JP5452357B2 - Vehicle data storage device - Google Patents

Description

  The present invention relates to a vehicle data storage device, and more particularly to a vehicle data storage device suitable for use in a vehicle control system including a plurality of ECUs connected by a network.

  In recent years, for the purpose of pursuing driving performance, safety, comfort, resource saving, energy saving, etc., a computer unit (ECU (Electronic Control Unit)) including many microprocessors is also installed in vehicles such as automobiles. ing.

  The ECU is mounted to control the powertrain system, body system, safety system, information system, etc. of the vehicle, and each ECU that controls the engine, brakes, steering, suspension, transmission as the vehicle motion system (these It may be an ECU that controls all or part of the body), power doors, power seats, air conditioners, ECUs that control lighting as body systems, and airbags and collision sensors as safety systems As each ECU and information system, there are a car navigation device, each ECU for controlling a car audio, and the like.

  In such an ECU, a pre-stored program is executed by CPU (Centra rProces ssi ng unit) in the ECU. Among the various data used in this program, data that is stored in advance with the program and cannot be changed, data that is generated when the ECU is started and destroyed when the ECU is stopped, and stored even when the power supply to the ECU is cut off There are various types of data such as data to be stored and stored in a storage medium suitable for each data.

  As this storage device, storage media such as a hard disk, various ROMs (R ead Only Memories) and various RAMs (Random Access Memories) are used. Each has various characteristics.

  Conventionally, each ECU prepares a storage device in the ECU when there is data that needs to be backed up (referred to as “backup data”) in data used in a program executed by a CPU in the ECU. In general, a backup method according to the operation state of the ECU is employed.

  For example, an ECU of a vehicle motion system that operates only while the ignition switch is on performs a self-shut-off process that saves data that needs to be stored when the ignition switch is off to a non-volatile memory and turns off the power of the ECU. Various backup methods are adopted depending on each ECU system, such as a battery backup RAM that can hold data while the battery voltage is supplied, and a type that stores data in this RAM. Has been.

  In recent years, there is data that needs to be backed up at a high level of importance, such as data that affects vehicle safety because it cannot be backed up, and data that is related to laws and regulations, among data that needs to be backed up For such important data, there is a demand for improving the reliability of backup data.

  From this point of view, as a method for improving the reliability of backup data, the ECU system has two storage devices, a battery backup RAM and an EEPROM, and stores data redundantly in both storage media. Thus, one that improves the reliability of data is known (see, for example, Patent Document 1).

JP 2004-21520 A

  By the way, when it is necessary to improve the reliability of the backup data from the viewpoint of safety and the like, and when the backup data is stored in a redundant manner, the method described in Patent Document 1 uses a plurality of memories in the ECU. The need to have a device arises. Therefore, there is a problem that the number of storage devices required for the ECU increases as the redundancy increases to 2 redundancy and 3 redundancy, and the cost of the ECU alone increases.

  An object of the present invention is to provide a vehicle data storage device capable of improving the redundancy of backup data while suppressing an increase in cost of a single ECU.

To achieve the above Symbol object, the present invention includes a first ECU that controls the first control object, and controls the different second control object from said first control object, the first Used in a vehicle control system having a second ECU connected to the ECU via a network, wherein the first ECU temporarily stores data, a first RAM for storing data, and a non-volatile memory for storing backup data The second ECU includes a second RAM that temporarily stores data, and a second data storage unit that includes a non-volatile memory that stores backup data. The first ECU transmits backup data in the first ECU to the second ECU via the network, and the first ECU A data transmission / reception processing unit that receives backup data from the ECU via the network, and the second ECU stores the backup data from the data transmission / reception processing unit in the second data storage unit, and In the vehicle data storage device, the vehicle data storage device further includes a data return processing unit that returns the backup data of the first ECU stored in the second data storage unit to the first ECU via the network . A third ECU is connected to the first ECU via a network, and the third ECU includes a third RAM for temporarily storing data and a non-volatile memory for storing backup data. The third data storage unit and the third ECU transmit backup data from the data transmission / reception processing unit to the third data storage unit. A data return processing unit that stores the backup data of the first ECU stored in the third data storage unit to the first ECU via the network, The data transmission / reception processing unit compares the data backed up by the first data storage unit with the data received from the second ECU. If the data does not match, the data transmission / reception processing unit among them, the number of matching is obtained by the so that to use the highest data.
With this configuration, it is possible to improve the redundancy of backup data while suppressing an increase in cost of the ECU alone.

  According to the present invention, it is possible to improve the redundancy of backup data while suppressing an increase in cost of the ECU alone.

1 is a block diagram illustrating an overall configuration of a vehicle control system including a vehicle data storage device according to an embodiment of the present invention. It is a block diagram which shows the detailed structure of the data storage device for vehicles by one Embodiment of this invention. It is a flowchart which shows operation | movement of the data storage device for vehicles by one Embodiment of this invention. It is a flowchart which shows operation | movement of the data storage device for vehicles by one Embodiment of this invention. It is a flowchart which shows operation | movement of the data storage device for vehicles by one Embodiment of this invention. It is explanatory drawing of the data set which the data storage device for vehicles by one Embodiment of this invention uses.

Hereinafter, the configuration and operation of a vehicle control system including a vehicle data storage device according to an embodiment of the present invention will be described with reference to FIGS.
First, the overall configuration of the vehicle control system including the vehicle data storage device according to the present embodiment will be described with reference to FIG.
FIG. 1 is a block diagram showing the overall configuration of a vehicle control system including a vehicle data storage device according to an embodiment of the present invention.

  The vehicle data storage device 1000 according to the present embodiment includes a first ECU 100 and a second ECU 200 that are connected via a network 300. In the illustrated example, it is assumed that two ECUs are connected to the network 300, but in reality, three or more ECUs are generally connected. In the present embodiment, for explanation, it is assumed that two ECUs are connected. Each of the ECUs 100 and 200 is mounted to control a vehicle power train system, body system, safety system, information system, and the like.

  The first ECU 100 includes a CPU 120 that controls the ECU, a ROM 130 that stores various programs, a RAM 140 that temporarily stores various data, and a data storage unit 150 that stores data necessary for backup (for example, EEPROM or Flash). A non-volatile memory such as a ROM and a hard disk) and a communication circuit 110 for performing data communication via a network.

  The second ECU 200 includes a CPU 220 that controls the ECU, a ROM 230 that stores various programs, a RAM 240 that temporarily stores various data, a data storage unit 250 that stores data necessary for backup, and a network. And a communication circuit 210 for performing data communication.

  In the present embodiment, the backup data of the first ECU 100 is stored in the data storage device 150 of the first ECU 100 and also in the data storage device 250 of the second ECU 200, thus taking a redundant configuration. ing.

  Since the first ECU 100 is an ECU serving as a data management source, the CPU 100 includes a control unit 120A used for original vehicle control and a data transmission / reception processing unit 120B used for data backup. Since the second ECU 200 is an ECU serving as a data storage source, the second ECU 200 includes a control unit 220A used for original vehicle control and a data return processing unit 220C used for data backup.

  As the data storage units 150 and 250 (for example, a nonvolatile memory such as an EEPROM, a flash ROM, and a hard disk), those having a storage capacity of about 1 KB to 2 KB are generally used. For example, when 1 KB is used as the data storage unit 250 of the second ECU 200, conventionally, only the backup data of the second ECU 200 is stored in the data storage unit 250 and there is a free space. In the present embodiment, the backup data of the first ECU 100 is stored in an empty area of the data storage unit 250. Therefore, the redundancy of backup data can be improved without increasing the cost of the ECU alone.

  At this time, if the capacity of the free space in the data storage unit 250 is small, the data that is highly important among the data to be backed up in the first ECU 100 is redundant in both the data storage unit 150 and the data storage unit 250. By storing only the data storage unit 150 that has a low degree of importance, the redundancy of the backup data can be improved without increasing the cost of the ECU alone.

  Further, when the capacity of the free space in the data storage unit 250 is small, the storage capacity of the data storage unit 250 can be increased from 1 KB to 2 KB. That is, only the storage capacity is increased without changing the number of data storage units 250. Conventionally, in the case where a single ECU includes a plurality of data storage units to provide a redundant configuration, it is necessary to provide two 1 KB data storage units. For this reason, when two data storage units having 1 KB are provided, the cost is higher than when the storage capacity is increased from 1 KB to 2 KB. In addition, in order to provide the added data storage unit, it is necessary to provide an installation area for the added data storage unit on the circuit board of the ECU, which increases the size of the ECU. On the other hand, by increasing only the storage capacity without changing the number of data storage units 250, it is possible to improve the redundancy of backup data while suppressing an increase in cost of the ECU alone. If the storage capacity of the data storage unit in one ECU is, for example, 1 KB to 2 KB and the storage area of the 2 KB data storage unit is divided into two parts, a substantially redundant configuration cannot be obtained.

  Note that storing backup data at three or more locations can be realized by providing a third ECU connected to the network with the same function as the data reply processing unit 220C of the second ECU 200.

  Further, in order to back up the data of the second ECU 200 to the first ECU 100, the second ECU 200 is provided with the function of the data transmission / reception processing unit 120B of the first ECU 100, and the first ECU 100 is provided with the second ECU 200. This can be realized by providing the function of the data reply processing unit of the ECU 200.

  The control unit 120A of the first ECU 100 outputs a control signal to the actuator ACT1 based on the vehicle state signal input from the sensor S1. Control unit 220A of second ECU 200 outputs a control signal to actuator ACT2 based on the vehicle state signal input from sensor 2S. For example, when the first ECU 100 controls a power train engine, the amount of fuel injected from the injector that is the actuator ACT1 is controlled based on a signal from a sensor S1 such as an accelerator opening sensor. For example, when the second ECU 200 controls a power train type automatic transmission, it controls a solenoid for shifting, which is the actuator ACT2, based on a signal from a sensor S2 such as a vehicle speed sensor. As described above, the first ECU 100 and the second ECU 200 are different ECUs to be controlled.

Next, the detailed configuration and operation of the vehicle data storage device according to the present embodiment will be described with reference to FIGS.
FIG. 2 is a block diagram showing a detailed configuration of the vehicle data storage device according to the embodiment of the present invention. In FIG. 2, the same reference numerals as those in FIG. 1 denote the same parts. 3 to 5 are flowcharts showing the operation of the vehicle data storage device according to the embodiment of the present invention. FIG. 6 is an explanatory diagram of a data set used by the vehicle data storage device according to the embodiment of the present invention.

  As shown in FIG. 2, the data transmission / reception processing unit 120B of the data management source ECU 100 of the vehicle data storage device 1000 of the present embodiment includes a data acquisition unit 121, a transmission determination unit 122, a transmission data set creation unit 123, The data transmission unit 124, the data return request unit 125, the data reception unit 126, the data comparison unit 127, and the data determination unit 128 are configured.

  The data reply processing unit 220C in the data storage source ECU 200 includes a data receiving unit 221, a storage necessity judging unit 222, a reply judging unit 223, a reply data set creating unit 224, and a data sending unit 225. Has been.

  The operation of each of the units 121 to 128 and 221 to 225 will be described with reference to FIGS.

  Next, processing up to data transmission of the data management source ECU 100 will be described with reference to FIG.

  The CPU 120 reads out the data transmission source of the data management source stored in the ROM 130 at a predetermined sampling period (for example, every 100 msec), and executes the processing of the data transmission / reception processing unit 120B.

  When this program is executed, in step S100, the data acquisition unit 121 determines whether or not the data acquisition cycle time set according to the change rate for each data has elapsed, and acquires the backup data. It is determined whether or not. For example, when backing up the engine speed, the data change rate is fast, so the data acquisition cycle time is set to a short value, for example, every 200 ms to 500 ms. For example, when backing up the cooling water temperature or the oil temperature, the data change rate is slow, so the data acquisition cycle time is set longer, for example, every 10 s. This eliminates the need for performing unnecessary data acquisition processing, thereby reducing the processing time required for the data acquisition processing. If it is determined that the acquisition is necessary, the process proceeds to the next step S110. If it is determined that the acquisition is not necessary, the data transmission process is terminated without performing the subsequent processes.

  If it is determined that acquisition is necessary, in step S110, the data acquisition unit 121 temporarily stores the acquired data in the RAM 140, and proceeds to the next step S120.

  In step S120, the transmission determination unit 122 compares the previous transmission data with the current transmission data, and determines that data transmission is necessary when there is a difference greater than or equal to a certain threshold in the data comparison result. If there is no difference in data, it is determined that transmission is unnecessary, and the data transmission process is terminated without performing the subsequent processes. The constant threshold value varies depending on the type of data to be backed up. When there is a difference of 1% to 20%, it is determined that data transmission is necessary. This eliminates the need to transmit data unnecessarily, thereby reducing the load on the network. When the flag is backed up, it is determined that data transmission is necessary if there is a difference between the previous time and the current time.

  In step S130, the transmission data set creation unit 123 creates a transmission data set as shown in FIG. 6A from the data temporarily stored in the RAM 140. The transmission data set includes at least a data body, a data set number, and a request flag. As a result, the data set can be identified by the data set number, storage requests, reply requests, etc. can be distinguished by the request flag, and the validity / invalidity of the reply data can be judged by the data validity judgment flag. The configuration can be shared, and communication via the network can be constructed more easily.

  The request flag of the transmission data set created by this processing is set as data update when only data update is desired, and is set as data storage when desired to be stored in the data storage unit 250. The data storage source can be configured to issue an instruction as to whether storage is necessary. That is, in the case of data update, data update in the RAM 240 of the second ECU 200 is executed. In the case of data storage, the data update of the RAM 240 of the second ECU 200 is executed and the data is also stored in the data storage unit 250 of the second ECU. In addition, data is also stored in the data storage unit 150 of the first ECU 100. Generally, the maximum number of data writes in a data storage unit (for example, a nonvolatile memory such as an EEPROM, a flash ROM, or a hard disk) is lower than the maximum number of data writes in the RAM. Therefore, for example, the data update process is executed (N−1) times, and only the data in the RAM 240 of the second ECU 200 is updated. When (N-1) times of data update are executed, in the next time, data storage processing is executed to update data in the RAM 240 of the second ECU 200, and data storage of the second ECU is performed. The unit 250 also stores data. As a result, the write processing to the data storage unit 250 can be reduced to 1 / N times while executing data backup N times. As will be described later in the processing of step S400 in FIG. 5, when the ignition is off, the latest data is backed up by writing the data stored in the RAM 240 into the data storage unit 250.

  Next, in step S140, the data transmission unit 124 transmits the data set created in step S140 to the network, and ends the data transmission process.

  Next, processing up to data reception by the data management source ECU 100 will be described with reference to FIG.

  The CPU 120 reads the data reception program of the data management source stored in the ROM 130 at the timing when the ECU is turned on, and executes the processing of the data transmission / reception processing unit 120B.

  In step S200, the data return request unit 125 determines whether the ECU can transmit / receive data to / from the network. When determining that the data transmission / reception is ready, the process proceeds to the next step S210. It will not proceed to the next step until data transmission / reception preparation is complete. The data reply request unit 125 determines that the data reception operation is ready when the first ECU 100 finishes the reset process.

  When the data transmission / reception preparation is completed, in step S210, the data transmission unit 124 creates a data set in which the request flag shown in the transmission data set in FIG. Then, the process proceeds to the next step S220. At this time, since the data portion of the transmission data set is unnecessary, the data portion may not exist. When receiving a reply data set as shown in the reply data set of FIG. 6B from the network 300, the data receiving unit 126 proceeds to the next step S230.

  When the reply data set is received, in step S230, the data comparison unit 127 compares the data stored in the data storage unit 150 with the data received in the reply data set, and proceeds to the next step S240.

  In step S240, the data determining unit 128 uses the data for the control of the data management source ECU 100 when determining that the comparison results match, and when determining that the comparison results do not match, Judged as unreliable. When comparing the data backed up in the data storage unit 150 and the data received from the second ECU 200, the data determination unit 128 has a threshold value for each data, and the data comparison result falls within the threshold value. In this case, it is determined that the data match. Here, the threshold value is changed depending on, for example, the type of data to be backed up, and when the difference is within a difference of 1% to 20%, it is determined that they match.

  When it is determined that the reliability is low, the data determination unit 128 reads data of default values (initial state values) stored in advance in the data storage unit 150 and uses them for control. The default value is a control value that can move the vehicle to a nearby repair shop or the like like a limp home. Also, when it is determined that the data does not match, and when three or more ECUs are used for data backup, the data of a plurality of reply data sets are compared, and the number of matches among them is one. Most data can be used for control of the data management source ECU 100. With such a configuration, even when data cannot be stored at the data management source, data stored correctly from the data received in the return data set can be used for control. In this flow, the data reception process is finished.

  Next, processing from data reception to data return of the data storage source ECU 200 will be described with reference to FIG. The CPU 220 reads the data management source data reception reply program stored in the ROM 230 at a predetermined sampling period (for example, every 100 msec), and executes processing in the reply processing unit 220C.

  In step S300, the data reception unit 221 determines whether data is received from the network. When there is data reception, the process proceeds to the next step S310, and when there is no data reception, the process proceeds to step S390 described later.

  If there is data reception, in step S310, the storage necessity determination unit 222 analyzes the request flag of the data set received from the network, and proceeds to the next step S320.

  In step S320, the storage necessity determination unit 222 determines whether or not there is a data update request. If there is an update request, the process proceeds to the next step S330, and if there is no update request, the process proceeds to step S340 described later.

  If there is an update request, in step S330, the storage necessity determination unit 222 updates the storage target data temporarily stored in the data storage source RAM 240 with the received data, and proceeds to the next step S340. In step S330, only the storage target data temporarily stored in the data storage source RAM 240 is updated, and data storage in the data storage unit 250 is not performed.

  Next, in step S340, the storage necessity determination unit 222 determines whether or not there is a data storage request. If there is a storage request, the process proceeds to the next step S350, and if there is no storage request, step S360 described later. Proceed to

  If there is a storage request, in step S350, the storage necessity determination unit 222 updates the storage target data temporarily stored in the data storage source RAM 240 with the received data, and further stores the storage target data. The data is stored in the unit 250, and the process proceeds to the next step S360.

  In step S360, the reply determination unit 223 determines whether or not there is a data reply request. If there is a reply request, the process proceeds to the next step S370, and if there is no reply request, the process proceeds to step S390 described later.

  If there is a reply request, the reply data set creation unit 224 creates a reply data set as shown in FIG. 6B from the data stored in the data storage unit 250 in step S370. The reply data set created by the reply data set creation unit 224 includes at least a data body, a data set number, and a data validity determination flag. Accordingly, since the validity / invalidity of the reply data can be determined by the data validity determination flag, the message configuration used in the network can be shared, and communication via the network can be more easily constructed. When there is no target storage data or when the target storage data cannot be stored correctly when creating a reply data set, the validity determination flag is invalidated. If the data is stored correctly, the validity determination flag is invalidated. Is valid. When the validity determination flag is invalid, the data portion is not used, and therefore the data portion does not need to exist.

  Next, in step S380, the data transmission unit 225 transmits the created reply data set to the network, and proceeds to the next step S390.

  Next, in step S390, the storage necessity determination unit 222 determines whether the backup process is necessary. Here, when it is time for the data storage source ECU 200 to back up data as a system (for example, turning off the ignition switch), the process proceeds to the next step S400, and when it is not the backup time, the process is terminated.

  In step S <b> 400, if there is storage target data temporarily stored in the RAM 240, the storage necessity determination unit 222 stores the data in the data storage unit 250. The process of step S400 is a process when the data management source ECU 100 transmits only the transmission data set of the data update request and the data storage source ECU 200 has reached a backup timing without a data storage request. With this configuration, even if the data management source issues only a data update request and stops operating without issuing a data storage request, the data value at the time of the last received data update request is stored. be able to.

  As described above, according to the present embodiment, data is redundantly stored in storage media of a plurality of ECUs connected via a network, thereby improving the reliability of data while suppressing the cost of the storage media. be able to.

  The embodiments disclosed above are examples in all respects and are not restrictive. The scope of the present invention is shown not only by the above description but also by the scope of the claims, and various modifications can be made according to the design and the like as long as they do not depart from the technical idea of the present invention. It is.

1000 ... Vehicle data storage device 100, 200 ... ECU
110, 210 ... communication circuit 120, 220 ... CPU
120A, 220A ... control unit 120B ... data transmission / reception processing unit 121 ... data acquisition unit 122 ... transmission judgment unit 123 ... transmission data set creation unit 124 ... data transmission unit 125 ... data return request unit 126 ... data reception unit 127 ... data comparison unit 128... Data judgment unit 130, 230 ... ROM
140, 240 ... RAM
150, 250 ... data storage unit 220C ... data reply processing unit 221 ... data receiving unit 222 ... storage necessity judgment unit 223 ... reply judgment unit 224 ... reply data set creation unit 225 ... data transmission unit 300 ... network bus

Claims (6)

A first ECU that controls the first control object, and a second ECU that controls a second control object that is different from the first control object, and is connected to the first ECU via a network Used in a vehicle control system having
The first ECU includes a first RAM that temporarily stores data, and a first data storage unit that includes a nonvolatile memory that stores backup data.
The second ECU is a vehicle data storage device having a second RAM for temporarily storing data and a second data storage unit including a nonvolatile memory for storing backup data,
The first ECU transmits / receives backup data in the first ECU to the second ECU via the network, and receives backup data from the second ECU via the network. With a processing unit,
The second ECU stores backup data from the data transmission / reception processing unit in the second data storage unit, and also stores backup data of the first ECU stored in the second data storage unit. A data reply processing unit that sends a reply to the first ECU via the network ;
In the vehicle data storage device,
And a third ECU connected to the first ECU via a network,
The third ECU
A third RAM for temporarily storing data;
A third data storage unit comprising a non-volatile memory for storing backup data;
The third ECU stores backup data from the data transmission / reception processing unit in the third data storage unit, and stores backup data of the first ECU stored in the third data storage unit. A data reply processing unit that sends a reply to the first ECU via the network;
The data transmission / reception processing unit compares the data backed up by the first data storage unit with the data received from the second ECU, and if these data do not match, the received backup data of the vehicle data storage apparatus which is characterized that you use the largest number of data matching. The vehicle data storage device according to claim 1,
The data transmission / reception processing unit
A data acquisition unit for acquiring the backup data used in the first ECU at a predetermined timing;
A transmission determination unit for determining whether or not to transmit the data acquired by the data acquisition unit to the second ECU;
A transmission data set creation unit for creating a transmission data set from data obtained from the data acquisition unit;
A data transmission unit that transmits the transmission data set to the network according to a result of the transmission determination unit;
A data return request unit for requesting a data return from the second ECU at a specific timing;
A data receiving unit for receiving data returned from the second ECU via the network;
A data comparison unit for comparing data received by the data reception unit;
A data determination unit for determining a data value to be used this time according to a comparison result in the data comparison unit;
With
The data reply processing unit
A data receiving unit for receiving data from the network;
A storage necessity determination unit for determining whether to store data received from the network;
A reply judgment unit for judging whether or not to return the stored data to the data management source,
A reply data set creation unit for creating a reply data set from the stored data;
A data transmission unit that transmits the transmission data set created by the transmission data set creation unit to the network according to a result of the reply determination unit;
Equipped with a,
The data comparison unit and the data determination unit compare the data backed up by the first data storage unit with the data received from the second ECU, and if the data match, If the data is used and they do not match, the default value stored in the first data storage unit is used for control,
The data determination unit has a threshold value for each data when comparing the data backed up in the first data storage unit and the data received from the second ECU, and the data comparison result There if falls within the threshold value, the vehicle data storage apparatus which is characterized that you determined that data match.   The vehicle data storage device according to claim 1,
  The data transmission / reception processing unit
  A data acquisition unit for acquiring the backup data used in the first ECU at a predetermined timing;
  A transmission determination unit for determining whether or not to transmit the data acquired by the data acquisition unit to the second ECU;
  A transmission data set creation unit for creating a transmission data set from data obtained from the data acquisition unit;
  A data transmission unit that transmits the transmission data set to the network according to a result of the transmission determination unit;
  A data return request unit for requesting a data return from the second ECU at a specific timing;
  A data receiving unit for receiving data returned from the second ECU via the network;
  A data comparison unit for comparing data received by the data reception unit;
  A data determination unit for determining a data value to be used this time according to a comparison result in the data comparison unit;
With
  The data reply processing unit
  A data receiving unit for receiving data from the network;
  A storage necessity determination unit for determining whether to store data received from the network;
  A reply determination unit for determining whether to return the stored data to the data management source;
  A reply data set creation unit for creating a reply data set from the stored data;
  A data transmission unit that transmits the transmission data set created by the transmission data set creation unit to the network according to a result of the reply determination unit;
With
  The vehicle data storage device, wherein the data reply request unit makes a reply request at a timing when the first ECU finishes the reset process and is ready to receive data. The vehicle data storage device according to claim 1,
The data transmission / reception processing unit
A data acquisition unit for acquiring the backup data used in the first ECU at a predetermined timing;
A transmission determination unit for determining whether or not to transmit the data acquired by the data acquisition unit to the second ECU;
A transmission data set creation unit for creating a transmission data set from data obtained from the data acquisition unit;
A data transmission unit that transmits the transmission data set to the network according to a result of the transmission determination unit;
A data return request unit for requesting a data return from the second ECU at a specific timing;
A data receiving unit for receiving data returned from the second ECU via the network;
A data comparison unit for comparing data received by the data reception unit;
A data determination unit for determining a data value to be used this time according to a comparison result in the data comparison unit;
With
The transmission determination unit determines the difference between the previous transmission data, the vehicle data storage apparatus which is characterized that you decide whether to transmit the obtained data. The vehicle data storage device according to claim 2,
The vehicle data storage device, wherein the data acquisition unit sets a timing for acquiring data according to a change speed of the data. The vehicle data storage device according to claim 2,
The transmission data set created by the transmission data set creation unit includes at least a data body, a data set number, and a request flag.
The reply data set created by the reply data set creation unit includes at least a data body, a data set number, and a data validity determination flag.

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