateway device in the present embodiment. The same parts as those in FIG. The gateway device 1 of the present embodiment is a gateway device that relays data communication between a plurality of network buses mounted on a vehicle, that is, a power train network bus B1, a body network bus B2, and a safety network bus B3. is there. In the gateway device 1, the driver circuit 16 is connected to the power train network bus B1, the driver circuit 18 is connected to the body network bus B2, and the driver circuit 20 is connected to the safety network bus B3.

  An engine control ECU 101 and a diagnosis ECU 102 are connected to the power train network bus B1, a door security ECU 201 is connected to the body network bus B2, and a follow-up travel control ECU 301 and an airbag control ECU 302 are connected to the safety network bus B3. Is connected. Each of the network buses B1, B2, and B3 is a CAN (Controller Area Network) specification transmission path configured by a twisted pair line as an example. The bit signals transmitted through the network buses B1, B2, and B3 are transmitted with a potential difference between the two lines, that is, a combination of a dominant level (“0”) and a recessive level (“1”).

  Therefore, the driver circuits 16, 18, and 20 convert the bit signal processed by each ECU or the control unit 14 into a combination of a voltage signal having a dominant level and a recessive level, and transmit it to the network buses B1, B2, B3, or The combination of dominant level and recessive level voltage signals received from the network buses B1, B2, B3 is converted into bit signals.

  The control unit 14 is configured by a CPU (Central Processing Unit) as an example. The CPU operates in accordance with a processing program stored in a memory (not shown), thereby realizing a function as a control unit that relays data communication between the network buses B1, B2, and B3 via the driver circuits 16, 18, and 20. Is done.

  Next, the operation of each part will be specifically described by dividing the ignition switch 3 into an off state and an on state. First, when the ignition switch 3 is off, that is, when the vehicle is parked or stopped, the control unit 14 enters a sleep state to prevent the battery 2 from being consumed. When the ignition switch 3 is off, for example, data is transmitted from the door security ECU 201 to the engine control ECU 101 to prevent the vehicle from being stolen. In this case, the door security ECU 201 detects whether or not the door is normally unlocked by the genuine key, and transmits the detection result data to the body network bus B2.

  A header is attached to this data, and the header includes address information of the destination engine control ECU 101. When this data is received by the driver circuit 18, the driver circuit 18 transmits a wakeup signal to the control unit 14 to activate the control unit 14, and then transmits the received data to the control unit 14. Then, the control unit 14 analyzes the header and recognizes that the transmission destination of the data is the engine control ECU 101, and transmits the received data to the driver circuit 16 connected to the powertrain network bus B1. Then, the driver circuit 16 transmits this data to the powertrain network bus B1, and the engine control ECU 101 finally receives this data. Then, the engine control ECU 101 recognizes that the door is normally unlocked, and permits the engine to start.

  Next, when the ignition switch 3 is on, that is, when the vehicle is running, the control unit 14 is activated from the sleep state and enters a standby state. When the ignition switch 3 is on, for example, data is transmitted from the follow-up travel control ECU 301 or the airbag control ECU 302 to the engine control ECU 101 in order to support safe traveling of the vehicle.

  First, if the inter-vehicle distance from the preceding vehicle detected by the in-vehicle radar or the like is too large, the follow-up travel control ECU 301 transmits data requesting an increase in engine output to accelerate and reduce the inter-vehicle distance. Transmit to bus B3. At this time, a header including address information of the engine control ECU 101 is attached to the transmitted data. This data is received by the control unit 14 via the driver circuit 20. Then, the control unit 14 analyzes the header and transmits this data to the driver circuit 16. Then, the driver circuit 16 transmits this data to the powertrain network bus B1, and the engine control ECU 101 finally receives this data. Then, the engine control ECU 101 instructs the engine to output the engine according to the request, and adjusts the inter-vehicle distance.

  Further, when the airbag is activated due to an impact caused by a collision or the like, the airbag control ECU 302 sends data requesting the engine control ECU 101 to stop the fuel supply to the engine in order to prevent the fuel from igniting. To the safety network bus B3. At this time, a header including address information of the engine control ECU 101 is attached to the transmitted data. This data is received by the control unit 14 via the driver circuit 20. Then, the control unit 14 analyzes the header and transmits this data to the driver circuit 16. Then, the driver circuit 16 transmits this data to the powertrain network bus B1, and the engine control ECU 101 finally receives this data. And engine control ECU101 stops the fuel supply to an engine according to a request | requirement.

  In the above configuration, the regulator circuit 12 receives power supply from both the power supply line S1 when the ignition switch 3 is off and from both the power supply lines S1 and S2 when the ignition switch 3 is on, and makes the voltage constant to control the controller 14. Power is supplied to the driver circuits 16, 18, and 20. When the power supply line S1 is disconnected, the ignition switch 3 is turned on so that the power supply line S2 functions as a backup power supply line. Then, since the current flowing through the diodes D2 and D3 increases, a diode having a large rated current that can withstand the load is required. However, by doing so, the circuit scale is increased and the cost is increased. Therefore, in this embodiment, the load on the diodes D2 and D3 is reduced by the procedure described below.

  FIG. 3 is a flowchart for explaining the operation procedure of the control unit 14 in the present embodiment. First, the control unit 14 receives the input of the ON signal of the ignition switch 3 and confirms that the ignition 3 is ON (S2). Then, the control unit 14 detects the voltage of the node N1 of the power supply line S1, and when this voltage is L level (YES in S4), that is, when the power supply line S1 is disconnected, only the driver circuit 16 transmits data. Is permitted and data transmission of the driver circuits 18 and 20 is prohibited (S6).

  Here, the driver circuits 16, 18, and 20 consume current to output a voltage signal as described above when transmitting data to the network bus, and conversely, when receiving a voltage signal from the network bus. Do not consume. Therefore, the amount of power supplied by the regulator circuit 12 can be reduced by limiting the driver circuit that performs data transmission.

  In addition, the driver circuit that is permitted to transmit data at that time is the driver circuit 16 that is necessary for data communication for ensuring safety of the vehicle and recovery from a failure. That is, in order to ensure vehicle safety and recover from a failure, data is transmitted from the ECUs of other network buses to the engine control ECU 101 and the diagnosis ECU 102 connected to the powertrain network bus B1. Therefore, in order to enable such data transmission, the control unit 14 permits data transmission of the driver circuit 16 and relays data from other driver circuits to the driver circuit 16. On the other hand, the control unit 14 does not relay transmission data to the driver circuits 18 and 20, and data transmission by the driver circuits 18 and 20 is prohibited. Alternatively, the control unit 14 may be configured to notify each driver circuit of permission / non-permission of data transmission separately from transmission data transmission.

  As an example of ensuring the safety of the vehicle, there is a case where the vehicle is evacuated to the road shoulder when a failure occurs that hinders good driving. At this time, data transmission is performed from the airbag control ECU 302 to the engine control ECU 101. That is, when the airbag is activated, the airbag control ECU 302 requests the engine control ECU 101 to stop the fuel supply, so that the retreat travel is impossible. Therefore, in order to perform the retreat travel, the airbag control ECU 302 requests the engine control ECU 101 to cancel the fuel supply stop.

  In this case, data communication from the airbag control ECU 302 is received by the driver circuit 18, but the data reception does not consume current. Therefore, the data can be received while the data transmission of the driver circuit 18 is stopped. Then, the control unit 14 relays this data, causes the driver circuit 16 to execute data transmission, and the data is transmitted to the engine control ECU 101. Then, the engine control ECU 101 cancels the fuel supply stop and starts the engine to execute the retreat travel.

  As an example of vehicle failure recovery, diagnostic data collection can be mentioned. That is, abnormal values of data detected by various sensors in each part of the vehicle are stored as diagnosis data in the save memory of each ECU, and the diagnosis ECU 102 collects this diagnosis data from each ECU. The collected diagnostic data is output to the computer of the maintenance shop during vehicle maintenance. Therefore, when the diagnostic ECU 102 collects diagnostic data, the driver circuit 16 is transmitted from the door security ECU 201 connected to the body network bus B2, the follow-up travel control ECU 301 connected to the safety network bus B3, or the airbag control ECU 302. The diagnosis data is transmitted to the diagnosis ECU 102 connected to the powertrain network bus B1.

  In this way, by limiting the driver circuit that performs data transmission, it is possible to reduce the amount of power supplied by the regulator circuit 12 and to perform data communication necessary for ensuring vehicle safety and failure recovery.

  Furthermore, in the above case, when data communication from another network bus to the powertrain network bus B1 is duplicated, the control unit 14 controls communication according to the following procedure.

  FIG. 4 is a sequence diagram showing a procedure of driver circuit communication control by the control unit 14. FIG. 4 shows an example in which the evacuation travel is performed during the diagnosis data collection. First, the diagnosis data is transmitted from the follow-up traveling control ECU 301 of the safety network bus B3 to the driver circuit 20 (S12), and the driver circuit 20 transmits this to the control unit 14 (S14). Then, the control unit 14 transmits diagnostic data to the driver circuit 16 (S16), and the driver circuit 16 transmits this data to the diagnostic ECU 102 of the powertrain network bus B1 (S18).

  Here, before the data transmission from the control unit 14 to the diagnosis ECU 102 via the driver circuit 16 (S16, S18) is completed, the airbag control ECU 302 sends a request for canceling the fuel supply stop to the engine control ECU 101 to the driver circuit 20. (S20), and the driver circuit 20 transmits this to the control unit 14 (S22). Then, the control unit 14 interrupts the transmission of the diagnosis data based on the preset priority (S24), and transmits a fuel supply stop cancellation request to the engine control ECU 101 via the driver circuit 16 (S26, S26). S28). Then, when the transmission of the release request is completed, the control unit 14 starts transmission of diagnostic data again (S30), and diagnostic data is transmitted to the diagnostic ECU 102 via the driver circuit 16 (S32, S34).

  In this manner, the control unit 14 can execute data communication necessary for evacuation travel with higher emergency and higher priority based on the preset priority.

  FIG. 5 is a sequence diagram illustrating a procedure of driver circuit communication control by the control unit 14 according to the modification. FIG. 5 shows a case where a driver circuit that is permitted to transmit data is dynamically switched. First, the diagnosis data is transmitted from the follow-up travel control ECU 301 of the safety network bus B3 to the driver circuit 20 (S112), and the driver circuit 20 transmits this to the control unit 14 (S114). Then, the control unit 14 transmits diagnostic data to the driver circuit 16 (S116), and the driver circuit 16 transmits this data to the diagnostic ECU 102 of the powertrain network bus B1 (S118).

  Next, in this modification, in order to execute the retreat travel, the engine control ECU 101 requests the airbag control ECU 302 to cancel the fuel supply stop. Therefore, the engine control ECU 101 transmits a release permission request to the driver circuit 16 (S120), and the driver circuit 16 transmits this request to the control unit 14 (S122). Then, the control unit 14 interrupts the transmission of the diagnosis data based on the preset priority (S124), prohibits the data transmission of the driver circuit 16, and permits the data transmission of the driver circuit 20 (S126). . Then, the control unit 14 transmits a release permission request to the airbag control ECU 302 via the driver circuit 20 (S128, S130).

  Then, in response to this, the airbag control ECU 302 transmits a release permission to the control unit 14 via the driver circuit 20 (S132, S134). Then, the control unit 14 prohibits data transmission of the driver circuit 20 and permits data transmission of the driver circuit 16 (S136), and transmits a release permission to the engine control ECU 101 via the driver circuit 16 (S138, S140). . Then, when the transmission of the release permission is completed, the control unit 14 starts transmitting the diagnosis data again (S142), and the diagnosis data is transmitted to the diagnosis ECU 102 via the driver circuit 16 (S144, S146).

  In this manner, the control unit 14 can execute data communication necessary for evacuation travel with higher emergency and higher priority based on the preset priority. At this time, by switching the driver circuits that are permitted to transmit data, the number of driver circuits that are permitted to transmit data at the same time can be limited, and current consumption for data transmission can be suppressed.

  In step S6 of FIG. 3, when data transmission of the driver circuit 16 is permitted and data transmission of the driver circuits 18 and 20 is prohibited, data transmitted from the driver circuits 18 and 20 to the driver circuit 16 is temporarily controlled. Received by the unit 14. And since the control part 14 judges prohibition of the data transmission, the consumption current concerning the judgment process of the control part 14 has arisen. Therefore, the control unit 14 can also prohibit data reception of the driver circuit 18 that is not involved in data communication with high priority. In this case, the control unit 14 stops the operation of the driver circuit 18 to prevent the driver circuit 18 from receiving data from the body network bus B2. Thereby, it is possible to avoid the transmission of these data to the control unit 14, and it is possible to further suppress the current consumption required for the determination process of the control unit 14.

  In the above description, the gateway apparatus 1 having the driver circuits 16, 18, and 20 has been described as an example. At that time, the number of driver circuits that are permitted to transmit data is not limited to one, and data transmission may be permitted to a number of driver circuits smaller than the total number of driver circuits and data transmission to other driver circuits may be prohibited. The effect in this embodiment can be acquired. An example of data communication that is preferentially permitted is not limited to the above, and a driver circuit in which data transmission is permitted / prohibited or a driver circuit in which data reception is permitted / prohibited can be arbitrarily set.

  Further, the network bus communication method is not limited to the above as long as the driver circuit consumes current for data transmission, and the present embodiment is applied.

  As described above, according to the present embodiment, even when a large number of network buses are connected, the gateway device can operate by supplying power from the backup power line without increasing the circuit scale. Even when current consumption for data transmission is suppressed, data communication for realizing a function with high priority can be more reliably executed.

It is a figure explaining the general structure of a gateway apparatus. It is a figure explaining the structural example of the gateway apparatus in this embodiment. It is a flowchart figure explaining the operation | movement procedure of the control part 14 in this embodiment. It is a sequence diagram which shows the procedure of the communication control of the driver circuit by the control part. It is a sequence diagram which shows the procedure of the communication control of the driver circuit by the control part 14 in a modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1: Gateway apparatus, 3: Ignition switch, S1, S2: Power supply line, 12: Regulator circuit, 14: Control part, 16, 18, 20: Driver circuit, B1: Powertrain system network bus, B2: Body system network bus , B3: Safety network bus

Claims (5)

In a gateway device that relays data communication between a plurality of network buses mounted on a vehicle,
A plurality of driver circuits that are provided for each network bus and that perform data transmission or reception with a network bus connected thereto,
Control that receives data transmitted between the network buses from a driver circuit connected to a network bus that is the transmission source of the data, and causes the driver circuit that is connected to a network bus that is the transmission destination of the data to transmit the data And
Regardless of whether the ignition of the vehicle is on or off, the first power supply line connected to the power supply or the second power supply line connected to the power supply when the ignition is on receives power supply, and the data transmission is performed. A regulator circuit for supplying power to the driver circuit
The gateway device characterized in that the control unit prohibits data transmission of at least one of the driver circuits when the first power supply line cannot supply power and the ignition is on. In claim 1,
The control unit prohibits data transmission of a first driver circuit that performs first data transmission, and transmits data of a second driver circuit that performs second data transmission having a higher priority than the first data transmission. A gateway device characterized by permitting. In claim 1,
The control unit is configured such that after the first driver circuit that is not prohibited from transmitting data starts the first data transmission, the second driver circuit that is prohibited from transmitting data has a higher priority than the first data transmission. A gateway device characterized in that when performing the second data transmission, the first data transmission is interrupted and the second driver circuit is caused to execute the second data transmission. In claim 1,
The gateway device characterized in that the control unit further prohibits data reception of at least one of the driver circuits when the first power supply line cannot supply power and the ignition is on. Provided for each of a plurality of network buses mounted on the vehicle, a network bus connected to each of them, a plurality of driver circuits that perform data transmission or reception, and data transmitted between the network buses, A control unit that receives from the driver circuit connected to the network bus and transmits the data to the driver circuit connected to the network bus that is the destination of the data, and is connected to the power source regardless of whether the ignition of the vehicle is on or off And a regulator circuit that receives power from a second power line connected to a power source when the ignition is on and supplies power to a driver circuit that performs the data transmission An apparatus control method comprising:
A method for controlling a gateway apparatus, comprising: a step of prohibiting data transmission of at least one of the driver circuits when the first power supply line cannot supply power and the ignition is on.

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