JP5966957B2 - Network monitoring apparatus and network monitoring method - Google Patents

Description

  The present invention relates to a network monitoring device and a network monitoring method for monitoring a state of a network to which a plurality of communication devices are connected in a vehicle or the like.

  As is well known, vehicles such as automobiles include an electronic control unit (ECU) that constitutes a navigation system, an ECU that electronically controls various devices such as an engine and a brake, a meter that displays various states of the vehicle, and the like. Many ECUs such as an ECU for controlling the devices are mounted. Each of these ECUs is connected to a data communication network, and various types of data are transmitted and received between the ECUs via the network in the vehicle. One such network is a controller area network (CAN).

  On the other hand, the processing contents and processing amount of data by each ECU vary depending on the traveling state of the vehicle, and accordingly, the communication amount and communication frequency between the ECUs also vary. And depending on such fluctuations in communication volume and communication frequency, data transmission / reception between the ECUs is concentrated, resulting in an increase in communication load on the network, which may cause communication delays and the like. Therefore, conventionally, there is a technique for monitoring the load state of a network, for example, as in the system described in Patent Document 1.

  The system described in Patent Document 1 monitors a network load (bus load) by a gateway device connected to a plurality of networks including one CAN bus. That is, the gateway device monitors a frame of a communication message sent to the CAN bus and monitors a bus load (communication load) on the CAN bus, and adjusts the bus load according to the bus load state. And a bus load adjusting means. Among these, the bus load monitoring means monitors the bus load by setting all message IDs at the communication speed designated on the bus side for which the bus load is to be calculated to be receivable. That is, the bus load (communication load) of the CAN bus is calculated based on the monitoring of all message IDs at the designated communication speed.

JP 2006-287738 A

  By the way, in recent years, there is a concern that the amount of communication increased due to higher functionality of the vehicle increases the communication load of the network and causes delay in communication. For this reason, even if it exists in a CAN bus, monitoring the network in real time is examined. On the other hand, higher performance of the vehicle also increases the processing load of each ECU mounted on the vehicle, but monitoring of the communication load of the network as described above reduces the processing load of the ECU, which tends to increase only. It can be even higher.

  The present invention has been made in view of such circumstances, and its purpose is in a network in which communication messages based on the CAN protocol are transmitted and received, and the processing load required for monitoring the communication load can be reduced. A network monitoring apparatus and a network monitoring method are provided.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
In order to achieve the above object, a network monitoring apparatus provided by the present invention is a network monitoring apparatus that monitors a communication load of a network through which communication messages based on the CAN protocol are transmitted and received, and for two communication messages having different message IDs. A detection unit that detects a communication interval of communication messages having the same message ID, and a transmission interval in which each communication interval of two communication messages having different detected message IDs is determined corresponding to each communication message. If it is too long, it is determined that the communication load of the network is high, on the condition that both the communication intervals of the two communication messages having different message IDs are determined as delays, and the delay determination unit that is determined as a delay, One of two communication messages with different message IDs That only square communication distance is determined as a delay on the condition, and a determination unit that determines an abnormality in the transmission of the communication message it is determined as a delay has occurred, the detecting unit, the same cycle transmission interval The gist is to detect the communication interval of the communication message .

Network monitoring method provided by the present invention in order to achieve the above object, there is provided a network monitoring method of monitoring a communication load of a network communication message based on the CAN protocol is transmitted and received by the network monitoring apparatus, the detection unit, a message The step of detecting the communication interval of communication messages having the same message ID for two communication messages having different IDs, and the communication interval of the two communication messages having different detected message IDs in the delay determining unit When it is longer than the transmission interval determined corresponding to the message, the step of determining as a delay, and when each communication interval of two communication messages having different message IDs is determined as a delay by the determination unit , It is determined that the network communication load is high, and the message When D is only one of the communication distance of two different communication message is determined as a delay, and a step of determining an abnormality in the transmission of the determined communication message as the delay has occurred, the detecting The gist of the process is to detect a communication interval of communication messages having the same transmission interval .

  According to such a configuration or method, it is determined that the communication load of the network has increased, and two communications with different message IDs are given to communication messages based on the CAN protocol as different values for each type of communication message. This can be done based on detection of message communication intervals. Therefore, compared with the case where all communication messages flowing through the network are monitored and detected, the processing load required for detecting that the communication load of the network is increased by monitoring and detecting two communication messages having different message IDs. Can be reduced. As a result, an increase in processing load required for monitoring the communication load of the network can be suppressed.

Note that if the network communication load is monitored based only on a communication message with one message ID, there is a risk that it may not be possible to distinguish between cases where there is an abnormality in transmission of the communication message and cases where the network communication load is increasing. There is. Therefore, the communication interval between two communication messages having different message IDs is monitored. As a result, it is possible to distinguish between a case where the communication load of the network is increasing and a case where an abnormality occurs in the transmission of the communication message, and an increase in the communication load of the network can be appropriately determined. It becomes like this. Moreover, when both of the communication intervals of the two communication messages are delayed, it is determined that the communication load of the network has increased, and when only one of the communication intervals is delayed, an abnormality has occurred in the transmission of the communication message. It can also be estimated. As a result, the maintenance management of the communication network is also suitably performed.
In addition, according to such a configuration, if the transmission intervals set for two communication messages having different message IDs are the same, the communication interval between the two communication messages is set when the communication load of the network increases. It is likely to be long as well. As described above, by using communication messages having the same transmission interval, it becomes possible to appropriately determine that the communication load of the network has increased, and also to appropriately determine abnormality that has occurred in transmission of communication messages. become.

  As a preferred configuration, at least two transmission devices are connected to the network, and a communication message with one message ID of two communication messages having different message IDs is one transmission device of the at least two transmission devices. The communication message with the other message ID is transmitted from the other transmitting device of the at least two transmitting devices.

  According to such a configuration, both communication messages transmitted from at least two transmission devices are monitored to delay the communication interval. As a result, it is possible to determine that the communication load of the network is high, excluding the case that is not caused by the high communication load of the network but due to abnormal transmission of the communication message of the transmission device. That is, it becomes possible to more appropriately determine that the communication load of the network is high.

  In addition, when only one of the communication messages has a long communication interval, the transmitting device that transmits the communication message is specified, so that the transmitting device in which an abnormality has occurred can be detected, and the transmitting device that configures the network Can be suitably managed.

As a preferred configuration, the detection unit detects a communication interval of communication messages set so as to be transmitted periodically.
According to such a configuration, if the detected communication interval is a communication interval of a communication message transmitted at a constant period, the communication interval of the communication message becomes long, for example, it becomes easy to compare with the corresponding transmission interval. It becomes easy to detect that the

As a preferred configuration, the delay determination unit does not use the communication interval of the next communication message having the same message ID as the communication message determined as the delay for the determination of the delay.
In the CAN protocol, there is a possibility that the communication interval of the communication message transmitted next to the communication message delayed from the set transmission interval is shorter than the set transmission interval.

  According to such a configuration, the communication interval of the communication message that may shorten the communication interval by being transmitted after the communication message with the delayed communication interval is not used for the determination of the delay. As a result, the influence of the communication interval shortened due to the increase in the communication load on the network on the determination of the delay can be reduced, so that the determination of the delay of the communication message is appropriately performed.

As a preferred configuration, the detection unit detects communication intervals of two communication messages having different message IDs at the same interval.
According to such a configuration, since the interval for detecting the communication interval of two communication messages having different message IDs is the same interval, the determination of the delay of the two detected communication intervals can be synchronized. Become. That is, it is possible to determine that the communication load on the network is high by determining the synchronized delay. In particular, if the timing at which the communication interval between two communication messages is detected is made closer, the synchronization can be improved, and the responsiveness of determination such as a high communication load on the network can be increased. As a result, a determination that the communication load on the network is high is preferably made.

  As a preferred configuration, the delay determination unit determines whether or not there is a delay in accordance with the timing at which the communication interval is detected, and the determination unit determines whether the delay of the network is in accordance with the timing at which the delay is determined by the delay determination unit. It is determined that the communication load is high or that there is an abnormality in the transmission of the communication message.

  According to such a configuration, it is possible to determine that the communication load is high within a short period of time after detecting the communication interval by determining the presence or absence of a delay in accordance with the interval at which the communication interval is detected. That is, it is possible to determine with high responsiveness that the communication load is high. Thereby, it becomes possible to quickly cope with an increase in communication load.

  As a preferred configuration, when the communication interval of one of two communication messages having different message IDs is determined as a delay, the determination unit determines whether the communication interval of the other communication message is also determined as a delay. Based on this, it is determined that the communication load of the network is high or that there is an abnormality in the transmission of the communication message.

  According to such a configuration, after it is determined that one of the communication intervals is delayed, it is determined whether there is a delay in the other communication interval. It is possible to reduce the processing load required to determine whether an abnormality has occurred.

  As a preferred configuration, the detection unit detects a time when the communication message having the same message ID is detected N times (N is a natural number) as the communication interval, and the delay determination unit has the same message ID. Is a transmission interval determined in correspondence with each message.

  According to such a configuration, the communication interval to be detected can be the time required when a communication message is detected a plurality of times. When a communication message with a short transmission interval is set, the communication interval is detected at each transmission interval, and the processing load increases. Therefore, by extending the detection interval by detecting the communication interval when a communication message is detected a plurality of times, the processing load required for detection processing, determination processing, determination processing, and the like can be suppressed.

The block diagram which shows the schematic structure about one Embodiment which actualized the communication system provided with the network monitoring apparatus which concerns on this invention. The schematic diagram which shows typically the communication space | interval of the two communication messages transmitted when the communication load is normal in the communication system of the embodiment. The schematic diagram which shows typically the communication space | interval of two communication messages transmitted when communication load is high in the communication system of the embodiment. The schematic diagram explaining a state when the communication interval of the communication message of the embodiment is normal. The schematic diagram explaining a state when the communication interval of the communication message of the embodiment is long. The schematic diagram which shows the example of the timing which detects the communication space | interval of the two communication messages transmitted in the communication system of the embodiment. The schematic diagram which shows typically the timing at which the delay determination of the communication interval of each communication message is performed in the communication system of the embodiment. The sequence diagram which shows the procedure in which the delay determination and abnormality determination of the communication interval of each communication message are performed in the communication system of the embodiment.

An embodiment embodying a communication system including a network monitoring device according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the vehicle 1 includes a communication system including a network monitoring device. The communication system includes a first electronic control unit (ECU) 10 as a transmission device, second to fifth ECUs 11 to 14 as transmission devices having the same configuration as the first ECU 10, and a network monitoring device. The monitoring ECU 20 includes a communication bus 15 that connects the first to fifth ECUs 10 to 14 and the monitoring ECU 20 so that they can communicate with each other. Thus, the first to fifth ECUs 10 to 14 can exchange (transmit and receive) various control information and the like via the communication bus 15. In addition, the monitoring ECU 20 can receive various control information and the like exchanged between the first to fifth ECUs 10 to 14 via the communication bus 15. Since the communication system is configured as a CAN (Controller Area Network) network, the CAN protocol is applied as a communication protocol.

  The communication bus 15 includes a communication line such as a twist cable, and transmits a communication message as a unit in communication in the CAN protocol via the communication line. The communication bus 15 may include wireless communication as a part of the communication path, or may include a path that passes through another network via a gateway or the like.

  The CAN protocol defines a frame that is a structure of a communication message, and an area for storing a “message ID” indicating the content of the communication message is provided in the frame. The message ID has a specific value determined for each type of communication message, and each ECU transmits a message ID corresponding to the content of information included in the communication message to be transmitted, and is included in the received communication message. The content of the information to be determined is determined based on the message ID.

  In the CAN protocol, since a message ID is determined for each information, an ECU that outputs a communication message to which a specific message ID is assigned is specified. For example, the first ECU 10 is the only ECU that transmits the first communication message M1 having a specific message ID, and the fourth ECU 13 is a specific message that is different from the message ID of the first communication message M1. It is the only ECU that transmits the second communication message M2 having the ID. On the other hand, all ECUs connected to the communication bus 15 can receive the communication message transmitted to the communication bus 15 unless the received communication message is regulated based on the message ID. For example, the monitoring ECU 20 can receive the first communication message M1 and the second communication message M2 transmitted to the communication bus 15, respectively. Note that various communication messages Mx and My (see FIGS. 2 and 3) other than the communication messages of the first communication message M1 and the second communication message M2 are displayed on the communication bus 15 according to the vehicle situation at that time. It is increasing and decreasing. That is, if the amount of each communication message flowing through the communication bus 15 is normal, the communication load of the communication bus 15 is normal. If the amount of each communication message is large, the communication load of the communication bus 15 is Get higher.

  Each of the first to fifth ECUs 10 to 14 is a control device that is used for various controls of the vehicle 1, for example, an ECU that controls a drive system, a traveling system, a vehicle body system, an information device system, or the like. is there. For example, an ECU for a drive system is an ECU for an engine, an ECU for a travel system is an ECU for a steering or a brake ECU, and an ECU for controlling a vehicle body system An ECU for a light and an ECU for a window can be mentioned, and an ECU for controlling an information device system includes an ECU for car navigation.

  Each of the first to fifth ECUs 10 to 14 and the monitoring ECU 20 includes an information processing unit (not shown) that executes processes required for various controls, and a CAN controller (not shown) that transmits and receives communication messages based on the CAN protocol. ). Since the information processing unit and the CAN controller are connected via an internal bus or the like, data related to various types of information included in the communication message can be exchanged between the information processing unit and the CAN controller. .

  The CAN controller transmits and receives communication messages to and from the communication bus 15. The CAN controller receives a communication message based on the CAN protocol and transmits a communication message based on the CAN protocol. That is, each ECU transmits / receives a communication message to / from the communication bus 15 via the CAN controller.

  The information processing unit includes a microcomputer having an arithmetic device (CPU) and a storage device. That is, the information processing unit temporarily stores an arithmetic device that executes arithmetic processing of the control program, a read-only memory (ROM) that stores the control program and data, and the arithmetic result of the arithmetic device. Volatile memory (RAM). Thus, the information processing unit reads a control program held in the storage device into the arithmetic device and executes it, thereby providing a predetermined function to the control target and controlling the control target.

  As shown in FIG. 2, for example, the first ECU 10 transmits the first communication message M1 to the communication bus 15 at a predetermined first transmission interval T1. That is, the information processing unit of the first ECU 10 instructs the CAN controller to transmit the first communication message M1 at the transmission timing for each first transmission interval T1. When the communication load of the network in the communication bus 15 is not high, the CAN controller of the first ECU 10 sends the first communication message M1 to the communication bus 15 according to the instruction of the transmission timing of the first communication message M1. Can be sent to. For this reason, the first communication message M1 has a value close to the transmission interval T1 in which the communication interval ΔT1 is set, and transmission is not delayed. Note that the value close to the transmission interval T1 is a time within a range deviating from the transmission interval T1 when the communication load of the network is not high, and the range is determined based on experiments and experiences, for example, ± 10 of the transmission interval T1. %.

  On the other hand, as shown in FIG. 3, when the communication load of the network in the communication bus 15 is high, the CAN controller of the first ECU 10 can receive the instruction of the transmission timing of the first communication message M1 even if the communication bus 15 Is busy, the first communication message M1 cannot be transmitted in response to the transmission timing instruction. That is, the CAN controller of the first ECU 10 requires the delay time D1 until the first communication message M1 is transmitted. For this reason, the first communication message M1 becomes longer by the delay time D1 than the transmission interval T1 in which the communication interval ΔT1 is set, and transmission is delayed.

  As shown in FIG. 2, for example, the fourth ECU 13 transmits the second communication message M2 to the communication bus 15 at a predetermined second transmission interval T2. That is, the fourth ECU 13 instructs the CAN controller to transmit the second communication message M2 at the transmission timing for each second transmission interval T2. When the communication load of the network in the communication bus 15 is not high, the CAN controller of the fourth ECU 13 sends the second communication message M2 to the communication bus 15 according to the instruction of the transmission timing of the second communication message M2. Can be sent to. For this reason, the second communication message M2 has a value close to the transmission interval T2 in which the communication interval ΔT2 is set, and transmission is not delayed. The value close to the transmission interval T2 is a time within a range deviating from the transmission interval T2 when the communication load of the network is not high, and the range is determined from experiments and experiences. For example, ± 10 of the transmission interval T2 %.

In the present embodiment, a case where the first transmission interval T1 and the second transmission interval T2 are the same interval will be described unless otherwise specified.
On the other hand, as shown in FIG. 3, when the communication load of the network in the communication bus 15 is high, the CAN controller of the fourth ECU 13 receives the instruction of the transmission timing of the second communication message M2, and the communication bus 15 Is busy, the second communication message M2 cannot be transmitted in response to the transmission timing instruction. That is, the CAN controller of the fourth ECU 13 requires the delay time D2 before transmitting the second communication message M2. For this reason, the second communication message M2 becomes longer by the delay time D2 than the transmission interval T2 in which the communication interval ΔT2 is set, and transmission is delayed.

  The monitoring ECU 20 shown in FIG. 1 has a communication load that has increased as a control program in the storage device of the information processing unit, a program for detecting a communication interval of communication messages, a program for determining that the communication interval is long. And a program for obtaining a log such as a communication interval. The monitoring ECU 20 holds various parameters necessary for the processing of the above-described program in the storage device of the information processing unit. The parameters include, for example, that the communication interval detection target is the first communication message M1 and the second communication message M2, the transmission interval T1 defined in the first communication message M1, and the second communication. A transmission interval T2 defined in the message M2 is included. The monitoring ECU 20 reads these into the arithmetic device and executes them to provide a predetermined function to the controlled object and control the controlled object. That is, the monitoring ECU 20 includes a communication interval detection unit 21 as a detection unit having a function of detecting a communication interval by executing a program for detecting a communication interval, and a program for determining that the communication interval is long is executed. Thus, a delay determination unit 22 having a function of determining that the communication interval is long is provided. The monitoring ECU 20 includes an abnormality determination unit 23 as a determination unit having a function of determining that the communication load is increased by executing a program for determining that the communication load is increased. A log acquisition unit 24 that acquires a log such as a communication interval by executing a program that acquires a log such as an interval is provided.

The communication interval detector 21 detects the communication interval of the communication message received from the communication bus 15 via the CAN controller.
As shown in FIG. 2, when the communication load of the network on the communication bus 15 is not high, the communication interval detector 21 detects a time close to the transmission interval T1 as the communication interval ΔT1 of the first communication message M1, A time close to the transmission interval T2 is detected as the communication interval ΔT2 of the second communication message M2.

  On the other hand, as shown in FIG. 3, when the communication load of the network in the communication bus 15 is high, the communication interval detector 21 has a delay time longer than the first transmission interval T1 as the communication interval ΔT1 of the first communication message M1. A time longer by D1 is detected, and a time longer than the second transmission interval T2 by the delay time D2 is detected as the communication interval ΔT2 of the second communication message M2.

  That is, as shown in FIG. 4 and FIG. 5, the communication interval detection unit 21 receives the first communication message M1 and receives the first communication message M1 as the value of the first communication message M1. ΔT15 is sequentially detected. Although not shown, the communication interval detection unit 21 receives the second communication message M2 for the second communication message M2 as in the case of detecting the communication interval ΔT1 of the first communication message M1. ΔT2 is detected.

  As shown in FIG. 6, the communication interval detector 21 detects the communication interval ΔT3 corresponding to the predetermined number of times of the first communication message M1 every time the first communication message M1 is received a predetermined number of times. It may be. The communication interval detection unit 21 can specify the number of receptions of the first communication message M1 by, for example, measuring the number of receptions of the first communication message M1 with a counter. For example, every time the first communication message M1 is received five times, the time from the first transmission time of the first communication message M1 to the fifth transmission time of the first communication message M1 is set as the communication interval ΔT3. May be detected. At this time, the communication interval ΔT3 is detected with a length about four times the first transmission interval T1 unless the communication load is high. By doing so, it is possible to suppress an increase in processing load required for detecting a communication interval of communication messages. Note that the communication interval ΔT4 for the predetermined number of times may be similarly detected for the second communication message M2.

  Further, as shown in FIG. 6, even if the first transmission interval T1 for the first communication message M1 and the second transmission interval T2 for the second communication message M2 are different, Transmission intervals T3 and T4 are set as common multiples of the transmission interval T1 and the second transmission interval T2. The number of first transmission intervals T1 that will be the set transmission interval T3 is the number of times of reception of the first communication message M1, and the number of second transmission intervals T2 that are also the set transmission interval T4 is the second communication. It may be the number of times the message M2 is received. For example, when the first transmission interval T1 is 20 ms and the second transmission interval T2 is 40 ms, if the transmission intervals T3 and T4 as common multiples are set to 200 ms, the number of receptions of the first communication message M1 is 10 times. The number of times the second communication message M2 is received is five. Thereby, when the communication load of the network is not high, the communication interval ΔT3 of the first communication message M1 and the communication interval ΔT4 of the second communication message M2 are set to transmission intervals T3 and T4 which are common multiples of the respective transmission intervals. It becomes possible to compare. In this way, by setting the same transmission interval (200 ms) by adjusting the number of receptions, etc., the timing for detecting the communication interval can be made closer, so that two communication messages with the same transmission interval are used. Similarly, the detection timing can be synchronized. In addition, if the two detection timings are synchronized, the time required to make an abnormality determination for determining a delay in communication intervals thereafter and determining that the communication load on the network is high, etc., is shortened, and the real-time nature of such determination and determination is improved. It becomes like.

  The delay determination unit 22 illustrated in FIG. 1 compares the communication interval (for example, ΔT1, ΔT2) detected by the communication interval detection unit 21 with the corresponding transmission interval (for example, T1, T2), thereby supporting the communication interval. It is determined that the transmission interval is longer than the transmission interval to be delayed.

  As illustrated in FIG. 7, the delay determination unit 22 determines the transmission delay of the first communication message M1 every time the communication interval ΔT1 of the first communication message M1 is detected (determination A). Further, the delay determination unit 22 determines the transmission delay of the second communication message M2 every time the communication interval ΔT2 of the second communication message M2 is detected (determination B). For example, when the communication interval ΔT1 of the first communication message M1 and the communication interval ΔT2 of the second communication message M2 are substantially the same, the determination interval TC1 is substantially the same as the communication intervals ΔT1 and ΔT2. Further, as shown in FIG. 7, if the detection timing of the communication interval ΔT1 and the detection timing of the communication interval ΔT2 are synchronized, the results of the determination A and the determination B can be obtained at the same time.

  The determination A and the determination B are not determined every time the first or second communication message M1 or M2 is received, but based on the fact that the first or second communication message M1 or M2 is received a predetermined number of times. The delay may be determined. For example, based on the fact that the communication intervals ΔT1, ΔT2 of the received first or second communication message M1, M2 are 10 times longer than the transmission intervals T1, T2, the first or second communication message M1, The transmission delay of M2 may be determined. As a result, it is possible to suitably determine transmission delay, such as eliminating temporary changes.

  Each time the communication interval ΔT11 to ΔT15 (see FIGS. 4 and 5) of the first communication message M1 is detected, the delay determination unit 22 compares the detected communication intervals ΔT11 to ΔT15 with the corresponding transmission interval T1. As a result of the comparison, the delay determination unit 22 determines that the detected communication intervals ΔT11 to ΔT15 are longer than the transmission interval T1 and a delay occurs, or that the delay is not long and no delay occurs. Although not shown, the delay determination unit 22 compares the detected communication interval ΔT2 with the corresponding transmission interval T2 each time the communication interval ΔT2 of the second communication message M2 is detected, and detects the detected communication. It is determined that the interval ΔT2 is longer than the transmission interval T2 and a delay occurs, or that the interval ΔT2 is not long and no delay occurs.

  As shown in FIG. 4, for example, when the communication load of the network in the communication bus 15 is not high (normal), the delay determination unit 22 determines that the communication intervals ΔT11 to ΔT15 are substantially the same as the transmission interval T1, and performs communication. It is determined that there is no delay in the intervals ΔT11 to ΔT15. That is, it is determined that there is no communication delay in the first communication message M1.

  As shown in FIG. 5, in the CAN protocol, the communication interval ΔT12 of the first communication message M1 transmitted next to the first communication message M1 delayed in transmission may be shorter than the set transmission interval T1. have. That is, the length of the communication interval ΔT1 may fluctuate due to an increase in the communication load on the network. Therefore, the communication interval ΔT12 of the communication message that may be shortened by being transmitted next to the communication message having the delayed communication interval ΔT11 is not used for the determination that the communication interval is long and the transmission is delayed. It may be. Thereby, the influence which the fluctuation | variation which arises in a communication interval by having increased the communication load of the network has on the determination of a communication delay can also be made small. That is, it is expected that the communication interval of the communication message becomes long and the detection of the occurrence of the delay in communication is performed more appropriately.

  That is, for example, when the communication load of the network in the communication bus 15 is high, the delay determination unit 22 determines that the two communication intervals ΔT11 and ΔT14 are longer than the transmission interval T1, and the three communication intervals ΔT12. , ΔT13, ΔT15 are not longer than the transmission interval T1, and it is determined that no delay occurs. Since such a change in the communication interval is caused by a high communication load on the network, the delay determining unit 22 changes the first communication message M1 based on the two communication intervals ΔT11 and ΔT14 that are longer than the transmission interval T1. Determines that a communication delay has occurred.

  The abnormality determination unit 23 determines that the communication load has increased based on the delay determination result of the delay determination unit 22. The abnormality determination unit 23 determines that there is a delay in the communication of the first communication message M1 by the delay determination unit 22 and the determination result that the communication of the second communication message M2 has a delay. Based on the above, the network abnormality is judged. The abnormality determination unit 23 determines that the network communication load is normal, the network communication load is high, or that there is an abnormality in the transmission of one communication message based on the network abnormality determination.

  As shown in FIG. 7, the abnormality determination unit 23 performs the determination A for determining the delay of the first communication message M1 and the determination B for determining the delay of the second communication message M2, An abnormality determination is performed to determine whether an abnormality has occurred in the network. Therefore, the abnormality determination unit 23 determines a network abnormality following the end of determination A and the end of determination B at each determination interval TC1.

  More specifically, the abnormality determining unit 23 determines that the communication of the first communication message M1 is not delayed and the network of the second communication message M2 is determined not to be delayed. It is determined that the communication load is normal.

  The abnormality determining unit 23 determines that the communication of the first communication message M1 is delayed and determines that the communication of the second communication message M2 is delayed. Judge that the load is high.

  Furthermore, when it is determined that the communication of the first communication message M1 is delayed while the abnormality determination unit 23 determines that the communication of the second communication message M2 is not delayed, It is determined that some abnormality has occurred in the transmission of the communication message M1. Similarly, when it is determined that the communication of the second communication message M2 is delayed, the abnormality determination unit 23 determines that the communication of the first communication message M1 is not delayed. It is determined that some abnormality has occurred in transmission of the communication message M2 of No. 2. At this time, the cause of the transmission abnormality occurring in the first communication message M1 or the second communication message M2 is, for example, an abnormality in the connection of the communication wiring, an abnormality in the processing program, an information processing unit or a CAN controller. And abnormalities in the sensors that transmit information to the ECU. In any case, based on the presence or absence of communication delay detected from the communication intervals ΔT1 and ΔT2 of the first communication message M1 and the second communication message M2, there is an abnormality related to the ECU that transmits the communication message. The occurrence can be detected.

  The log acquisition unit 24 causes the storage unit 25 to store the communication interval ΔT1 at which the first communication message M1 is detected, the communication interval ΔT2 at which the second communication message M2 is detected, and the like. The log acquisition unit 24 also stores in the storage unit 25 the determination result of the presence / absence of abnormality by the abnormality determination unit 23, the determination result of the cause of the abnormality, and the like.

  The storage unit 25 includes all or a part of a storage area provided in a known storage device, and the log data acquired by the log acquisition unit 24 is stored in the storage area. The storage unit 25 can output the stored log data to the outside through communication via the communication bus 15 or other communication paths. As a result, the communication load status of the network can be grasped later through analysis of log data or the like.

The operation will be described.
As shown in FIGS. 2 and 3, the delay determination unit 22 compares the communication interval ΔT1 of the first communication message M1 detected by the communication interval detection unit 21 with the corresponding transmission interval T1, and the communication interval ΔT1 is transmitted. It is determined whether or not the delay is longer than the interval T1. Similarly, the delay determination unit 22 compares the communication interval ΔT2 of the second communication message M2 detected by the communication interval detection unit 21 with the corresponding transmission interval T2, and the communication interval ΔT2 is delayed longer than the transmission interval T2. It is determined whether or not.

  In the case shown in FIG. 2, the delay determination unit 22 determines that the communication interval ΔT1 is not longer than the transmission interval T1 and is substantially the same, and is not delayed, and the communication interval ΔT2 is not longer than the transmission interval T2 and substantially the same. It is determined that there is no delay. Based on the determination result that the communication interval ΔT1 is not delayed by the delay determination unit 22 and the determination result that the communication interval ΔT2 is not delayed, the abnormality determination unit 23 does not have a high communication load on the network. It is determined that the communication load is normal.

  In the case shown in FIG. 3, the delay determination unit 22 determines that the communication interval ΔT1 is delayed longer than the transmission interval T1, and determines that the communication interval ΔT2 is longer than the transmission interval T2. Then, the abnormality determination unit 23 determines that the communication load of the network is high based on the determination result that the communication interval ΔT1 is delayed by the delay determination unit 22 and the determination result that the communication interval ΔT2 is also delayed. To do.

  Furthermore, the abnormality determination unit 23 determines the first communication message M1 based on the determination result that the communication interval ΔT1 is delayed by the delay determination unit 22 and the determination result that the communication interval ΔT2 is not delayed. Judge that there is an error in transmission. Thereby, it is estimated that abnormality has arisen in 1st ECU10 which transmits the 1st communication message M1.

  In addition, the abnormality determination unit 23 determines the second communication message M2 based on the determination result that the communication interval ΔT1 by the delay determination unit 22 is not delayed and the determination result that the communication interval ΔT2 is delayed. Judge that there is an error in transmission. According to this, it is presumed that an abnormality has occurred in the fourth ECU 13 that transmits the second communication message M2.

As described above, the network monitoring apparatus according to the present embodiment has the effects listed below.
(1) Two first and second communication messages having different message IDs, which are given to the communication message based on the CAN protocol as different values for each type of communication message, as a determination that the communication load of the network has increased This can be performed based on detection of communication intervals ΔT1 and ΔT2 between M1 and M2. Therefore, compared with the case where all communication messages flowing through the network are monitored and detected, the network communication load is increased by monitoring and detecting the two first and second communication messages M1, M2 having different message IDs. It is possible to reduce the processing load required to detect the occurrence. As a result, an increase in processing load required for monitoring the communication load of the network can be suppressed.

  Note that if the network communication load is monitored based only on a communication message with one message ID, there is a risk that it may not be possible to distinguish between cases where there is an abnormality in transmission of the communication message and cases where the network communication load is increasing. There is. Therefore, the communication intervals ΔT1 and ΔT2 of the two first and second communication messages M1 and M2 having different message IDs are monitored. As a result, it is possible to distinguish between a case where the communication load of the network is increasing and a case where an abnormality occurs in the transmission of the communication message, and an increase in the communication load of the network can be appropriately determined. It becomes like this. Moreover, when both of the communication intervals ΔT1 and ΔT2 of the two first and second communication messages M1 and M2 are delayed, it is determined that the communication load of the network has increased, and only one of the communication intervals is delayed. It is possible to estimate that an abnormality has occurred in the transmission of the communication message. As a result, the maintenance management of the communication network is also suitably performed.

  (2) The first and second communication messages M1 and M2 respectively transmitted from at least two ECUs, ie, the first ECU 10 and the fourth ECU 13, monitor whether the communication intervals ΔT1 and ΔT2 are delayed. As a result, it is possible to determine that the communication load of the network is high, excluding cases caused by abnormal transmission of the communication message of the ECU, not due to the high communication load of the network. That is, it becomes possible to more appropriately determine that the communication load of the network is high.

  In addition, when only one of the communication messages has a long communication interval, the ECU that transmits the communication message is specified. Therefore, the ECU in which an abnormality has occurred can be detected, and the transmission apparatus that configures the network is managed. Can be suitably performed.

  (3) If the communication intervals ΔT1 and ΔT2 detected by the communication interval detector 21 are communication intervals of the first and second communication messages M1 and M2 transmitted at a constant period, the corresponding transmission intervals T1 and T2 Thus, the process of detecting that the communication interval of communication messages is long becomes easy.

  (4) If the transmission intervals T1 and T2 set in the first and second communication messages M1 and M2 having different message IDs are the same, the first and second when the communication load of the network increases. Similarly, the communication intervals ΔT1 and ΔT2 of the communication messages are likely to be long. As described above, by using the first and second communication messages M1 and M2 having the same transmission interval T1 and T2, it becomes possible to appropriately determine that the communication load of the network has increased, and the communication message. It is also possible to appropriately determine an abnormality that has occurred in the transmission of.

  (5) In the CAN protocol, there is a possibility that the communication interval of the communication message transmitted next to the communication message delayed from the set transmission interval is shorter than the set transmission interval. Therefore, the communication interval ΔT12 of the first communication message M1, which may be shortened by being transmitted after the first communication message M1 with the communication interval ΔT11 delayed, is not used for the determination of the delay. To do. As a result, the influence of the communication interval shortened due to the increase in the communication load on the network on the determination of the delay can be reduced, so that the determination of the delay of the communication message is appropriately performed.

  (6) Since the intervals for detecting the communication intervals ΔT1, ΔT2 of two first and second communication messages having different message IDs are the same interval, the delay of the two detected communication intervals ΔT1, ΔT2 is determined. It can be synchronized. That is, it is possible to determine that the communication load on the network is high by determining the synchronized delay. In particular, if the timings for detecting the communication intervals ΔT1 and ΔT2 of the first and second communication messages M1 and M2 are made closer, the synchronization will be improved and the responsiveness of judgment such as high communication load on the network will be increased. You can also As a result, an abnormality determination such as a high communication load on the network is suitably performed.

  (7) The delay determination unit 22 determines the presence / absence of a delay at a determination interval TC1 that matches the interval at which the communication intervals ΔT1 and ΔT2 are detected, thereby detecting the communication load within a short time after detecting the communication intervals ΔT1 and ΔT2. Will be able to judge that is high. That is, it is possible to determine with high responsiveness that the communication load is high. Thereby, it becomes possible to quickly cope with an increase in communication load.

  (8) The communication interval to be detected can be the time required when a communication message is detected a plurality of times. When a communication message with a short transmission interval is set, the communication interval is detected at each transmission interval, and the processing load increases. Therefore, by extending the detection interval by detecting the communication interval when a communication message is detected a plurality of times, the processing load required for detection processing, determination processing, determination processing, and the like can be suppressed.

(Other embodiments)
In addition, the said embodiment can also be implemented with the following aspects.
In the above embodiment, the log acquisition unit 24 detects the communication interval ΔT1 where the first communication message M1 is detected, the communication interval ΔT2 where the second communication message M2 is detected, and whether there is an abnormality by the abnormality determination unit 23 The case where the storage unit 25 stores the determination result and the determination result regarding the cause of the abnormality is illustrated. However, the present invention is not limited to this, and the log acquisition unit may store at least one of the communication interval, the determination result of the presence / absence of abnormality by the abnormality determination unit, and the determination result of the cause of the abnormality in the storage unit. Further, the log acquisition unit may store various information such as position information and date / time information obtained from GPS or the like in the storage unit. As a result, it is possible to expand the application range of the network monitoring device and improve the convenience of network management.

  In the above-described embodiment, the log acquisition unit 24 has exemplified the case where the abnormality determination unit 23 stores the determination result of the presence / absence of abnormality and the determination result of the cause of the abnormality in the storage unit 25. However, the present invention is not limited to this, and the log acquisition unit may store the number of times there is an abnormality or no abnormality determined by the abnormality determination unit, the number of causes of the determined abnormality, and the like. For example, the log acquisition unit may manage each number of times so as to increase the number of times of abnormality or the like until a condition for resetting is detected. In this way, it is possible to reduce the amount of various types of information stored in the storage unit.

  -In above-mentioned embodiment, log acquisition part 24 illustrated about the case where various information are memorize | stored in the memory | storage part 25. FIG. However, the present invention is not limited to this, and the log acquisition unit may store information that needs to be used immediately in the RAM of the information processing unit. As a result, the real-time property of the rationale regarding abnormality determination can be improved.

  In the above embodiment, the delay determination unit 22 transmits the first communication message based on the detected communication intervals ΔT11 to ΔT15 each time the communication intervals ΔT11 to ΔT15 of the first communication message M1 are detected. The case where it is determined whether or not a delay has occurred is illustrated. However, the present invention is not limited to this, and the delay determination unit may determine whether or not there is a delay in transmission based on the communication interval required when the communication message of the first communication message is received a plurality of times. For example, the delay determination unit may determine that there is a delay in communication on the condition that the communication interval is continuously longer than the transmission interval by a predetermined number of times (such as 50 times). In addition, the delay determination unit is provided on the condition that the communication interval is longer than the predetermined number of determinations (such as 40 times), that is, a predetermined ratio or more, by comparing the communication interval of the predetermined number (such as 50 times) and the transmission interval. It may be determined that there is a delay in transmission. For example, the determination A and the determination B illustrated in FIG. 7 may determine that there is a delay in transmission of the communication message due to such a condition.

As a result, the level relating to the delay determination is changed depending on the state of the communication load of the network, so that the delay determination can be performed more suitably.
In the case of the above configuration, based on the determination that the communication interval is long, for example, the predetermined number of 50 times is reduced to 45 times, the number of 40 times of determination is reduced to 35 times, or a predetermined ratio May be reduced. As a result, the level at which an abnormality is detected can be increased in accordance with an increase in the frequency of delay occurring in the communication interval of communication messages, and management related to detection of communication load on the network can be suitably performed. Become.

  In the above embodiment, the case where each communication interval ΔT1, ΔT2 is detected in response to the transmission of the first communication message M1 or the second communication message M2 has been illustrated. However, the present invention is not limited to this. First, only the communication interval of the first communication message is detected, and the communication of the second communication message is performed on the condition that the communication interval of the first communication message is long (delayed). You may switch so that an interval may be detected. Log data can also be used to determine such switching.

  At this time, the abnormality determination unit may make an abnormality determination based on the previous delay determination (determination A) and the delay determination performed next (determination B). For example, first, only the communication interval of the message ID “0x200” is detected, and after it is determined that there is a delay in the communication of this communication message, then only the communication interval of the message ID “0x300” is detected. It may be determined whether or not there is a delay in the transmission of the communication message. Then, when it is determined that there is a delay in the transmission of the communication message with the message ID “0x300”, the abnormality determination unit determines that the communication load is high, and transmits the communication message with the message ID “0x300”. When it is determined that there is no delay, it may be determined that there is an abnormality in transmission of the message ID “0x200”. Note that after the determination of the message ID “0x300” is completed, the message ID subject to delay determination may be returned to “0x200”.

  That is, by determining whether or not there is a delay in the other communication interval ΔT1, ΔT2 after it is determined that one of the communication intervals ΔT1, ΔT2 is delayed, it is possible to detect the communication interval, determine the delay, The processing load related to the determination can be reduced. As a result, the design flexibility and application range of the network monitoring device can be expanded.

  In the above embodiment, the case where the abnormality determination unit 23 determines the abnormality of the network following the determination A and the determination B is illustrated. However, the present invention is not limited thereto, and the abnormality determination unit may make an abnormality determination based on a plurality of determinations A and a plurality of determinations B. For example, when the determination A or the determination B determines that a delay has occurred in transmission continuously for a predetermined number of times (such as 10 times) or more, an abnormality determination may be made.

As a result, the level relating to the abnormality determination is changed depending on the communication load status of the network, so that the abnormality determination can be performed more suitably.
In the above embodiment, the case where the abnormality determination unit 23 determines the abnormality of the network following the determination A and the determination B is illustrated. However, the present invention is not limited to this, and after confirming that the determination A has been completed, the abnormality determination may be performed after confirming that the determination B has been completed.

  As shown in FIG. 8, for example, the abnormality determination unit 23 periodically checks whether or not the determination A, which is the determination process for the communication message M1, is completed in the abnormality determination process, and determines the communication message M2. It is confirmed whether or not the decision B is finished. Then, when neither the determination A nor the determination B is completed, the abnormality determination unit 23 does not perform the abnormality determination, and subsequently performs the end confirmation of the determination A and the end confirmation of the determination B. On the other hand, the abnormality determination unit 23 sets an end flag when confirming the end of the determination A, and thereafter repeatedly confirms the end of the determination B. When the end of the determination B is confirmed, the determination result of the determination A and An abnormality determination in the network may be performed based on the determination result of determination B. Conversely, the abnormality determination unit 23 may set an end flag when confirming the end of the determination B, and thereafter repeatedly confirm the end of the determination A.

  Thereby, even when the determination A and the determination B are out of synchronization, or even when the determination interval between the determination A and the determination B is different, an abnormality related to the network based on the two determinations A and B with different determination timings. Judgment can be made appropriately.

  In the above embodiment, the case where the determination A and the determination B are synchronized (determination is completed at substantially the same time) is illustrated. However, there is a risk that synchronization will be lost. Therefore, the abnormality determination unit not only determines an abnormality when determination A and determination B end in synchronization, but also confirms that determination B has ended after confirming that determination A has ended as described above. Then, a process for making an abnormality determination may also be provided. As a result, even when there is a deviation in the synchronization of the delay determination, the abnormality determination can be performed appropriately.

  In the above embodiment, the case where the first communication message M1 is transmitted from the first ECU 10 and the second communication message M2 is transmitted from the fourth ECU 13 is illustrated. However, the present invention is not limited to this, and the two communication messages may be transmitted from any of the first to fifth ECUs. That is, the monitoring ECU can make a network abnormality determination based on any two communication messages selected from receivable communication messages. As a result, the application range of the network monitoring apparatus can be expanded.

  In the above embodiment, the case where the first communication message M1 and the second communication message M2 are transmitted from different ECUs has been illustrated. However, the present invention is not limited to this, and the first communication message and the second communication message may be transmitted from the same ECU. Also at this time, when it is determined that both the communication interval of the first communication message and the communication interval of the second communication message are delayed, it can be determined that the communication load of the network is high. Further, when it is determined that only one of the communication interval of the first communication message and the communication interval of the second communication message is determined to be delayed, it is determined that an abnormality has occurred in transmission of the delayed communication message. can do. At this time, the cause of the abnormality occurring in the transmission includes, for example, an abnormality of the processing program, an abnormality of sensors that transmit information to the ECU, and the like.

  In the above embodiment, the case where the first to fifth ECUs 10 to 14 are connected to the communication bus 15 is illustrated. However, the present invention is not limited to this, and two or more ECUs are included in the communication bus. It only has to be connected. Thereby, the application range of such a network monitoring device can be expanded.

  In the above embodiment, the case where the first to fifth ECUs 10 to 14 and the monitoring ECU 20 are connected to the communication bus 15 is illustrated. However, the present invention is not limited to this, and the device connected to the network may be other than the ECU, such as a gateway or other various devices. As a result, the network monitoring apparatus can be applied to a network to which various apparatuses are connected.

  -In above-mentioned embodiment, it illustrated about the case where monitoring ECU20 was provided separately from 1st-5th ECU10-14. However, the present invention is not limited to this, and a network monitoring function provided in the monitoring ECU may be provided in the first to fifth ECUs. The network monitoring function provided in the monitoring ECU can be provided in the first to fifth ECUs that perform various controls because the processing load on the ECU is suppressed. Moreover, you may provide in a gateway and other various apparatuses. As a result, the application range of the network monitoring device can be expanded.

  -In above-mentioned embodiment, the case where the vehicle 1 was a motor vehicle was illustrated. However, the present invention is not limited to this, and the communication system may be provided in a moving body other than the vehicle of the automobile, for example, a ship, a railroad, an industrial machine, a robot, or the like. As a result, the application range of the network monitoring device can be expanded.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 10-14 ... 1st-5th ECU (electronic control apparatus), 15 ... Communication bus, 20 ... Monitoring ECU, 21 ... Communication interval detection part, 22 ... Delay determination part, 23 ... Determination part, 24 ... log acquisition unit, 25 ... storage unit, D1, D2 ... delay time, M1 ... first communication message, M2 ... second communication message, T1 ... first transmission interval, T2 ... second transmission interval, T3, T4 ... transmission interval, ΔT1 to ΔT4 ... communication interval, TC1 ... determination interval, ΔT11 to ΔT15 ... communication interval.

Claims (9)

A network monitoring device for monitoring a communication load of a network through which a communication message based on a CAN protocol is transmitted and received,
A detection unit for detecting a communication interval of communication messages having the same message ID for two communication messages having different message IDs;
A delay determination unit that determines a delay when each communication interval of two communication messages having different detected message IDs is longer than a transmission interval determined corresponding to each communication message;
It is determined that the communication load of the network is high on the condition that both communication intervals of two communication messages having different message IDs are determined as delays, and one of the two communication messages having different message IDs is selected. A determination unit that determines that an abnormality has occurred in transmission of a communication message determined as a delay, on condition that only a communication interval is determined as a delay ;
The network monitoring device , wherein the detection unit detects a communication interval of communication messages having the same transmission interval . At least two transmitting devices are connected to the network, and a communication message having one message ID of two communication messages having different message IDs is transmitted from one transmitting device of the at least two transmitting devices. The network monitoring device according to claim 1, wherein the communication message having the other message ID is transmitted from another transmitting device of the at least two transmitting devices. The network monitoring device according to claim 1, wherein the detection unit detects a communication interval of communication messages that are set to be transmitted at regular intervals. The delay determining unit, a network monitoring apparatus according to any one of claims 1 to 3 not used for the determination of the delay communication interval following the communication message of the same message ID and communication message is determined as a delay. The network monitoring device according to any one of claims 1 to 4 , wherein the detection unit detects communication intervals of two communication messages having different message IDs at the same interval. The delay determination unit determines whether or not there is a delay in accordance with the timing at which the communication interval is detected,
The determination unit can be of any claim 1 to 5 for determining that an abnormality in the transmission of that or the communication message is higher communication load of the network according to the timing at which the delay by the delay determining unit is determined has occurred The network monitoring device according to claim 1. When the communication interval of any one of two communication messages having different message IDs is determined as a delay, the determination unit determines whether the communication interval of the other communication message is also determined as a delay. The network monitoring apparatus according to claim 6 , wherein a determination is made that the communication load of the communication message is high or an abnormality has occurred in transmission of the communication message. The detection unit detects a time when the communication message having the same message ID is detected N times (N is a natural number) as the communication interval,
The delay determining unit, any one of claims 1 to 7 to the transmission interval which is determined corresponding to said each message a time required when the communication message each message ID is the same is transmitted N times The network monitoring device according to item. A network monitoring method for monitoring a communication load of a network through which a communication message based on a CAN protocol is transmitted and received by a network monitoring device ,
A step of detecting a communication interval of communication messages having the same message ID for two communication messages having different message IDs in a detection unit ;
A step of determining, as a delay, when each communication interval of two communication messages having different detected message IDs is longer than a transmission interval determined corresponding to each communication message by a delay determination unit;
The determination unit determines that the communication load of the network is high when both communication intervals of two communication messages having different message IDs are determined as delays, and one of the two communication messages having different message IDs. Determining that there is an abnormality in the transmission of the communication message determined as the delay when only the communication interval is determined as a delay ,
Network monitoring method characterized by transmission interval to detect a communication distance of the communication message with the same period in the step of the detecting.

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