JP7036664B2 - Control device and log acquisition device that perform log recording with time stamp - Google Patents

Description

The present invention relates to a system having a function of synchronizing time with a plurality of devices in a vehicle, and relates to a control device and a log acquisition device for recording a log with a time stamp.

Conventionally, as shown in FIG. 10, a plurality of control devices (navigation 901, travel support device 902, engine 903, brake 904) in the vehicle are connected via a communication interface, and the time of a timer mounted on those control devices is connected. It is known that a time stamp is given by using the time of the synchronized timer when the log is acquired.

The log with the time stamp acquired as described above is acquired by using an external log acquisition device 114, and the operation of the entire system in which a plurality of control devices are linked is analyzed using the log. As a system for acquiring the log with the above time stamp, for example, the data processing system described in Patent Document 1 has been proposed.

Further, as shown in FIG. 11, in a plurality of vehicles 1001 and 1002, vehicle information including the time is recorded in each vehicle, and for example, the recorded information 1003 of the own vehicle and the other vehicle recorded when an accident occurs. It is known to analyze an accident using the recorded information 1004. As the above system, for example, the operation information processing apparatus described in Patent Document 2 has been proposed.

In these systems, when analyzing the operation using logs acquired by multiple devices or multiple vehicles, the events recorded in the logs are sorted in the order of occurrence based on the time stamps given to each log. Perform motion analysis by tracing. However, in order to match the time stamps of the logs recorded in multiple devices or multiple vehicles, it is necessary that the timers provided for each device have the same time, and for that purpose, the timers between the devices must be the same. The process of aligning the time of the above, that is, the time synchronization process is performed.

For example, in the case of a system that spans multiple vehicles, the reference time is set based on the received time after receiving, for example, GPS (Global Positioning System) radio waves or standard frequency reporting radio waves. Perform time synchronization processing. That is, after performing the time synchronization process as described above, the log is acquired and the time stamp is added.

JP-A-2015-35158 Japanese Patent No. 3861811

In the above system, in order to record a log with a time stamp, it is necessary to perform time synchronization processing by receiving reference time from the outside in advance and distributing time information by communication between devices. There is. In addition, it may take minutes to receive the time by receiving GPS or standard frequency radio waves, and it takes a considerable amount of time to acquire the time and complete the time synchronization process between the devices. It takes. Until these processes are completed, there is a problem that log recording cannot be started, or even if the log is recorded, a correct time stamp cannot be given. As a result, there is a problem in the operation analysis using those logs.

An object of the present invention is to provide a control device and a log acquisition device for performing log recording with a time stamp, which can give a correct time stamp even to a log recorded before the time synchronization is completed.

In order to solve the above problems, the present invention has a communication unit for communicating with a device mounted on a vehicle, a timer mounted on the vehicle, and a recording unit for storing log information mounted on the vehicle. And, log recording with a time stamp provided with a control unit that performs time synchronization processing with a reference time holding device that holds a reference time using the communication unit, and adds and records a time stamp synchronized with the time to the log information. In the control device that performs The feature is that the temporarily assigned time stamp is corrected to the time-synchronized time stamp and recorded by using the information obtained in the time synchronization process at any time after the time synchronization process is completed. And.

According to the present invention, it is possible to provide a control device for adding a correct time stamp to a log and recording the log even before the time synchronization process is completed, or a device for acquiring a log with the correct time stamp. You can. This facilitates analysis using the logs acquired by those control devices.

Configuration diagram of the control device of the first embodiment Explanatory diagram of time stamp calculation processing of Example 1 Explanatory drawing of rate deviation calculation processing of Example 1 Explanatory drawing of operation of Example 1 Explanatory drawing of log recording contents of Example 1 Explanatory drawing of time stamp correction processing of Example 1 Explanatory diagram of log contents acquired by the log acquisition device of the first embodiment Explanatory drawing of transmission delay time calculation process of Example 2 Explanatory drawing of time stamp correction processing of Example 2 Configuration diagram of the system in the vehicle Explanatory diagram of the situation of using log recording

Hereinafter, examples of the present invention will be described with reference to the drawings.

1 to 7 are explanatory views of the first embodiment. FIG. 1 is a configuration diagram of a control device. FIG. 2 is an explanatory diagram of the time stamp calculation process, and FIG. 3 is an explanatory diagram of the rate deviation calculation process. FIG. 4 is an explanatory diagram of the operation, and FIG. 5 is an explanatory diagram of the log recording contents. FIG. 6 is an explanatory diagram of the time stamp correction process, and FIG. 7 is an explanatory diagram of the log contents acquired by the log acquisition device.

The first embodiment is an example in which the time stamp given before the time synchronization process is corrected by using the parameters acquired in the time synchronization process.

First, the configuration of the control device of the first embodiment will be described with reference to FIG. The various control devices shown in FIG. 1 show typical configuration diagrams of the control devices installed in the vehicle as shown in FIG. 10. The control device consists of a vehicle 101, a first control device 102 installed in the vehicle, an antenna 103 for receiving a time signal, a time acquisition unit 104 for acquiring time information from the received signal, and a first control device. (1) A control unit 105 that controls the time synchronization process of the control device, a communication interface 106, a communication bus 107 to which the communication interface 106 is connected, a second control device 108, a communication interface 109, and a second control device. A control unit 110 that controls time synchronization processing and log acquisition processing, a local timer 111 provided in the own device, a log recording unit 112, a third control device 113 having the same configuration as the second control device, and a vehicle. The log acquisition device 114 for acquiring the log recorded in the second control device 108 or the third control device 113 by connecting from the outside, the communication interface 115, the control unit 116 of the log acquisition device, and the acquired log. It is composed of a log storage unit 117 for storing.

In the configuration shown in FIG. 1, the first control device 102 serves as a master that serves as a reference for time synchronization, and the second control device 108 and the third control device 113 have the role of a slave that adjusts its own time to the master time. There is. The time acquisition unit 104 of the first control device 102 is, for example, a GPS receiver or a standard frequency reporting radio wave receiver, and acquires a standard time at the time of reception. Further, the time acquisition unit 104 is provided with a timer inside, and the acquired standard time is set in the internal timer, and once set, the internal timer autonomously ticks the time. When there is a time acquisition request from the control unit 105, the time information is output based on the internal timer. In addition, the standard time is received from GPS or the like on a regular basis, and the value of the internal timer is updated each time. Further, the first control device 102 performs time synchronization processing by distributing the time of the time acquisition unit 104 via the communication interface 106 under the control of the control unit 105.

On the other hand, the local timer 111 of the second control device 108 starts timing at the time when the device is started and automatically ticks the time, and outputs the timer value at that time in response to the request from the control unit 110. do. The time information transmitted from the first control device 102 is received via the communication interface 109, the control unit 110 generates a time stamp using the received time information and the local timer 111, and logs to the log recording unit 112. Make a record of.

It should be noted that the local timer 111 after the control device is started is such that even if the timer starts counting from the time of starting, for example, the previous timer value saved separately is read and the time is continuously measured from that value. It doesn't matter which one. The communication bus 107 is a communication bus for devices in the vehicle such as CAN (Control Area Network), Ethernet, or FlexRay.

Next, a procedure for generating a time-synchronized time stamp in the second control device 108 will be described with reference to FIGS. 2 to 4. In addition, as a general time synchronization processing procedure, there are IEEE Std 802.1AS standard, IEEE Std 1588 standard, and the like, and the following description is a processing procedure similar to these processing procedures.

First, the control unit 105 of the first control device 102 transmits a Sysn message 201 indicating the start of time synchronization, and further acquires the time T1 at the time of transmitting the message from the time acquisition unit 104. Further, the second control device 108 records the timer value T2 of the local timer 111 at the time when the Sync message 201 is received. Next, the first control device 102 stores the value of the time T1 at the time when the Sync message is transmitted in the Followup message 202 and transmits the value. The second control device 108 acquires and records the value of T1 stored in the received Followup message. The value of the delivered time T1 and the value of the received timer time T2 are recorded as a history of the time synchronization process as shown in FIG. The above Sync message and Follow-up message are repeatedly transmitted, and the latest time is delivered from the master side to the slave side each time.

When a log is recorded by the second control device 108 and a time stamp needs to be assigned after the Sync message and the Follow-up message have been received, the control unit 110 has a time stamp at that time. Calculate the value as follows.

First, the timer value T3 is acquired from the local timer 111 at the time when the log recording occurs. Further, the difference (T3-T2) between the timer values T3 and T2 is calculated by using the history information of the latest reception from the time synchronization history shown in FIG. As a result, the elapsed time from the time when the Sync message is first received can be obtained. However, since this elapsed time is the time measured by the local timer 111, the time advance of the local timer 111 may be faster or slower than the original time advancement. Therefore, a coefficient for correcting the progress of the timer time, that is, a rate deviation R (details will be described later) is multiplied. The value of the time stamp is obtained by adding the elapsed time after this correction to the delivered time T1. That is, the value of the time stamp at the time when the log recording occurs is calculated by the following formula. As described above, the delivery time T1 used for the calculation and the timer value T2 at the time of reception use the most recent delivery time before the log recording occurs.
Timestamp time TL = delivery time T1 + (elapsed time (T3-T2) x rate deviation R) ... Equation 1

In the above equation 1, the rate deviation R is a coefficient for correcting how the timer advances, and how to obtain it will be described below. The advance of the clock of the local timer 111 does not always match the advance of the master. Therefore, the rate deviation R represents the ratio of the advance of the master side to the advance of the local timer.

FIG. 3 is an explanatory diagram of the procedure for calculating the rate deviation R, and the procedure will be described with reference to the figure. Similar to the delivery of the time already described with reference to FIG. 2, the first control unit transmits the Sync message 301, and further stores the time T1a at the time of transmitting the message in the subsequent Followup message 302 and transmits the message. On the other hand, in the second control device, the timer value T2a of the local timer 111 at the time of receiving the Sync message and the value of T1a stored in the subsequent Followup 302 are recorded as, for example, history information 401 of the time synchronization history shown in FIG. do. In the example shown in the figure, an example is shown in which the value of T1a initially received is 00:10: 0.00 and the value of T2a is 60 seconds.

The Sync message and the Follow-up message are repeated, and the Sync message 303 and the Follow-up message 304 are transmitted in the same manner as described above. Record.
When the Sync message and the Follow-up message are received from the second time onward, the second control device side calculates the difference between the previous delivery time and the current delivery time, that is, the elapsed time (T1b-T1a). Further, the difference between the previous reception time and the current time, that is, the elapsed time of the local timer (T2b-T2a) is calculated, and the rate deviation R is obtained by the following formula.
Rate deviation R = elapsed time (T1b-T1a) ÷ elapsed time (T2b-T2a) ... Equation 2

For example, in the example shown in FIG. 4, when the history information 402 is recorded, the elapsed time of the delivery time is calculated using the history information 401. In the example shown in the figure, the elapsed time of the delivery time is 20.000 seconds from (10 minutes 20.000 seconds-10 minutes 0.000 seconds). The elapsed time of the local timer is 19.980 seconds from (79.980 seconds-60.000 seconds). Further, the rate deviation, which is a ratio of these, is 1.001, that is, 100.1% from (20.0000 seconds ÷ 19.980 seconds). That is, it indicates that the reference time is advanced by 1.001 seconds while the local timer of the second control device is advanced by 1 second. Therefore, by integrating this rate deviation with the elapsed time of the local timer, it can be converted into the elapsed time of the reference time. The above rate deviation is calculated each time a time synchronization message is received, and the latest value is always used when obtaining the time stamp value.

Next, the operation of adding a time stamp to the log in the second control device will be described with reference to FIG.

The figure shows an example of the recorded contents of the log, where 501a to 505a show the recorded contents before the time stamp is corrected, and 501b to 505b show the recorded contents after the time stamp is corrected. The contents to be recorded consist of the value of the time stamp, the type of the time stamp, the necessity of correcting the time stamp, and the recorded information of the log.

In the figure, 501a is a log generated before receiving the first time synchronization message. In this case, the timer value of the local timer 111 is provisionally recorded as the value of the time stamp, and the local time is simultaneously recorded as the type of the timer stamp. In addition, since this time stamp value needs to be corrected after the time synchronization process is completed, it is recorded that the correction is necessary as the correction necessity information.

Next, 502a is a log when a Sync message of time synchronization is received. As the time stamp value, the time value received at the time of the Followup message is recorded, and as the time stamp value, it is recorded that the time is synchronized. In addition, since it is not necessary to correct the time stamp, it is recorded that it is not necessary as correction necessity information.

Reference numeral 503a is a log after receiving the first time synchronization message. At this point, since the rate deviation has never been calculated, the value of the local timer is recorded as the time stamp value as in the case of log recording 501a. Other items are also recorded in the same manner as in the log storage 501a.

Reference numeral 504a is a log when the Sync message of the second time synchronization is received, and recording is performed in the same manner as the log recording 502a.

Reference numeral 505a is a log recording after the time synchronization is completed and the calculation of the rate deviation is completed. The procedure shown in FIG. 2 is based on the delivery time received in the second time synchronization message and the rate deviation calculated at that time. And calculate and record the time stamp value. Record that the time is synchronized as the time stamp value. In addition, since it is not necessary to correct the time stamp, it is recorded that it is not necessary as correction necessity information.

Subsequently, the operation of correcting the time stamp will be described. Since the log records 501a and 503a are logs before the time synchronization is completed as described above, the value of the local timer is temporarily recorded as a time stamp, and therefore the correction is performed.

First, with reference to FIG. 6, a procedure for calculating the time of the time stamp of the log recording before receiving the time synchronization message will be described. The first Sync message 601 and the Follow-up message 602 are transmitted from the first control device 102 in the same manner as already described with reference to FIG. 2, and the second control device 108 that has received the transmission time T1c and the time of reception. The value T2c of the local timer 111 is recorded as the time synchronization history shown in FIG.

The time stamp value of the log generated before the above time synchronization message is delivered is calculated as follows. First, the difference between the local timer value T4c recorded in the log and the local timer value when the time synchronization message generated after that is received is the difference between the timer values (T2c-T4c), that is, the time synchronization message. Calculate the retroactive time from the time of reception. Furthermore, the rate deviation is integrated into this retroactive time and converted into the retroactive amount of the time as the reference time. As the value of the rate deviation used at this time, the value calculated at the time of receiving the second time synchronization message is used. Then, the value of the time stamp can be obtained by subtracting the retroactive time after this correction from the delivered time. That is, the value of the time stamp before receiving the time synchronization message is calculated by the following formula.
Time stamp time before the completion of time synchronization Time TLc = Delivery time T1c- (retroactive time (T2c-T4c) x rate deviation R) ... Equation 3

For example, the log shown in FIG. 5 will be described as an example. In this example, the control unit 110 of the second control device 108 receives the second time synchronization message, completes the calculation of the rate deviation, prepares the parameters necessary for correcting the time stamp, and then records the log. The log record 501a and the log record 503a that are required to be corrected are extracted and corrected.

The log recording 501a has the time stamp value (30.000 seconds) and the local timer value (60.000 seconds) when the first time synchronization message is received from the history information 401 recorded in the time synchronization history of FIG. 30.000 seconds is calculated as the retroactive time (60.000 seconds-30.000 seconds). Further, the rate deviation of 100.1% at that time is integrated (30.000 × 1.001) from the history information 402 of the second time synchronization in the retroactive time to obtain 30.030 seconds. Finally, the above integrated value (30.030 seconds) is subtracted from the first delivery time (00:10:0.000 seconds) from the history information 401, and the time stamp value is 00: 09: 29.970 seconds. To get. The corrected log information 501b is recorded with the obtained time stamp value as a new value.

Further, since the log record 503a is a log when the rate deviation has not been calculated because it has already been received after the first time synchronization message, only the value of the rate deviation is calculated when the second time synchronization message is received. Is used to correct the time stamp. That is, the elapsed time (70) from the local timer value (60.000 seconds) when the first time synchronization message is received from the time stamp value (70.000 seconds) and the history information 401 recorded in the time synchronization history of FIG. 10.000 seconds is calculated as .000 seconds-60.000 seconds). Further, the rate deviation of 100.1% at that time is integrated (10.000 × 1.001) from the history information 402 of the second time synchronization in the elapsed time to obtain 10.010 seconds. Finally, the above integrated value (10.010 seconds) is added from the first delivery time (00:10:0.000 seconds) from the history information 401, and the time stamp value is 00:10: 10.010 seconds. To get. The corrected log information 503b is recorded with the obtained time stamp value as a new value. Information indicating the corrected time is added to these corrected log records as a time stamp type, and information indicating corrected is added as correction necessity information.

The modification of the log record 503a was described in the above description by the procedure of adding the elapsed time from the delivery time at the time of receiving the first time synchronization message, but from the delivery time of the second time synchronization message. The same value can be calculated even if the procedure of subtracting the retroactive time is performed.

As described above, the log record recorded in the log recording unit 112 of the second control device 108 is read out by the log acquisition device 114 connected from the outside of the vehicle. Further, the log record recorded in the third control device 113 is also read out in the same manner and stored in the log storage unit 117 of the log acquisition device 114. By using these accumulated logs and analyzing the time stamp information between each control device, it is possible to analyze the cooperative operation between the devices.

FIG. 7 shows the log contents of the second control device 108 stored in the log storage unit 117 of the log acquisition device 114. The contents acquired from each control device and stored in the log storage unit 117 include device type 1101, time stamp 1102, time stamp type 1103, log recording information 1104, and the like. The log contents of the third control device 113 are also accumulated with the same contents as described above. The time stamp type 1103 is information indicating whether or not the time stamp given to the log is the corrected time information. As already mentioned, the time stamp is corrected using the time synchronization information after the time when the log was recorded, so the time value is slightly higher than the original time stamp calculation. The accuracy may be inferior. Therefore, by indicating that the time is the corrected time by the time stamp type 1103, it is possible to express the difference in the time accuracy between the corrected time stamp and the non-corrected time stamp. As a result, when analyzing the cooperative operation between multiple devices based on the time stamps of these logs, the analyst analyzes the logs, keeping in mind the difference in the accuracy of the event occurrence order. It will be possible to do.

In the case of the explanation using FIG. 5, for example, the above-mentioned correction of the time stamp is described so as to be performed when the second time synchronization message is received and the calculation of the rate deviation is completed. However, this modification does not necessarily have to be performed at that time, and may be performed at any time after the information necessary for the modification is obtained.

For example, this time stamp correction process may be performed when the log is read from the log acquisition device 114. In that case, since it is possible to prevent the processing load from increasing due to the correction of the time stamp during normal operation of the control device, the effect of suppressing the power consumption of the device and the effect of not impairing the processing stability are expected. can. Alternatively, not only the log information but also the time synchronization history information shown in FIG. 4 may be read out on the log acquisition device 114 side, and the time stamp correction process may be performed on the log acquisition device side. Even in this case, the effect of reducing the processing load on the control device side can be obtained in the same manner as described above.

In the above embodiment, the rate deviation value is calculated based on the elapsed time each time the time synchronization message is received by the second control device, but it is not always necessary to calculate the rate deviation value. For each multiple receptions, the calculation may be performed based on the elapsed time required for the multiple receptions at that time. In addition, the explanation was given using the case where the value of the rate deviation is calculated by the second control device as an example, but the value of this rate deviation may be measured in advance and held as a fixed value, and that value may be used. do not have. In that case, the time stamp can be added without waiting for the reception of the second time synchronization message. Therefore, for example, the time stamp value of the log recording 503a in FIG. 5 is the time stamp value without recording the local timer value. It is possible to record the correct time stamp from the beginning of recording.

Further, when the timing accuracy of the local timer 111 is sufficiently high and its influence is negligible, the rate deviation does not necessarily have to be considered. In that case, the process is equivalent to calculating the rate deviation R value as 100% (1.000 ...) in each of the above calculation procedures.

Further, in the above example, the timer value of the local timer 111 is described as a temporary time stamp given to the log before the time synchronization, but this value does not necessarily have to be the value of the local timer itself, and the timer value. It may be a value that has undergone some conversion processing, and may be any value as long as it can be corrected to the correct time stamp after the time synchronization is completed.

As described above, in this embodiment, even if the log is before the first time synchronization message is received, the timer value of the local timer is once recorded, and after the time synchronization message is received, the information is used for the time stamp. Correction is possible, and the utilization of logs before time synchronization is improved.

Next, Example 2 will be described with reference to FIGS. 8 and 9. The description of the parts having the same function will be omitted. The second embodiment is an example in which the time stamp in the control device shown in FIG. 1 is corrected by adding the transmission delay time required for the delivery of the time synchronization message. The second embodiment performs the same operation as that shown in the first embodiment except that the transmission delay is corrected. Further, as an example of the communication bus 107 in the vehicle that measures the delay time, there is, for example, Ethernet.

First, the procedure for measuring the transmission delay time will be described with reference to FIG. The second control device 108 transmits the DelayReq message 701, which is a request for measuring the delay time, and further records the timer value T5 of the local timer 111 at the time of the transmission. Upon receiving the message, the first control device 102 returns a response message, DayRes702, which stores the time T6 at which the DayReq message 701 is received. Further, the DelayRes_Followup message 703 storing the reply time T7 is transmitted. The second control device 108 records the timer value T8 of the local timer when the DeliveryRes message 702 is received. Further, the subsequent DelayRes_Followup message 703 is received, and the stored time T7 is acquired.

In the second control device 108, the transmission delay time is calculated as follows using the values of the time T5 to the time T8. First, the elapsed time from the transmission of the DelayReq message on the second control device 108 side to the reception of the DelayRes message, that is, the difference between the timer values T8 and T5 (T8-T5) is calculated. However, since this elapsed time is the time measured by the local timer 111, it is converted into the elapsed time of the reference time by multiplying it by the rate deviation R in order to correct the progress. As for the value of the rate deviation R, the Sync message and the Follow-up message are received a plurality of times by the same procedure as already described with reference to FIG. (Ii) It is calculated from the ratio of the elapsed time on the control device 108 side. Further, the difference (T7-T6) between the times T7 and T6 is calculated as the elapsed time from the reception of the DelayReq message by the first control device 102 to the transmission of the DelayRes message. The difference between the elapsed time on the second control device 108 side and the elapsed time on the first control device 102 side is the delay time required for the round trip between the DelayReq message and the ReleaseRes message. Finally, the transmission extension time is obtained by dividing the round-trip delay time by 2. That is, the transmission delay time TD at the time of transmitting a message via the communication bus 107 is calculated by the following formula.
Transmission delay time TD = ((rate deviation R × (T8-T5))-(T7-T6)) ÷ 2 ... Equation 4

Next, a method of correcting the time stamp value of the log generated before the time synchronization message is delivered will be described with reference to FIG. As a correction method, the delivery time with the correction of the transmission delay is obtained by adding the transmission delay time to the delivery time. Specifically, the first control device 102 transmits the Sync message 801 as in the above-described example, and continuously stores the transmission time T1d of the message in the subsequent Followup message 802 and transmits the message. The second control device 108 records the value T2d of the local timer 111 when the Sync message 801 is received, and acquires the time T1d stored in the Followup message 802. However, since the transmission delay time TD is required at the time of delivery at this time T1d, the time for that amount is added. That is, the time stamp time is calculated by regarding the time (T1d + TD) to which the transmission delay time is added as the delivered time. Difference between the local timer value T4d recorded in the log generated before the Sync message 801 and the local timer value when the time synchronization message generated after that is received (T2d-T4d), that is, the retroactive time calculation from the time when the time synchronization message is received. do. Furthermore, the rate deviation is integrated into this retroactive time and converted into the retroactive amount of the time as the reference time. Then, the time stamp value can be obtained by subtracting the corrected retroactive time from the corrected delivery time (T1d + TD). That is, the value TLd of the time stamp before receiving the time synchronization message is calculated by the following formula.
Time stamp time before the completion of time synchronization Time TLd = Delivery time T1 + Transmission delay TD- (retroactive time (T2d-T4d) x rate deviation R) ... Equation 5

In the above time stamp correction process, the delay time TD is calculated, the rate deviation R is calculated, and the time is distributed from the master side. conduct.

Further, the time stamp that does not need to be corrected can be calculated by replacing the delivery time T1 used for calculating the time stamp time shown in Equation 1 with a value (T1 + TD) to which the transmission delay is added.

In the above-described embodiment, the transmission delay time is calculated using each message of DelayReq, ReleaseRes, and DelayRes_Followup, but the transmission delay time is measured and recorded by another means in advance, and the recorded value in advance. You may use.

Further, in the calculation of the rate deviation, it was explained that the Sync message and the Follow-up message are received multiple times, and the ratio of the elapsed time on the first controller side and the elapsed time on the second controller side during that period is calculated. , The communication message used for this can be replaced with a DevayRes message and a DelayRes_Folloop message.

Further, as in the first embodiment, the time stamp correction process does not necessarily have to be performed at that time as long as the necessary information is available, and even if the time stamp is corrected when the log is read from the outside, the log is read again. It may be performed by the log acquisition device, which can reduce the load on the control device. Furthermore, by adding information indicating whether or not the time stamp value has been corrected to the contents of the log read by the log acquisition device, it is possible to provide the log analyst with information on the accuracy of the time stamp. The same is true for what you can do.

As described above, in this embodiment, a correct time stamp can be added even to the log before the time synchronization process is performed, and a more accurate time stamp can be added by adding the transmission delay time. Is possible and the utilization of logs is improved.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

101: Vehicle 102: First control device 103: Antenna 104: Time acquisition unit 105: Control unit 106: Communication interface 107: Communication bus 108: Second control device 109: Communication interface 110: Control unit 111: Local timer 112: Log Recording unit 113: Third control device 114: Log acquisition device 115: Communication interface 116: Control unit 117: Log storage unit

Claims (6)

In a control device mounted on a vehicle and performing log recording with a time stamp,
The control device is
A communication unit mounted inside the vehicle and outside the control device for communicating with a reference time holding device having a reference time.
With a timer
A recording unit for saving log information and
It is provided with a control unit that performs time synchronization processing with the reference time holding device using the communication unit, adds a time-synchronized time stamp to the log information, and records the time stamp in the recording unit .
The control unit sets a time stamp that is not time-synchronized based on the timer value of the timer in the log recording information recorded in the recording unit before the completion of the first time synchronization process after the control device is started. Temporarily grant,
At some point after the completion of at least two time synchronization processes, the timer value of the timer is corrected using the information obtained in the time synchronization process, and the corrected timer value is used to temporarily assign the timer value. A control device for performing log recording with a time stamp , wherein the time stamp is corrected to a time stamp synchronized with the time and recorded in the recording unit. In the control device that performs log recording with a time stamp according to claim 1.
The control unit performs time synchronization processing based on the reference time received from the reference time holding device in the time synchronization processing.
The transmission delay time when receiving the reference time from the reference time holding device, and
The difference in the time advance between the reference time holding device and the timer,
A control device that performs log recording with a time stamp, which is characterized in that the time stamp is corrected based on the information of either one or both. In the control device that performs log recording with a time stamp according to claim 1 or claim 2.
The control unit is a control device that performs log recording with a time stamp, which is characterized in that the time stamp is corrected when a log is called from a log acquisition device connected to the outside. In the control device that performs log recording with a time stamp according to any one of claims 1 to 3.
The control unit transmits log recording information and time stamp information to an externally connected log acquisition device.
A control device for performing log recording with a time stamp, which comprises adding time stamp type information indicating whether or not the time stamp has been corrected to the time stamp information and transmitting the time stamp information. In a control device mounted on a vehicle and performing log recording with a time stamp,
The control device is
A communication unit mounted inside the vehicle and outside the control device for communicating with a reference time holding device having a reference time.
With a timer
A recording unit for saving log information and
A control unit that performs time synchronization processing with the reference time holding device that holds the reference time using the communication unit, adds a time stamp synchronized with the time to the log information, and records the time stamp in the recording unit . Prepare,
The control unit sets a time stamp that is not time-synchronized based on the timer value of the timer in the log recording information recorded in the recording unit before the completion of the first time synchronization process after the control device is started. Temporarily grant,
Furthermore, the information necessary for correcting the temporarily assigned time stamp is recorded as time synchronization history information.
A control device for performing log recording with a time stamp, characterized in that the time synchronization history information is transmitted together with log recording information to a log acquisition device connected to the outside of the vehicle . Connect to the control device that performs log recording with a time stamp according to claim 5.
A log acquisition device that acquires log recording information recorded in the control device.
The time synchronization history information is acquired from the control device together with the log recording information, and the time synchronization history information is acquired from the control device.
A log acquisition device characterized in that the time stamp temporarily assigned to the log recording information is corrected by using the time synchronization history information acquired from the control device.

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