JP7815964B2 - Electronic control unit - Google Patents

Description

The present invention relates to an electronic control device.

For example, in-vehicle electronic control units (hereinafter referred to as ECUs (Electronic Control Units)), software is configured to be rewritable for purposes such as improving functionality and resolving malfunctions. For example, Patent Document 1 discloses a configuration in which software is rewritten by obtaining rewrite data from a central ECU that functions as a central gateway and writing the obtained rewrite data to a storage unit.

Japanese Patent Application Laid-Open No. 2021-24555

The processing load on an ECU fluctuates due to a variety of factors. If the processing load on a target ECU, which is the subject of software rewriting control, fluctuates while the software is being rewritten, the fluctuations in processing load could cause malfunctions. In other words, if the cycle for obtaining rewrite data from the central ECU and the block size of the rewrite data do not match the processing load on the target ECU, it could become difficult to properly process the rewrite data obtained from the central ECU, making it difficult to properly rewrite the software. Furthermore, if the software rewrite cycle is set to a uniformly long value in order to prevent further increases in processing load due to software rewriting when the target ECU is performing high processing load, there is a risk that the software rewrite will take a long time.

The present invention was made in consideration of the above circumstances, and its purpose is to provide an electronic control device that can properly rewrite software even when the processing load fluctuates.

According to the invention described in claim 1, software is rewritten by writing rewrite data. A rewrite data acquisition unit (11a) acquires the rewrite data from an external device. A rewrite data writing unit (11b) writes the rewrite data to a storage unit. A processing load determination unit (11c) determines the processing load of the electronic control unit. A transmission mode change request unit (11d) requests a change of the transmission mode of the rewrite data in the external device based on the determination result of the processing load determination unit. The processing load determination unit determines whether a process that increases the processing load is in operation as the processing state of the electronic control unit without calculating the processing load, and if it determines that a process that increases the processing load is not in operation, it determines whether a vehicle state condition that increases the processing load is met. The transmission mode change request unit requests a change of the transmission mode when the processing load determination unit determines that a process that increases the processing load is in operation or that a vehicle state condition that increases the processing load is met.

The processing load of the electronic control unit is determined, and a request is made to change the transmission mode of the rewrite data in the external device based on the processing load determination result. By requesting a change in the transmission mode of the rewrite data in the external device in response to fluctuations in the processing load of the electronic control unit, the cycle for obtaining rewrite data from the external device and the block size of the rewrite data can be made to follow the processing load, and the rewrite data obtained from the external device can be processed appropriately. This allows software rewriting to be carried out appropriately even when the processing load of the electronic control unit fluctuates.

Functional block diagram showing the first embodiment Flowchart showing processing of the ECU to be rewritten Flowchart showing processing of the ECU to be rewritten Flowchart showing processing of the central ECU Functional block diagram showing a second embodiment Flowchart showing processing of the ECU to be rewritten Flowchart showing processing of the ECU to be rewritten Flowchart showing processing of the central ECU

Hereinafter, several embodiments will be described with reference to the drawings. Note that in the embodiments described below, descriptions of parts that overlap with the preceding embodiments may be omitted.
(First embodiment)

The first embodiment will be described with reference to Figures 1 to 4. As shown in Figure 1, a vehicle-side system 1 mounted on a vehicle includes a central ECU 2 that functions as a central gateway and a rewrite target ECU 3 that is the target of software rewrite control by the central ECU 2, which are connected to each other via an in-vehicle network 4 so that data communication is possible. The software includes applications that realize specific functions and can also be referred to as programs. The in-vehicle network 4 is, for example, CAN (Controller Area Network) (registered trademark), FLEXRAY (registered trademark), CXPI (Clock Extension Peripheral Interface) (registered trademark), etc.

The central ECU 2 is connected to a TCU (Telematics Control Unit) 5, an on-board communication device that functions as a data communication device. The TCU 5 is able to receive distribution packages sent from an OTA center 6 by wirelessly connecting to the OTA center 6 via a communication network 7. The TCU 5 is also able to communicate data with on-board communication devices 8 of other vehicles and roadside communication devices 9 installed on the roadside by wirelessly connecting to the on-board communication devices 8 of other vehicles and roadside communication devices 9.

When the TCU 5 receives the distribution package transmitted from the OTA center 6, it transfers the received distribution package to the central ECU 2. When the central ECU 2 receives the distribution package from the TCU 5, it extracts the rewrite data from the transferred distribution package and transmits the extracted rewrite data to the rewrite target ECU 3, as well as a rewrite request to the rewrite target ECU 3, causing the rewrite target ECU 3 to rewrite the software.

The central ECU 2 is also wired to a reprogramming tool (not shown), enabling it to receive distribution packages sent from the reprogramming tool. When the central ECU 2 receives the distribution package sent from the reprogramming tool, it extracts rewrite data from the received distribution package and sends the extracted rewrite data to the reprogramming target ECU 3, as well as a rewrite request to the reprogramming target ECU 3, causing the reprogramming target ECU 3 to rewrite its software. In other words, the reprogramming target ECU 3 rewrites its software in response to the reprogramming data and reprogramming request sent from the central ECU 2. When the central ECU 2 sends reprogramming data to the reprogramming target ECU 3, the central ECU 2 functions as an external device.

When the reprogramming tool and the ECU 3 to be rewritten are directly connected, the reprogramming tool sends the rewrite data to the ECU 3 to be rewritten and also sends a rewrite request to the ECU 3 to be rewritten, causing the ECU 3 to rewrite its software. In other words, the ECU 3 to be rewritten also rewrites its software when the reprogramming tool sends the rewrite data and a rewrite request. When the reprogramming tool sends the rewrite data to the ECU 3 to be rewritten, the reprogramming tool functions as an external device.

The central ECU 2 manages the software rewriting of multiple ECUs 3 to be rewritten. The central ECU 2 is equipped with a control unit 10, which is primarily a microcomputer having a CPU, RAM, ROM, I/O, etc. The control unit 10 executes computer programs stored in a non-transient physical storage medium to perform processing corresponding to the computer programs and control the operation of the central ECU 2.

The control unit 10 includes a transmission mode change unit 10a. The transmission mode change unit 10a has the function of changing the transmission cycle of the rewrite data. When the transmission mode change unit 10a receives a transmission cycle change request from an external device, it changes the transmission cycle of the rewrite data in accordance with the received transmission cycle change request.

The ECU 3 to be rewritten is, for example, a device that controls the drive system, a device that controls the ADAS (Advanced Driving Assistant System), or a device that controls the multimedia system. The ECU 3 to be rewritten comprises a control unit 11, which is primarily a microcomputer having a CPU, RAM, ROM, I/O, etc., and a storage unit 12, which is primarily ROM. The control unit 11 executes a computer program stored in a non-transient physical storage medium, thereby performing processing corresponding to the computer program and controlling the operation of the ECU 3 to be rewritten.

The control unit 11 includes, for each function, a rewrite data acquisition unit 11a, a rewrite data writing unit 11b, a processing load determination unit 11c, a transmission mode change request unit 11d, a write mode change unit 11e, and a write result confirmation unit 11f.

The rewrite data acquisition unit 11a receives and acquires rewrite data transmitted from the central ECU 2. The rewrite data writing unit 11b writes the rewrite data to the storage unit 12 in blocks. In this case, the rewrite data writing unit 11b can select the rewrite data writing cycle from either a low-cycle mode in which the rewrite data is written at a low cycle, or a high-cycle mode in which the rewrite data is written at a high cycle. The rewrite data writing unit 11b can also change the block size when writing rewrite data to the storage unit 12.

The processing load determination unit 11c determines the processing load of the rewrite target ECU 3. Specifically, the processing load determination unit 11c determines whether the processing state of the rewrite target ECU 3 is a process that results in a high processing load, and determines the processing load of the rewrite target ECU 3. The processing load determination unit 11c determines whether the vehicle state satisfies the conditions for a vehicle state that results in a high processing load, and determines the processing load of the rewrite target ECU 3.

The processing load determination unit 11c determines the processing load of the ECU 3 to be rewritten based on sensor information detected by the sensor. The processing load determination unit 11c determines the processing load of the ECU 3 to be rewritten based on the brake operation state and engine speed. The processing load determination unit 11c determines that the vehicle is running with the engine at high speed if the brake operation state is off and the engine speed remains equal to or greater than the first threshold for a predetermined period of time or longer. The processing load determination unit 11c determines that the vehicle is running with the engine at low speed if the brake operation state is off and the engine speed remains equal to or greater than the second threshold but less than the first threshold for a predetermined period of time or longer. The processing load determination unit 11c determines that the vehicle is idling if the brake operation state is on and the engine speed remains equal to or greater than the third threshold but less than the second threshold for a predetermined period of time or longer. The processing load determination unit 11c determines that the vehicle is idling-stop if the brake operation state is on and the engine speed remains less than the third threshold for a predetermined period of time or longer. The processing load determination unit 11c determines the processing load of the rewrite target ECU 3 based on the determination result of whether the vehicle is running at high engine speed, running at low engine speed, idling, or idling stop. The processing load determination unit 11c acquires, for example, data as communication information with the outside of the vehicle via road-to-vehicle communication or vehicle-to-vehicle communication, and determines the processing load of the rewrite target ECU 3 based on the determination result of the acquired data.

When it is determined that the processing state of the ECU 3 to be rewritten is a process that increases the processing load, when it is determined that the vehicle state satisfies the conditions for a vehicle state that increases the processing load, or when it is determined that the processing load is equal to or greater than a threshold, the transmission mode change request unit 11d transmits a transmission period change request to the central ECU 2 to instruct the central ECU 2 to set the transmission period to a long period. On the other hand, when it is determined that the processing state of the ECU 3 to be rewritten is not a process that increases the processing load, when it is determined that the vehicle state does not satisfy the conditions for a vehicle state that increases the processing load, and when it is determined that the processing load is less than the threshold, the transmission mode change request unit 11d transmits a transmission period change request to the central ECU 2 to instruct the central ECU 2 to set the transmission period to a short period .

When the central ECU 2 receives a transmission cycle change request from the rewrite target ECU 3, it changes the transmission cycle of the rewrite data in accordance with the received transmission cycle change request, and transmits the rewrite data to the rewrite target ECU 3 in accordance with the changed transmission cycle.

When the write mode change unit 11e determines that the processing state of the ECU 3 to be rewritten is a process that increases the processing load, when the vehicle state satisfies the conditions for a vehicle state that increases the processing load, or when the processing load is determined to be equal to or greater than a threshold, the write mode change unit 11e notifies the rewrite data writing unit 11b of a write cycle change request instructing the rewrite data writing unit 11b to set the write cycle to a long cycle. On the other hand, when the write mode change unit 11e determines that the processing state of the ECU 3 to be rewritten is not a process that increases the processing load, when the vehicle state does not satisfy the conditions for a vehicle state that increases the processing load, and when the processing load is determined to be less than the threshold, the write mode change unit 11e notifies the rewrite data writing unit 11b of a write cycle change request instructing the rewrite data writing unit 11b to set the write cycle to a short cycle.

When the rewrite data writing unit 11b receives a write cycle change request from the write mode change unit 11e, it changes the write cycle of the rewrite data in accordance with the received write cycle change request.

The write result confirmation unit 11f confirms the result of writing the rewrite data by the rewrite data writing unit 11b, for example, using a CRC (Cyclic Redundancy Check). If the result of writing the rewrite data is normal, the write result confirmation unit 11f sends a normal notification indicating the normal writing result to the central ECU 2. If the result of writing the rewrite data is abnormal, the write result confirmation unit 11f sends an abnormality notification indicating the abnormal writing result to the central ECU 2.

Next, the operation of the above-described configuration will be explained with reference to Figures 2 to 4. Here, we will explain the processing performed by the rewrite target ECU 3 and the processing performed by the central ECU 2 in turn.

(1-1) Processing Performed by the Rewrite Target ECU 3 In the rewrite target ECU 3, the control unit 11 performs a processing load determination process. When the control unit 11 starts the processing load determination process, it determines whether or not a process that will increase the processing load is currently in operation (A1). If the control unit 11 determines that a process that will increase the processing load is currently in operation (A1: YES), it proceeds to step A5. If the control unit 11 determines that a process that will increase the processing load is not currently in operation (A1: NO), it determines whether or not the vehicle state conditions that will increase the processing load are met (A2).

If the control unit 11 determines that the vehicle state conditions for a high processing load are met (A2: YES), it also proceeds to step A5. If the control unit 11 determines that the vehicle state conditions for a high processing load are not met (A2: NO), it calculates the processing load of the ECU 3 to be rewritten (A3) and determines whether the calculated processing load is equal to or greater than a threshold value (A4).

If the control unit 11 determines that the calculated processing load is equal to or greater than the threshold value (A4: YES), it also proceeds to step A5. If the control unit 11 determines that the calculated processing load is not equal to or greater than the threshold value (A4: NO), it proceeds to step A10.

When the control unit 11 proceeds to step A5, it determines that the processing load of the rewrite target ECU 3 is high (A5), transmits a transmission cycle change request to the central ECU 2 requesting that the transmission cycle be set to a long cycle (A6), and waits to receive rewrite data from the central ECU 2 (A7). In this case, when the central ECU 2 receives a transmission cycle change request requesting that the transmission cycle be set to a long cycle from the rewrite target ECU 3, it sets the transmission cycle of the rewrite data to a long cycle and transmits the rewrite data to the rewrite target ECU 3 according to the long transmission cycle. When the control unit 11 determines that it has received the rewrite data transmitted from the central ECU 2 (A7: YES), it sets a long cycle mode in which the rewrite data is written at a long cycle (A8), and writes the rewrite data to the memory unit 12 at a long cycle (A9).

On the other hand, when the control unit 11 proceeds to step A10, it determines that the processing load of the rewrite target ECU 3 is low (A10), transmits a transmission cycle change request to the central ECU 2 requesting a short transmission cycle (A11), and waits to receive rewrite data from the central ECU 2 (A12). In this case, when the central ECU 2 receives a transmission cycle change request from the rewrite target ECU 3 requesting a short transmission cycle, it shortens the transmission cycle of the rewrite data and transmits the rewrite data to the rewrite target ECU 3 according to the shortened transmission cycle. When the control unit 11 determines that it has received the rewrite data transmitted from the central ECU 2 (A12: YES), it sets a short cycle mode in which the rewrite data is written at a short cycle (A13), and writes the rewrite data to the memory unit 12 at a short cycle (A14).

After writing the rewrite data, the control unit 11 determines whether writing of the block size has been completed (A15). If the control unit 11 determines that writing of the block size has been completed (A15: YES), it determines whether writing of all the rewrite data has been completed (A16). If the control unit 11 determines that writing of all the rewrite data has not been completed (A16: NO), it returns to step A1 and repeats step A1 and subsequent steps.

When the control unit 11 determines that writing of all rewrite data has been completed (A16: YES), it checks the writing result of the rewrite data, for example, using CRC (A17), and determines whether the writing result of the rewrite data is normal (A18). When the control unit 11 determines that the writing result of the rewrite data is normal (A18: YES), it sends a normal notification indicating the normal writing result to the central ECU 2 (A19), and ends the processing load determination process. When the control unit 11 determines that the writing result of the rewrite data is abnormal rather than normal (A18: NO), it sends an abnormal notification indicating the abnormal writing result to the central ECU 2 (A20), and ends the processing load determination process.

(1-2) Processing Performed by the Central ECU 2 In the central ECU 2, the control unit 10 performs a change request determination process. When the control unit 10 starts the change request determination process, it determines whether a transmission period change request has been received from the rewrite target ECU 3 (B1). When the control unit 10 determines that a transmission period change request transmitted from the rewrite target ECU 3 has been received (B1: YES), it determines whether the received transmission period change request is a request to set the transmission period to a long period or a request to set the transmission period to a short period (B2, B3).

If the control unit 10 determines that the received transmission cycle change request is a request to set the transmission cycle to a long cycle (B2: YES), it sets the transmission cycle of the rewrite data to a long cycle (B4), transmits the rewrite data to the rewrite target ECU 3 in accordance with the long transmission cycle (B5), and terminates the change request determination process. On the other hand, if the control unit 10 determines that the received transmission cycle change request is a request to set the transmission cycle to a short cycle (B3: YES), it sets the transmission cycle of the rewrite data to a short cycle (B6), transmits the rewrite data to the rewrite target ECU 3 in accordance with the short transmission cycle (B7), and terminates the change request determination process.

The above describes a case where a transmission cycle change request is sent to the central ECU 2 to change the transmission cycle of the rewrite data sent from the central ECU 2 to the rewrite target ECU 3, but the transmission cycle change request may also be sent to the TCU 5 or the OTA center 6. The transmission cycle of the rewrite data sent from the TCU 5 to the central ECU 2 may also be changed by sending a transmission cycle change request to the TCU 5. The transmission cycle of the rewrite data sent from the OTA center 6 to the TCU 5 via the communication network 7 may also be changed by sending a transmission cycle change request to the OTA center 6. In other words, the transmission cycle of the rewrite data transmitted over the communication path from the OTA center 6, which is the sender of the rewrite data, to the rewrite target ECU 3 may be changed.

As described above, according to the first embodiment, the following advantageous effects can be obtained.
The rewrite target ECU 3 determines the processing load and requests the central ECU 2 to change the transmission period of rewrite data based on the processing load determination result. By requesting the central ECU 2 to change the transmission period of rewrite data in accordance with fluctuations in the processing load of the rewrite target ECU 3, the period for obtaining rewrite data from the central ECU 2 can be made to follow the processing load, and the rewrite data obtained from the central ECU 2 can be appropriately processed. This allows software rewriting to be performed appropriately even when the processing load of the rewrite target ECU 3 fluctuates.

In the rewrite target ECU 3, the rewrite data write period is changed in response to a request from the central ECU 2 to change the rewrite data transmission period based on the processing load determination result. By changing the rewrite data write period, the period for obtaining rewrite data from the central ECU 2 and the period for writing rewrite data can be made to follow the processing load, allowing the rewrite data obtained from the central ECU 2 to be processed appropriately.

The processing state of the rewrite target ECU 3 is determined, and the processing load is determined based on the result of determining whether a process that increases the processing load is in operation. As the processing load of the rewrite target ECU 3 changes depending on the processing state, the cycle for obtaining rewrite data from the central ECU 2 can be adjusted to match the processing load.

The rewrite target ECU 3 determines the vehicle state and determines the processing load based on the results of the determination of whether the vehicle state conditions that result in a high processing load are met. The cycle for obtaining rewrite data from the central ECU 2 can be adjusted to follow the processing load, in line with the fluctuations in the processing load of the rewrite target ECU 3 depending on the vehicle state.

The processing load of the rewrite target ECU 3 is determined based on sensor information. As the processing load of the rewrite target ECU 3 changes based on the sensor information, the cycle for obtaining rewrite data from the central ECU 2 can be adjusted to match the processing load.

The processing load of the rewrite target ECU 3 is determined based on the brake operation state and engine speed. As the processing load of the rewrite target ECU 3 fluctuates depending on the brake operation state and engine speed, the cycle for obtaining rewrite data from the central ECU 2 can be adjusted to match the processing load.

In the ECU 3 to be rewritten, the processing load is determined based on communication information between the TCU 5 and the onboard communication device 8 or roadside communication device 9 of other vehicles. The cycle for obtaining rewrite data from the central ECU 2 can be adjusted to match the processing load, following fluctuations in the processing load of the ECU 3 to be rewritten based on communication information between the TCU 5 and the onboard communication device 8 or roadside communication device 9 of other vehicles.

Second Embodiment
The second embodiment will be described with reference to Figures 5 to 8. The first embodiment is configured to transmit a transmission cycle change request to the central ECU 2 in accordance with the processing load of the ECU 3 to be rewritten, whereas the second embodiment is configured to transmit a block size change request to the central ECU 2 in accordance with the processing load of the ECU 3 to be rewritten.

In this case, the transmission mode change unit 10a has the function of changing the block size of the rewritten data. When the transmission mode change unit 10a receives a block size change request from outside, it changes the block size of the rewritten data in accordance with the received block size change request and transmits block size information indicating the changed block size to the sender of the block size change request.

The transmission mode change request unit 11d sends a block size change request to the central ECU 2 instructing the setting of a small block size when it is determined that the processing state of the ECU 3 to be rewritten is a process that increases the processing load, when it is determined that the vehicle state satisfies the conditions for a vehicle state that increases the processing load, or when it is determined that the processing load is equal to or greater than a threshold. On the other hand, the transmission mode change request unit 11d sends a block size change request to the central ECU 2 instructing the setting of a large block size when it is determined that the processing state of the ECU 3 to be rewritten is not a process that increases the processing load, when it is determined that the vehicle state does not satisfy the conditions for a vehicle state that increases the processing load, and when it is determined that the processing load is less than a threshold.

Next, the operation of the above-described configuration will be explained with reference to Figures 6 to 8. Here, we will explain the processing performed by the rewrite target ECU 3 and the processing performed by the central ECU 2 in turn.

(2-1) Processing Performed by the Rewrite Target ECU 3 When the control unit 11 of the rewrite target ECU 3 proceeds to step A5, it determines that the processing load of the rewrite target ECU 3 is high (A5), transmits a block size change request requesting a smaller block size to the central ECU 2 (A21), and waits for reception of rewrite data from the central ECU 2 (A23). In this case, when the central ECU 2 receives the block size change request requesting a smaller block size from the rewrite target ECU 3, it sets the block size of the rewrite data to a smaller size and transmits the rewrite data to the rewrite target ECU 3 in accordance with the set smaller block size.

On the other hand, when the control unit 11 proceeds to step A10, it determines that the processing load of the rewrite target ECU 3 is low (A10), sends a block size change request requesting a larger block size to the central ECU 2 (A22), and waits to receive rewrite data from the central ECU 2 (A23). In this case, when the central ECU 2 receives a block size change request requesting a larger block size from the rewrite target ECU 3, it sets the block size of the rewrite data to a larger size and transmits the rewrite data to the rewrite target ECU 3 in accordance with the larger block size.

When the control unit 11 determines that it has received the rewrite data transmitted from the central ECU 2 (A23: YES), it writes the received rewrite data to the storage unit 12 (A24). After writing the rewrite data, the control unit 11 determines whether writing of the block size's worth of data has been completed (A15), and then performs steps A16 to A20 described above.

(2-2) Processing Performed by the Central ECU 2 In the central ECU 2, the control unit 10 performs a change request determination process. When the control unit 10 starts the change request determination process, it determines whether a block size change request has been received from the rewrite target ECU 3 (B11). When the control unit 10 determines that a block size change request transmitted from the rewrite target ECU 3 has been received (B11: YES), it determines whether the received block size change request is a request for a small block size setting or a large block size setting (B12, B13).

If the control unit 10 determines that the received block size change request is a request to set the block size to a small value (B12: YES), it sets the block size of the rewrite data to a small value (B14), transmits the rewrite data to the rewrite target ECU 3 in accordance with the set small block size (B15), and terminates the change request determination process. On the other hand, if the control unit 10 determines that the received block size change request is a request to set the block size to a large value (B13: YES), it sets the block size of the rewrite data to a large value (B16), transmits the rewrite data to the rewrite target ECU 3 in accordance with the set large block size (B17), and terminates the change request determination process.

The above describes a case where a block size change request is sent to the central ECU 2 to change the block size of the rewrite data sent from the central ECU 2 to the rewrite target ECU 3. However, in this case, the block size change request may also be sent to the TCU 5 or the OTA center 6. The block size of the rewrite data sent from the TCU 5 to the central ECU 2 may also be changed by sending a block size change request to the TCU 5. The block size of the rewrite data sent from the OTA center 6 to the TCU 5 via the communication network 7 may also be changed by sending a block size change request to the OTA center 6. In other words, the block size of the rewrite data transmitted over the communication path from the OTA center 6, which is the sender of the rewrite data, to the rewrite target ECU 3 may be changed.

As described above, according to the second embodiment, the following advantageous effects can be obtained.
The rewrite target ECU 3 determines the processing load and requests the central ECU 2 to change the block size of the rewrite data based on the result of the processing load determination. By requesting the central ECU 2 to change the block size of the rewrite data in accordance with fluctuations in the processing load of the rewrite target ECU 3, the block size of the rewrite data obtained from the central ECU 2 can be made to follow the processing load, and the rewrite data obtained from the central ECU 2 can be appropriately processed. This allows software rewriting to be performed appropriately even when the processing load of the rewrite target ECU 3 fluctuates.

(Other embodiments)
Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

The first and second embodiments may be combined. That is, the rewrite target ECU 3 may request changes to both the transmission cycle and block size of the rewrite data in the central ECU 2 based on the results of the processing load determination. By requesting changes to both the transmission cycle and block size of the rewrite data in the central ECU 2 in response to changes in the processing load of the rewrite target ECU 3, it is possible to adjust both the cycle for obtaining rewrite data from the central ECU 2 and the block size of the rewrite data to match the processing load.

The control unit and method described in this disclosure may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and method described in this disclosure may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and method described in this disclosure may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible recording medium.

In addition to the inventions set forth in the claims, the present disclosure includes the following inventions.
[1]
An electronic control device that rewrites software by writing rewrite data,
a rewrite data acquisition unit (11a) for acquiring rewrite data from an external device;
a rewrite data writing unit (11b) that writes the rewrite data into a storage unit;
a processing load determination unit (11c) for determining a processing load of the electronic control device;
a transmission mode change request section (11d) for requesting a change of the transmission mode of the rewrite data in the external device based on a determination result of the processing load determination section.
[2]
The electronic control device according to [1], wherein the transmission mode change request unit requests a change in the transmission cycle of the rewrite data transmitted from the external device based on a determination result of the processing load determination unit.
[3]
The electronic control device described in [1], wherein the transmission mode change request unit requests a change in the transmission period of the rewrite data transmitted over a communication path from the sender of the rewrite data to the electronic control device based on the judgment result of the processing load judgment unit.
[4]
An electronic control device according to [2] or [3], which is provided with a write mode change unit (11e) that changes the write period of the rewrite data in the rewrite data writing unit in response to the request from the transmission mode change request unit to change the transmission mode of the rewrite data in the external device.
[5]
The electronic control device according to any one of [1] to [4], wherein the transmission mode change request unit requests a change in the block size of the rewrite data transmitted from the external device based on the judgment result of the processing load judgment unit.
[6]
An electronic control device described in any one of [1] to [4], wherein the transmission mode change request unit requests a change in the block size of the rewrite data transmitted over a communication path from the sender of the rewrite data to the electronic control device based on the judgment result of the processing load judgment unit.
[7]
The electronic control device according to any one of [1] to [6], wherein the processing load determination unit determines a processing state of the electronic control device and determines a processing load of the electronic control device based on the determined processing state.
[8]
The processing load determination unit determines the vehicle state of a vehicle equipped with the electronic control device, and determines the processing load of the electronic control device based on the determined vehicle state.
[9]
The electronic control device according to any one of [1] to [8], wherein the processing load determination unit determines the processing load of the electronic control device based on sensor information detected by a sensor.
[10]
The electronic control device according to any one of [1] to [9], wherein the processing load determining unit determines the processing load of the electronic control device based on communication information between an in-vehicle communication device and an external communication device.

In the diagram, 2 is the central ECU (external device), 3 is the ECU (electronic control unit) to be rewritten, 5 is the TCU (on-board communication device), 8 is the on-board communication device of another vehicle (external communication device), 9 is the roadside communication device (external communication device), 11a is the rewrite data acquisition unit, 11b is the rewrite data writing unit, 11c is the processing load determination unit, 11d is the transmission mode change request unit, and 11e is the write mode change unit.

Claims (10)

An electronic control device that rewrites software by writing rewrite data,
a rewrite data acquisition unit (11a) for acquiring rewrite data from an external device;
a rewrite data writing unit (11b) that writes the rewrite data into a storage unit;
a processing load determination unit (11c) for determining a processing load of the electronic control device;
a transmission mode change request unit (11d) that requests a change of the transmission mode of the rewritten data in the external device based on a determination result of the processing load determination unit,
the processing load determination unit determines whether a process that will increase the processing load is in operation as a processing state of the electronic control device without calculating the processing load , and if it determines that a process that will increase the processing load is not in operation, determines whether a vehicle state condition that will increase the processing load is met;
The transmission mode change request unit requests a change of the transmission mode when the processing load determination unit determines that a process that increases the processing load is in operation or that the vehicle state conditions that increase the processing load are met . The electronic control device described in claim 1, wherein the transmission mode change request unit requests a change in the transmission cycle of the rewrite data transmitted from the external device based on the determination result of the processing load determination unit. The electronic control device described in claim 1, wherein the transmission mode change request unit requests a change in the transmission cycle of the rewrite data transmitted over a communication path from the sender of the rewrite data to the electronic control device based on the determination result of the processing load determination unit. An electronic control device as described in claim 2 or 3, further comprising a write mode change unit (11e) that changes the write cycle of the rewrite data in the rewrite data writing unit in response to a request from the transmission mode change request unit to change the transmission mode of the rewrite data in the external device. The electronic control device described in claim 1, wherein the transmission mode change request unit requests a change in the block size of the rewrite data transmitted from the external device based on the determination result of the processing load determination unit. The electronic control device described in claim 1, wherein the transmission mode change request unit requests a change in the block size of the rewrite data transmitted over a communication path from the sender of the rewrite data to the electronic control device based on the determination result of the processing load determination unit. The electronic control device described in claim 1, wherein the processing load determination unit determines the processing state of the electronic control device and determines the processing load of the electronic control device based on the determined processing state. The electronic control device described in claim 1, wherein the processing load determination unit determines the vehicle state of the vehicle in which the electronic control device is installed, and determines the processing load of the electronic control device based on the determined vehicle state. The electronic control device described in claim 1, wherein the processing load determination unit determines the processing load of the electronic control device based on sensor information detected by a sensor. The electronic control device described in claim 1, wherein the processing load determination unit determines the processing load of the electronic control device based on communication information between an in-vehicle communication device and an external communication device.