JP7794670B2 - Control device and vehicle - Google Patents

Description

The present invention primarily relates to in-vehicle control devices.

Patent Document 1 describes the configuration of an event data recorder (EDR) that stores information indicating vehicle driving behavior that meets a standard, such as sudden deceleration, in on-board non-volatile memory. According to Patent Document 1, when the remaining memory capacity of the non-volatile memory falls below a standard, the information to be written to the non-volatile memory is sent to a server outside the vehicle via a communications device.

Japanese Patent Application Laid-Open No. 2021-120792

Depending on the communication environment, it may be difficult to achieve proper communication, so this information may need to be stored in on-board non-volatile memory. Meanwhile, semiconductor memory such as flash memory is typically used as non-volatile memory, and from the standpoint of the number of write cycles and the associated reliability, it is desirable to prevent unnecessary use of non-volatile memory.

The present invention was developed in response to the above-mentioned issues, and aims, for example, to prevent unnecessary use of non-volatile memory in a configuration in which information on driving behavior is stored in non-volatile memory.

One aspect of the present invention relates to a control device, the control device comprising:
A control device for controlling writing to a non-volatile memory , configured to be mountable on a vehicle including a wheel and a driving assistance device that performs predetermined driving assistance ,
a writing means for writing data corresponding to the driving behavior of the vehicle into the nonvolatile memory when the driving behavior of the vehicle satisfies a standard;
a counting means for counting the number of writes by the writing means;
a limiting means for limiting the amount of data that the writing means writes to the nonvolatile memory based on the measurement result of the measuring means ;
The driving assistance includes two or more modes with different driving assistance levels, and when the limiting means limits the amount of data that the writing means writes to the non-volatile memory, the driving assistance is changed to a mode with a lower driving assistance level .

This invention makes it possible to prevent unnecessary use of non-volatile memory.

FIG. 1 is a block diagram showing a system configuration of a vehicle. 10 is a flowchart illustrating a method for controlling writing to a nonvolatile memory. 10 is a table showing a method for managing contents written to a nonvolatile memory. FIG. 10 is a schematic diagram showing a method for measuring the number of writes to a nonvolatile memory.

The following embodiments are described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the claimed invention, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be combined in any desired manner. Furthermore, the same reference numbers are used for identical or similar components, and duplicate descriptions will be omitted.

First Embodiment
(System configuration)
1 is a block diagram showing an example of the system configuration of a vehicle 1 according to the first embodiment. The vehicle 1 includes wheels 11, a driving operation device 12, a detection device 13, a driving assistance device 14, a volatile memory 15, a non-volatile memory 16, a control device 17, and a position identification device 18. In this embodiment, the vehicle 1 is a four-wheeled vehicle having two front wheels and two rear wheels as the wheels 11, but in other embodiments, the vehicle 1 may be a two-wheeled vehicle or a three-wheeled vehicle, and the number of wheels 11 is not limited to this example.

The driving operation device 12 includes an acceleration operator 121, a deceleration operator 122, and a steering operator 123. Generally, an accelerator pedal is used as operator 121, and a brake pedal may be used as operator 122. A steering wheel may also be used as operator 123. Other types of operators, such as levers or buttons, may also be used for operators 121-123.

Detection device 13 detects the driving behavior of vehicle 1. Driving behavior typically indicates factors directly or indirectly related to the longitudinal and/or lateral speed and acceleration of vehicle 1. Examples include the amounts of operation of controls 121-123 that realize acceleration, deceleration, and steering of vehicle 1, or physical quantities corresponding thereto. As an example, detection device 12 detects the amounts of operation of each of controls 121-123.

Note that the detection content by the detection device 13 is not limited to this example; the detection device 13 is capable of detecting various conditions regarding the vehicle 1, regardless of whether the vehicle 1 is moving or not, and is capable of acquiring information indicating these conditions.

The detection results of the detection device 13 can be stored in the volatile memory 15, which will be described later, along with related information from the time of the detection. Examples of this related information include time information indicating the time of the detection, and location information indicating the position of the vehicle 1 on the map data at the time of the detection.

The driving assistance device 14 performs predetermined driving assistance. The concept of driving assistance includes assisting with at least one of acceleration, deceleration, and steering. With this driving assistance device 14, the vehicle 1 has a driving assistance mode and a manual driving mode as its operating modes. In the driving assistance mode, the driving assistance device 14 assists with some or all of the acceleration, deceleration, and steering operations, thereby reducing the burden on the occupant as a driver. On the other hand, in the manual driving mode, the occupant is the main driver of the vehicle 1, and performs all of the acceleration, deceleration, and steering operations as the driver.

Note that when the driving assistance device 14 assists with all acceleration, deceleration, and steering operations, the driving operation of the vehicle 1 is mainly performed by the driving assistance device 14, and such an operating mode may be referred to as an autonomous driving mode and distinguished from the driving assistance mode.

Furthermore, the concept of driving assistance may include indirect assistance in addition to direct assistance with driving operations. Therefore, the driving assistance device 14 may also be capable of performing functions such as calculating a driving route to a destination and notifying the occupants or driver regarding the route.

Volatile memory 15, details of which will be described later, temporarily stores the detection results of detection device 13. DRAM (dynamic random access memory) can generally be used as volatile memory 15.

The non-volatile memory 16, details of which will be described later, can store a portion of the detection results of the detection device 13 that were temporarily stored in the volatile memory 15. Any known semiconductor memory or semiconductor element memory may be used for the non-volatile memory 16. Typical examples include NAND-type flash memory such as eMMC (embedded multi-media card), UFS (universal flash storage), and SSD (solid state drive), but NOR-type flash memory may also be used.

The control device 17 continuously stores the detection results of the detection device 13 in the volatile memory 15, and selects a portion of these and stores them in the non-volatile memory 16 when predetermined conditions are met. In other words, the detection device 13 continuously detects the driving behavior of the vehicle 1, and the detection results are sequentially written to the volatile memory 15. On the other hand, when predetermined conditions are met, a corresponding portion of the detection results written to the volatile memory 15 is selected and written to the non-volatile memory 16.

Examples of the above condition being met include when the absolute value of acceleration when vehicle 1 accelerates is greater than a reference value, or when the absolute value of acceleration when vehicle 1 decelerates is greater than a reference value. Another example of the above condition being met is when the impact value applied to vehicle 1 from the outside is greater than a reference value. Therefore, when an unexpected event occurs to vehicle 1, that is, when the driving behavior of vehicle 1 meets the criteria, the detection results of detection device 13 can be selectively written to non-volatile memory 16.

In addition, the individual functions of the control device 17 may be implemented by either software or hardware. For example, the multiple functions of the control device 17 may be implemented by one or more processor circuits with memory individually reading and executing programs. Alternatively, the multiple functions may be implemented by driving multiple corresponding circuit units (e.g., ASICs (application-specific integrated circuits)).

The positioning device 18 identifies the position of the vehicle 1 on the map data of the vehicle 1, making it possible to acquire the position information. An example of the positioning device 18 is a GNSS (Global Navigation Satellite System) sensor. Examples of map data include those typically used in car navigation systems, such as HD (High-Definition) maps and SD (Standard) maps. Another example is an environmental map generated or updated based on information about past travels of the vehicle 1. For example, the driving assistance device 14 described above can provide driving assistance based on the position information acquired by the positioning device 18.

These elements 12 to 18 are capable of sending and receiving signals via a system bus or the like. With this configuration, the control device 17 controls writing to the non-volatile memory 16. In this embodiment, if an unforeseen event occurs in the vehicle 1, part of the detection results of the detection device 13 are stored in the non-volatile memory 16 as information (or data) indicating the event.

For ease of explanation, these elements 12-18 are shown here as separate units, but at least some of their functions may be provided separately or integrated with other parts. In other words, elements 12-18 may be formed by one or more ECUs (electronic control units), and multiple ECUs may be installed in corresponding positions on vehicle 1 depending on the function and application.

In the following description, an unforeseen event that occurs in vehicle 1 will be referred to as an "event," and information written to non-volatile memory 16 will be referred to as "event data." Because event data is written as a record to non-volatile memory 16, control device 17, together with detection device 13 and non-volatile memory 16 (and, incidentally, volatile memory 15), will be referred to as an "event data recorder." Event data is erased from non-volatile memory 16 after a predetermined period of time has elapsed, or in order from oldest to newest, and is then overwritten with new data.

(Regarding utilization of non-volatile memory)
In addition to the event data described above, information (or data) necessary for realizing driving assistance in the driving assistance mode is written by the control device 17 to the nonvolatile memory 16. The information to be written to the nonvolatile memory 16 in the driving assistance mode is regulated by predetermined laws and regulations, and examples thereof include:
"Attachment 123: Technical Standards for Operational Status Recording Devices" of the "Road Transport Vehicle Safety Standards (as of April 28, 2021)," Ministry of Land, Infrastructure, Transport and Tourism, https://www.mlit.go.jp/common/001346769.pdf
Examples include:

As a result, if the above-mentioned event data is unnecessarily written to non-volatile memory 16 at a high frequency, it will cause premature deterioration of non-volatile memory 16. This may make it difficult to utilize non-volatile memory 16 in driving assistance mode, or even make it difficult to perform driving assistance itself. Therefore, it is necessary to suppress or reduce unnecessary writing of event data to non-volatile memory 16.

Figure 2 is a flowchart showing an example of a method for controlling the writing of event data to non-volatile memory 16. This flowchart is mainly executed by control unit 17, and its outline is that when the number of writes to non-volatile memory 16 is large, the amount of event data to be written to non-volatile memory 16 is limited. Furthermore, this flowchart is started when vehicle 1 is started (when vehicle 1 becomes ready to drive), regardless of whether it is in driving assistance mode or manual driving mode.

In step S2000 (hereinafter simply referred to as "S2000"; the same applies to other steps described below), the control device 17 acquires the detection results of the detection device 13 (information indicating the driving mode of the vehicle 1) and writes them to the volatile memory 15. From this perspective, the control device 17 can be said to function as an acquisition unit and a writing unit.

In S2010, the control device 17 determines whether an event (unforeseen event) has occurred. From this perspective, the control device 17 can be said to function as a determination unit. Here, as an example, it is determined that an event has occurred in response to the absolute value of the acceleration occurring in the vehicle 1 becoming greater than a reference value. Therefore, the determination in S2010 can be made substantially simultaneously with the writing of the detection result of the detection device 13 to the volatile memory 15 (S2000). Furthermore, the determination in S2010 may be made based on an acceleration sensor that may typically be mounted on the vehicle 1, but alternatively/additionally, it may also be made based on the detection result of the detection device 13. If an event has occurred, the process proceeds to S2020; if not, the process returns to S2000.

If no event has occurred, processing returns from S2010 to S2000. As described above, the detection device 13 continuously detects the driving behavior of the vehicle 1, and the detection results are constantly written to the volatile memory 15. Note that the detection results of the detection device 13 written to the volatile memory 15 in S2000 are erased, for example, after a predetermined time has elapsed; in other words, relatively recent detection results are temporarily stored in the volatile memory 15.

In S2020, the control device 17 generates a signal Sig0 indicating that the event data is to be written to the non-volatile memory 16. From this perspective, the control device 17 can be said to function as a signal generator. Details will be described later, but based on the signal Sig0, some of the corresponding examination results stored in the volatile memory 15 are read out. Here, the control device 17 has a built-in counter, and when the signal Sig0 is generated, it counts up a value Val0 indicating the number of writes to the non-volatile memory 16.

In the following description, signal Sig0 may be referred to as the write execution signal Sig0, and value Val0 may be referred to as the write count measurement value Val0.

In S2030, the control device 17 determines whether the write count measurement value Val0 has reached the threshold value Val _TH1 . From this perspective, the control device 17 can be said to function as a determination unit. If Val0≧Val _TH1 , the process proceeds to S2040; if not (if Val0<Val _TH1 ), the process proceeds to S2110.

In S2040, the control device 17 determines whether the write count measurement value Val0 has reached the threshold value Val _TH2 (> Val _TH1 ). From this perspective, the control device 17 can be said to function as a determination unit. If Val0≧Val _TH2 , the process proceeds to S2310; otherwise (if Val0<Val _TH2 ), the process proceeds to S2210.

In S2110, the control device 17 reads a portion of the detection results of the detection device 13 from the volatile memory 15 based on the execution signal Sig0 and writes the portion as event data to the non-volatile memory 16. From this perspective, the control device 17 can be said to function as both a reading unit and a writing unit. Here, in S2110, Val0<Val _TH1 , and the number of times the event data is written to the non-volatile memory 16 can be said to be relatively small. Therefore, the event data written to the non-volatile memory 16 in S2110 only needs to be a data amount based on a predetermined standard (this will be referred to as event data D1 to distinguish it from other event data described below). Note that the event data D1 is the detection results of the detection device 13 for a predetermined period based on the timing of the generation of the signal Sig0.

In S2210, Val _TH1 ≦ Val0 < Val _TH2 , and it can be said that the number of times the event data is written to the nonvolatile memory 16 is relatively large. Therefore, in S2210, the amount of event data to be written to the nonvolatile memory 16 is more limited than in S2110, and the event data with the limited amount (referred to as event data D2 for the sake of distinction) is written to the nonvolatile memory 16. From this perspective, it can be said that the control device 17 functions as a reading unit, a writing unit, and a limiting unit.

Here, in S2210, the driving assistance device 14 may additionally be notified that the number of writes to the non-volatile memory 16 is relatively large. The driving assistance mode may include two or more modes with different driving assistance levels (degree of driving assistance). In this case, the driving assistance device 14 changes the current mode to a mode with a lower driving assistance level based on the above notification, thereby making it possible to impose predetermined restrictions on the information to be written to the non-volatile memory 16 in the driving assistance mode.

For example, if the driving assistance mode includes a first mode and a second mode with a lower driving assistance level, and the driving assistance device 14 is executing the first mode at the time of the notification, the driving assistance device 14 can change the driving assistance mode from the first mode to the second mode in response to the notification. If the driving assistance mode includes three or more modes, the driving assistance mode may be changed to a mode with a gradually lower driving assistance level.

In S2310, Val0≧Val _TH2 , and it can be said that the number of times the event data is written to the nonvolatile memory 16 is even greater. Therefore, in S2310, the amount of event data to be written to the nonvolatile memory 16 is further limited compared to S2210, and the event data with this further limited amount (referred to as event data D3 for the sake of distinction) is written to the nonvolatile memory 16. From this perspective, it can be said that the control device 17 functions as a reading unit, a writing unit, and a limiting unit.

As in S2210, in S2310, the driving assistance device 14 may be notified that the number of writes to the non-volatile memory 16 is even greater. In this case, the driving assistance mode may be changed to one with a lower driving assistance level than in S2210. For example, it may be changed to one that does not require the recording of event data, or it may be changed to a manual driving mode.

The thresholds Val _TH1 and Val _TH2 may be set to values of, for example, several hundred or several thousand, but are not limited to these, and may be preset to values based on the design of the nonvolatile memory 16.

Here, with regard to the above-mentioned event data D1, D2, and D3 indicating the detection results of the detection device 13, limiting the data volume merely requires reducing the amount of space used in the non-volatile memory 16, which essentially corresponds to a small data size. Therefore, for example, if the detection device 13 detects multiple items (e.g., acceleration, deceleration, steering, etc.) and event data D1 indicates the detection results of those multiple items, event data D2 or D3 may indicate the detection results of only some of those multiple items. Furthermore, for example, if event data D1 indicates the detection results for a predetermined period based on the timing of the occurrence of signal Sig0, event data D2 or D3 may indicate the detection results for a shorter period. Furthermore, if the number of times the event data is written to non-volatile memory 16 (i.e., the measurement value Val0) is unnecessarily large, the control device 17 limits the amount of event data to be written to non-volatile memory 16. This reduces the area of non-volatile memory 16 used when writing event data, appropriately prevents unnecessary use of non-volatile memory 16, and thus reduces deterioration of non-volatile memory 16.

When the write count measurement value Val0 approaches the allowable upper limit (> Val _TH2 ), in this case when Val _TH1 ≦ Val0< Val _TH2 , the nonvolatile memory 16 should be replaced with a new one. Therefore, in such a case, the occupant or driver should be notified that the nonvolatile memory 16 needs to be replaced. This may be achieved by a device (e.g., a liquid crystal display) that the driving assistance device 14 may additionally include, or by a sound source that may typically be installed in the vehicle 1. In this case, execution of the driving assistance mode may additionally be restricted.

As described above, according to this embodiment, when the driving behavior of the vehicle 1 satisfies a criterion, the control device 17, when writing event data to the non-volatile memory 16, limits the amount of data stored in the event data based on the results of measuring the number of writes to the non-volatile memory 16. The greater the number of writes, the greater the limited amount of data stored. Therefore, unnecessary use of the non-volatile memory 16 is appropriately prevented, and deterioration of the non-volatile memory 16 can be suppressed.

Furthermore, if the driving assistance mode includes two or more modes with different driving assistance levels, the driving assistance device 14 can still provide driving assistance in a mode with a relatively low driving assistance level even after the amount of event data to be written to the non-volatile memory 16 has been limited. Therefore, driving assistance can be provided in a mode with a relatively low driving assistance level until the non-volatile memory 16 is replaced, for example, until the vehicle 1 arrives at a repair shop.

In this embodiment, event data D1 is the detection results of the detection device 13 for a predetermined period based on the timing of the generation of signal Sig0, but the detection results may also include those for the period before and after the generation of signal Sig0. That is, it is preferable to record not only the driving behavior of vehicle 1 before the occurrence of an event, but also the driving behavior of vehicle 1 after the occurrence of an event in non-volatile memory 16 as event data. This can be achieved by reading from volatile memory 15 and writing to non-volatile memory 16 the detection results that are continuously detected by detection device 13 and continuously written to volatile memory 15 even after the generation of signal Sig0.

In addition, in this embodiment, a counter built into the control device 17 is used to measure the write count measurement value Val0, but the counter may be provided separately from the control device 17, for example, in the non-volatile memory 16. The counter may measure the measurement value Val0 by counting down, i.e., it may be measured cumulatively.

Furthermore, in this embodiment, in addition to event data, information necessary for realizing the driving assistance mode is also written to the non-volatile memory 16. However, the configuration of the storage device is not limited to this example, as long as unnecessary use of the non-volatile memory 16 is appropriately prevented. Therefore, in other embodiments, for example, another non-volatile memory into which information necessary for realizing the driving assistance mode is to be written may be provided separately from the non-volatile memory 16.

Second Embodiment
The data amounts of the event data written to the nonvolatile memory 16 may be standardized, for example, as 32 KB (kilobytes) for event data D1, 16 KB for event data D2, and 8 KB for event data D3. Therefore, it may be necessary to measure the number of writes in a manner corresponding to the standardization.

Thus, although the first embodiment exemplifies generating signal Sig0 in response to the occurrence of an event and counting up write count measurement value Val0 (see S2020 in Figure 2), it is preferable to measure measurement value Val0 for each specified area of non-volatile memory 16.

For example, in the example of the aforementioned event data D1 (32 KB), event data D2 (16 KB), and event data D3 (8 KB), with an 8 KB unit block, four blocks are used for event data D1, two blocks are used for event data D2, and one block is used for event data D3. These blocks can also be expressed as memory blocks.

In addition, memory capacity is generally managed for each address. Therefore, by assigning a single address to each memory block, it is possible to measure the measurement value Val0 for each address.

For example, as shown in FIG. 3(a), the measured value Val0 may be measured and managed for each physical address in the non-volatile memory 16. As another example, as shown in FIG. 3(b), the measured value Val0 may be measured for each event data and managed for two or more physical addresses. In these cases, the counter that measures the measured value Val0 may be provided in the non-volatile memory 16. The control device 17 may obtain information indicating the measured value Val0 from the non-volatile memory 16.

Furthermore, as shown in FIG. 3(c), a logical address is associated with the physical address of the non-volatile memory 16 so that it can be accessed by an external device. The write count measurement value Val0 may be managed using this logical address.

Furthermore, the capacity of a single address in memory may vary depending on the device structure of the non-volatile memory 16 itself. Therefore, the measured value Val0 may be managed for each physical address, as in the example of Figure 3(a), but it may be managed for each event data when two or more physical addresses are required to record the event data, as in the example of Figure 3(b).

Furthermore, if the write count measurement value Val0 of a physical address associated with a logical address is higher than the measurement values Val0 of other physical addresses, the logical address may be reassociated with a physical address with a smaller measurement value Val0 (a physical address with fewer write counts). This makes it possible to reduce the difference in write count measurement values Val0 between those physical addresses, thereby leveling out the number of writes across multiple memory blocks.

If the counter is provided in non-volatile memory 16, the control device 17 can use a page table showing the correspondence between logical addresses and physical addresses when obtaining information indicating the write count measurement value Val0 from non-volatile memory 16.

As shown in FIG. 4, a monitoring unit 19 may also be provided to monitor data transferred from volatile memory 15 to non-volatile memory 16. The monitoring unit 19 may be provided to monitor the system bus connecting elements 12 to 18, or may be provided to monitor input data to non-volatile memory 16. This makes it possible to measure the write count measurement value Val0 based on the monitoring results of the monitoring unit 19. In this case, the control device 17 simply obtains information indicating the write count measurement value Val0 from the monitoring unit 19.

This measurement method allows the non-volatile memory 16 to be used so that the number of writes to multiple blocks is averaged. In this case, whether or not to limit the amount of event data to be written to the non-volatile memory 16 may be determined based on the calculated value (e.g., average, maximum, total, etc.) of the measurement value Val0.

In the above explanation, for ease of understanding, each element has been given a name related to its function. However, each element is not limited to having the content described in the embodiment as its main function, and may have that function as an auxiliary function. Therefore, each element is not strictly limited to the expression, and the expression can be replaced with a similar expression. In a similar vein, the expression "apparatus" may be replaced with "unit," "component," "piece," "member," "structure," "assembly," etc., or may be omitted.

For example, nonvolatile memory 16 may be referred to as a nonvolatile memory section, a nonvolatile memory device, etc. to distinguish it from a memory cell.

The above-described embodiments prevent unexpected shutdowns of driving assistance and enable highly convenient vehicles to be used for a wide range of purposes, which can contribute to building the foundations for industry and technological innovation and promoting welfare in an increasingly diverse society. Furthermore, it is possible to prevent unnecessary increases in the number of writes to non-volatile memory 16 and/or make appropriate use of non-volatile memory 16, which can contribute to reducing or preventing unnecessary disposal of non-volatile memory 16.

(Summary of the embodiment)
Some features of the above embodiment can be summarized as follows:
A first aspect relates to a control device (e.g., 17), the control device comprising:
An in-vehicle control device for controlling writing to a non-volatile memory (e.g., 16),
a write means (e.g., S2110, S2210, S2310) for writing data corresponding to the driving behavior of the vehicle to the nonvolatile memory when the driving behavior satisfies a criterion;
A counting unit (e.g., S2020) for counting the number of writes by the writing unit;
and limiting means (e.g., S2110, S2210, S2310) for limiting the amount of data that the writing means writes to the nonvolatile memory based on the measurement result of the measurement means. With this feature, the event data can be stored without the nonvolatile memory being used unnecessarily.

The second aspect is
The limit on the amount of data increases as the number of times the write operation is performed increases. With this feature, it is possible to appropriately prevent unnecessary use of the nonvolatile memory.

The third aspect is
The measuring means measures the number of writes for each address of the nonvolatile memory. This feature makes it possible to appropriately utilize multiple areas of the nonvolatile memory.

The fourth aspect is
The driving manner of the vehicle satisfies the criteria,
the absolute value of acceleration during acceleration of the vehicle is greater than a reference value;
The absolute value of the acceleration when the vehicle is decelerating is greater than a reference value; and
The impact value applied to the vehicle from the outside is greater than a reference value.
According to this feature, the event data can be stored.

The fifth aspect is
The nonvolatile memory includes a semiconductor memory (for example, 16). The control device described above is applicable to realizing control of writing to a semiconductor memory such as a flash memory.

The sixth aspect is
The vehicle may further include a notification means (e.g., 14) that notifies the user that the nonvolatile memory needs to be replaced based on the measurement results of the measurement means. This feature allows the user of the vehicle to appropriately replace the nonvolatile memory. While the embodiment illustrates the replacement of the nonvolatile memory alone, the entire unit in which the nonvolatile memory is implemented, such as a memory ECU, may also be replaced.

A seventh aspect relates to a vehicle (e.g., 1), the vehicle comprising:
A control device (e.g., 17) according to any one of claims 1 to 6;
Wheels (e.g., 11);
and a driving assistance device (e.g., 14) that executes predetermined driving assistance. That is, the above-described control device is applicable to a typical vehicle.

The eighth aspect is
A detection device (e.g., 13) for detecting the driving mode;
a volatile memory (e.g., 15) for temporarily storing the detection result of the detection device;
and a non-volatile memory (e.g., 16);
The writing means is characterized in that, when the detection result satisfies the criterion, the corresponding part of the data temporarily stored in the volatile memory is written to the nonvolatile memory. With this feature, the event data can be stored without the nonvolatile memory being used unnecessarily.

A ninth aspect is
The writing means further writes information necessary for executing the driving assistance into the nonvolatile memory. That is, the above-mentioned control device is applicable to a typical vehicle equipped with a driving assistance device.

A tenth aspect is
The driving assistance includes at least one of an acceleration operation, a deceleration operation, and a steering operation. According to this feature, driving assistance for any of an acceleration operation, a deceleration operation, and a steering operation can be appropriately realized.

An eleventh aspect is
The driving assistance includes two or more modes with different driving assistance levels,
When the limiting means limits the amount of data written to the nonvolatile memory by the writing means, the driving assistance device changes the driving assistance to a mode with a lower driving assistance level. With this feature, driving assistance at a relatively low driving assistance level can be used without unnecessary use of the nonvolatile memory.

A twelfth aspect is
The writing means writes the data corresponding to the driving mode into the nonvolatile memory when an instruction to write the data into the nonvolatile memory is received from the driving assistance device. According to this feature, data necessary for realizing driving assistance can be recorded in the nonvolatile memory.

The invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the invention.

1: Vehicle, 16: Non-volatile memory, 17: Control device.

Claims (11)

A control device for controlling writing to a nonvolatile memory , configured to be mountable on a vehicle including wheels and a driving assistance device that performs predetermined driving assistance ,
a writing means for writing data corresponding to the driving behavior of the vehicle into the nonvolatile memory when the driving behavior of the vehicle satisfies a standard;
a counting means for counting the number of writes by the writing means;
a limiting means for limiting the amount of data that the writing means writes to the nonvolatile memory based on the measurement result of the measuring means ;
The driving assistance includes two or more modes with different driving assistance levels, and when the limiting means limits the amount of data that the writing means writes to the non-volatile memory, the driving assistance is changed to a mode with a lower level . 2. The control device according to claim 1, wherein the limited data amount increases as the number of times the write operation is performed increases. 3. The control device according to claim 1, wherein the measuring means measures the number of times the write operation is performed for each address of the nonvolatile memory. The driving manner of the vehicle satisfies the criteria,
the absolute value of acceleration during acceleration of the vehicle is greater than a reference value;
The absolute value of the acceleration when the vehicle is decelerating is greater than a reference value; and
The impact value applied to the vehicle from the outside is greater than a reference value.
The control device according to any one of claims 1 to 3, characterized in that it includes at least one of the following: The control device according to any one of claims 1 to 4, wherein the nonvolatile memory includes a semiconductor memory. 6. The control device according to claim 1, further comprising a notification unit that notifies the user that the nonvolatile memory needs to be replaced based on the measurement result of the measurement unit. A control device according to any one of claims 1 to 6;
Wheels and
A vehicle comprising: a driving assistance device that performs predetermined driving assistance. a detection device for detecting the driving mode;
a volatile memory for temporarily storing the detection result of the detection device;
a non-volatile memory,
8. The vehicle according to claim 7, wherein the writing means writes a corresponding portion of the data temporarily stored in the volatile memory to the nonvolatile memory when the detection result satisfies the criterion. 9. The vehicle according to claim 7, wherein the writing means further writes information required for executing the driving assistance into the nonvolatile memory. The vehicle according to any one of claims 7 to 9, wherein the driving assistance includes at least one of an acceleration operation, a deceleration operation, and a steering operation. 11. The vehicle according to claim 7, wherein the writing means writes the data corresponding to the driving mode into the nonvolatile memory when an instruction to write the data into the nonvolatile memory is received from the driving assistance device .