JP2009071773A - Relay and connection unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent generation of a delay in a process of an NM message when receiving a network management message (NM message) in a relay and connection unit. <P>SOLUTION: A relay and connection unit 10 which is made to be interposed among a plurality of busses 31 which are respectively connected to ECUs 30 is characterized in comprising a relay processing unit 12, a network management processing unit 14 for performing a network management function with respective ECUs by transmitting and receiving the network management message (NM message) to and from the other ECUs, and a determining unit 22 to be connected to the network management processing unit, to be connected to the relay processing unit via a buffer, for determining whether a massage is a data message or the NM message after receiving the message from the other ECUs, for transmitting the NM message to the network management processing unit without interposing the buffer, and for transmitting the data message to the buffer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an in-vehicle relay connection unit, and more particularly, to prevent a delay from occurring in processing of a message received by the relay connection unit.

  Conventionally, a network is constructed by connecting buses for multiplex communication connected with an electronic control unit (ECU) for controlling devices mounted on a vehicle via a relay connection unit (gateway), An in-vehicle communication system that relays data messages transmitted and received between ECUs belonging to different buses by the relay connection unit is employed.

  In order to ensure the safety and reliability of communication of the in-vehicle communication system, a network management system has been proposed. As shown in Non-Patent Document 1, a network management system is a network management control or node where nodes such as ECUs and relay connection units connected to a multiplex communication bus send and receive network management messages (NM messages) to each other. It is used to determine node errors. By network cooperative control, it is detected from the NM message that the operation state of another node is a normal state (normal operation state) that is a high power consumption state, a sleep state that is a power saving consumption state, and the like, and based on the detection result Thus, the transition processing is performed by determining to which operating state the own node is to be shifted.

In the in-vehicle communication system, when the network management system is executed, the relay connection unit receives an NM message in addition to a data message transmitted and received between ECUs belonging to different buses.
The NM message may have the same format as the data message. In such a system, the relay connection unit receives these messages without distinguishing between data messages and NM messages. FIG. 7 is a configuration diagram of a conventional relay connection unit 1, which is connected to buses 2A and 2B. When the CAN controller 3 receives a message from the bus 2, all the received messages are stored in the buffer 4. The management unit 5 connected to the buffer 4 determines the type of message stored in the buffer 4 from an identifier (ID) unique to each message. Further, the management unit 5 transmits the NM message from the buffer 4 to the network management processing unit 6 when the message in the buffer 4 is an NM message, and the data message from the buffer to the relay processing unit 7 when the message is a data message. Each processing unit performs a predetermined process using each message received from the buffer 4.

When a plurality of ECUs send a large number of data messages to the bus, the relay connection unit receives a large amount of data messages. Therefore, it takes a long time to process the management unit as described above, and a large amount of data messages waiting to be processed in the buffer. Is stored. When there are a plurality of messages stored in the buffer, the management unit processes the messages in order from the message stored first. When the relay connection unit receives the NM message in this state, the processing of the NM message is performed. It will be done after the data message awaiting processing.
On the other hand, the network management system performs error determination and operation state detection by transmitting and receiving NM messages between ECUs and relay connection units connected to the in-vehicle communication system, and the relay connection unit that has received the NM messages. Needs to send a response NM message to the bus within a predetermined time.
However, when the relay connection unit receives an NM message in a state where a large amount of data messages waiting for processing are stored in the buffer as described above, a delay occurs in processing of the NM message in the management unit and the network management processing unit, There is a problem that the relay connection unit cannot transmit a response NM message to the bus within a predetermined time.

Network Management Concept and Application Programming Interface Published: July 26, 2004 Publisher: OSEK / VDX Internet (URL: http://portal.osek-vdx.org/files/pdf/specs/nm253.pdf)

  The present invention has been made in view of the above-described problem. Even when an NM message is further received in a state where a large amount of data messages to be relayed by the relay connection unit are stored in a buffer, the processing delay of the NM message is achieved. The issue is to prevent the occurrence of network problems and to reliably execute the network management function.

In order to solve the above problems, the present invention is an in-vehicle relay connection unit that is interposed between a plurality of buses to which electronic control units are connected, and relays messages with the electronic control units belonging to different buses. And
A receiver for receiving a message from the other electronic control unit;
A transmitter for transmitting a message to the other electronic control unit;
A relay processing unit for transmitting a message received by the receiving unit from the transmitting unit;
A network management processing unit that transmits and receives a network management message (NM message) to and from the other electronic control unit to execute a network management function of each electronic control unit;
Connected to the network management processing unit and connected to the relay processing unit via a buffer, receives a message from the other electronic control unit from the bus, and determines whether the message is a data message or the NM message. A determination unit that transmits the NM message to the network management processing unit without passing through the buffer, and transmits the data message to the buffer;
A relay connection unit is provided.

When receiving the message, the determination unit of the relay connection unit of the present invention determines the message type, which is either a data message or an NM message, and if it determines that the received message is an NM message, The NM message is transmitted directly to the network management processing unit without storing.
When the relay connection unit receives an NM message in a state where a large amount of data message to be relayed is stored in the buffer, the NM message is also stored in the buffer in the prior art. May be processed, and there is a possibility that a delay occurs in the processing of the NM message. However, in the present invention, since the discriminating unit immediately determines the type of message and transmits it to each processing unit, there is no delay in processing the NM message, and the network management function such as network cooperative control is reliably executed. can do.

In particular,
A controller having at least an identifier storage unit that stores an ID of the NM message, the determination unit, the reception unit, and the transmission unit;
The determination unit determines whether the message is a data message or the NM message by comparing the ID of the received message with the ID stored in the identifier storage unit.

  The format of the data message and the NM message is the same, and each message has a unique identifier (ID). The discriminating unit discriminates the data message and the NM message based on the ID, compares the ID stored in the identifier storage unit with the ID of the received message, and stores the ID of the received message in the identifier storage unit. If it is an ID, the message is an NM message.

A diagnostic processing unit is provided for receiving diagnostic diagnostic messages.
The identifier storage unit stores an ID of a diagnostic message,
When determining that the message is the diagnosis message, the determination unit may transmit the diagnosis message to the diagnosis processing unit without passing through the buffer.
In the receiving unit, not only the NM message but also the diagnostic message is discriminated from the ID, and the diagnostic message is transmitted directly to the diagnostic processing unit, thereby preventing a delay of the diagnostic message processing.

Interposing a relay discriminator between the discriminator and the buffer;
If the ID of the received message is not described in the identifier storage unit, the determination unit determines that the message is the data message and transmits the message to the relay determination unit.
The relay determining unit determines whether the data message is relayed or discarded based on the ID of the data message, transmits the data message to the buffer in the case of relay, and discards the data message in the case of discard. Is preferred.

  A message that is not determined to be an NM message or a diagnostic message by the determination unit is transmitted as a data message to the relay determination unit. The relay determination unit determines whether the data message is a message relayed to another ECU or a message discarded without being relayed to any ECU, and transmits the data message relayed to another ECU to the buffer. . Therefore, NM messages, diagnostic messages, and data messages to be discarded are not stored in the buffer, only data messages that need to be relayed are stored, and the relay processing unit performs relay processing of the data messages in the buffer. Do it sequentially.

The identifier storage unit stores an ID of a data message that needs to be relayed and an ID of a data message to be discarded,
The determination unit transmits the data message to the buffer when determining that the received message is a data message that needs to be relayed, and determines that the data message is determined to be a data message to be discarded. It may be discarded.

  As described above, according to the relay connection unit of the present invention, when the determination unit of the reception unit receives a message, it determines whether it is a data message or an NM message, and the received message is an NM message. If it is determined, the NM message is transmitted directly to the network management processing unit without being stored in the buffer. For this reason, even when a NM message is received in a state where a large amount of data messages to be relayed by the relay connection unit are stored in the buffer, there is no delay in processing the NM message, and network cooperative control is performed. Network management functions such as can be executed reliably.

Embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a first embodiment of the present invention.
The in-vehicle relay connection unit 10 of the present invention forms a network by interposing electronic control units (ECUs) 30 between buses 31 connected to each other, and transmits and receives data messages between the ECUs 3030 belonging to different buses 31. Is relayed.
In this embodiment, the relay connection unit 10 is interposed between the two buses 31A and 31B to form a network, and the two ECUs 30A and 30B are connected to the two buses 31A and 31B, respectively. The communication protocol is CAN (Controller Area Network).

  As shown in FIG. 1, the relay connection unit 10 includes CAN controllers 20 </ b> A and 20 </ b> B, a diagnosis processing unit 11, a relay processing unit 12, a buffer 13, a network management processing unit 14, and a relay determination unit 15. Yes.

The CAN controllers 20A and 20B are connected to the buses 31A and 31B, respectively, and receive messages transmitted from other ECUs 30 via the bus 31.
There are three messages transmitted / received by the CAN controller 20: a data message, a diagnostic message, and an NM message. The data message is transmitted / received between the ECUs 30 connected to different buses 31 and is a message used for controlling the in-vehicle device connected by the relay connection unit 10 and connected to the ECU 30. The diagnostic message is a message used in the diagnostic processing unit 11, and the NM message is a message used in the network management processing unit 14.

As shown in FIG. 2, the CAN controller 20 </ b> A includes a transmission / reception buffer 21 that constitutes a reception unit and a transmission unit, an ID discrimination unit 22 that constitutes a discrimination unit, and an identifier storage unit 23. The CAN controller 20B has the same configuration.
The transmission / reception buffer 21 is connected to the bus 31 and temporarily stores messages received from the bus 31. The message frames of the data message, the diagnostic message, and the NM message have the same configuration, and the transmission / reception buffer 21 transmits / receives these messages without distinction.

The identifier storage unit 23 includes a table for determining the type of received message. Data messages, diagnostic messages, and NM messages are distinguished by an identifier (ID) that is a unique value of each message. FIG. 3 is an example of a table, and describes whether a message is a diagnostic message or an NM message for each message ID received by the relay connection unit 10. Only the IDs of the diagnosis message and the NM message are described in the table, and the message whose ID is not described in the table is a data message.
Note that the ID of the data message may be described in the table. In this case, the ID determination unit 22 described later uses the table to determine that the received message ID is a data message.

  The ID determination unit 22 is connected to the transmission / reception buffer 21 and is also connected to the identifier storage unit 23. When a message is received from the transmission / reception buffer 21, a table is read from the identifier storage unit 23, and the type of the received message is determined with reference to the table. For example, when the ID of the received message is 1, the ID determination unit 22 determines that the message is a diagnostic message with reference to the table of FIG.

  The ID determination unit 22 is connected to the network management processing unit 14, the diagnosis processing unit 11, and the relay determination unit 15. When it is determined that the received message is an NM message, the ID determination unit 22 transmits the NM message to the network management processing unit 14. When the received message is determined as a diagnosis message, the ID determination unit 22 transmits the diagnosis message to the diagnosis processing unit 11. If the received message ID is not in the table, it is transmitted to the relay determination unit 15 as a data message.

  When the arbitration field in which the ID is stored in the message frame is stored in the transmission / reception buffer 21, the ID determination unit 22 receives the message from the transmission / reception buffer 21, reads the ID, and determines the type of the message. Yes. Note that after the message is stored in the transmission / reception buffer 21 to the end, the ID determination unit 22 may determine the type of the message.

The diagnosis processing unit 11 transmits and receives a diagnosis message and a diagnosis message when a diagnosis (not shown) for diagnosing a failure of the relay connection unit 10 is connected to the in-vehicle communication system.
The network management processing unit 14 transmits and receives NM messages to and from other ECUs 30 connected to the bus 31, thereby performing network cooperative control and error determination, and ensuring communication safety and reliability of the in-vehicle communication system. Yes.

  When receiving the data message from the CAN controller 20, the relay determination unit 15 determines whether or not the relay connection unit 10 needs to relay the data message to another ECU 30. The relay discriminating unit 15 includes a relay table (not shown) that describes the ID of a data message that needs to be relayed. The relay determination unit 15 determines whether or not the ID of the received data message is in the relay table, and if it is in the relay table, stores the data message in the buffer 13. If it is not in the relay table, discard the data message.

The buffer 13 is connected to the relay determination unit 15 and stores data messages in the order received. In addition, a data message to be transmitted to the bus 31 is temporarily stored.
The relay processing unit 12 is connected to the buffer 13 and performs relay processing of the data message stored in the buffer 13. The relay processing unit 12 includes a routing table (not shown) indicating a relay destination for each data message ID. The relay processing unit 12 sequentially reads out the data messages stored in the buffer 13 in advance, determines the relay destination by referring to the routing table from the ID of the data message, and transmits the data message to the buffer 13.

  The CAN controllers 20A and 20B, the diagnosis processing unit 11, the relay processing unit 12, the buffer 13, the network management processing unit 14, and the relay determination unit 15 of the relay connection unit 10 are configured by an integrated circuit (IC). Also good.

Next, the operation when the relay connection unit 10 of the present invention receives a message and transmits it to the relay processing unit 12, the diagnosis processing unit 11, and the network management processing unit 14 will be described with reference to the flowchart of FIG.
In step S <b> 1, the CAN controller 20 </ b> A receives the message, and the message is stored in the transmission / reception buffer 21.
In step S2, the ID determination unit 22 reads a message from the transmission / reception buffer 21 and reads a table from the identifier storage unit 23, and refers to the table to determine the message type from the message ID. If the message is an NM message, the process proceeds to step S3. If the message is a diagnostic message, the process proceeds to step S5. If the message ID is not described in the table, it is determined that the message is a data message and the process proceeds to step S7.

In step S <b> 3, the ID determination unit 22 transmits an NM message to the network management processing unit 14.
In step S4, the network management processing unit 14 performs processing such as state transition of the ECU 30 using the NM message.
In step S <b> 5, the ID determination unit 22 transmits a diagnosis message to the diagnosis processing unit 11.
In step S6, the diagnosis processing unit 11 performs processing such as failure diagnosis using a diagnosis message.

In step S <b> 7, the ID determination unit 22 transmits a data message to the relay determination unit 15.
In step S8, the relay determination unit 15 refers to the relay table from the ID of the data message, and determines whether or not the other ECU 30 needs to relay the data message. If relaying is necessary, the process proceeds to step S9. If relaying is not necessary, the process proceeds to step S11.
In step S9, the data message is stored in the buffer 13.
In step S10, the relay processing unit 12 reads the data message from the buffer 13, and refers to the routing table to determine the relay destination of the data message.
In step S11, the relay determination unit 15 determines that the data message is not relayed to the bus 31, and therefore discards the data message.

  According to the present invention, when the D determination unit of the CAN controller 20 receives a message, the D determination unit determines whether the message is a data message or an NM message, and determines that the received message is an NM message. Transmits the NM message directly to the network management processing unit 14 without storing it in the buffer 13, so that the NM message is stored in the buffer 13 with a large amount of data messages to be relayed by the relay connection unit 10. Even if it is received, a delay in processing of the NM message does not occur, and a network management function such as network cooperative control can be reliably executed.

5 and 6 show a second embodiment of the present invention.
In the second embodiment, the relay determination unit 15 is not provided, and the CAN controller 20 is connected to the buffer 13. The ID determination unit 22 of the CAN controller 20 determines whether to relay the data message.
The identifier storage unit 23 of the CAN controller 20 includes, for example, a table shown in FIG. This table describes whether the message is a diagnostic message, an NM message, or a data message for each message ID received by the relay connection unit 10. Further, it is described that if the message is a data message but the relay processing unit 12 does not relay, the message is discarded.

  When the ID determination unit 22 reads the message stored in the transmission / reception buffer 21, the ID of the message is compared with the table. For example, when the message ID is 100, the ID determination unit 22 determines that the message is a data message and transmits the message to the buffer 13. When the message ID is 110, the ID determination unit 22 determines that the message is to be discarded, and performs the discarding process.

Thus, by performing the function of the relay determination unit 15 by the ID determination unit 22 of the CAN controller 20, the number of parts can be reduced, and the configuration of the relay connection unit 10 is simplified.
In addition, since another structure and an effect are the same as that of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

It is a block diagram which shows 1st Embodiment of the relay connection unit which is this invention. It is a block diagram of a CAN controller. It is an example of the table which discriminates the kind of message. It is a flowchart which shows operation | movement of a relay connection unit. It is a block diagram of the relay connection unit which shows 2nd Embodiment. It is an example of the table which discriminates the kind of message. It is a figure which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Relay connection unit 11 Diag processing part 12 Relay processing part 13 Buffer 14 Network management processing part 15 Relay discrimination | determination part 20 (20A, 20B) CAN controller 21 Transmission / reception buffer 22 ID discrimination | determination part 23 Identifier storage part 30 Electronic control unit (ECU)
31 (31A, 31B) Bus

Claims (5)

An in-vehicle relay connection unit that is interposed between a plurality of buses to which electronic control units are connected, and relays messages with the electronic control units belonging to different buses,
A receiver for receiving a message from the other electronic control unit;
A transmitter for transmitting a message to the other electronic control unit;
A relay processing unit for transmitting a message received by the receiving unit from the transmitting unit;
A network management processing unit that transmits and receives a network management message (NM message) to and from the other electronic control unit to execute a network management function of each electronic control unit;
Connected to the network management processing unit and connected to the relay processing unit via a buffer, receives a message from the other electronic control unit from the bus, and determines whether the message is a data message or the NM message. A determination unit that transmits the NM message to the network management processing unit without passing through the buffer, and transmits the data message to the buffer;
A relay connection unit characterized by comprising: A controller having at least an identifier storage unit that stores an ID of the NM message, the determination unit, the reception unit, and the transmission unit;
The relay connection unit according to claim 1, wherein the determination unit determines whether the message is a data message or the NM message by comparing an ID of a received message with an ID stored in the identifier storage unit. A diagnostic processing unit is provided for receiving diagnostic diagnostic messages.
The identifier storage unit stores an ID of a diagnostic message,
3. The relay connection unit according to claim 1, wherein when the determination unit determines that the message is the diagnosis message, the determination unit transmits the diagnosis message to the diagnosis processing unit without passing through the buffer. Interposing a relay discriminator between the discriminator and the buffer;
If the ID of the received message is not described in the identifier storage unit, the determination unit determines that the message is the data message and transmits the message to the relay determination unit.
The relay determination unit determines whether the data message is relayed or discarded based on the ID of the data message, transmits the data message to the buffer in the case of relay, and discards the data message in the case of discard. The relay connection unit according to claim 2 or claim 3. The identifier storage unit stores an ID of a data message that needs to be relayed and an ID of a data message to be discarded,
The determination unit transmits the data message to the buffer when determining that the received message is a data message that needs to be relayed, and determines that the data message is determined to be a data message to be discarded. The relay connection unit according to claim 2 or 3, which is discarded.

Images