Software update system

Abstract

To provide a software update system which continuously and properly transmits update data to an on-vehicle ECU even when an update device transmitting the update data to the on-vehicle ECU is switched.SOLUTION: A software update system A executes update processing of software for an on-vehicle ECU 30. The software update system A comprises: a server 1 which stores divided packages obtained by plurally dividing update data in association with package IDs; the on-vehicle ECU 30 which can execute the update processing; and an update device 2 which transmits update information received from the on-vehicle ECU 30 to the server 1 and can transmit the divided packages received from the server 1 to the on-vehicle ECU 30. The on-vehicle ECU 30 creates and stores the update information including the package IDs of the received divided packages and the update device ID of the update device 2 in a state of being communication-connected. The server 1 extracts the divided package(s) not received in the on-vehicle ECU 30 based on the update information and transmits the same to the on-vehicle ECU 30.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a software update system that performs software update processing for an in-vehicle ECU [Electronic Control Unit].

Background Art

[0002] Vehicles are equipped with in-vehicle ECUs that perform various control processes. In such in-vehicle ECUs, software update processing is performed to modify and change the processing content. For example, Patent Document 1 describes an in-vehicle device that acquires software update data from an external server using a communication terminal and performs software update processing based on the acquired update data.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, there are various update devices such as an update device that transmits update data to an in-vehicle ECU using wireless communication and an update device that transmits update data to an in-vehicle ECU using wired communication. In recent years, the data volume of update data has been increasing, and it may take time to transmit the update data to the in-vehicle ECU. For this reason, it is conceivable to switch the update device during the transmission of the update data to the in-vehicle ECU, but the configuration described in Patent Document 1 does not consider such switching.

[0005] Therefore, the present disclosure will describe a software update system that can continuously and appropriately transmit update data to an in-vehicle ECU even when the update device that transmits the update data to the in-vehicle ECU is switched. [Means for solving the problem]

[0006] One aspect of the present disclosure is a software update system for performing software update processing for an in-vehicle ECU, comprising: a server that stores divided software update data into multiple packages associated with the package ID [identifier] of each divided package; an in-vehicle ECU capable of executing software update processing; and a plurality of update devices that can communicate with the in-vehicle ECU and, while in a state of communication connection with the in-vehicle ECU, can transmit divided packages received from the server to the in-vehicle ECU, wherein the in-vehicle ECU includes: an update information storage unit that generates and stores update information including the package ID of the received divided package and the update device ID of the update device in a state of communication connection; an update information transmission unit that transmits update information to the update device in a state of communication connection; a package receiving unit that receives divided packages from the update device in a state of communication connection; and the received The update device has an update processing unit that performs software update processing based on the divided packages, and the update device has a first transmission unit that transmits update information received from the in-vehicle ECU to the server while in a state of communication connection with the in-vehicle ECU, and a second transmission unit that transmits divided packages received from the server to the in-vehicle ECU while in a state of communication connection with the in-vehicle ECU, and the server has a storage unit that stores divided packages and package IDs in association, an update information receiving unit that receives update information transmitted from the update device, an extraction unit that extracts divided packages stored in the storage unit that have not been received by the in-vehicle ECU based on the package IDs of the received divided packages included in the received update information, and a package transmission unit that transmits the extracted divided packages to the update device corresponding to the update device ID included in the received update information.

[0007] In the above software update system, the package transmission unit may determine the priority so that, if the communication method between the update device identified by the update device ID and the in-vehicle ECU is wired communication, the split package with the largest data volume is transmitted first among the multiple split packages to be transmitted. If the communication method between the update device identified by the update device ID and the in-vehicle ECU is wireless communication, the package transmission unit may determine the priority so that, among the multiple split packages to be transmitted, the split package with the smallest data volume is transmitted first. [Effects of the Invention]

[0008] According to one aspect of this disclosure, even if the update device that transmits update data to the in-vehicle ECU is switched, the update data can continue to be transmitted appropriately to the in-vehicle ECU. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a block diagram showing the overall configuration of a software update system according to an embodiment. [Figure 2] Figure 2 is a sequence diagram showing the flow of the update process performed in the software update system. [Modes for carrying out the invention]

[0010] The following describes exemplary embodiments with reference to the drawings. In each drawing, identical or equivalent elements are denoted by the same reference numerals, and redundant explanations are omitted.

[0011] As shown in Figure 1, the software update system A performs software update processing for the in-vehicle ECU 30. The in-vehicle ECU 30 is installed in an in-vehicle unit 3 mounted in the vehicle. The in-vehicle unit 3 is not particularly limited as long as it is equipped with the in-vehicle ECU 30. The software update system A comprises a server 1, multiple update devices 2, and the in-vehicle ECU 30. Figure 1 shows an example where two update devices are provided. Also, when distinguishing between the multiple update devices 2, they may be referred to as the first update device 2A and the second update device 2B.

[0012] First, let's describe the overall overview of software update system A. Server 1 stores software update programs for operating the in-vehicle ECU 30. Here, Server 1 stores the update data in multiple divided packages, associating each divided package with its package ID.

[0013] The update device 2 is used to perform software update processing for the in-vehicle ECU 30. The update device 2 can communicate with the in-vehicle ECU 30 in various ways. When the update device 2 is connected to the in-vehicle ECU 30, it can transmit update data (divided packages) received from the server 1 to the in-vehicle ECU.

[0014] For example, the update device 2 can communicate with the in-vehicle unit 3 (in-vehicle ECU 30) via wired or wireless communication. This wired communication may be performed, for example, by connecting a dedicated communication cable between the update device 2 and the in-vehicle unit 3 (in-vehicle ECU 30). Furthermore, if the vehicle on which the in-vehicle unit 3 is installed is an electric vehicle (BEV: Battery Electric Vehicle), this wired communication may be performed via a cable used to supply power to the vehicle. In other words, the power supply equipment for the vehicle may also function as the update device 2.

[0015] This wireless communication may be conducted based on various communication standards, such as Wi-Fi communication and Bluetooth® communication. The wireless communication between the update device 2 and the in-vehicle unit 3 may be conducted while the vehicle equipped with the in-vehicle unit 3 is in motion. Furthermore, communication between the update device 2 and the server 1 may be conducted by various methods, such as wired communication.

[0016] The in-vehicle ECU 30 of the in-vehicle unit 3 receives divided update data in split packages from the server 1 via the update device 2. Based on the received split packages, the in-vehicle ECU 30 can perform software update processing to operate itself.

[0017] Here, for example, the amount of data for updating the in-vehicle ECU 30 may be large. In such cases, it is conceivable to switch the update device 2 in the middle of the update process. For example, while updating the in-vehicle unit 3 using the first update device 2A which performs wireless communication, it is conceivable to switch to the second update device 2B which performs wired communication and continue the update process.

[0018] The switching of the update device 2 used in this update process is performed, for example, by the user of the vehicle equipped with the in-vehicle unit 3 or by a worker performing maintenance on the vehicle. The following describes in detail the configuration that allows the software update process of the in-vehicle ECU 30 to be continued from where it left off even when the update device 2 is switched.

[0019] The in-vehicle ECU 30 is an electronic control unit having a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], etc. The in-vehicle ECU 30 realizes various functions by, for example, loading a program recorded in the ROM into the RAM and executing the program loaded into the RAM by the CPU. The in-vehicle ECU 30 may include an operating surface memory for storing an executing program and a non-operating surface memory for storing an updating program. Functionally, the in-vehicle ECU 30 includes an update information storage unit 31, an update information transmission unit 32, a package reception unit 33, and an update processing unit 34.

[0020] The update information storage unit 31 generates update information including a package ID of a received divided package received from the server 1 via the update device 2 and an update device ID of the update device 2 in a communication-connected state. The update information storage unit 31 stores the generated update information. The update device 2 in a communication-connected state is the update device 2 capable of communicating with the vehicle-mounted device 3 by wired communication or wireless communication as described above. Each time the update information storage unit 31 receives a divided package, it updates the package ID of the received divided package included in the update information. Also, each time the communication-connected update device 2 is switched, the update information storage unit 31 updates the update device ID included in the update information.

[0021] The update information may further include various types of information related to software updates, such as version information (update version information) of software for operating the in-vehicle ECU 30 and status information indicating the update status.

[0022] The update information transmission unit 32 transmits the update information stored in the update information storage unit 31 to the update device 2 in a communication-connected state. Here, the update information transmission unit 32 may transmit the update information in response to a request from the update device 2 in a communication-connected state. That is, when the update device 2 is connected to the in-vehicle unit 3 to perform the software update process of the in-vehicle ECU 30, the update information transmission unit 32 may transmit the update information in response to a request from the update device 2. Also, each time the update information is updated by the update information storage unit 31, the update information transmission unit 32 may transmit the new update information to the update device 2.

[0023] The package reception unit 33 receives the divided packages from the update device 2 in a communication-connected state. In this way, the package reception unit 33 can receive the divided packages stored in the server 1 via the communication-connected update device 2.

[0024] The update processing unit 34 performs a software update process based on the divided packages received by the package reception unit 33. For example, the update processing unit 34 can perform the software update process by writing the received divided packages into the non-operating surface memory that stores the program being updated.

[0025] When performing the software update process of the in-vehicle ECU 30 of the in-vehicle unit 3, the update device 2 is communicatively connected to the in-vehicle unit 3 (in-vehicle ECU 30). This communication connection is performed, for example, by the user of the vehicle equipped with the in-vehicle unit 3 or an operator who performs vehicle maintenance work. For example, when the update device 2 and the in-vehicle unit 3 are communicatively connected by wireless communication, the update device 2 and the in-vehicle unit 3 may be communicatively connected by the user or the like operating the in-vehicle unit 3. For example, when the update device 2 and the in-vehicle unit 3 are communicatively connected by wired communication, the update device 2 and the in-vehicle unit 3 may be communicatively connected by the user or the like connecting the communication cable provided in the update device 2 to the in-vehicle unit 3.

[0026] The update device 2 is equipped with an update ECU 20. In addition to the update ECU 20, the update device 2 is also equipped with communication equipment for communicating with the server 1 and the in-vehicle unit 3, respectively. The update ECU 20 is an electronic control unit with the same configuration as the in-vehicle ECU 30. Functionally, the update ECU 20 is equipped with a first transmitter 21 and a second transmitter 22.

[0027] The first transmitting unit 21, while in a communication connection with the in-vehicle unit 3 (in-vehicle ECU 30), receives update information transmitted from the update information transmitting unit 32 of the in-vehicle ECU 30. The first transmitting unit 21 then transmits the received update information to the server 1. The first transmitting unit 21 may also request the update information transmitting unit 32 of the in-vehicle unit 3 to transmit the update information.

[0028] The second transmitting unit 22, while in communication with the in-vehicle unit 3 (in-vehicle ECU 30), transmits the segmented packages received from the server 1 to the in-vehicle unit 3 (in-vehicle ECU 30). Alternatively, the second transmitting unit 22 may transmit the segmented packages to the in-vehicle unit 3 sequentially after receiving all of the segmented packages transmitted from the server 1. Furthermore, the second transmitting unit 22 may transmit each of the segmented packages received from the server 1 to the in-vehicle unit 3 sequentially.

[0029] Server 1 stores update data for performing software update processing on the in-vehicle ECU 30. Server 1 transmits the divided update data in a divided package to the in-vehicle unit 3 via one of the multiple update devices 2. Specifically, Server 1 includes a server ECU 10. Server ECU 10 is an electronic control unit with the same configuration as the in-vehicle ECU 30. Functionally, Server ECU 10 includes a storage unit 11, an update information receiving unit 12, an extraction unit 13, and a package transmission unit 14.

[0030] The storage unit 11 stores the divided packages of the update data, associating them with the package ID of each divided package. The storage unit 11 may also store update version information of the update data along with these divided packages. The update information receiving unit 12 receives the update information transmitted from the first transmitting unit 21 of the update device 2.

[0031] The extraction unit 13 extracts from the divided packages stored in the storage unit 11 that have not been received by the in-vehicle device 3 (in-vehicle ECU 30), based on the package ID of the received divided package included in the received update information. For example, the extraction unit 13 can also extract the divided package of the appropriate version of the update data based on the update version information included in the update information.

[0032] The package transmission unit 14 identifies the update device 2 corresponding to the update device ID included in the update information received by the update information receiving unit 12. The package transmission unit 14 transmits the divided package extracted by the extraction unit 13 to the identified update device 2. This identified update device 2 is the update device 2 that is in a communication connection with the in-vehicle unit 3 in order to perform software update processing. In this way, the package transmission unit 14 can identify the update device 2 to which the divided package will be transmitted based on the update device ID included in the update information.

[0033] Next, we will explain the flow of the software update process for the in-vehicle ECU 30 performed in software update system A. Here, we will explain using the example of a case where the update device 2 used for the update process is switched to the second update device 2B in the middle of the update process using the first update device 2A.

[0034] As shown in Figure 2, when the first update device 2A is connected to the in-vehicle unit 3, the update information transmission unit 32 of the in-vehicle ECU 30 mounted on the in-vehicle unit 3 transmits update information to the first update device 2A (update information transmission step S1). Here, the update information transmission unit 32 can transmit update information to the first update device 2A in response to a request for transmission of update information from the first update device 2A. The first transmission unit 21 of the first update device 2A transmits the update information received from the in-vehicle unit 3 to the server 1 (update information transmission step S2).

[0035] The extraction unit 13 of server 1 receives update information transmitted from the first update device 2A. Based on this, server 1 can recognize the update device 2 (in this case, the first update device 2A) connected to the in-vehicle unit 3 and the divided packages that the in-vehicle unit 3 has already received, based on the update information. Then, server 1, the first update device 2A, and the in-vehicle unit 3 perform the software update process in update processing step S3.

[0036] Here, the extraction unit 13 of server 1 extracts the split packages that have not been received by the in-vehicle unit 3. The package transmission unit 14 of server 1 transmits the extracted split packages to the first update device 2A. The second transmission unit 22 of the first update device 2A receives the split packages transmitted from server 1 and transmits the received split packages to the in-vehicle unit 3. The package receiving unit 33 of the in-vehicle unit 3 receives the split packages transmitted from the first update device 2A. The update processing unit 34 of the in-vehicle unit 3 performs software update processing based on the received split packages.

[0037] Here, we will describe a more detailed example of the software update process in update step S3. Note that the following examples of update processes are just examples, and the update process is not limited to these examples.

[0038] (Example of update process 1) First, let's describe the first example of the update process. In this first example, each time the in-vehicle unit 3 finishes receiving a split package, one split package at a time is sent from the server 1 to the in-vehicle unit 3 via the first update device 2A. Specifically, the package transmission unit 14 of the server 1 sends one of the multiple split packages extracted by the extraction unit 13 to the first update device 2A. The second transmission unit 22 of the first update device 2A sends the split package received from the server 1 to the in-vehicle unit 3.

[0039] The update processing unit 34 of the in-vehicle unit 3 performs update processing based on the split package transmitted from the first update device 2A. Once the update processing based on the received split package is completed, the update information storage unit 31 of the in-vehicle unit 3 updates the package ID of the received split package included in the update information.

[0040] When the update information is updated, the update information transmission unit 32 of the in-vehicle unit 3 transmits the updated update information to the first update device 2A. The first transmission unit 21 of the first update device 2A transmits the update information received from the in-vehicle unit 3 to the server 1. The extraction unit 13 of the server 1 extracts any unreceived split packages based on the received update information. The update process is then carried out by repeating the above-described process flow.

[0041] In this first example, the package transmission unit 14 of server 1 determines the transmission priority of the extracted divided packages based on the communication method between the first update device 2A and the in-vehicle unit 3 (in-vehicle ECU 30). The package transmission unit 14 may then transmit the divided packages to the first update device 2A based on the determined priority. The package transmission unit 14 can identify the communication method between the first update device 2A and the in-vehicle unit 3, for example, from the update device ID included in the received update information.

[0042] More specifically, the package transmission unit 14 can, for example, determine a priority so that, when the communication method between the first update device 2A and the in-vehicle unit 3 is wired communication, the segmented packages with larger data volumes are transmitted first. Furthermore, the package transmission unit 14 can, for example, determine a priority so that, when the communication method between the first update device 2A and the in-vehicle unit 3 is wireless communication, the segmented packages with smaller data volumes are transmitted first.

[0043] Depending on the communication method between the first update device 2A and the in-vehicle unit 3, the communication stability and speed may differ. Therefore, the package transmission unit 14 determines the priority of transmission of segmented packages based on the communication method, so that segmented packages suitable for transmission and reception using the current communication method are transmitted first. For example, wireless communication may have lower communication stability and slower communication speeds compared to wired communication. Therefore, the package transmission unit 14 determines the priority based on whether the communication method is wired or wireless, so that it can take into account the characteristics of the communication method and transmit segmented packages suitable for transmission and reception using the current communication method first.

[0044] (Second example of update processing) Next, a second example of the update process will be described. In this second example, all (or more) of the split packages that the in-vehicle unit 3 has not received are sent to the first update device 2A. The first update device 2A stores the multiple split packages that have been sent and sends one split package at a time to the in-vehicle unit 3 each time the in-vehicle unit 3 has finished receiving the split packages. Specifically, the package transmission unit 14 of the server 1 sends all (or more) of the multiple split packages extracted by the extraction unit 13 to the first update device 2A.

[0045] The first update device 2A stores multiple split packages transmitted from the server 1. The second transmission unit 22 of the first update device 2A transmits one of the stored split packages to the in-vehicle unit 3. The update processing unit 34 of the in-vehicle unit 3 performs update processing based on the split package transmitted from the first update device 2A. Once the update processing based on the received split package is completed, the update information storage unit 31 of the in-vehicle unit 3 updates the package ID of the received split package included in the update information.

[0046] When the update information is updated, the update information transmission unit 32 of the in-vehicle unit 3 transmits the updated update information to the first update device 2A. The second transmission unit 22 of the first update device 2A transmits to the in-vehicle unit 3 any segmented packages that it has stored but has not yet received from the in-vehicle unit 3, based on the update information received from the in-vehicle unit 3. The update process is then carried out by repeating the above-described process flow.

[0047] In this second example, the second transmitting unit 22 of the first update device 2A determines the transmission priority of the multiple divided packages transmitted from the server 1 based on the communication method between the first update device 2A and the in-vehicle unit 3 (in-vehicle ECU 30). The second transmitting unit 22 may then transmit the divided packages to the in-vehicle unit 3 based on the determined priority. The communication method between the first update device 2A and the in-vehicle unit 3 is predetermined.

[0048] More specifically, the second transmitting unit 22 of the first update device 2A can determine a priority so that, for example, when the communication method between the first update device 2A and the in-vehicle unit 3 is wired communication, the segmented packages with larger data volumes are transmitted first among the multiple stored segmented packages. Furthermore, the second transmitting unit 22 of the first update device 2A can determine a priority so that, for example, when the communication method between the first update device 2A and the in-vehicle unit 3 is wireless communication, the segmented packages with smaller data volumes are transmitted first among the multiple stored segmented packages.

[0049] Depending on the communication method between the first update device 2A and the in-vehicle unit 3, the communication stability and speed may differ. Therefore, the second transmitter 22 determines the priority of transmission of segmented packages based on the communication method, so that segmented packages suitable for transmission and reception using the current communication method are transmitted first. For example, wireless communication may have lower communication stability and slower communication speeds compared to wired communication. Therefore, the second transmitter 22 determines the priority based on whether the communication method is wired or wireless, so that it can take into account the characteristics of the communication method and transmit segmented packages suitable for transmission and reception using the current communication method first.

[0050] Now, let's assume that during the update process step S3 shown in Figure 2, the update device 2 is switched from the first update device 2A to the second update device 2B. When the update device 2 is switched to the second update device 2B, the update process using the first update device 2A is terminated.

[0051] When the second update device 2B establishes a communication connection with the in-vehicle unit 3, the update information transmission unit 32 of the in-vehicle ECU 30 mounted on the in-vehicle unit 3 transmits update information to the second update device 2B (update information transmission step S4). Here, the update information transmission unit 32 can transmit update information to the second update device 2B in response to a request for transmission of update information from the second update device 2B. When the first transmission unit 21 of the second update device 2B receives transmission information from the in-vehicle unit 3, it transmits the received update information to the server 1 (update information transmission step S5).

[0052] The extraction unit 13 of server 1 receives update information transmitted from the second update device 2B. Based on this update information, server 1 can recognize the update device 2 (in this case, the second update device 2B) connected to the in-vehicle unit 3 and the split packages already received by the in-vehicle unit 3. Then, server 1, the second update device 2B, and the in-vehicle unit 3 perform the software update process in update processing step S6, similar to the update processing step S3 described above.

[0053] As described above, Server 1 stores the update data for software update processing by dividing it into multiple parts. Based on the update information transmitted from the in-vehicle unit 3, Server 1 can recognize the update device 2, which is in communication with the in-vehicle unit 3, and the divided packages that have already been received by the in-vehicle unit 3. Server 1 can then transmit any unreceived divided packages to the in-vehicle unit 3 via the update device 2, which is in communication with the in-vehicle unit 3.

[0054] Furthermore, the update device 2 may be switched. Even in this case, the server 1 can recognize the update device 2 that has newly established a communication connection with the in-vehicle unit 3, and the segmented packages that have been received so far by the in-vehicle unit 3, based on the update information transmitted from the in-vehicle unit 3. The server 1 can then transmit segmented packages that have not been received so far to the in-vehicle unit 3 via the newly connected update device 2.

[0055] In other words, software update system A is not configured to send the entire update data from the beginning and perform the update process even if update device 2 is switched. Software update system A can take over the transmission of update data from where it left off even if update device 2 is switched. Thus, software update system A can continue to appropriately transmit update data to the in-vehicle ECU even if the update device that transmits update data to the in-vehicle ECU is switched. Therefore, software update system A can take over the software update process of the in-vehicle ECU 30 from where it left off and continue the update process even if update device 2 is switched.

[0056] Furthermore, the update process in the in-vehicle ECU 30 may fail due to, for example, communication errors, write errors, or processing timeouts. Even in this case, the software update system A can continue the update process from where it failed. [Explanation of symbols]

[0057] 1...Server, 2...Update device, 2A...First update device (update device), 2B...Second update device (update device), 3...In-vehicle unit, 11...Storage unit, 12...Update information receiving unit, 13...Extraction unit, 14...Package transmission unit, 21...First transmission unit, 22...Second transmission unit, 30...In-vehicle ECU, 31...Update information storage unit, 32...Update information transmission unit, 33...Package receiving unit, 34...Update processing unit, A...Software update system.

Claims

1. A software update system that performs software update processing for an in-vehicle ECU, A server that stores the divided software update data, which is divided into multiple packages, and associates these divided packages with their respective package IDs. The in-vehicle ECU capable of performing the software update process, The system comprises a plurality of update devices that can communicate with the in-vehicle ECU and, while in a state of communication with the in-vehicle ECU, can transmit the divided packages received from the server to the in-vehicle ECU. The aforementioned in-vehicle ECU is An update information storage unit generates and stores update information including the package ID of the received divided package and the update device ID of the update device in a communication-connected state, An update information transmission unit that transmits the update information to the update device which is in a communication connection state, A package receiving unit that receives the divided package from the update device in a communication-connected state, An update processing unit that performs software update processing based on the received split package, It has, The update device is A first transmission unit, while in a state of communication connection with the in-vehicle ECU, transmits the update information received from the in-vehicle ECU to the server, A second transmission unit, while in a state of communication connection with the in-vehicle ECU, transmits the divided package received from the server to the in-vehicle ECU, It has, The aforementioned server, A storage unit that stores the divided package and the package ID in association, An update information receiving unit that receives the update information transmitted from the update device, An extraction unit extracts from the divided packages stored in the storage unit that have not been received by the in-vehicle ECU, based on the package ID of the received divided package included in the received update information, A package transmission unit that transmits the extracted segmented package to the update device corresponding to the update device ID included in the received update information, A software update system having the following features.

2. The software update system according to claim 1, wherein the update information storage unit updates the update information each time the reception of the divided package is completed.

3. The software update system according to claim 1 or 2, wherein the package transmission unit determines the transmission priority of the extracted divided packages based on the communication method between the update device and the in-vehicle ECU, which is identified from the update device ID included in the received update information, and transmits the divided packages based on the determined priority.

4. The aforementioned package transmission unit, If the communication method between the update device identified by the update device ID and the in-vehicle ECU is wired communication, a priority is determined so that among the multiple divided packages to be transmitted, the divided package with the largest amount of data is transmitted first. The software update system according to claim 3, wherein, when the communication method between the update device identified by the update device ID and the in-vehicle ECU is wireless communication, priority is determined so that among the multiple divided packages to be transmitted, the divided package with the smallest amount of data is transmitted first.

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