JP4603899B2 - Gateway device with communication error detection function and communication system - Google Patents

Description

  The present invention relates to a gateway device with a communication error detection function capable of detecting a communication error and a communication system.

  Conventionally, in a vehicle such as an automobile, a communication system using a CAN (Controller Area Network) is often provided. An example of such a vehicle communication system is an in-vehicle LAN (local area network), which is very useful for controlling vehicles and in-vehicle devices.

However, when a communication error occurs in such a communication system, there is a risk of hindering control of the vehicle or in-vehicle equipment. Therefore, when a communication error occurs, it is required to immediately identify the cause of the communication error and solve it. Thus, conventionally, various techniques have been proposed for specifying the cause of a communication error (see Patent Document 1 and Patent Document 2).
In addition to the in-vehicle LAN, there is a great demand for a technique for immediately identifying the cause of a communication error in other communication systems.

JP 2004-17676 A JP 2004-136816 A

  By the way, when constructing a communication system, it is often the case that a plurality of networks are prepared according to the type of message to be transmitted / received, the purpose, the frequency of transmission / reception, etc. Has been made. For example, taking an in-vehicle LAN using CAN as an example, an information network for navigation system control, a body control network for headlamp control, a safety network for airbag control, engine control, etc. A communication system is constructed by connecting engine / powertrain networks for the above-mentioned with a gateway.

  In the communication system constructed by connecting a plurality of networks with the gateway as described above, the cause of the communication error should be detected promptly. However, it has been difficult for conventional techniques to detect the cause of a communication error in a communication system constructed by connecting a plurality of networks. In particular, in a communication system in which a plurality of networks are connected by a gateway, some messages transmitted from a predetermined node device may be transmitted to a node device in another network via the gateway. In such a case, if a reception error occurs in the receiving node device, it is difficult to detect whether the cause is in the transmitting node device or the gateway device.

  The present invention was devised in view of the above problems, and detects where a communication error occurs in a communication system when a communication error occurs in a communication system constructed by connecting a plurality of networks with a gateway. An object is to propose a gateway device and a communication system with a communication error detection function.

The gateway device of the present invention is configured so that a message transmitted from a transmitting device connected to the first network to a receiving device connected to the second network is received by the receiving device. And a second network, a gateway device for connecting a message transmitted from the transmission device via the first network, and a message received by the reception device via the second network and transmitting means for transmitting to the receiving apparatus Te, and receiving the counting means for counting the message received by the receiving means, and transmitting the counting means for counting the message sending means has transmitted an in transmit counting means, the gateway device normally If the difference from the second determination value based on the number of messages to be transmitted by the transmission means is greater than a second allowable value, the gate E b equipment of the gateway device transmits the abnormality determining means for determining a transmission error of the message comprises a (hereinafter, also referred to as a second communication error determination means), the gateway apparatus transmits abnormality determining means, a total of the receiving counting means When the difference between the numerical value and the first determination value based on the number of messages to be received by the receiving means when the transmitting device is normal is equal to or less than the first allowable value, the determination is performed while the count value in the reception counting means is if the difference between the first determination value is larger than the first tolerance value you characterized by not performing the determination.
In addition, the gateway device further includes transmission internal transmission abnormality determination means (hereinafter also referred to as first communication error determination means) that determines a transmission abnormality of a message from the transmission apparatus based on a counting result of the reception counting means. May be.

The reception means has a reception buffer for receiving messages transmitted at a predetermined cycle, the reception counting means counts messages stored in the reception buffer, and the first communication error determination means is a transmission device. It is preferable that a transmission error of a message from the transmission device is determined based on a comparison result between the first determination value based on the number of messages to be received by the reception unit and the count value of the reception counting unit when the reception unit is normal. better not.

Furthermore, transmission means has a transmission buffer for transmitting the message received by the receiving means at a predetermined period, transmitting the counting means is configured so that to the number of messages in total transmitted from the transmission buffer it is not preferable to be.

Furthermore, the counting time setting means for setting the time interval for counting the messages by the reception counting means and the transmission counting means, and the count values of the reception counting means and the transmission counting means are reset when the time set by the counting time setting means has elapsed. it is not preferable be configured to further include a reset means for. As a result, it is possible to accurately detect an abnormal transmission position of a message using an appropriate counting time interval according to the characteristics of the message.

Another gateway device of the present invention is configured so that a message transmitted from a transmission device connected to the first network to a reception device connected to the second network is received by the reception device. And a second network for receiving a message transmitted from the transmitting device via the first network, and a message received by the receiving device via the second network. and transmitting means for transmitting to the receiving apparatus, a receiving counting means for counting the message received by the receiving means, and transmitting the counting means for counting the message sending means has transmitted, from the transmission device based on the counting result of receiving the counting means a first communication error determination means for determining transmission error message, the gateway instrumentation based on the counting result of the transmission counting means And a second communication error determination means for determining transmission error message, if it is determined that transmission error of the message from the transmitting apparatus by the first communication error determination means, the determination of the second communication error determination means it characterized in that not performed.

The transmission means has a transmission buffer for transmitting the message received by the reception means at a predetermined cycle, and the transmission counting means counts the message transmitted from the transmission buffer, and second communication error determination means Is configured to determine the abnormal transmission of the message from the gateway device based on the comparison result between the second determination value based on the number of messages to be transmitted by the transmission unit when the gateway device is normal and the count value of the transmission counting unit. it is not preferable to be.

Furthermore, the communication system of the present invention is connected to the first network to which the transmission device is connected, the second network to which the reception device is connected, and the first network and the second network. further comprising a gateway device according to any one of the invention you characterized. This makes it easy to determine where in the communication system a communication error has occurred.

  According to the gateway device with communication error detection function and the communication system of the present invention, it is possible to determine where a communication error has occurred in the communication system.

  Hereinafter, the present invention will be described with reference to embodiments, but the present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented without departing from the gist of the present invention.

  1 to 4 are diagrams for explaining an embodiment of the present invention. FIG. 1 schematically shows an outline of a communication system and a gateway device. FIG. 2 explains a functional configuration of a communication error detection unit. FIG. 3 is a diagram for explaining the counting of the reception counter value and the transmission counter value, and FIG. 4 is a flowchart for explaining the communication error detection procedure.

  The communication system of this embodiment is an in-vehicle LAN using CAN as a communication protocol. Here, CAN is a multi-master type communication protocol capable of transmitting a message from all transmission devices connected to the network when the network is free, and the transmission device that has quickly accessed the network obtains the transmission right. Be able to. When a plurality of transmitting devices start transmitting at the same time, the priority order is determined based on the IDs of the transmitted messages, and the transmitting device transmitting the message having the ID with the higher priority level has the transmission right. To get.

FIG. 1 schematically shows the outline of the communication system of the present embodiment. In FIG. 1, a block arrow indicates a direction in which a message is transmitted, a solid line arrow indicates a message flow, and a broken line arrow indicates a signal flow between the reception buffer and the transmission buffer and the controller.
As shown in FIG. 1, the communication system according to the present embodiment includes a first network CAN1, a second network CAN2, and a gateway device 1.

  The first network CAN1 is a bus-type network in which at least one node device 2 is connected as a transmitting device and a receiving device, and is configured to be able to communicate according to the CAN protocol. The node device 2 is a communication device capable of receiving and transmitting messages (signals), and includes electronic components such as a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory). ing. Further, the node device 2 can transmit / receive messages to / from other node devices (not shown) and the gateway device 1 connected to the first network CAN1 via the first network CAN1.

  On the other hand, the second network CAN2, like the first network CAN1, is a bus-type network in which at least one node device 3 is connected as a transmitting device and a receiving device, and performs communication according to the CAN protocol. It is configured to be able to. Similarly to the node device 2, the node device 3 is a communication device capable of receiving and transmitting messages, and is configured by known electronic components such as a CPU, a RAM, and a ROM. Further, the node device 3 can also transmit / receive messages to / from other node devices (not shown) in the second network CAN2 and the gateway device 1 via the second network CAN2.

  In FIG. 1, only one node device 2 and 3 is drawn and shown, but normally, the first network CAN1 and the second network CAN2 have node devices other than the node devices 2 and 3, respectively. Is provided. Further, the node devices 2 and 3 are configured as electronic control units (ECUs) for performing vehicle control and the like according to the respective purposes.

  In the present embodiment, it is assumed that messages A to C are transmitted from the node device 2 to the node device 3, and messages D to F are transmitted from the node device 3 to the node device 2. However, the number of messages is not limited to six, and an arbitrary number of messages can be used. Usually, a larger number of messages are transmitted and received between the node devices 2 and 3. That is, the message transmitted to the first network CAN1 and the second network CAN2 includes a message that is periodically transmitted at a constant period and a message that is irregularly generated due to the occurrence of a certain event. . Each of the messages A to F described in the present embodiment is a group of a plurality of messages that are periodically transmitted at a constant cycle. The node A or the gateway device 1 uses the messages A to F. Error determination is performed.

  Further, the gateway device 1 is a communication device that connects between the first network CAN1 and the second network CAN2, and therefore the node device 2 and 3 connected to the transmission-side networks CAN1 and CAN2 to the reception-side network CAN2. , Messages A to C and D to F transmitted to the node devices 3 and 2 connected to CAN 1 are received by the node devices 3 and 2 on the receiving side. The gateway device 1 is also composed of electronic components such as a CPU, RAM, and ROM.

  The configuration of the gateway device 1 will be described in detail. The gateway device 1 includes reception buffers (reception means) 4A to 4F prepared for each message A to F and transmissions prepared for each message A to F. Buffers (transmission means) 5 </ b> A to 5 </ b> F and a controller 6 that performs each control of the gateway device 1 are provided. As a result, the messages A to F received by the reception buffers 4A to 4F are sent to the corresponding transmission buffers 5A to 5F according to the control of the controller 6, respectively. Further, each message in the transmission buffers 5A to 5F is transmitted to the destination node devices 2 and 3 via the first or second networks CAN1 and CAN2 under the control of the controller 6. . Note that the receiving unit and the transmitting unit may include configurations other than the reception buffers 4A to 4F and the transmission buffers 5A to 5F, respectively.

  In this embodiment, the reception buffers 4A to 4C and the transmission buffers 5A to 5C correspond to messages A to C transmitted from the node device 2 to the node device 3. Therefore, the messages A to C transmitted from the node device 2 are received by the reception buffers 4A to 4C via the first network CAN1, stored in the reception buffers 4A to 4C, and transmitted from the reception buffers 4A to 4C. 5A to 5C, transmitted from the transmission buffers 5A to 5C to the node device 3 via the second network CAN2, and received by the node device 3.

On the other hand, the reception buffers 4D to 4F and the transmission buffers 5D to 5F correspond to messages D to F transmitted from the node device 3 to the node device 2. Accordingly, the messages D to F transmitted from the node device 3 are received by the reception buffers 4D to 4F via the second network CAN2, stored in the reception buffers 4D to 4F, and transmitted from the reception buffers 4D to 4F. 5D to 5F, transmitted from the transmission buffers 5D to 5F to the node device 2 via the first network CAN1, and received by the node device 2.
In this embodiment, since there are six types of messages A to F, six reception buffers 4A to 4F and six transmission buffers 5A to 5F are prepared. However, when the number of message types changes, the reception buffers and The number of transmission buffers is also changed according to the number of message types.

The controller 6 controls the transfer of messages between the reception buffers 4A to 4F and the transmission buffers 5A to 5F, the transmission control of messages A to F from the transmission buffers 5A to 5F to the destination node devices 2 and 3, and the like. Message transmission / reception control can be performed. In addition, the controller 6 can detect where the communication error occurs in the communication system when a communication error occurs in the communication system of the present embodiment, and detects the communication error for realizing the error detection. Part 7 is provided.
Hereinafter, a control block diagram of the communication error detection unit 7 is shown in FIG. 2, and detection of the communication error in this embodiment will be described.

  As shown in FIG. 2, the communication error detection unit 7 includes a reception counter 8 as a reception counting unit, a transmission counter 9 as a transmission counting unit, a first determination value storage unit 10, a second determination value storage unit 11, and a first determination unit. A communication error determination unit 12 as a communication error determination unit and a second communication error determination unit, a counter reset unit 13 as a reset unit, an error processing unit 14, and a determination control unit 15 as a counting time setting unit are provided. In terms of hardware, these are configured such that the CPU, memory, and the like constituting the controller 6 exhibit their functions.

  The reception counter 8 is a counter that counts the messages received and stored for each of the reception buffers 4A to 4F when the reception buffers 4A to 4F receive the message. Further, the reception counter 8 continues to store the reception counter value for each message until the reception counter value (counting result, count value) is reset by the counter reset unit 13.

  The transmission counter 9 is a counter that counts messages transmitted for each of the transmission buffers 5A to 5F when the transmission buffers 5A to 5F transmit messages. Furthermore, the transmission counter 9 continues to store the transmission counter value for each message until the counter reset unit 13 resets the transmission counter value (counting result, count value).

  Further, the first determination value storage unit 10 is a storage unit that stores a first determination value used for determination by the communication error determination unit 12. The first determination value is used to determine that a communication error has occurred from the node devices 2 and 3 that are the transmission sources of the messages A to F to the networks CAN1 and CAN2 on the side to which the transmission source node devices 2 and 3 are connected. This is a determination value to be used, and is determined for each message A to F. The first determination value is determined based on the number of messages to be received by the reception buffers 4A to 4F when the node devices 2 and 3 that are transmission sources are normal. In the present embodiment, a value calculated by the following formula (1) is used as the first determination value. In equation (1), the reset cycle time is the time from when the reception counter 8 starts counting or after the reception counter value is reset once until the reception counter value is next reset. Yes, it is also the time interval at which the reception counter 8 and transmission counter 9 count messages.

First judgment value = (reset cycle time) / (message transmission cycle) (1)
The first determination value represents the number of messages A to F that should have been transmitted from the source node devices 2 and 3 in the reset cycle time when the source nodes 2 and 3 are normal. . For example, if the reset cycle time is 100 msec and the transmission cycle of message A is 10 msec, the first determination value is 10. If the node device 2 is normal, ten messages A are transmitted from the node device 2 at intervals of 10 msec within 100 msec, and therefore the first determination value should match the reception counter. However, some errors actually occur depending on the communication status.

  The second determination value storage unit 11 is a storage unit that stores a second determination value used for determination by the communication error determination unit 12. The second determination value is a determination value used to determine that an error has occurred in the gateway device 1 and is determined for each message A to F. The second determination value is determined based on the number of messages to be transmitted by the transmission buffers 5A to 5F when the gateway device 1 is normal. In this embodiment, the value calculated by the following formula (2) is used as the second determination value. In equation (2), the reset cycle time is the time from when the transmission counter 9 starts counting or after the transmission counter value is reset once until the transmission counter value is reset next time. is there.

Second determination value = (reset cycle time) / (message transmission cycle) (2)
The second determination value represents the number of messages A to F that the gateway device 1 should have transmitted during the reset cycle time when the gateway device 1 is normal. If the gateway device 1 is normal, the second determination value should match the transmission counter value. In this embodiment, since the reset cycle times of the reception counter 8 and the transmission counter 9 are set to be the same, the reset cycle times of the equations (1) and (2) are equal, and therefore the first determination value And the second determination value are equal to each other.

  Further, the communication error determination unit 12 is a determination unit for determining whether or not a first communication error has occurred based on the reception counter value counted by the reception counter 8. It is a determination unit for determining whether or not a second communication error has occurred based on the reception counter value and the transmission counter value counted by the transmission counter 9. Here, the first communication error is a communication error that occurs from the node devices 2 and 3 that are the transmission sources of the messages A to F to the networks CAN1 and CAN2 on the side to which the transmission source node devices 2 and 3 are connected. This mainly refers to abnormal transmission of messages from the node devices 2 and 3. The second communication error refers to a communication error that has occurred in the gateway device 1 and mainly refers to an abnormal transmission of a message from the gateway device 1.

  Specifically, the communication error determination unit 12 responds to each message A to F from the reception counter 8, the transmission counter 9, the first determination value storage unit 10, and the second determination value storage unit 11 under the control of the determination control unit 15. The received reception counter value, the transmission counter value, the first determination value, and the second determination value are read out, the first communication error is determined based on the comparison result obtained by comparing the reception counter value with the first determination value, and the reception It is determined whether or not a second communication error has occurred based on a comparison result comparing the counter value with the first determination value and a comparison result comparing the transmission counter value and the second determination value. .

  Specifically, the communication error determination unit 12 calculates the absolute value of the difference between the reception counter value and the first determination value (hereinafter referred to as “reception comparison result value” as appropriate) for each message A to F, and receives the reception. If the comparison result value is larger than the first allowable value, it is determined that the first communication error has occurred.

The reception comparison result value is a value that should be less than or equal to the first allowable value if the communication system is normal.
Therefore, when the reception comparison result value becomes larger than the first allowable value, the network device CAN1, on the side to which the transmission source node devices 2 and 3 are connected from the node devices 2 and 3 that are transmission sources of the messages A to F. This indicates that a communication error has occurred up to CAN2.

  Usually, when the communication error determination unit 12 performs the above comparison, a predetermined error occurs between the set value and the actual measurement value. However, in consideration that such an error does not affect the error determination. By using one tolerance value, error determination can be performed without causing erroneous determination. The first allowable value is a value experimentally obtained for each message A to F so that the first communication error can be appropriately determined.

  Further, the communication error determination unit 12 calculates the absolute value of the difference between the transmission counter value and the second determination value (hereinafter, appropriately referred to as “transmission comparison result value”) for each message A to F. When the transmission comparison result value is larger than the second allowable value and the reception comparison result value is equal to or less than the first allowable value (that is, when it is not determined that the first communication error has occurred). It is determined that a second communication error has occurred.

  The transmission comparison result value is a value that should be equal to or less than the second allowable value if the communication system is normal. Therefore, when the transmission comparison result value is larger than the second allowable value, a communication error has occurred from the node devices 2 and 3 that are the transmission sources of the messages A to F to the transmission buffers 5A to 5F of the gateway device 1. Is none other than showing. When it is not determined that the first communication error has occurred, the gateway device 1 has successfully received the messages A to F from the node devices 2 and 3 that are the transmission sources of the messages A to F. Become. Therefore, a communication error has occurred in the gateway device 1.

  In addition, as in the case of the determination of the first communication error, usually, a predetermined error occurs when the comparison is performed for the determination of the second communication error. Judgment can be made without being affected by. Note that the second tolerance value is also experimentally obtained for each message A to F so that the second communication error can be appropriately determined in the same manner as the first tolerance value.

In the present embodiment, the communication error determination unit 12 includes a first determination unit 16 and a second determination unit 17.
Based on the received reception counter value, transmission counter value, first determination value, and second determination value, the first determination unit 16 determines that the reception comparison result value is less than or equal to the first allowable value and the transmission comparison result is the second allowable value. When the value is equal to or less than the value, it is determined that the communication is normally performed.

The second determination unit 17 compares the reception comparison result value with the first determination value when the first determination unit 16 does not determine that the communication is normally performed. When the reception comparison result value is larger than the first allowable value, it is determined that the first communication error has occurred, and in other cases (that is, when the reception comparison result value is less than or equal to the first allowable value) 2 It is determined that a communication error has occurred.
The determination result in the communication error determination unit 12 is sent to the error processing unit 14.

Further, the counter reset unit 13 resets all the reception counter value and the transmission counter value every predetermined reset cycle time according to the control of the determination control unit 15 so that the reception count value and the transmission count value become zero. Yes. Therefore, as shown in FIG. 3A, the reception counter 8 counts the messages A to F each time the reception buffers 4A to 4F receive the messages A to F. However, when the reset cycle time elapses, the reception counter value Is reset to zero. Further, as shown in FIG. 3B, the transmission counter 9 counts the messages A to F every time the transmission buffers 5A to 5F transmit the messages A to F. However, when the reset cycle time elapses, the transmission counter value is counted. Is reset to zero.

  Further, when the communication error determination unit 12 determines that a first communication error or a second communication error has occurred, the error processing unit 14 performs error processing according to the communication error. Here, the error processing unit 14 is connected to a vehicle indicator (not shown), and when it is determined that a first communication error or a second communication error has occurred, the indicator indicates that the communication error has been detected. It is supposed to be displayed.

  Further, the determination control unit 15 controls the communication error determination unit 12 and the counter reset unit 13. Further, the determination control unit 15 can measure a time for determining the timing for performing the determination (hereinafter referred to as “reset time” as appropriate), and the reset time elapses the reset cycle time. Every time, the communication error determination unit 12 makes a determination periodically, and the counter reset unit 13 resets the reception counter value and the transmission counter value. Furthermore, the determination control unit 15 can arbitrarily set the reset cycle time.

The communication system and gateway device 1 of the present embodiment are configured as described above. Therefore, at the time of use, the determination control unit 15 sets a reset cycle time and then detects a communication error as follows.
As shown in FIG. 4, first, when the communication system is activated, the communication error detector 7 starts detecting a communication error (step s1). Further, with the activation of the communication system, the reception counter 8 and the transmission counter 9 start counting each message A to F, and count each message A to F every time the messages A to F are transmitted and received.

Next, in step s2, the determination control unit 15 initializes the reset time.
Subsequently, in step s3, the determination control unit 15 determines whether or not the reset cycle time has elapsed after initialization of the reset time. The determination control unit 15 repeats the determination in step s3 if the reset cycle time has not elapsed, and proceeds to step s4 if it has elapsed.

  In step s4, the determination control unit 15 causes the communication error determination unit 12 to capture a predetermined message counter value and determination value. In this embodiment, it is assumed that the communication error detection unit 7 detects communication errors in the order of messages A, B.

Therefore, under the control of the determination control unit 15, the communication error determination unit 12 first reads the reception count value of the message A from the reception counter 8, reads the transmission count value of the message A from the transmission counter 9, and the first determination The first determination value corresponding to the message A is read from the value storage unit 10, and the second determination value corresponding to the message A is read from the second determination value storage unit 11. Note that the read reception count value is equal to the number of messages A received by the reception buffer 4A, and the read transmission count value is equal to the number of messages A transmitted from the transmission buffer 5A.
After reading the count value and determination value, the process proceeds to step s5.

In step s5, the first determination unit 16 compares the reception counter value with the first determination value to calculate the reception comparison result value, and compares the transmission counter value with the second determination value. The transmission comparison result value is calculated. If the reception comparison result value is less than or equal to the first tolerance value and the transmission comparison result is less than or equal to the second tolerance value, the process proceeds to step s6, where it is determined that the communication is normal, and then the process proceeds to step s11. . On the other hand, otherwise, that is, when the reception comparison result value is larger than the first allowable value or the transmission comparison result is larger than the second allowable value, the process proceeds to step s7 through the NO route of step s5. move on.

In step s7, the second determination unit 17 compares the reception counter value with the first determination value. Specifically, it is determined whether or not the reception comparison result, which is the absolute value of the difference between the reception counter value and the first determination value, is greater than the first allowable value. If the reception comparison result is larger than the first allowable value, the process proceeds to step s8 through the YES route in step s7. Otherwise, the process proceeds to step s9 through the NO route in step s7. In step s8, the second determination unit 17 determines that a first communication error has occurred in the communication system. On the other hand, in step s9, since it is determined that the reception comparison result value is equal to or smaller than the first allowable value and the transmission comparison result value is larger than the second allowable value, the second determination unit 17 It is determined that a second communication error has occurred in the communication system.
After steps s8 and s9, the process proceeds to step s10.

  In step s10, error processing is performed. Specifically, the error processing unit 14 controls the indicator of the vehicle to display the occurrence of the first communication error or the second communication error determined to have occurred. Thereafter, the process proceeds to step s11.

  In step s11, the determination control unit 15 determines whether or not communication errors of all messages A to F have been detected. If all messages A to F have been detected, the process proceeds to step s12. If all messages have not been detected, the process returns to step s4, and the counter values of the next messages B, C. The determination values are sequentially read by the communication error determination unit 12, and steps s4 to s11 are repeated to detect a communication error.

In step s12, since the communication error detection of all the messages A to F is completed, the determination control unit 15 controls the counter reset unit 13 to receive the reception counter value in the reception counter 8 and the transmission counter value of the transmission counter unit 11. Are reset to zero respectively.
And it returns to step s2 and repeats said communication error detection.
As described above, the gateway device 1 determines whether or not the first communication error and the second communication error have occurred, and detects the communication error.

As described above, the gateway device 1 and the communication system according to the present embodiment can detect where a communication error occurs in the communication system.
That is, by determining whether or not a first communication error has occurred, it is possible to detect a communication error that occurs from the node devices 2 and 3 to the first networks CAN1 and CAN2 in the communication system. Further, by determining whether or not the second communication error has occurred, it is possible to detect a communication error caused by the communication error in the gateway device 1 in the communication system.

  In particular, in a multi-master type network such as CAN, it has been extremely difficult to specify the location where a communication error has occurred. Therefore, the configuration of the gateway device 1 and the communication system according to the present embodiment is used to configure the communication system. Being able to detect where a communication error has occurred is a huge advantage.

Further, according to the gateway device 1 and the communication system of the present embodiment, even when two or more messages A to F are transmitted and received between the networks CAN1 and CAN2 of the communication system, a communication error is detected for each message A to F. Can be done.
If the same reset cycle time is provided in the entire communication system as in the present embodiment, all the node devices 2 and 3 on the networks CAN1 and CAN2 connected to the gateway device 1, that is, the gateway device 1 is used. It is possible to monitor all the node devices 2 and 3 that transmit and receive the messages A to F at the same timing.

As mentioned above, although one Embodiment of this invention was described in detail, this invention is not limited to said Embodiment, In the range which does not deviate from the summary of this invention, it can change arbitrarily and can implement.
For example, in the above-described embodiment, both the first communication error and the second communication error can be determined. However, only one of these may be determined as appropriate.

  Further, the communication error detection procedure is not limited to that of the above-described embodiment, and can be implemented with any modification as long as the first communication error or the second communication error can be detected. For example, the communication error may be detected as shown in the flowchart of FIG. That is, in the procedure of FIG. 5, the reception comparison result value is compared with the first allowable value in step s5 ′, and if the reception comparison result value is equal to or smaller than the first allowable value, the process proceeds to step s7 ′; Proceed to step 1 to determine the first communication error. In step s7 ', the transmission comparison result value is compared with the second allowable value. If the transmission comparison result value is equal to or smaller than the second allowable value, the process proceeds to step s6, where it is determined that the communication is normal. Proceeding to step s9, a second communication error is determined. Even in such a detection procedure, it is possible to detect the first communication error and the second communication error and detect where the communication error occurs in the communication system. Note that the steps shown in FIG. 5 using the same reference numerals as in FIG. 4 represent the same steps as in FIG.

  Further, in the above-described embodiment, the in-vehicle LAN using the CAN has been described as an example. However, the present invention is applicable to a communication system using a protocol other than the CAN and a communication system using a network other than the in-vehicle LAN. Can be applied.

In the above embodiment, the case where the node device periodically transmits a message has been described as an example. However, the communication error can be detected even when the message is not periodically transmitted. For example, if the first determination value, the second determination value, the first allowable value, and the second allowable value are set experimentally or empirically, or set as a compatible value by feedback, the system may be changed. Even if various communication states change, it can respond flexibly.
Furthermore, the reset cycle time is not constant in all communication systems, and different reset cycle times may be used for each message, each source node device, and the like.

Further, a specific error processing method in the error processing unit 14 is arbitrary. For example, the occurrence of a communication error and the content of the communication error may be recorded. In that case, since the position where the communication error occurs can be easily specified at the time of repair, the repair can be performed efficiently.
Furthermore, as the first and second networks connected by the gateway device of the present invention, a known network such as a star type or a ring type other than the bus type may be used arbitrarily.

  The gateway device and communication system with a communication error detection function of the present invention can be widely used in any field using a communication system, including FA (factory automation), ships, medical equipment, industrial equipment, etc. It is suitable for use in a communication system using CAN such as a vehicle communication system.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram schematically illustrating an outline of a communication system and a gateway device according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional block diagram for explaining a functional configuration of a communication error detection unit, describing an embodiment of the present invention. An embodiment of the present invention will be described. (A) and (b) are diagrams for explaining counting of a reception counter value and a transmission counter value, respectively. FIG. 10 is a flowchart for explaining a procedure for detecting a communication error, explaining one embodiment of the present invention. It is a flowchart explaining the point of communication error detection, explaining the modification of one Embodiment of this invention.

Explanation of symbols

1 Gateway device 2, 3 Node device (transmitting device, receiving device)
4A to 4F Reception buffer 5A to 5F Transmission buffer 6 Controller 7 Communication error detection unit 8 Reception counter 9 Transmission counter 10 First determination value storage unit 11 Second determination value storage unit 12 Communication error determination unit (first communication error determination means, Second communication error determination means)
13 counter reset unit 14 error processing unit 15 determination control unit 16 first determination unit 17 second determination unit

Claims (8)

The first network and the second network so that a message transmitted from a transmission device connected to the first network to a reception device connected to the second network is received by the reception device; A gateway device for connecting
Receiving means for receiving the message transmitted from the transmitting device via the first network;
Transmitting means for transmitting the message received by the receiving means to the receiving device via the second network;
Reception counting means for counting messages received by the receiving means;
Transmission counting means for counting messages transmitted by the transmission means;
A counting value in said transmit counting means, when the difference between the second judgment value which the gateway device is based on the number of messages to be transmitted and the transmission unit in the normal is greater than the second allowable value, the gateway equipment A gateway device transmission abnormality determination means for determining the transmission abnormality of the message of ,
The transmission abnormality determining means in the gateway apparatus has a difference between a count value in the reception counting means and a first determination value based on the number of messages that the receiving means should receive when the transmitting apparatus is normal is less than or equal to a first allowable value. The determination is performed when the difference is greater than the first allowable value, and the determination is not performed.
A gateway device with a communication error detection function.   A transmission abnormality determination means in the transmission device that determines transmission abnormality of the message from the transmission device based on the counting result of the reception counting means;
The gateway device with a communication error detection function according to claim 1. The receiving means has a reception buffer for receiving a message transmitted at a predetermined cycle;
The reception counting means counts the message stored in the reception buffer;
The transmission apparatus transmission abnormality determination means includes:
Before Symbol determines the first judgment value, the transmission error of the message from the transmitting device based on a result of comparison between the count value of the receiving counter means,
The gateway device with a communication error detection function according to claim 2 . The transmission means includes a transmission buffer for transmitting the message received by the reception means at a predetermined cycle;
The transmission counting unit, count the messages that are sent from the transmission buffer,
Wherein the communication error detection function with the gateway device according to any one of claims 1-3. Counting time setting means for setting a time interval for the reception counting means and the transmission counting means to count the message;
A reset means for resetting the count values of the reception counting means and the transmission counting means when the time set by the counting time setting means has elapsed ,
The gateway device according to claim 1, wherein the gateway device is characterized by that. The first network and the second network so that a message transmitted from a transmission device connected to the first network to a reception device connected to the second network is received by the reception device; A gateway device for connecting
Receiving means for receiving the message transmitted from the transmitting device via the first network;
Transmitting means for transmitting the message received by the receiving means to the receiving device via the second network;
Reception counting means for counting messages received by the receiving means;
Transmission counting means for counting messages transmitted by the transmission means;
First communication error determination means for determining an abnormal transmission of a message from the transmission device based on a counting result of the reception counting means;
Second communication error determining means for determining a transmission error of the message of the gateway device based on a counting result of the transmission counting means ;
When the transmission error of the message from the transmission device is determined by the first communication error determination unit, the determination by the second communication error determination unit is not performed.
A gateway device with a communication error detection function. The transmission means includes a transmission buffer for transmitting the message received by the reception means at a predetermined cycle;
The transmission counting means counts the message transmitted from the transmission buffer,
The second communication error determination means includes
Determining an abnormal transmission of a message from the gateway device based on a comparison result between a second determination value based on the number of messages to be transmitted by the transmission unit and the count value of the transmission counting unit when the gateway device is normal ;
The gateway device with a communication error detection function according to claim 6. A first network to which the transmitting device is connected;
A second network to which the receiving device is connected;
The gateway device according to claim 1, which is connected between the first network and the second network .
A communication system with a communication error detection function.

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