JP2019175263A - Log recording device, control method, and program - Google Patents

Abstract

To provide a log recording device capable of giving appropriate time information to a log before time synchronization is performed.SOLUTION: A log recording device 10 is provided with: a clock unit 13 which counts time starting from a first point of time; a communication IF 11 which transmits or receives communication data; a generation unit 14 which generates and holds log information including content of the communication data and first time information showing time of the clock unit 13 in transmission or reception by the communication IF 11; and a conversion unit 15 which acquires second time information showing time starting from a second point of time from the outside, compares the acquired second time information with time counted by the clock unit 13, and converts the first time information included in the log information held by the generation unit 14 into third time information starting from the second point of time to record the log information in a recording medium.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a log recording device, a control method, and a program.

  A log recording device that records a log of communication data in a network in a vehicle is used. The log recording device records a log including information indicating the content of communication data and time information indicating the time when the communication data is transmitted or received.

  Conventionally, a logging system that records a message from a processor as a log is disclosed (Patent Document 1). The logging system disclosed in Patent Literature 1 records time information generated by a clock included in the logging system in a log.

JP2015-95061A

  Incidentally, a plurality of communication devices are connected to the network in the vehicle. In addition, a time server that distributes time information is connected to the network, and the plurality of communication devices achieve time synchronization by receiving the time information distributed by the time server.

  However, the communication apparatus is in a state in which time synchronization is not performed between the time when the communication apparatus is activated and the time information distributed by the time server is received. When the communication device records a log of communication data in this state, the time that is not synchronized with other communication devices is recorded in the log, and there is a problem that the time recorded in the log becomes inaccurate. .

  The present invention has been made to solve the above problem, and an object thereof is to provide a log recording device and the like that can give appropriate time information to a log before time synchronization is performed.

  In order to solve the above-described problem, a log recording apparatus according to an aspect of the present invention includes a clock unit that measures time starting from a first time point, a communication interface that transmits or receives communication data, and the communication data And a generation unit that generates and holds log information including the contents of the first time information indicating the time of the clock unit at the time of transmission or reception by the communication interface, and a time starting from the second time point Is included in the log information held by the generation unit by comparing the acquired second time information and the time measured by the clock unit. And converting the first time information into third time information starting from the second time point, and recording the log information on a recording medium.

  According to this, the log recording device holds log information generated before receiving time information from a time server external to the log recording device. When the time information is received from the external time server, the time information included in the retained log information is converted based on the received time information retroactively. As a result, the time information starting from the starting point of the time information measured by the external time server is also added to the log information generated before receiving the time information from the external time server and recorded on the recording medium. be able to. In this way, the log recording apparatus can give appropriate time information to the log before time synchronization is performed.

  In addition, the generation unit includes the content of communication data transmitted or received by the communication interface after the conversion unit acquires second time information, and the clock unit at the time of transmission or reception by the communication interface. Log information including first time information indicating a time, and the conversion unit starts the second time point with the first time information included in the log information generated by the generation unit. The log information may be recorded on a recording medium after being converted into fourth time information.

  According to this, after acquiring time information from an external time server, the log recording apparatus records log information to which time information is added starting from the start point of the time information timed by the external time server. To record. Therefore, the log recording apparatus can give appropriate time information before and after time synchronization is performed.

  Further, the recording unit records the log information in a file in the recording medium, acquires the second time information, and then acquires new second time information. The log information generated by the generation unit after obtaining the two-time information may be recorded in a new file in the recording medium.

  According to this, when new time information is acquired from an external time server, the log recording device records log information after the acquisition in a new file. If new time information is acquired and log information is recorded in the same file before and after the acquisition, log information with different origins of time information will be mixed in one file. The time difference between the log information in the file becomes inaccurate or the order of the log information is reversed. Therefore, when new time information is acquired from an external time server, the log information is recorded in a new file, thereby avoiding the inaccuracy of the time difference and the reverse of the order. it can. Therefore, the log recording device can give appropriate time information to the log before time synchronization is performed while avoiding inaccuracies in the time difference in the log file and reversal of the order.

  Further, the conversion unit may record the creation time of the new file starting from the second time point at the beginning of the new file.

  According to this, the log recording device generates a file in which the creation time of the file is recorded at a predetermined position at the beginning of the file. Therefore, a device or a user who uses the log generated by the log recording device can acquire the creation time of the file simply by reading a predetermined position in the file. Therefore, the log recording device can give appropriate time information to the log before time synchronization is performed while easily obtaining the creation time of the file from the file.

  The conversion unit records the log information on the recording medium without performing the conversion when the second time information cannot be acquired even after a predetermined time has elapsed since the initialization of the communication interface. May be.

  According to this, when the time information cannot be acquired from the external time server, the log recording device stores the log information with the time information timed by itself. Therefore, the log recording device can avoid recording log information without time information when time synchronization is not performed.

  The generation unit holds the generated log information by recording the log information on a recording medium, and the conversion unit reads the log information from the recording medium on which the generation unit has recorded the log information and performs the conversion. You may do.

  According to this, the log recording apparatus can hold log information generated before receiving time information from an external time server more easily by using the recording medium.

  The communication interface may transmit or receive the communication data to a network in the vehicle.

  According to this, the log recording device can give appropriate time information to the log before time synchronization is performed in the network in the vehicle.

  Further, the control method according to one aspect of the present invention is a method for controlling a log recording apparatus, a time measuring step for measuring a time starting from the first time point, a communication step for transmitting or receiving communication data, A generation step of generating and holding log information including the content of the communication data and first time information indicating the time measured in the time measurement step at the time of transmission or reception in the communication step; The second time information indicating the time starting from the time is acquired from the outside, the acquired second time information is compared with the time measured in the time measuring step, and the log held in the generation step Converting the first time information included in the information into third time information starting from the second time point, and recording the log information on a recording medium.

  Thereby, there exists an effect similar to the said log recording apparatus.

  A program according to an aspect of the present invention is a program for causing a computer to execute the control method of the log recording device.

  Thereby, there exists an effect similar to the said log recording apparatus.

  Note that the present invention can be realized not only as an apparatus but also as a method using steps as processing units constituting the apparatus, as a program for causing a computer to execute the steps, or as a computer read recording the program. It can also be realized as a possible recording medium such as a CD-ROM, or as information, data or a signal indicating the program. These programs, information, data, and signals may be distributed via a communication network such as the Internet.

  According to the present invention, the log recording apparatus can give appropriate time information to a log before time synchronization is performed.

FIG. 1 is an explanatory diagram illustrating a configuration of a communication system according to an embodiment. FIG. 2 is a block diagram illustrating a configuration of the log recording apparatus according to the embodiment. FIG. 3 is an explanatory diagram of a frame including time information acquired from the network by the log recording apparatus. FIG. 4 is an explanatory diagram showing the contents of a file in which log information according to the embodiment is recorded. FIG. 5 is an explanatory diagram illustrating a method of converting time information by the conversion unit according to the embodiment. FIG. 6 is a flowchart showing a process of recording a log using time information acquired from the outside by the log recording apparatus according to the embodiment. FIG. 7 is a flowchart showing a process of recording a log after the log recording apparatus acquires time information from the outside according to the embodiment.

  Hereinafter, embodiments will be specifically described with reference to the drawings.

  Each of the embodiments described below shows a preferred specific example of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connecting forms of the constituent elements, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept of the present invention are described as optional constituent elements that constitute a more preferable embodiment. In addition, the same code | symbol is attached | subjected to the same component and description may be abbreviate | omitted.

(Embodiment)
In this embodiment, a log recording apparatus that can give appropriate time information to a log before time synchronization is described.

  FIG. 1 is an explanatory diagram showing a configuration of a communication system 1 according to the present embodiment. The communication system 1 is a communication system that is connected to a CAN (Controller Area Network), which is a network provided in a vehicle, and is controlled by a CAN protocol, for example.

  As shown in FIG. 1, the communication system 1 includes a time server 5, a log recording device 10, and ECUs (Electronic Control Units) 101, 102, and 103. Each component described above is connected to the network N and can communicate with each other via the network N.

  The time server 5 is a server device that distributes time information to the network N. The time server 5 measures the current time by a clock unit provided therein, and repeatedly transmits the current time to the network N. The starting point of the time that the time server 5 measures is also referred to as the second time point.

  The ECU 101 is a control unit that controls functions of a vehicle engine, a brake, a steering (not shown), and the like. The ECU 101 is connected to the network N, and receives control data for controlling the engine and the like from other devices such as an ECU via the network N. In addition, the ECU 101 transmits response data to a device such as another ECU via the network N. In addition, the ECU 101 receives time information distributed by the time server 5 via the network N, and sets the received time information in its own device, so that the time server 5 and other devices in the communication system 1 Synchronize the time.

  The ECUs 102 and 103 are control units similar to the ECU 101, and operate independently of the ECU 101. Here, the case where the communication system 1 includes three ECUs is described as an example, but the number of ECUs is not limited to this.

  The log recording device 10 is a log recording device that records a log of communication data. The log recording device 10 is a recording device that transmits or receives communication data and records a log including the content of the communication data and time information at the time of transmission or reception. In addition, the log recording device 10 receives time information distributed by the time server 5 via the network N, and records a log using the received time information.

  In this way, the log recording device 10 records time information synchronized with the time server 5 in the log. The starting point of the time measured by the log recording device 10 is also referred to as the first time point. In general, the first time point is different from the second time point, which is the starting point of the time information timed by the time server 5.

  The log recording device 10 is not synchronized in time with the time server 5 and other devices in the communication system 1 from when it is activated until it receives the time information distributed by the time server 5. . When the log recording apparatus 10 records a log using the time information held internally in this state, a log to which time information that is not synchronized is added can be generated.

  Therefore, it is possible to suppress generation of a log to which time information is attached in an unsynchronized state, and to give appropriate time information to log information generated before receiving time information distributed by the time server 5. The log recording apparatus 10 capable of performing the above will be described in detail below.

  FIG. 2 is a block diagram showing a configuration of the log recording apparatus 10 according to the present embodiment.

  As illustrated in FIG. 2, the log recording device 10 includes a communication IF (interface) 11, a function unit 12, a clock unit 13, a generation unit 14, a conversion unit 15, and a storage unit 16. Note that the log recording device 10 may be realized as a dedicated device for recording logs, or may be realized as one function in a device that exhibits other predetermined functions.

  The communication IF 11 is a communication interface connected to the network N. When the communication IF 11 acquires data to be transmitted to another device such as the ECU 101 from the function unit 12, the communication IF 11 transmits a frame including the acquired data to the network N. The communication IF 11 receives a frame from another device such as the ECU 101 via the network N. When the received frame includes data to be provided to the function unit 12, the communication IF 11 12 to provide. Further, the communication IF 11 receives a frame including time information distributed by the time server 5 (also referred to as “time frame”). The time frame received by the communication IF 11 is provided to the conversion unit 15. Note that the frame transmitted and received by the communication IF 11 is, for example, a communication frame according to the CAN protocol.

  The function unit 12 is a processing unit that performs predetermined information processing and transmits / receives information to / from other devices connected to the network N. For example, the function unit 12 performs information processing related to command generation based on CAN data. When the log recording device 10 is realized as one function in the device that exhibits other predetermined functions, the portion that performs the other predetermined functions corresponds to the functional unit 12. The functional unit 12 is not an essential component.

  The clock unit 13 measures the time starting from a predetermined time point (that is, the first time point). The predetermined time point is a past time point fixed in advance in the log recording device 10. The accuracy of the time measured by the clock unit 13 is, for example, about milliseconds. The time measured by the clock unit 13 is also referred to as internal time, and the information indicating the internal time is also referred to as internal time information. The time measured by the clock unit 13 may be calculated depending on, for example, an OS (Operating System) (not shown) provided in the log recording device 10.

  The generation unit 14 generates log information 17 including the contents of communication data transmitted and received by the communication IF 11 and time information (also referred to as first time information) indicating the time of the clock unit 13 at the time of transmission or reception. It is a processing unit. Further, the generation unit 14 temporarily holds the generated log information 17. The log information 17 is held in a volatile recording medium such as a RAM (Random Access Memory) or a non-volatile recording medium such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive).

  The conversion unit 15 is a processing unit that converts the log information 17 generated by the generation unit 14 and records the converted log information 17 in the storage unit 16. The conversion unit 15 acquires time information indicating the time starting from the second time point from the outside, compares the acquired time information with the time (internal time) measured by the clock unit 13, and generates the generation unit. The first time information included in the log information 17 generated by 14 is converted into time information (also referred to as third time information) starting from the second time point, and is recorded in the storage unit 16. Here, “external” means the outside of the log recording apparatus 10, in other words, another apparatus connected to the network N, and one specific example is the time server 5. In this conversion, the conversion unit 15 performs conversion after reading the log information 17 generated by the generation unit 14 and held in the recording medium. Note that the time information indicating the time from the second time point acquired by the conversion unit 15 from the time server 5 is also referred to as synchronization time information or second time information. Acquisition of the synchronization time information from the time server 5 by the conversion unit 15 is also referred to as time synchronization.

  The storage unit 16 is a storage medium in which log information 17 is recorded. The storage unit 16 is a nonvolatile recording medium such as an HDD or an SSD. The storage unit 16 stores log information 17 after conversion by the conversion unit 15 as a file 18. The file 18 in which the log information 17 is stored is switched when the time synchronization with the time server 5 is newly performed. As a result, the storage unit 16 is in a state where one or more files 18 are stored.

  After the conversion unit 15 acquires time information from the time server 5, the generation unit 14 includes the contents of the communication data transmitted or received by the communication IF 11 and the clock unit 13 at the time of transmission or reception by the communication IF 11. Log information 17 including time information indicating the time is generated. Then, the conversion unit 15 converts the time information included in the log information 17 generated by the generation unit 14 into a time starting from the second time point (also referred to as fourth time information), and the log information 17 Record on a recording medium. Here, the generation unit 14 may provide the generated log information 17 to the conversion unit 15 without temporarily holding the log information 17. This is because the conversion unit 15 has already acquired the synchronization time information from the time server 5, so that the conversion unit 15 that has received the log information 17 can immediately convert the time information.

  At this time, the conversion unit 15 records the log information 17 in a new file 18. As a result, the storage unit 16 is in a state where a plurality of files 18 are recorded. As a result, the log information 17 included in each of the plurality of files 18 has only one starting point of the time information, thereby avoiding inaccuracy of the time difference between the log information 17 and reversal of the order. be able to.

  Note that the conversion unit 15 may create a new file 18 when one file 18 exceeds a predetermined size (for example, several hundred kilobytes). By doing in this way, the acquisition time at the time of acquiring (downloading) the file 18 which is log information can be reduced. Further, when a predetermined time has elapsed since the previous time synchronization, the conversion unit 15 may create a new file 18 even if the file 18 does not exceed the predetermined size. Here, for example, the time until the time difference between the time of the time server 5 and the time of the clock unit 13 exceeds the allowable range can be adopted as the predetermined time. By monitoring the time of the time server 5 and the time of the clock unit 13, it is possible to know how the time difference changes with the passage of time. When this time lag increases with the passage of time, the time until the time lag exceeds the allowable range can be predicted. Therefore, the new file 18 as described above can be created. By doing in this way, the file 18 is generated after the time synchronization with the file 18 including the log information 17 generated before the time synchronization is performed (that is, when the time synchronization is not performed). There is an advantage that file management can be performed separately from the file 18 containing the log information 17 that has been recorded.

  FIG. 3 is an explanatory diagram of the frame 21 including time information acquired from the network N by the log recording apparatus 10. The frame 21 is, for example, transmitted by the time server 5 to the network N, but is not limited thereto.

  As shown in FIG. 3, the frame 21 includes a time information field 22. The time information field 22 includes information specifying the date and time. The information for specifying the date and time is, for example, information for specifying the date shown in the year / month / day format (“2018/01/01” in FIG. 3, that is, January 1, 2018), and the hour / minute / second format. And information specifying the time ("01:02:03" in FIG. 3, that is, 1: 2: 3). The format of information described in the time information field 22 is not limited to the above. Specifically, the order of year / month / day or the order of hour / minute / second may be different. In addition, “/” and “:”, which are delimiters for year / month / day or hour / minute / second, may or may not be different.

  FIG. 4 is an explanatory diagram showing an example of the contents of the file 31 in which the log information 17 according to the present embodiment is recorded. The format of the file 31 shown in FIG. 4 is not limited as long as the following elements are included.

  As shown in FIG. 4, the file 31 includes a header portion 32 and one or more log entries 33. The file 31 corresponds to the file 18 in FIG.

  The header part 32 is a field arranged at the head in the file 31 and describes the date and time when the file 31 was created in a predetermined format. Based on the time information acquired from the time server 5, the creation time of the file 31 starting from the second time point is recorded in the header part 32 by the conversion part 15. One header section 32 exists in one file 31.

  One or more log entries 33 are fields existing behind the header portion 32 in the file 31. Each of the one or more log entries 33 corresponds to the log information 17 and includes time information 35 indicating the time when the communication data is transmitted or received and the content 36 of the communication data. Each of the one or more log entries 33 is provided corresponding to transmission or reception of one communication data. The time information 35 is time information after being converted by the conversion unit 15.

  FIG. 5 is an explanatory diagram showing a time information conversion method by the conversion unit 15 according to the present embodiment.

  FIG. 5 shows an axis of time t that is timed by the time server 5 (that is, a time axis of synchronization time information), an axis of time u that is timed by the clock unit 13 (that is, a time axis of internal time information), and Are shown side by side. In FIG. 5, the same time is shown at the same position in the left-right direction.

  In FIG. 5, the starting point (second time point) of the synchronization time information is time t0, and the starting point (first time point) of the internal time information is time u0. The time in the internal time information included in the log information 17 generated and held by the generation unit 14 is time u1, and the time when the time u1 is expressed by the synchronization time information is time t1. Also, the time when the time server 5 distributes the time information is time t2 in the synchronization time information, and the time when the time t2 is expressed by the internal time information is u2.

  At this time, the conversion unit 15 converts the time u1 to the time t1 in the synchronization time information using the following (Equation 1).

  t1 = u1- (t2-u2) (Formula 1)

  This relational expression has a function of converting the time axis of the internal time information into the time axis of the synchronous time information. More specifically, this corresponds to obtaining the time t1 in the synchronization time information by shifting the time u1 in the internal time information using the time difference (t2−u2) between the internal time information and the synchronization time information.

  Note that the conversion performed by the conversion unit 15 can also be expressed as in (Equation 2) below. In this case, time t1 is obtained as time t2 in the synchronization time information traced back by the time difference (u2-u1) in the internal time information.

  t1 = t2- (u2-u1) (Formula 2)

  By using this conversion, the conversion unit 15 converts the time u1 included in all held log information 17 into the time t1 in the external time information (synchronization time information).

  FIG. 6 is a flowchart showing a process of recording a log using time information acquired from an external time server by the log recording apparatus 10 according to the present embodiment.

  As illustrated in FIG. 6, in step S <b> 101, the generation unit 14 determines whether the communication IF 11 has transmitted or received a frame from the network N. If it is determined that the communication IF 11 has transmitted or received a frame (Yes in step S101), the process proceeds to step S102. If not (No in step S101), step S101 is executed again. That is, the generation unit 14 waits in step S101 until the communication IF 11 transmits or receives a frame. For example, the frame transmitted by the communication IF 11 is a frame transmitted from the functional unit 12 to another device via the network N, and the frame received by the communication IF 11 is transmitted from the other device via the network N by the functional unit 12. This is a frame to be received.

  In step S <b> 102, the generation unit 14 determines whether an end condition for a predetermined acquisition period for acquiring time information from the time server 5 is satisfied. If it is determined that the end condition is satisfied (Yes in step S102), the process proceeds to step S103. If not (No in step S102), the process proceeds to step S106. Here, the acquisition period is a predetermined period for the log recording device 10 to acquire time information from the time server 5. Further, the acquisition period end condition may be, for example, that a predetermined time (for example, about 10 seconds to 1 minute) has elapsed since the initialization of the communication IF 11. Thereby, the conversion unit records the log information 17 in the storage unit 16 without conversion when the time information cannot be acquired from the time server 5 even after a predetermined time has elapsed since the initialization of the communication IF 11. It will be. In addition, the acquisition period end condition includes that a predetermined number of frames have been transmitted / received since the initialization of the communication IF 11 and that a frame having a predetermined amount of data has been transmitted / received since the initialization of the communication IF 11. Can do. For example, the predetermined number can be 10,000, and the predetermined data amount can be 200 kBytes. These values may vary depending on the traffic that is assumed to flow through the network N.

  In step S103, the generation unit 14 generates log information 17 including the content of communication data included in the frame received by the communication IF 11 in step S101 and time information indicating the time of transmission or reception of the frame. Then, the generation unit 14 holds the generated log information 17.

  In step S104, the generation unit 14 determines whether the frame received by the communication IF 11 in step S101 is a time frame. If it is a time frame (Yes in step S104), the process proceeds to step S105. If not (No in step S104), the process proceeds to step S101.

  In step S105, the conversion unit 15 acquires the time frame received by the communication IF 11. Then, the conversion unit 15 compares the time measured by the clock unit 13 with the time information included in the frame received in step S101, and the time difference between them ((t2-u2) in (Equation 1)). Is calculated. And the conversion part 15 converts the time information contained in the log information 17 hold | maintained at step S103 into the time information (3rd time information) in synchronous time information.

  In step S <b> 106, the conversion unit 15 stores the log information 17 converted in step S <b> 105 in the file 18 in the storage unit 16.

  Through the series of processes shown in FIG. 6, the log recording apparatus 10 can record by adding appropriate time information to the log before time synchronization is performed.

  FIG. 7 is a flowchart showing a process of recording a log after the log recording apparatus 10 acquires time information from an external time server according to the present embodiment. The process shown in FIG. 7 is executed after the series of processes shown in FIG.

  As illustrated in FIG. 7, in step S <b> 201, the generation unit 14 determines whether the communication IF 11 has transmitted or received a frame from the network N. If it is determined that the communication IF 11 has transmitted or received a frame (Yes in step S201), the process proceeds to step S202. If not (No in step S201), step S201 is executed again. That is, the generation unit 14 waits in step S201 until the communication IF 11 transmits or receives a frame. The frame transmitted by the communication IF 11 is the same as step S101 in FIG.

  In step S202, the generation unit 14 determines whether the frame received by the communication IF 11 in step S201 is a time frame. If it is a time frame (Yes in step S202), the process proceeds to step S203, and if not (No in step S202), the process proceeds to step S206.

  In step S203, the generation unit 14 determines whether or not a predetermined time has elapsed since the previous update process of the file 18 (step S205 described later). If it is determined that the predetermined time has elapsed (Yes in step S203), the process proceeds to step S204. If not (No in step S203), the process proceeds to step S206.

  In step S204, the generation unit 14 compares the time counted by the clock unit 13 with the time information included in the frame received in step S201, and compares the time difference between them ((t2-u2 in (Equation 1)). )) Is calculated.

  In step S205, the conversion unit 15 generates a new file 18 in the storage unit 16, and records the creation time of the file 18 in the synchronization time information at the top of the generated new file 18. Note that the processing in step S205 is also referred to as file 18 update processing.

  In step S206, the generation unit 14 generates log information 17 including the content of communication data included in the frame received in step S201 and time information indicating the time of transmission or reception of the frame. When generating the log information 17, the generation unit 14 generates the log information 17 including the time information indicated by the clock unit 13, and then converts the included time information into synchronous time information. .

  In step S207, the generation unit 14 stores the log information 17 generated in step S206 in the storage unit 16. When step S207 is completed, step S201 is executed.

  Through a series of processes shown in FIG. 7, the log recording device 10 records a log including the contents of communication data to be transmitted and received and time information at the time of transmission or reception.

  In addition, the communication system 1 deployed in each vehicle may be connected to an external network. An external log recording device connected to the log recording device 10 of each vehicle via an external network may be provided. In this case, the external log recording device collects log files from each log recording device 10 via the external network. This configuration has an advantage that an administrator of an external log recording device can refer to and utilize the control data controlled in each vehicle on the external log recording device on behalf of the user of the vehicle.

  As described above, the log recording apparatus according to the present embodiment holds log information generated before receiving time information from a time server external to the log recording apparatus. When the time information is received from the external time server, the time information included in the retained log information is converted based on the received time information retroactively. As a result, the time information starting from the starting point of the time information measured by the external time server is also added to the log information generated before receiving the time information from the external time server and recorded on the recording medium. be able to. In this way, the log recording apparatus can give appropriate time information to the log before time synchronization is performed.

  In addition, after acquiring the time information from the external time server, the log recording device records the log information to which the time information starting from the starting point of the time information measured by the external time server is recorded on the recording medium. . Therefore, the log recording apparatus can give appropriate time information before and after time synchronization is performed.

  Further, when new time information is acquired from an external time server, the log recording device records log information after the acquisition in a new file. If new time information is acquired and log information is recorded in the same file before and after the acquisition, log information with different origins of time information will be mixed in one file. The time difference between the log information in the file becomes inaccurate or the order of the log information is reversed. Therefore, when new time information is acquired from an external time server, the log information is recorded in a new file, thereby avoiding the inaccuracy of the time difference and the reverse of the order. it can. Therefore, the log recording device can give appropriate time information to the log before time synchronization is performed while avoiding inaccuracies in the time difference in the log file and reversal of the order.

  In addition, the log recording device generates a file in which the creation time of the file is recorded at a predetermined position at the beginning of the file. Therefore, a device or a user who uses the log generated by the log recording device can acquire the creation time of the file simply by reading a predetermined position in the file. Therefore, the log recording device can give appropriate time information to the log before time synchronization is performed while easily obtaining the creation time of the file from the file.

  In addition, when the time information cannot be acquired from an external time server, the log recording device stores log information with time information timed by itself. Therefore, the log recording device can avoid recording log information without time information when time synchronization is not performed.

  In addition, the log recording apparatus can more easily hold log information generated before receiving time information from an external time server by using a recording medium.

  Further, the log recording device can give appropriate time information to the log before time synchronization is performed in the network in the vehicle.

  Note that the present invention can be realized not only as an apparatus but also as a method using steps as processing units constituting the apparatus, as a program for causing a computer to execute the steps, or as a computer read recording the program. It can also be realized as a possible recording medium such as a CD-ROM, or as information, data or a signal indicating the program. These programs, information, data, and signals may be distributed via a communication network such as the Internet.

  Although the log recording device and the like of the present invention have been described based on the embodiment, the present invention is not limited to this embodiment. Unless it deviates from the meaning of this invention, the form which carried out the various deformation | transformation which those skilled in the art will think to this embodiment, and the form constructed | assembled combining the component in different embodiment are also contained in the scope of the present invention. .

  The present invention can be applied to a log recording apparatus that can give appropriate time information to a log before time synchronization. Specifically, the present invention can be applied to a log recording device that records communication logs in various networks including a network in a vehicle.

DESCRIPTION OF SYMBOLS 1 Communication system 5 Time server 10 Log recording device 11 Communication IF
12 functional section 13 clock section 14 generation section 15 conversion section 16 storage section 17 log information 18, 31 file 21 frame 22 time information field 32 header section 33 log entry 35 time information 36 contents of communication data 101, 102, 103 ECU
N network

Claims (9)

A clock unit for measuring the time starting from the first time point,
A communication interface for transmitting or receiving communication data; and
A generating unit that generates and holds log information including the content of the communication data and first time information indicating the time of the clock unit at the time of transmission or reception by the communication interface;
Second time information indicating the time starting from the second time point is acquired from the outside, the acquired second time information is compared with the time measured by the clock unit, and the generation unit holds the second time information. A conversion unit that converts the first time information included in the log information into third time information starting from the second time point and records the log information on a recording medium. apparatus. The generator is
First time information indicating the content of communication data transmitted or received by the communication interface after the conversion unit has acquired second time information, and the time of the clock unit at the time of transmission or reception by the communication interface Log information including
The converter is
2. The first time information included in the log information generated by the generation unit is converted into fourth time information starting from the second time point, and the log information is recorded on a recording medium. The log recording device described in 1. The converter is
Recording the log information in a file in the recording medium;
After acquiring the second time information, if new second time information is acquired, the log information generated by the generating unit after acquiring the new second time information is stored in the recording medium. The log recording apparatus according to claim 1, wherein the log recording apparatus records the new file. The log recording apparatus according to claim 3, wherein the conversion unit records the creation time of the new file starting from the second time point at the beginning of the new file. The conversion unit records the log information on the recording medium without performing the conversion when the second time information cannot be acquired even after a predetermined time has elapsed since the initialization of the communication interface. Item 5. The log recording device according to any one of Items 1 to 4. The generation unit holds the generated log information by recording it on a recording medium,
The log recording apparatus according to claim 1, wherein the conversion unit performs the conversion by reading the log information from the recording medium on which the generation unit has recorded the log information. The log recording device according to any one of claims 1 to 6, wherein the communication interface transmits or receives the communication data to a network in a vehicle. A method of controlling a log recording device,
A time measuring step for measuring the time starting from the first time point;
A communication step for transmitting or receiving communication data; and
Generating and storing log information including the content of the communication data and first time information indicating the time measured in the time measuring step at the time of transmission or reception in the communication step; and
Second time information indicating the time starting from the second time point is acquired from the outside, the acquired second time information is compared with the time measured in the time measuring step, and held in the generation step A conversion step of converting the first time information included in the log information into third time information starting from the second time point and recording the log information on a recording medium.   A program for causing a computer to execute the method for controlling the log recording apparatus according to claim 8.

Images