JP2008089426A - Data recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data recorder that can prevent holding of data showing an operation state having low necessity to hold, can certainly hold data showing an operation state having high necessity to hold, and can perform further appropriate holding control of data. <P>SOLUTION: The data recorder includes a recording means (S3) for recording data acquired from a means for detecting a vehicle state, a brake treading state detecting means (S4) for detecting the treading state of the brake of the vehicle, threshold setting switching means (S5 and S6) for changing setting of acceleration threshold for determining a predetermined operation state from the acceleration of the vehicle based on the treading state of the brake detected by the brake treading state detecting means, and a data holding means (S12) for holding data recorded by the recording means when the acceleration of the vehicle establishes the predetermined condition in a set state of the acceleration threshold changed by the threshold setting switching means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a data recording apparatus, and more particularly to a data recording apparatus that is mounted on a moving body such as a vehicle and that can record various data for grasping a driving state during traveling.

Conventionally, in order to grasp the vehicle status immediately before the accident, the vehicle speed, steering angle,
A data recording device that saves data such as brake pressure, acceleration, and images in a flash memory and reads the data stored in the flash memory after an accident so that the situation of the accident can be grasped, so-called a vehicle drive recorder Has been proposed (see, for example, Patent Document 1 below).

In the conventional data recording apparatus, conditions such that the acceleration (deceleration) of the vehicle detected by the acceleration sensor (G sensor) exceeds a predetermined threshold and the state in which the threshold is exceeded continue for a predetermined period are satisfied. In this case, data storage in the flash memory is started.

Further, in recent years, as the threshold value, a lower threshold value (low G threshold value) for determining a dangerous driving state such as sudden braking that does not lead to a collision, and a higher threshold value for determining a driving state leading to a collision. (High G threshold) is set (both are fixed values), and not only the data immediately before the collision but also a device capable of storing data when a dangerous driving such as sudden braking is performed has been proposed. .

FIG. 1 is a timing chart for explaining a data storage operation to a flash memory performed by a conventional data recording apparatus in which the low G threshold and the high G threshold are set as fixed values. The state of the ignition switch (IG), (b) the operation of recording data in the RAM, (c) the acceleration (deceleration) detected by the acceleration sensor, (d) the high G detection counter and the low G detection The count state of the counter, (e) shows the operation of saving the data recorded in the RAM to the flash memory.

When the data recording device detects that the ignition switch is turned on at time t ₁ ,
Processing for recording data detected by various sensors or the like in the RAM is started. Subsequent time t ₂
Section including the ~t ₄ shows an operation state in case of a collision without braking, at time t
₂ , when it is detected that the acceleration (deceleration) of the vehicle has exceeded the low G threshold, the low G detection counter starts counting, and then at time t ₃ , the acceleration has exceeded the high G threshold. When detected, the high G detection counter starts counting, and at time t ₄ when the high G detection counter count reaches 2, it is determined that there is a collision, and the data before the collision recorded in the RAM is stored in the flash memory. Start the transfer and save process.

The section including the next time t ₅ ~t _6, shows the operation state in the case of a collision with brake, at time t _5, detects that the vehicle acceleration (deceleration) exceeds a low G threshold Then, the low G detection counter starts counting. Then, since the collided while somewhat decelerated braked, acceleration, without exceeding the high G threshold, and without reaching the count number also determined value of the low-G detection counter (5 times), the time t ₆ In this case, the pre-collision data is not stored in the flash memory even though a collision has actually occurred. In this section, there is a phenomenon that becomes a problem that the data before the collision must be stored in the flash memory but not stored.

Section including the next time t ₇ ~t ₈ shows the operation state when subjected to sudden braking,
When it is detected at time t ₇ that the acceleration (deceleration) of the vehicle has exceeded the low G threshold, the low G
Time t when the counter for detection starts and the count of the counter for low G reaches 5
_{In step 8} , it is determined that the brake is sudden, and the process of transferring the data before the sudden brake recorded in the RAM to the flash memory and storing it is started.

Section including the following time t ₉ ~t _10, shows the operation state when running rough road (the bumpy road) when no braking, at time t _9, the vehicle acceleration (reduced When the speed) exceeds the low G threshold, the low G detection counter starts counting,
Over time t ₉ ~t _10, in synchronization with the count cycle, the intermittent acceleration is detected that exceeds the low G threshold, low G detection counter counting is continued, the time count is a 5 t ₁₀ is a section in which a phenomenon that causes a problem that a sudden braking is determined (incorrect determination) and data that is less necessary to be stored is stored in the flash memory.

The high G threshold value is used to determine the driving state leading to a collision such as an accident, and flashes when the detected acceleration (deceleration) of the vehicle exceeds the high G threshold value by a predetermined count continuously. Saving of data to memory is started. However, in the case of a collision due to an accident or the like, as described above, it is considered that there are many cases in which the vehicle collides in a state where the brake is applied and the vehicle is decelerated to some extent just before the collision.

When the vehicle collides with the brake applied, the vehicle acceleration detected as described above is high G
It is also assumed that the collision cannot be determined without exceeding the threshold, and because the collision has a short event time,
Even in the determination using the low G threshold, the count number of the low G detection counter cannot reach the determination value, and in such a case, data immediately before the collision that is highly required to be stored cannot be stored. There was a risk of problems.

The low G threshold value is mainly used for determining dangerous driving conditions such as sudden braking, and the detected acceleration (deceleration) of the vehicle continuously exceeds the low G threshold value by a predetermined count. In case,
Saving data to the flash memory is started. However, on rough roads such as uneven roads with poor road surface conditions, acceleration exceeding the low G threshold is intermittent for a certain period of time due to strong impact from the road surface, even though the brake operation is not performed as described above. In such a case, there is a problem that the data is stored even though the brake is not applied suddenly, and the flash memory may be used wastefully.

Further, in Patent Document 2 below, for the same problem as described above, that is, because the acceleration determination reference value is high, the traveling data immediately before the collision may not be saved even in the case of a collision, Abnormal state of vehicle (collision) when it is determined that the vehicle speed is equal to or lower than the reference value (substantially 0) within a predetermined time from when it is determined that the magnitude of the vehicle acceleration is equal to or higher than the reference value. And a vehicular data recording device configured to store the immediately preceding traveling data is disclosed.

However, in the technique described in Patent Document 2, since the acceleration reference value (threshold value) is set as a fixed value, depending on the reference value setting, the data immediately before the collision may be saved while decelerating. May not occur, and Patent Document 2 does not particularly describe a countermeasure when acceleration exceeding a low G threshold is detected on a rough road or the like, and unnecessary travel data in such a case is unnecessary. The problem of being unable to prevent proper preservation remained.
JP 2000-6854 A JP 2000-335450 A

Means for solving the problems and their effects

The present invention has been made in view of the above-described problems, and can prevent the storage of data indicating an operation state with a low necessity for storage, while the data indicating an operation state with a high necessity for storage. It is an object of the present invention to provide a data recording apparatus capable of reliably storing data and performing more appropriate data storage control.

In order to achieve the above object, a data recording apparatus (1) according to the present invention includes a recording means for recording data acquired from a means for detecting a vehicle state, and a brake depression state detection means for detecting a depression state of a brake of the vehicle. And a threshold setting switching means for switching setting of an acceleration threshold value for determining a predetermined driving state from the acceleration of the vehicle based on the brake depression state detected by the brake depression state detection means, and the threshold setting switching means And a data storage unit that stores data recorded by the recording unit when the acceleration of the vehicle satisfies a predetermined condition in the setting state of the acceleration threshold value switched by step (a).

According to the data recording device (1), the setting of the acceleration threshold value for determining the predetermined driving state from the vehicle acceleration is switched based on the brake depression state detected by the brake depression state detection means. Compared with the conventional device in which the acceleration threshold value is always set to a fixed value, the setting state of the acceleration threshold value can be switched corresponding to the depression state of the brake.

Therefore, by appropriately switching the setting of the acceleration threshold value in accordance with the depression state of the brake, it is possible to more reliably save data indicating an operation state that is highly necessary to save the data. On the other hand, it is possible to prevent the storage of the data indicating the operation state with a low necessity of storing the data, to perform the storage control of the data more appropriately, and to store the data It can be used more effectively.

Embodiments of a data recording apparatus according to the present invention will be described below with reference to the drawings. FIG.
It is the block diagram which showed roughly the principal part of the data recording device which concerns on embodiment.
In the figure, reference numeral 1 denotes a data recording apparatus. The data recording apparatus 1 includes an A / D converter 2, a decoder 3, an image processing unit 4, a RAM 5, a ROM 6, a CPU 7, a flash memory 8, and an encoder 9. Has been.

In addition, a CCD camera 11 for imaging the front situation during travel is provided by A of the data recording apparatus 1.
The image data connected to the / D converter 2 and captured by the CCD camera 11 installed in the vehicle is converted into a digital signal by the A / D converter 2, processed by the decoder 3, and the image processing unit 4 The image is compressed by the above and then recorded in the RAM 5.

Further, a vehicle speed sensor 12 for detecting the vehicle speed, and a steering angle sensor 13 for detecting the steering angle of the steering wheel.
A brake pressure sensor 14 for detecting the brake pressure, an acceleration sensor 15 for detecting the acceleration of the vehicle, a GPS receiver 16 for detecting the current position of the vehicle, a direction indication switch 17 for outputting an operation signal of the direction indicator, and a time measuring means 18 is connected to the CPU 7 of the data recording apparatus 1. The CPU 7 captures signals from these detection means 12 to 18 for detecting the vehicle state, and records them in the RAM 5 together with the image data picked up by the CCD camera 11. (Recording means). The signals from these detection means 12 to 18 may be obtained via another control device such as an engine control device connected via the in-vehicle LAN.

Further, the CPU 7 detects whether or not the brake is depressed based on a signal from the brake pressure sensor 14 (brake depression state detecting means), and based on the presence or absence of the brake depression, the CPU 7 does not cause a collision. To switch to a setting that permits the use of the first acceleration threshold value (that is, the low G threshold value) for determining a dangerous driving state such as a brake or a setting that prohibits the use, and to determine the driving state leading to a collision In the setting state of the second acceleration threshold (that is, the high G threshold) (threshold setting switching means) and the low G threshold and the high G threshold set by the threshold setting switching means. When the vehicle acceleration (deceleration) detected at 15 satisfies a predetermined condition, the data recorded in the RAM 5 is stored in the flash memory 8. That function and a (data storage means). RO
M6 stores various data necessary for control, such as a program executed by the CPU 7, and setting information of a low G threshold and a high G threshold. Instead of the flash memory 8, another nonvolatile memory in which data is not lost even when the power is turned off can be adopted.

The data stored in the flash memory 8 is subjected to signal processing such as decompression of compressed image data in the encoder 9 at the time of analysis, and can be reproduced and output as an image and sensor information from the output terminal 10.

FIG. 3 is a timing chart for explaining a data storage operation to the flash memory 8 performed by the CPU 7 in the data recording apparatus 1 according to the embodiment, where (a) shows the state of the ignition switch (IG), and (b). (C) is acceleration (deceleration) detected by the acceleration sensor 15, (d) is a brake signal (depressed at H, not depressed at L), (e) is high G Count state of detection counter and low G detection counter, (
f) shows the operation of storing the data recorded in the RAM 5 in the flash memory 8.

The feature point is that the setting of the high G threshold and the low G threshold is switched based on the depression state of the brake, and when the brake is not depressed (that is, the brake signal is L). ) Is set to prohibit the use of the low G threshold (that is, the low G detection counter is not counted even when the detected acceleration (deceleration) exceeds the low G threshold). Th ₁ is set as the high G threshold. In FIG. 3C, a setting state for prohibiting the use of the low G threshold is indicated by a one-dot chain line.

On the other hand, when the brake is stepped on (that is, when the brake signal is H), the use of the low G threshold is permitted (that is, the detected acceleration (deceleration) exceeds the low G threshold). The low G detection counter is set to count), and the high G threshold is T
Th ₂ lower than h ₁ is set. The high G threshold value Th ₂ is set to a value lower than the reference value Th ₁ so that a collision can be detected in a state where the vehicle is decelerated to some extent while the brake is applied. Each set value of the high G threshold values Th ₁ and Th ₂ and the low G threshold value Tl is set to be an optimum value for each vehicle type.

When the data recording device 1 detects that the ignition switch is turned on at time t ₁₁ , the data recording device 1 starts a process of recording the data detected by the various detection units 11 to 18 in the RAM 5. The section including subsequent times t _{12 to} t ₁₄ shows the operating state when a collision occurs without applying the brake.

In this case, at time t _12, the vehicle acceleration (deceleration) exceeds a low G threshold, but since the brake signal is at L, and a setting to prohibit the use of low G threshold, low G detection counter After that, when it is detected at time t ₁₃ that the acceleration of the vehicle has exceeded the high G threshold (Th ₁ ), the high G detection counter starts counting, and the counter becomes 2 at time t ₁₄ became, it determines a collision, starts to store and transfer the data before the collision recorded in the RAM5 the flash memory 8.

The section including the next times t _{15 to} t ₁₈ shows the operating state when a collision occurs while the brake is applied. When the brake signal H is detected at time t ₁₅ , the setting of the acceleration threshold is switched. That is, the low G threshold is switched from the setting for prohibiting its use to the setting for permitting use (that is, when the detected acceleration exceeds the low G threshold, the low G detection counter starts counting), The set value of the high G threshold is switched from Th ₁ to Th ₂ .

Then, at time t _16, when the vehicle acceleration (deceleration) is detected that exceeds the low G threshold (Tl), it starts counting of the counter for detecting low G, then, at time t _17, the acceleration of the vehicle Is detected to exceed the high G threshold (Th ₂ ), the high G detection counter starts counting, and at time t ₁₈ when the high G detection counter becomes 2, a collision (collision while applying a brake) is started. ) And the process of transferring and storing the pre-collision data recorded in the RAM 5 to the flash memory 8 is started. As described above, when the brake is depressed, the high G threshold is set by switching to Th ₂ lower than Th _1, so that it is possible to accurately determine a collision while the brake is applied, Data can be stored securely.

The section including the next time t ₁₉ ~t _20, shows the operation state when subjected to sudden braking, at time t _19, the vehicle acceleration (deceleration) exceeds a low G threshold (Tl) Upon detecting the starts counting of the counter for detecting low G, at time t ₂₀ to the low-G detection counter reaches 5, determines that sudden braking, a flash memory data before sudden braking recorded in the RAM5 The process of transferring to 8 and saving is started.

The section including the next time t ₂₁ ~t _23, shows the operation state when running on a bad road when no braking, at time t _21, when detecting the L of the brake signal, the acceleration The setting of the threshold is switched, that is, the low G threshold is switched from the setting that permits the use to the setting that prohibits the use (that is, even if the detected acceleration exceeds the low G threshold, the low G detection counter The setting value of the high G threshold is switched from Th ₂ to Th ₁ .

Then, over a period of time t ₂₂ ~t _23, intermittently, it is the acceleration exceeds the low G threshold, since a setting to prohibit the use of low G threshold, the low G detection counter counting is started In other words, unnecessary storage of data on a rough road or the like in which the acceleration intermittently exceeds the low G threshold without the brake being depressed is prevented.

Further, the section including the next time t ₂₄ ~t _26, shows the operation state when running on a bad road while applying the brakes, at time t _24, when detecting the H of the braking signal, The setting of the acceleration threshold is switched. That is, the low G threshold is switched from the setting for prohibiting the use to the setting for permitting the use (that is, when the detected acceleration exceeds the low G threshold, the low G detection counter starts counting). The threshold value is switched from Th ₁ to Th ₂ .

Thereafter, from time t _{25 to} t ₂₆ , the peak of acceleration is intermittently detected, but since the brake is applied, the acceleration is less than the low G threshold (Tl), and the low G detection counter The count is not started and data is not saved.

Next, processing operations performed by the CPU 7 in the data recording apparatus 1 according to the embodiment will be described based on the flowchart shown in FIG. This processing operation is repeatedly executed after the ignition switch is turned on.

First, in step S1, a low G detection counter (m) and a high G detection counter (n)
In the next step S2, data from the various detection means 11 to 18 is acquired, and in the next step S3, the detected data is recorded in the RAM 5, and then the step S
Proceed to 4. When there is no free space for recording in the RAM 5, new data is overwritten and recorded on old data.

In step S4, it is determined whether or not the brake is depressed. If it is determined that the brake is depressed, the process proceeds to step S5, and in step S5, the use of the low G threshold (Tl) is permitted. Then, the set value of the high G threshold is set to Th ₂ , and then the process proceeds to step S6.

In step S6, the acceleration (detection G) detected by the acceleration sensor 15 is reduced to a low G threshold (T
l), and if it is determined that the detected G exceeds the low G threshold (Tl), the process proceeds to step S7. In step S7, 1 is added to the low G detection counter (m), Thereafter, the process proceeds to step S8.

In step S8, it is determined whether or not the low G detection counter (m) has reached the determination value M, and if it is determined that the low G detection counter (m) has not reached the determination value M, step S8 is performed. The process proceeds to S9. In Step S9, it is determined whether or not the detected G exceeds the high G threshold (Th ₂ ). If it is determined that the detected G exceeds the high G threshold (Th ₂ ), the process proceeds to Step S10. 1 is added to the counter (n) for G detection, and then the process proceeds to step S11.

In step S11, it is determined whether or not the high G counter (n) has reached the determination value N. If it is determined that the high G counter (n) has not reached the determination value N, the process returns to step S2. ,
If it is determined that the high G counter (n) has reached the determination value N, the process proceeds to step S12.

In step S12, a process of saving the data recorded in the RAM 5 to the flash memory 8 is started, and then the process ends. On the other hand, if it is determined in step S8 that the low G detection counter (m) has reached the determination value M, the process proceeds to step S12, where the process of storing the data recorded in the RAM 5 in the flash memory 8 is started. Finish the process.

On the other hand, if it is determined in step S6 that the detected acceleration does not exceed the low G threshold value (Tl), the process proceeds to step S13, the low G detection counter (m) is reset, and then the process returns to step S2 to perform the processing. repeat. If it is determined in step S9 that the detected acceleration does not exceed the high G threshold (Th ₂ ), the process proceeds to step S14, the high G detection counter (n) is reset, and then the process returns to step S2. Repeat the process.

On the other hand, if it is determined in step S4 that the brake is not depressed, step S4 is performed.
In step S15, while setting to prohibit use of the low G threshold (Tl),
The set value of the high G threshold is set to Th ₁ and then the process proceeds to step S16.

In step S16, the low-G detection counter (m) is reset, and then step S1
In Step S17, it is determined whether or not the detected acceleration exceeds the high G threshold (Th ₁ ). If it is determined that the detected acceleration exceeds the high G threshold (Th ₁ ), the process proceeds to Step S18, and Step S18. Then, 1 is added to the counter (n) for high G detection, and then the process proceeds to step S19.

In step S19, it is determined whether or not the high G counter (n) has reached the determination value N. If it is determined that the high G counter (n) has not reached the determination value N, the process returns to step S2. ,
If it is determined that the high G counter (n) has reached the determination value N, the process proceeds to step S12, where the RAM
5 starts the process of saving the data recorded in the flash memory 8 and then ends the process.

On the other hand, if it is determined in step S17 that the detected acceleration does not exceed the high G threshold (Th ₁ ), the process proceeds to step S20. In step S20, the high G detection counter (n
) Is reset, and then the process returns to step S2 to repeat the process.

According to the data recording apparatus 1 according to the above embodiment, when switching from a state where the brake is depressed (brake signal H) to a state where the brake is depressed (brake signal L) is detected, the low G threshold value (first acceleration) Since the high G threshold value (second acceleration threshold value) is switched to Th ₁ while switching to a setting for prohibiting the use of the threshold value), the low G value is set when the brake is not depressed.
By setting to prohibit the use of the threshold value, it is necessary to save it when traveling on rough roads where acceleration that intermittently exceeds the low G threshold value is detected even though the brake is not depressed. Therefore, it is possible to prevent the storage of low-performance data, and the flash memory 8 can be used effectively.

In addition, when switching from a state where the brake is not depressed (brake signal L) to a state where the brake is depressed (brake signal H) is detected, the setting is switched to a setting that permits the use of the low G threshold, and the high G threshold is used as a reference. Since it is switched to Th ₂ which is lower than Th ₁ , even when the vehicle collides in a state of deceleration to some extent while applying a brake, the collision can be correctly determined using the high G threshold Th ₂ switched to a lower value. Thus, the data before the collision can be reliably stored, and the storage control of the highly necessary data can be performed more appropriately.

In the above embodiment, the brake pressure sensor 14 determines whether or not the brake is depressed.
However, in another embodiment, whether or not the brake is depressed is determined based on the ON / OFF signal of the stop lamp switch that detects the depression state of the brake pedal. You may make it judge.

Further, in the above embodiment, based on whether or not the brake is depressed (whether or not depressed), the setting is switched to a setting that permits the use of the low G threshold or a setting that prohibits the use,
The set value of the high G threshold value is switched. In another embodiment, the brake depression strength (change in brake pressure) is calculated based on the signal from the brake pressure sensor 14, and the brake is applied. It is also possible to adopt a configuration in which the setting value of the high G threshold value is switched while switching to the setting for permitting the use of the low G threshold value or the setting for prohibiting the use based on the strength of the stepping on.

For example, the brake depression strength (change in brake pressure) is a predetermined strength (change rate) A.
If it is above, it is set to permit the use of the low G threshold, and the set value of the high G threshold is set to Th.
_{While the} threshold Th is set to a value Th ₂ lower than ₁ , if the brake depression strength is less than the predetermined value B (however, the predetermined value B ≦ the predetermined value A), the use of the low G threshold is prohibited. , High G
The threshold setting may be configured to set to Th _1.

According to such a configuration, the vehicle is traveling on a rough road where acceleration is detected that intermittently exceeds the low G threshold in a state where the brake is lightly depressed (the brake depression strength is less than the predetermined value B). However, since it is set to prohibit the use of the low G threshold, even if an acceleration that intermittently exceeds the low G threshold is detected, the count is not started and the road is decelerated while decelerating. Data storage during traveling can be prevented, and more appropriate storage control can be performed.

Further, the setting value of the low G threshold value and the setting value of the high G threshold value are switched according to the brake depression strength, that is, the low G threshold setting value according to the brake depression strength, Several G threshold setting values may be prepared, and the low G threshold setting value and the high G threshold setting value may be appropriately switched in accordance with the detected brake depression strength.

For example, when the setting value of the low G threshold is set to a reference value when the brake depression is strong,
As the brake depression becomes weaker, the set value is switched so that the value becomes higher than the reference value, and the high G threshold setting value is obtained when the case where the brake depression is weak is used as the reference value.
The set value can be switched so that the value becomes lower than the reference value as the brake is depressed more strongly.

According to this configuration, when the brake is not depressed as in the above embodiment, the low G
Even without switching to a setting that prohibits the use of the threshold value, it is possible to prevent the storage of data that is not necessary, such as when driving on rough roads.
It is possible to store data in the case of a collision more reliably.

Further, the setting value of the low G threshold value and the setting value of the high G threshold value are switched based on whether or not the brake is depressed. That is, the setting value of the low G threshold value is more depressed than when the brake is depressed. When there is no brake, the value is switched so that the value is higher. On the other hand, the setting value of the high G threshold is switched so that the value when the brake is depressed is lower than when the brake is not depressed. Also good.

According to this configuration, when the brake is not depressed, the low G threshold is set to be higher than that when the brake is depressed (that is, a higher threshold that does not exceed the impact of traveling on a rough road). Therefore, when there is no depression of the brake as in the above embodiment,
Even without switching to a setting that prohibits the use of the low G threshold, it is possible to prevent the storage of data that is not necessary when driving on rough roads, and data such as when there is a collision after decelerating while braking Can also be reliably stored.

In the data recording apparatus 1 according to the above-described embodiment, the case where the low G threshold and the high G threshold are set as the acceleration threshold has been described. However, in another embodiment, only the high G threshold, that is, The above-described data storage control is also applied to a device configured to store only the driving state data leading to the collision, or a device configured to store only the low G threshold value and the dangerous driving state data not leading to the collision. Can be applied.

It is a timing diagram for explaining the data storage operation to the flash memory performed by the conventional data recording device. It is the block diagram which showed roughly the principal part of the data recording device which concerns on embodiment of this invention. FIG. 5 is a timing diagram for explaining an operation of storing data in a flash memory performed by the data recording apparatus according to the embodiment. It is the flowchart which showed the processing operation which CPU in the data recording device which concerns on embodiment.

Explanation of symbols

1 Data recording device 5 RAM
6 ROM
7 CPU
8 Flash memory

Claims (4)

Recording means for recording data obtained from means for detecting the vehicle state;
A brake depression state detecting means for detecting a depression state of the brake of the vehicle;
Threshold setting switching means for switching the setting of an acceleration threshold value for determining a predetermined driving state from the acceleration of the vehicle based on the brake depression state detected by the brake depression state detection means;
A data storage means for storing the data recorded by the recording means when the acceleration of the vehicle satisfies a predetermined condition in the setting state of the acceleration threshold value switched by the threshold setting switching means; A data recording apparatus characterized by the above. The acceleration threshold includes a first acceleration threshold for determining a dangerous driving state that does not lead to a collision, and a second acceleration threshold for determining a driving state leading to a collision,
The brake depression state detecting means detects presence or absence of depression of the brake;
The threshold setting switching means;
When switching from the state where the brake is depressed to the state where the brake is depressed is detected by the brake depression state detecting means, the setting is made to prohibit the use of the first acceleration threshold, and the second acceleration threshold is changed to the second acceleration threshold. While switching to the set value of 1,
When switching from a state where the brake is not depressed to a state where the brake is not depressed is detected by the brake depression state detection means, the setting is made to allow the use of the first acceleration threshold, and the second acceleration threshold is set to the second acceleration threshold. 2. The data recording apparatus according to claim 1, wherein the data recording apparatus switches to a second set value that is lower than the first set value. The acceleration threshold includes a first acceleration threshold for determining a dangerous driving state that does not lead to a collision, and a second acceleration threshold for determining a driving state leading to a collision,
The brake depressing state detecting means detects the depressing strength of the brake;
The threshold setting switching means;
Based on the brake depression intensity detected by the brake depression state detection means, the setting is made to switch the setting to permit or prohibit the use of the first acceleration threshold, and to change the second acceleration threshold. 2. The data recording apparatus according to claim 1, wherein the set value is switched. The acceleration threshold includes a first acceleration threshold for determining a dangerous driving state that does not lead to a collision, and a second acceleration threshold for determining a driving state leading to a collision,
The brake depressing state detecting means detects the depressing strength of the brake;
The threshold setting switching means;
The setting value of the first acceleration threshold value and the setting value of the second acceleration threshold value are switched based on the strength of depression of the brake detected by the brake depression state detecting means. The data recording apparatus according to claim 1.

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