JP2007096799A - Monitoring apparatus of vehicle-mounted electronic control network - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To specify and analyze a cause of a bus load increase in a vehicle-mounted electronic control network of a vehicle-mounted LAN or the like. <P>SOLUTION: A monitoring apparatus is provided with: bus communication state monitoring portions 31 and 32 to monitor the communication state of a communication bus 2; an abnormal state information storage 34 to store in advance the abnormal state information which is an information related to the communication state in the past when an abnormality was generated in the communication state of the communication bus 2; and a collator 35 to compare and collate a monitoring result by the bus communication state monitoring portions 31 and 32 with the abnormal state information in the abnormal state information storage 34. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a monitoring device for an in-vehicle electronic control network such as an in-vehicle LAN (Local Area Network).

Conventionally, in a vehicle such as an automobile, a communication system using a CAN (Controller Area Network) or the like is often provided. An example of such a vehicle communication system is an in-vehicle LAN, which is very useful for controlling vehicles and in-vehicle devices.
When constructing such a communication system, prepare multiple networks (buses) according to the type of message to be transmitted / received, purpose, frequency of transmission / reception, etc., and connect these networks so that they can communicate with each other by a gateway device. Is often performed as one aspect of the system configuration. For example, taking an in-vehicle LAN using CAN as an example, an information system network for navigation system control, a body control system network for headlamp control, a safety network for air bag control, engine control, etc. For example, a communication system is constructed by connecting an engine / power train network and the like by a gateway device [gateway ECU (Electrical Control Unit)].

  In such a communication system (vehicle-mounted LAN), the conventional technique monitors the transmission interruption of the communication partner node and implements fail-safe against the fact that communication data is not sent from the partner node, or detects at each node. The abnormal information of the vehicle itself (abnormality of the in-vehicle sensor, etc.) is transmitted to another node on communication data, the node that received the data stores it, and further, the abnormal information is notified to the outside wirelessly. Has been done.

In addition, as a prior art regarding a vehicle-mounted LAN, there is also a technique proposed by Patent Documents 1 and 2 below, for example.
The technology of Patent Document 1 is not limited to a load such as a sensor that can be directly connected, and is intended to widely collect output from a plurality of loads provided on a vehicle as vehicle operation information. In this technique, in addition to a plurality of nodes distributedly connected to the bus line, an additional node is connected to the bus line, and a vehicle in which the plurality of nodes and a plurality of loads are mounted on the additional node is connected. The related item monitoring result related to the vehicle operation information indicating the state is collected from the bus line, and the vehicle operation information is generated based on the collected related item monitoring result.

In addition, the technology of Patent Document 2 aims to prevent the bus from being occupied by an abnormal node so that communication from another node can be performed when an abnormality occurs in the communication line. In this technique, when a transition from a state where data can be transmitted / received via the communication line (first state) to a state where data cannot be transmitted / received (second state) is repeated a predetermined number of times, The transmission from the repeated node is stopped.
JP 2000-67390 A JP 2002-359625 A

However, in a communication system such as an in-vehicle LAN, in the conventional technology, it is impossible to identify and analyze a factor that causes a high load on the network (bus) itself and to identify a physical abnormality of the bus. In the case of communication, if there is an abnormality in the bus, it is fatal and it is difficult to identify the abnormal part.
The present invention has been made in view of such problems, and an object of the present invention is to make it possible to identify and analyze the cause of an increase in bus load in an in-vehicle electronic control network such as an in-vehicle LAN. Another object of the present invention is to make it possible to identify a physical abnormality of the bus.

  In order to achieve the above object, an on-vehicle electronic control network monitoring device according to the present invention (Claim 1) is a monitoring device connected to a communication bus of an on-vehicle electronic control network. A bus communication state monitoring unit for monitoring the state, an abnormal state information storage unit for preliminarily storing abnormal state information that is information related to a past communication state when an abnormality has occurred in the communication state of the communication bus, and the bus The present invention is characterized in that a collation unit for comparing and collating the monitoring result by the communication state monitoring unit with the abnormal state information in the abnormal state information storage unit is provided.

Here, the bus communication state monitoring unit includes a communication log monitoring unit that records and monitors the communication content of the communication bus as a communication log, and a waveform monitoring unit that monitors an electrical communication waveform of the communication bus. (Claim 2).
In addition, the bus communication state monitoring unit may include a communication log monitoring unit that records and monitors the communication content of the communication bus as a communication log (Claim 3), It may be configured to include a waveform monitoring unit for monitoring a simple communication waveform (claim 4).

Further, the communication log monitoring unit records a communication content of the communication bus as a communication log, performs statistics and analysis of the communication log recorded in the communication log recording unit, and outputs the result as the result. A communication log statistic / analysis unit output to the comparison unit as a comparison target and comparison target with the abnormal state information may be provided.
The communication log recording unit may be configured to output the recorded communication log to the outside via the communication bus.

Further, the waveform monitoring unit analyzes a waveform recording unit that records electrical waveform data of the communication bus and the waveform data recorded by the waveform recording unit, and compares the result with the abnormal state information. A waveform analysis unit that outputs to the verification unit as a verification target may be provided.
Further, the waveform recording unit may be configured to output the recorded waveform data to the outside via the communication bus.

Further, the bus communication state monitoring unit may be configured to be able to externally set whether or not to monitor the communication state via the communication bus.
The monitoring apparatus of the present invention may further include an external output unit that outputs a result of collation by the collation unit to the outside via the communication bus (claim 10).

According to the present invention, the following effects and advantages can be obtained.
(1) By installing a monitoring device on the communication bus, it is possible to analyze the cause of the bus load increase (communication state of the communication bus).
(2) Since the communication log and waveform data can be acquired, it is possible to analyze whether the bus load has increased due to a large amount of transmission data, or whether the bus load has increased due to a hardware abnormality. . Moreover, since log acquisition can be set arbitrarily, log acquisition and waveform acquisition according to conditions can be performed.

(3) Since the communication log can be taken out via the communication bus, efficient analysis on the desk is possible.
(4) Since analysis by comparison with data at the time of occurrence of a past abnormality (abnormal state information) is possible, the cause of increasing the bus load can be easily identified. Therefore, the development time can be shortened. In the market, it is possible to detect defects early and take early countermeasures.

(5) The cause of the increase in bus load is not only a large amount of transmission data itself, but it is also assumed that the communication bus is physically damaged. In addition, it is possible to specify in detail the cause of the bus load increase.
(6) By collating the physical waveform monitoring results with the past abnormal waveforms, it is possible to identify the cause of the increase in bus load as accurately as possible, and to drastically reduce the time required for analysis. is there.

[A] Description of an Embodiment FIG. 1 is a block diagram showing a configuration of a main part of an in-vehicle LAN (in-vehicle electronic control network) according to an embodiment of the present invention. The in-vehicle LAN shown in FIG. In-vehicle electronic control network (communication bus) 2 to which nodes (ECU nodes) 1-1 to 1-n (n is an integer equal to or larger than 2 and n = 4 in FIG. 1) is connected; A monitoring node (monitoring device) 3 connected to the in-vehicle electronic control network (hereinafter simply referred to as “network” or “bus”) 2 is configured.

  Here, the in-vehicle LAN of this example applies CAN as a communication protocol, for example. CAN is a multi-master type communication protocol that can transmit a message from all ECU nodes 1-i (i = 1 to n) connected to the bus 2 when there is a vacancy in the bus 2. The ECU node 1-i that has previously accessed 2 can obtain the transmission right. For this reason, the bus 2 is configured to be able to perform communication according to the CAN protocol.

  The ECU nodes (hereinafter also simply referred to as “nodes”) 1-i connected to the bus 2 are communication devices capable of transmitting and receiving data (packets) in a predetermined frame format. It consists of required electronic components such as Central Processing Unit (ROM), ROM (Read Only Memory), RAM (Random Access Memory), and communication controller, and can send and receive data to and from other ECU nodes via bus 2. ing.

The monitoring node 3 monitors communication on the bus 2 (vehicle-mounted LAN communication), calculates the bus load at the time of data transmission / reception, records the error situation occurring at that time, and separately records the recorded data. By analyzing, it is possible to analyze the cause of the increase in bus load and determine the allowable range of the bus load.
For this reason, the monitoring node 3 of this example includes a communication log (data) monitoring function unit 31, a waveform monitoring function unit 32, a collation function unit 33, an abnormal state database (DB) 34, and a notification function unit 35, for example. Has been.

  Here, the communication log monitoring function unit 31 and the waveform monitoring function unit 32 described above function as a bus communication state monitoring unit that monitors the communication state of the bus 2. The above communication content is recorded as a communication log and has a function of statistically analyzing the communication log. For this purpose, the communication log recording unit 311 that records the communication log and the communication log recording unit 311 record the communication log. The communication log statistic / analysis unit 312 for statistically analyzing and analyzing the communication log is configured, and the function of the communication log statistic / analysis unit 312 makes it possible to analyze factors that increase the bus load. . The communication log recording unit 311 is configured to have a required memory such as a RAM, and the communication log recorded in the memory can be appropriately taken out to another storage medium or the like via the bus 2. It has become.

  The waveform monitoring function unit 32 has a function of monitoring the electrical communication waveform of the bus 2 (recording and analyzing the waveform data). For this purpose, the waveform recording of the electrical waveform data of the bus 2 is performed. It comprises a recording unit 321 and a waveform analysis unit 322 that analyzes the waveform data recorded by the waveform recording unit 321 and analyzes factors that cause high bus loads (overload) and abnormalities (disconnection, etc.). ing. The waveform recording unit 321 is also configured to include a required memory such as a RAM, and the waveform data recorded in the memory can be appropriately taken out to another storage medium or the like via the bus 2. It has become.

  Next, the abnormal state DB (abnormal state information storage unit) 34 stores in advance abnormal state information that is information related to the past communication state when an abnormality has occurred in the communication state of the bus 2. Past abnormal phenomena (statistics / analysis results) related to the above communication log are stored as abnormal state information, and past abnormal waveform data when abnormality (including high load state) occurs on the bus 2 is abnormal state information. Can be stored as The DB 34 is configured using a required recording medium such as a RAM or a hard disk.

  The collation function unit (collation unit) 33 includes an analysis result obtained by the communication log statistics / analysis unit 312 and an analysis result (abnormal state information) corresponding to a past abnormal phenomenon stored in the abnormal state DB 34 in advance. Are compared to determine whether or not there is an abnormality (including a high load state) in the bus 2, and the analysis result obtained by the waveform analysis unit 322 and the past abnormality stored in the abnormal state DB 34 are determined. Compared with waveform data, it has a function of determining whether or not there is an abnormality in the bus 2.

  The notification function unit (external output unit) 35 has a function of notifying (outputting) the collation result (abnormality presence / absence) of the collation function unit 33 to the user via the bus 2. The user can access the monitoring node 3 and receive the notification by connecting a maintenance terminal or the like to the bus 2, and the contents recorded in the communication log recording unit 311 and the waveform recording unit 321 can be received. It can be taken out as appropriate.

In addition, the communication log monitoring function unit 31 (communication log statistics / analysis unit 312), the waveform monitoring function unit 32 (waveform analysis unit 322), the collation function unit 33, and the notification function unit 35 are not illustrated, for example. It can be realized as one function such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor).
In FIG. 1, the collation function unit 33 and the abnormal state DB 34 are common to the communication log monitoring function unit 31 and the waveform monitoring function unit 32. You may prepare independently.

Hereinafter, the monitoring process by the monitoring node 3 of the present embodiment configured as described above will be described in detail.
For example, as shown in FIG. 2, the monitoring node 3 first checks whether or not there is a communication log and waveform monitoring request (setting) by the user (step S1). (NO route of step S1), if there is a request, the communication log recording unit 311 of the communication log monitoring function unit 31 acquires and records the communication contents on the bus 2, and the waveform recording unit of the waveform monitoring function unit 32 The waveform data of the bus 2 is acquired by 321 and recorded (from the YES route of step S1 to step S2). That is, the monitoring node 3 of this example can appropriately set the necessity of monitoring the communication log and waveform for the bus 2 via the bus 2.

  Here, as shown in FIG. 3, for example, as shown in FIG. 3, the communication log recording unit 311 each time data is transmitted / received on the bus 2, the time at that time, the identification information of the node 1-i that is the destination of the data (ID) (hereinafter referred to as node ID), data length, data content, etc. are recorded. By analyzing the “time” and “data length” of this communication log by the communication log statistics / analysis unit 312, it is possible to calculate the amount of data communication per unit time and calculate the load on the bus 2. Become.

  Next, the monitoring node 3 uses the communication log statistics / analysis unit 312 of the communication log monitoring function unit 31 to analyze the communication log recorded as described above (step S3). For example, the communication log statistics / analysis unit 312 determines the data transmission cycle to the bus 2 for each node ID based on the content of the communication log recorded by the communication log recording unit 311 as shown on the right side of FIG. If there is a part (abnormality occurrence point; see arrow 10) where the transmission cycle is extremely different from the other as shown in the upper right side of FIG. 4, the communication log is acquired and stored. To do. The storage of the communication log at this time may be performed when the same phenomenon (transmission cycle abnormality) occurs even once for the same node 1-i, or a predetermined number of times (for example, 10 times continuously). It may be performed when it occurs, and the number of times can be designated via the bus 2 by the user (maintenance terminal).

  Further, the communication log statistics / analysis unit 312 is actually transmitted with the data length “2” when the original data length is “8” as indicated by reference numeral 11 in the lower right part of FIG. (That is, the occurrence of a communication error) can be detected, and the time and node ID can be acquired and stored. The storage at this time may also be performed when the same phenomenon (data length abnormality) occurs even once for the same node 1-i, or occurs for a predetermined number of times (for example, 10 times continuously). The number of times may be specified by the user (maintenance terminal) via the bus 2.

On the other hand, the waveform analysis unit 322 analyzes and statistics the waveform data recorded by the waveform recording unit 321, and analyzes a factor that causes a high bus load and abnormality (disconnection, etc.) based on the result (step S <b> 4).
Next, the monitoring node 3 uses the verification function unit 33 to compare and verify the analysis results output from the communication log statistics / analysis unit 312 and the waveform analysis unit 322 as an object to be compared, and the abnormal state stored in the abnormal state DB 34. The information is compared and collated (step S5), and the result is transmitted (output) to the notification function unit 35.

  That is, for example, in the example described above with reference to FIG. 4, the collation function unit 33 has the same phenomenon as the communication log stored in the communication log statistics / analysis unit 312 with the possibility of abnormal transmission cycles. Is compared and collated with the past communication log (abnormal state information), and the result (the presence / absence of transmission cycle abnormality) is transmitted to the notification function unit 35. That is, the monitoring node 3 can perform statistics and cause investigation of the communication log in the monitoring node 3 and notify the user of the most likely cause. In the case of an abnormal data length, the result of collation with past abnormal state information is transmitted to the notification function unit 35 in the same manner.

Further, the collation function unit 33 compares and collates the analysis result of the waveform analysis unit 322 with the abnormal waveform data at the time of the occurrence of the past abnormality stored in the abnormal state DB 34 with respect to the waveform data. 2) whether or not there is a physical abnormality in itself 2).
Here, examples of the abnormal waveform data will be described with reference to FIGS. 5, 6A, and 6B. FIG. 5 is a configuration block diagram for explaining sampling points in the waveform diagrams shown in FIGS. 6 (A) and 6 (B). As shown in FIG. 5, the bus 2 is composed of two pair lines (CAN_H, CAN_L). FIG. 6A shows a case where one of the lines (CAN_H) is disconnected, as shown in FIG. Shows the waveform data when the other (CAN_L) line is disconnected.

That is, for example, in FIGS. 6 (A) and 6 (B), the waveforms with symbols H and L indicate the waveform data immediately before waveform shaping at the CAN receiver shown in FIG. The waveform with Rx indicates the waveform data after waveform shaping by the CAN receiver shown in FIG.
These abnormal waveform data are converted into digital data and stored in the abnormal state DB 34. As described above, abnormal waveform data at two locations before and after (input / output) of the CAN receiver is used for waveform comparison to detect not only a disconnection abnormality but also whether the bus 2 is disconnected or the monitoring node 3. It is possible to determine whether the line is broken.

  As shown in FIG. 2, the notification function unit 35 first checks whether or not there is a notification request to the user (step S6). If there is no notification request, the communication log statistics / analysis unit 312 and the waveform are checked. The process ends without notifying the user of the collation result transmitted from the analysis unit 322 (NO route of step S6). That is, the monitoring node 3 of the present example can appropriately set the necessity of notifying the user of the collation result via the bus 2.

On the other hand, if there is a notification request, the notification function unit 35 notifies the user (maintenance terminal or the like) of the collation result via the bus 2 (from the YES route in step S6 to step S7), and after step S1. Repeat the process.
For example, in the example described above with reference to FIG. 4, the notification function unit 35 can notify the user via the bus 2 that a transmission cycle abnormality or data length abnormality of the node ID = 2D2 has occurred.

As described above, according to the present embodiment, the communication log (statistics) & (cause investigation) is performed in the monitoring node, and the function that notifies the user of the most probable cause is provided.
The following effects or advantages can be obtained.
(1) By installing the monitoring node 3 on the bus 2, it is possible to analyze the cause of the bus load increase (communication state of the bus 2).

(2) Since the communication log and waveform data can be acquired, it is possible to analyze whether the bus load has increased due to a large amount of transmission data, or whether the bus load has increased due to a hardware abnormality. . Moreover, since log acquisition can be set arbitrarily, log acquisition and waveform acquisition according to conditions can be performed.
(3) Since it is possible to acquire “packet transmission time (communication time)”, “ID”, “packet length”, “bus load”, and “communication error status”, only the monitoring node 3 can perform normal bus monitoring. The same level of measurement as the tool can be performed.

(4) Since the communication log can be taken out via the bus 2, efficient analysis is possible on the desk.
(5) Since analysis by comparison with data at the time of occurrence of a past abnormality (abnormal state information) is possible, the cause of increasing the bus load can be easily identified. Therefore, it is possible to shorten the development time at the ECU prototype stage. In the market, it is possible to detect defects early and take early countermeasures. Furthermore, the analysis results can be transmitted to the outside wirelessly (which can be achieved by connecting a wireless transmitter to the bus 2), so that it is possible to reduce the number of personnel required for data collection and easily obtain samples. Become.

(6) The cause of the increase in bus load is not limited to a large amount of transmission data itself, and it is assumed that the bus 2 is physically damaged. In addition, it is possible to specify in detail the cause of the bus load increase.
(7) When a plurality of nodes 1-i are connected to the bus 2, it is difficult to specify the factor that increases the bus load, and even more so, if the content is caused by hardware. According to the above-described embodiment, by collating the physical waveform monitor result with the past abnormal waveform, the cause of the bus load increase can be notified to the user as accurately as possible, which is necessary for the analysis. Time can be drastically reduced.

Needless to say, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in the embodiment described above, both the communication log monitoring function unit 31 (communication log recording unit 311, communication log statistics / analysis unit 312) and the waveform monitoring function unit 32 (waveform recording unit 321, waveform analysis unit 322) monitor. The node 3 is provided, but only one of them may be provided.

  As described above in detail, according to the present invention, a bus load is monitored by monitoring a communication state of a bus of an in-vehicle electronic control network such as an in-vehicle LAN (acquisition of communication log, statistics and analysis, waveform recording and analysis). It is possible to accurately find the cause of the increase, and it is easy to find out that there is a physical abnormality in the communication waveform. Therefore, it is considered extremely useful in the technical field using an in-vehicle electronic control network.

It is a block diagram which shows the principal part structure of the vehicle-mounted LAN (vehicle-mounted electronic control network) which concerns on one Embodiment of this invention. 3 is a flowchart for explaining an operation of a monitoring node shown in FIG. 1. It is a figure which shows an example of the communication log acquired by the communication log monitoring function part (communication log recording part) shown in FIG. It is a figure for demonstrating the specific operation example of the communication log statistics and analysis part shown in FIG. FIG. 7 is a configuration block diagram for explaining sampling locations of the waveform diagrams shown in FIGS. 6 (A) and 6 (B). (A) is an example of waveform data at the time of bus disconnection (CAN_H) recorded in the abnormal state DB shown in FIG. 1, and (B) is a bus disconnection (CAN_L) recorded in the abnormal state DB shown in FIG. It is a figure which shows an example of the waveform data at the time.

Explanation of symbols

1-1 to 1-n Communication nodes (ECU nodes)
2 In-vehicle electronic control network (communication bus)
3 Monitoring node (monitoring device)
31 Communication log monitoring function section (bus communication status monitoring section)
311 Communication log recording unit 312 Communication log statistics / analysis unit 32 Waveform monitoring function unit (bus communication state monitoring unit)
321 Waveform recording unit 322 Waveform analysis unit 33 Verification function unit (Verification unit)
34 Abnormal state database (DB)
35 Notification function part (external output part)

Claims (10)

A monitoring device connected to a communication bus of an in-vehicle electronic control network,
A bus communication state monitoring unit for monitoring the communication state of the communication bus;
An abnormal state information storage unit that stores in advance abnormal state information that is information related to a past communication state when an abnormality has occurred in the communication state of the communication bus;
An on-vehicle electronic control network monitoring device comprising: a collation unit that compares and collates the monitoring result of the bus communication state monitoring unit with the abnormal state information in the abnormality information storage unit. The bus communication state monitoring unit
A communication log monitoring unit for recording and monitoring communication contents of the communication bus as a communication log;
2. The vehicle electronic control network monitoring device according to claim 1, further comprising a waveform monitoring unit for monitoring an electrical communication waveform of the communication bus. The bus communication state monitoring unit
2. The monitoring apparatus for an in-vehicle electronic control network according to claim 1, further comprising a communication log monitoring unit that records and monitors communication contents of the communication bus as a communication log. The bus communication state monitoring unit
2. The vehicle electronic control network monitoring device according to claim 1, further comprising a waveform monitoring unit that monitors an electrical communication waveform of the communication bus. The communication log monitoring unit
A communication log recording unit for recording communication contents of the communication bus as a communication log;
A communication log statistic / analysis unit that performs statistics and analysis of the communication log recorded in the communication log recording unit and compares the result with the abnormal state information and outputs the result to the verification unit as a verification target 4. The on-vehicle electronic control network monitoring device according to claim 2, wherein the on-vehicle electronic control network monitoring device is provided.   6. The on-vehicle electronic control network monitoring device according to claim 5, wherein the communication log recording unit is configured to output the recorded communication log to the outside via the communication bus. The waveform monitoring unit
A waveform recording unit for recording electrical waveform data of the communication bus;
The waveform data recorded in the waveform recording unit is analyzed, the result is compared with the abnormal state information, and the waveform analysis unit is output as a verification target to the verification unit. The monitoring apparatus of the vehicle-mounted electronic control network of Claim 2 or 4.   8. The vehicle electronic control network monitoring apparatus according to claim 7, wherein the waveform recording unit is configured to output the recorded waveform data to the outside via the communication bus.   The bus communication state monitoring unit is configured to be able to externally set whether or not to monitor the communication state via the communication bus. In-vehicle electronic control network monitoring device.   10. The on-vehicle electronic control network monitoring device according to claim 1, further comprising an external output unit that outputs a collation result by the collation unit to the outside via the communication bus. .

Images