JP5846815B2 - Drive recorder - Google Patents

Description

  The present invention relates to a drive recorder mounted on a vehicle as a vehicle-mounted device, and more particularly to management of data recorded on a predetermined recording medium.

  In general, many drive recorders mounted on vehicles automatically record data such as images taken by a vehicle-mounted camera and vehicle speed on a recording medium such as a memory card. Conventionally, there are a trigger recording type in which recording is performed for a predetermined time using an event such as the occurrence of a traffic accident as a trigger, and a constant recording type drive recorder in which recording is always performed regardless of the event.

  By the way, in the drive recorder as described above, since a recording medium such as a memory card is a data storage destination, the capacity of recordable data is limited. However, since the data to be recorded is added gradually every time an event occurs or with the passage of time, it is not possible to record and store all acquired data. Therefore, in the drive recorder, when there is no free space where data can be recorded on the recording medium, the old recording data is deleted from the recording medium in time to secure a new free space, or the old recording data Generally, data is written so as to overwrite.

As the conventional technology of the drive recorder, for example, the technologies disclosed in Patent Literature 1 and Patent Literature 2 are known.
Patent Document 1 discloses a drive recorder that can store and retain information related to the traveling state of the host vehicle for a longer period of time. Specifically, multiple types of travel data are created, priorities are assigned according to the types of travel data, the priorities of travel data that have become less important over time are reduced, and recording media is free. When the capacity is reduced, it is proposed to delete the driving data in ascending order of priority.

  Patent Document 2 discloses a recording apparatus that collects information capable of performing accident verification in detail. Specifically, it is proposed that vehicle information indicating the current state of the vehicle is recorded at regular time intervals, and when an accident is detected, it is recorded at a shorter time interval than before the accident. In addition, it is determined whether the impact is at the accident level based on the magnitude of the impact. If the impact is at the accident level, the information immediately before the accident is protected by prohibiting overwriting of records for 10 minutes, for example, before detecting the accident. Is disclosed.

JP 2009-15789 A International Publication No. 2007/110958 Pamphlet

  By the way, the always-recording type drive recorder can be used for recording information representing the operation status of a business vehicle such as a taxi vehicle or a truck. In the case of a commercial vehicle, it may be possible to record, as video data, a video of a driver and passengers in the vehicle in addition to a video taken outside the vehicle such as a road. The in-vehicle video can be used by the administrator to grasp the situation such as the safe driving of the driver and the response to the passengers. It can also be used to check the status of passengers left behind in a taxi vehicle, for example.

  In the case of a drive recorder for a taxi vehicle, it is often sufficient for the management of business that only the data taken on the day remains as the data of the video taken outside the vehicle. However, after about a week has passed since the ride, for example, taxi companies may receive inquiries from passengers about forgotten items. Therefore, images taken inside the vehicle should be stored for a longer period than data outside the vehicle. Is desirable.

  However, a recording medium such as a memory card attached to the drive recorder has a limited recording data capacity, and the data including the video has a large capacity, so it is not possible to save all the data acquired over a long period of time. . That is, when there is no more free space on the recording medium, old data is automatically deleted in order to secure a new recording area.

  If the prior art of Patent Document 1 is adopted, different priorities can be assigned to the types of data to be recorded. Therefore, for example, it is conceivable to increase the priority of video data taken inside the vehicle and lower the priority of video data taken outside the vehicle.

  However, even if the priority of the video data obtained by photographing the inside of the vehicle is increased, not all recorded data within a period (for example, one week) required for management remains. Even when the priority of video data taken outside the vehicle is lowered, recorded data may remain longer than the time length required for management, and the recording capacity of the recording medium is limited. The area cannot be used efficiently.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to enable efficient use of a recording area of a recording medium having a limited capacity and to manage a time range required for management. An object of the present invention is to provide a drive recorder capable of reliably leaving recorded data.

In order to achieve the above-described object, the drive recorder according to the present invention is characterized by the following (1) to ( 4 ).
(1) Two or more types of recording target data different from each other generated in accordance with the operation of a vehicle are acquired periodically or in response to a predetermined event occurrence, and the acquired recording target data is stored in a predetermined recording medium. A drive recorder that sequentially records in the free space above,
A time length upper limit holding unit that holds a predetermined recording time length upper limit for at least one type of first data of the two or more types of recording target data;
When a free area on the recording medium does not exist or is insufficient, the recording time length of the first data recorded on the recording medium is compared with the recording time length upper limit value, and the recording time A recording control unit for erasing unnecessary data from an area in which the first data is recorded and securing a new empty area when the upper limit value is exceeded ,
Whether the recording control unit includes a free area on the recording medium in a situation where the recording target data includes second data and third data that are different from the first data. Alternatively, if the recording time length of the first data recorded on the recording medium is within the upper limit value of the recording time length when there is a shortage, the second data recorded on the recording medium The recording time length is compared with the recording time length of the third data recorded on the recording medium, and the longer recording time length of the second data and the third data is given priority. Select and delete unnecessary data from the area where the selected data is recorded to secure a new free area .
( 2 ) The drive recorder according to (1) above,
When the recording time length of the first data exceeds the recording time length upper limit value, the recording control unit excludes the data to be protected in the area where the first data is recorded. Find the oldest recorded data and delete this data as unnecessary data.
( 3 ) The drive recorder according to ( 1 ) above,
When the recording control unit secures the new empty area, the recording control unit excludes the data to be protected from the area where the second data or the third data selected is recorded. Find the oldest data and delete this data as unnecessary data.
( 4 ) The drive recorder according to (1) above,
The recording control unit records, as the two or more types of recording target data, at least a plurality of types of image data captured by a plurality of in-vehicle cameras that capture different locations.

According to the drive recorder having the configuration (1), the recording time length of the first data recorded on the recording medium can be limited to the predetermined recording time length upper limit value. Accordingly, it is possible to prevent the first data from being stored for an unnecessarily long period, and to efficiently use the recording area of the recording medium having a limited capacity. Furthermore, the data required for managing the length within the upper limit value of the recording time length can be surely left for the first data. Further, the recording time length can be made uniform for the second data and the third data.
According to the drive recorder having the configuration ( 2 ), it is possible to protect the data in the highly important portion of the first data so that it is not erased even if it becomes older in time.
According to the drive recorder having the above configuration ( 3 ), the second data and the data in the highly important portion of the third data are protected from being erased even if they become older in time. Can do.
According to the drive recorder having the above configuration ( 4 ), for example, the recording time length of the video data obtained by photographing the outside of the vehicle and the recording time length of the video data obtained by photographing the inside of the vehicle can be managed independently. It is possible to reliably leave only necessary data.

  According to the drive recorder of the present invention, it is possible to efficiently use a recording area of a recording medium having a limited capacity, and it is possible to reliably leave recording data in a time range required for management.

  The present invention has been briefly described above. Further, details of the present invention will be further clarified by reading through the modes for carrying out the invention described below with reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating a configuration example of a main part of the drive recorder of the embodiment. FIG. 2 is a flowchart showing main operations of the drive recorder shown in FIG. FIG. 3 is a schematic diagram showing a configuration example of data recorded by the drive recorder shown in FIG.

  Specific embodiments relating to the drive recorder of the present invention will be described below with reference to the drawings.

<Device configuration>
A configuration example of a main part of the drive recorder 100 in the present embodiment is shown in FIG. In the present embodiment, a constant recording type drive recorder 100 that is mounted as a vehicle-mounted device on a commercial vehicle such as a taxi or a truck is assumed.

  As shown in FIG. 1, the drive recorder 100 includes a recording control unit 10, interfaces 11 to 14, an in-vehicle camera 21 for in-vehicle shooting, an in-vehicle camera 22 for in-vehicle shooting, a vehicle speed (speed) sensor 23, and an acceleration (G) sensor. 24, a nonvolatile memory 25 and a recording medium 30 are provided.

  Of these components, the in-vehicle camera 21 for in-vehicle shooting, the in-vehicle camera 22 for in-vehicle shooting, and the vehicle speed sensor 23 are installed in advance on the vehicle side on which the drive recorder 100 is mounted. Other components are incorporated in the in-vehicle device of the drive recorder 100.

  The vehicle-mounted camera 21 for outside-camera shooting is arranged, for example, on the vehicle interior side of the front windshield of the host vehicle, and is fixed so as to be able to photograph the scenery in front of the vehicle in the traveling direction, that is, the road surface of the road or the vehicle ahead. Is done. Of course, it is also conceivable to take a scene behind the vehicle from the position near the window glass at the rear of the vehicle.

  The in-vehicle camera 22 for in-vehicle shooting is arranged in the vehicle interior of the vehicle, and is fixed in a direction in which, for example, the situation of the driver in the vicinity of the driver's seat, the situation of the passenger in the vicinity of the rear seat, or both can be taken. The

  In the example shown in FIG. 1, it is assumed that the vehicle-mounted camera 21 for shooting outside the vehicle and the vehicle-mounted camera 22 for shooting inside the vehicle are installed one by one, but a plurality of vehicle-mounted cameras for shooting outside the vehicle that can shoot different places. 21 and / or a plurality of in-vehicle photographing in-vehicle cameras 22 may be connected to the drive recorder 100.

  The recording control unit 10 is constituted by an electronic circuit including a microcomputer, and realizes processing required for controlling the drive recorder 100 by executing a program prepared in advance. The operation of the recording control unit 10 will be described in detail later.

  The vehicle speed sensor 23 detects the rotation of the transmission output shaft of the vehicle by a predetermined amount and generates a pulse signal. Therefore, by measuring the number of pulses of the pulse signal output from the vehicle speed sensor 23 and the generation cycle, information on the vehicle speed and the travel distance can be acquired.

  The acceleration sensor 24 is used for detecting an abnormally large acceleration at the time of a traffic accident, and acceleration accompanying sudden acceleration or sudden deceleration. The acceleration sensor 24 detects the magnitude of acceleration in the traveling direction (front-rear direction) and lateral direction of the vehicle.

  The interface 11 converts a video signal obtained by photographing with the on-vehicle camera 21 for photographing outside the vehicle into a predetermined digital signal, and outputs it as video data that can be processed by the recording control unit 10. The interface 12 converts a video signal obtained by shooting by the in-vehicle shooting on-vehicle camera 22 into a predetermined digital signal and outputs it as video data that can be processed by the recording control unit 10. The interface 13 converts the vehicle speed pulse signal output from the vehicle speed sensor 23 into a signal suitable for the processing of the recording control unit 10. The interface 14 converts a signal output from the acceleration sensor 24 into a digital signal that can be processed by the recording control unit 10.

  The recording medium 30 is composed of, for example, a memory card with a built-in nonvolatile memory, and is used for storing various data acquired by the drive recorder 100. Data can be freely written to and read from the recording medium 30 by access from the recording control unit 10.

<Configuration example of constant data used for control>
The nonvolatile memory 25 shown in FIG. 1 holds data such as constants necessary for the control of the recording control unit 10 in advance. In the present embodiment, data of a recording control table having contents as shown in the following Table 1 is also registered in the nonvolatile memory 25.

  In the recording control table shown in Table 1 above, for each of the three types of data DA, DB, and DC, information indicating whether or not there is a recording time length limit and information indicating a recording time length upper limit value can be registered. It is configured. Specifically, the data DA corresponds to vehicle information (vehicle speed, acceleration, etc.), the data DB corresponds to vehicle outside video data obtained by shooting by the vehicle-mounted camera 21 for shooting outside the vehicle, and the data DC corresponds to the vehicle-mounted camera 22 for shooting inside the vehicle. This corresponds to in-vehicle video data obtained by shooting.

  That is, by using this recording control table by the recording control unit 10, it is possible to limit the recording time length for each of data DA, DB, and DC of different types. It should be noted that the contents of the recording control table may be appropriately rewritten according to specifications such as an actual environment in which the drive recorder 100 is used and conditions required by a company that manages the vehicle.

<Description of recording time length>
A specific example of the structure of data recorded by the drive recorder 100 shown in FIG. 1 is shown in FIG. The data structure shown in FIG. 3 represents the result of recording, and the time axis in FIG. 3 indicates the time when the data was recorded.

  During operation of the vehicle, the drive recorder 100 repeatedly acquires each of the vehicle information data DA, the outside video data DB, and the in-vehicle video data DC at a constant cycle (for example, every 0.1 second), and these are time-sequentially. Data can be sequentially recorded and stored in the recording medium 30. However, since the capacity of data that can be recorded by the recording medium 30 is finite and determined in advance, after writing a predetermined amount of data, there is no empty area in the recording medium 30 where new data is to be written. Therefore, in order to continue writing new data, it is necessary to delete (erase) old data to secure a new free space, or to control old data to be invalidated and overwritten as free space. .

  In the recording example shown in FIG. 3, for the vehicle information data DA, all the data in the range acquired during the period from the past time t3 to the current time t5 is recorded. Old data has already been deleted. However, since special protection information is assigned to data in the range from time t1 to time t2, it remains without being deleted. Since the recording time length TA of the data DA is not specified in the above-described recording control table, it varies depending on the data capacity of the recording medium 30 and other factors.

  Further, regarding the outside video data DB, all data in the range acquired during the period from the past time t4 to the current time t5 is recorded, but the old data before the time t4 has already been deleted. However, since special protection information is assigned to data in the range from time t1 to time t2, it remains without being deleted. The recording time length TB of the video data DB outside the vehicle has a constant length that matches the recording time length upper limit value (6 hours in this case) specified in the recording control table.

  As for the in-vehicle video data DC, all the data in the range acquired during the period from the past time t3 to the current time t5 is recorded, but the old data before the time t3 has already been deleted. However, since special protection information is assigned to data in the range from time t1 to time t2, it remains without being deleted. The recording time length TC of the in-vehicle video data DC is not specified in the above-described recording control table, and thus varies depending on the data capacity of the recording medium 30 and other factors.

  It should be noted that data that is specially protected, such as the range from time t1 to time t2 shown in FIG. 3, is important even if it is outdated, such as data acquired when the occurrence of a traffic accident is detected. It corresponds to data with a certain value.

<Explanation of device operation>
The main operations of the drive recorder 100 shown in FIG. 1 are shown in FIG. The operation shown in FIG. 2 is actually realized by the processing of the microcomputer of the recording control unit 10 shown in FIG. The operation shown in FIG. 2 will be described below.

  In step S11, the recording control unit 10 repeatedly acquires recording target data at a constant cycle (for example, at intervals of 0.1 seconds). Specifically, the vehicle speed value calculated based on the vehicle speed pulse output from the vehicle speed sensor 23 and the acceleration value corresponding to the signal output from the acceleration sensor 24 are acquired as the vehicle information data DA. In addition, the image captured by the vehicle-mounted camera 21 for in-vehicle shooting is acquired as the vehicle-side image data DB, and the image captured by the vehicle-mounted camera 22 for in-vehicle shooting is acquired as the in-vehicle image data DC.

  In step S <b> 12, the recording control unit 10 identifies whether or not there is a predetermined or larger free area in which data can be written on the recording medium 30. Even if the data has been previously written in the area, it is recognized as a free area if the data has already been deleted (erased) or invalidated. If there is sufficient free space, the process proceeds from step S12 to S13, and if not, the process proceeds to step S14.

  In step S13, the recording control unit 10 writes and stores the latest data DA, DB, and DC acquired in step S11 as time-series data in a free area on the recording medium 30 by classifying each type of data.

  Further, when it is recognized that the importance of data recorded in the current time zone is high, for example, when an acceleration having a magnitude exceeding a predetermined threshold is detected, “protection” is performed on the data recorded in step S13. The information indicating is added. The presence or absence of protection may be identified for each type of data DA, DB, and DC. In that case, it is assumed that conditions relating to the presence or absence of protection are registered in the recording control table described above.

  In step S14, the recording control unit 10 refers to the content of the above-described recording control table existing on the nonvolatile memory 25, and for the data having the recording time length restriction, the designated recording time length upper limit value (in this example, 6 hours). Then, the current recording time length on the recording medium 30 of the corresponding type of data (in this example, the video data DB outside the vehicle) is compared with the recording time length upper limit value and recorded with a length equal to or longer than the recording time length upper limit value. If YES in step S15, the process advances to step S15. If the recording time length is less than the upper limit, the process advances to step S16.

  In the recording control table shown in Table 1, the recording time length is limited only for the outside-vehicle video data DB, but the recording time length can be limited for each of a plurality of types of data. In that case, the same processing as in steps S14 and S15 is performed for each type of data with a limited recording time length.

  In step S15, the recording control unit 10 has the oldest recorded time out of the area where the data to be processed (in this example, the outside video data DB with a recording time length restriction) is recorded on the recording medium 30. Detect some data and delete the corresponding data. However, even if the data is older in time, the range to which the information indicating “protection” is added is excluded from the deletion target. By deleting old data, a new free area is secured on the recording medium 30.

  In step S16, the recording control unit 10 sets the current recording time length on the recording medium 30 for the data for which the recording time length restriction is not specified on the recording control table, that is, the vehicle information data DA and the in-vehicle video data DC. Compare.

  For example, in the state at the current time t5 shown in FIG. 3, the recording time length TA of the vehicle information data DA is compared with the recording time length TC of the in-vehicle video data DC. If the condition “TA> TC” is satisfied, the process proceeds to step S17; otherwise, the process proceeds to step S18.

  If there are three or more types of data for which no recording time length restriction is specified, one type of data with the longest current recording time length is selected from these data, and this is selected in the next step S17. It becomes a processing target.

  In step S17, the recording control unit 10 records the oldest recorded time from an area in which data to be processed (data DA without a recording time length limitation in this example) is recorded on the recording medium 30. Is detected and the corresponding data is deleted. However, even if the data is older in time, the range to which the information indicating “protection” is added is excluded from the deletion target. By deleting old data, a new free area is secured on the recording medium 30.

  In step S18, the recording control unit 10 has the oldest recorded time from the area in which the data to be processed (in this example, in-vehicle video data DC with no recording time length limitation) is recorded on the recording medium 30. Detect some data and delete the corresponding data. However, even if the data is older in time, the range to which the information indicating “protection” is added is excluded from the deletion target. By deleting old data, a new free area is secured on the recording medium 30.

<Advantages of Drive Recorder 100>
When the drive recorder 100 executes the operation shown in FIG. 2, the result shown in FIG. 3 is obtained. That is, for the outside video data DB having a recording time limit on the above-described recording control table, the data is recorded only in the range of a length (in this example, 6 hours) that substantially matches the specified recording time length upper limit value. The old data remaining on the previous 30 is automatically deleted except for the protected range. For other data (DA, DC) that has no recording time length limitation, the recording time length (TA, TC) of the stored data is controlled to be substantially equal.

  Therefore, in the example shown in FIG. 3, the data in the past 6 hours in the range necessary for management can be reliably stored on the recording medium 30 for the outside-vehicle video data DB. Also, since data exceeding the upper limit of the recording time length (6 hours) is deleted preferentially, it is possible to prevent unnecessary data having a large data capacity from occupying the area of the recording medium 30, and the recording medium 30 data capacities can be used effectively.

  Further, with respect to other data (DA, DC) that has no limitation on the recording time length, it is possible to prevent the recording time length (TA, TC) from varying, and the range due to the limitation on the data capacity of the recording medium 30. You can save as much data as possible. For example, data that is useful even after a week has passed, such as in-car video data (DC) in the case of a taxi vehicle, can be stored on the recording medium 30 as it is to some extent. It is.

  In the drive recorder 100 shown in FIG. 1, the above-described recording control table is arranged on the nonvolatile memory 25. However, when the administrator does not need to change the above-described recording time length upper limit value or the like. May be stored as fixed data on a read-only memory (ROM), or may be incorporated in a program executed by the recording control unit 10.

DESCRIPTION OF SYMBOLS 10 Recording control part 11, 12, 13, 14 Interface 21 In-vehicle camera for vehicle outside photography 22 In-vehicle camera for in-vehicle photography 23 Vehicle speed sensor 24 Acceleration sensor 25 Non-volatile memory 30 Recording medium 100 Drive recorder DA Vehicle information data DB Outside vehicle image data DC In-car video data TA, TB, TC Recording time length

Claims (4)

Two or more types of recording target data different from each other generated in accordance with the operation of the vehicle are acquired periodically or in response to a predetermined event occurrence, and the acquired recording target data is free on a predetermined recording medium. A drive recorder for sequentially recording in an area,
A time length upper limit holding unit that holds a predetermined recording time length upper limit for at least one type of first data of the two or more types of recording target data;
When a free area on the recording medium does not exist or is insufficient, the recording time length of the first data recorded on the recording medium is compared with the recording time length upper limit value, and the recording time In a drive recorder provided with a recording control unit that erases unnecessary data from the area where the first data is recorded and secures a new empty area when the upper limit value is exceeded ,
Whether the recording control unit includes a free area on the recording medium in a situation where the recording target data includes second data and third data that are different from the first data. Alternatively, if the recording time length of the first data recorded on the recording medium is within the upper limit value of the recording time length when there is a shortage, the second data recorded on the recording medium The recording time length is compared with the recording time length of the third data recorded on the recording medium, and the longer recording time length of the second data and the third data is given priority. Select and erase unnecessary data from the area where the selected data is recorded to secure a new free area
A drive recorder characterized by that . When the recording time length of the first data exceeds the recording time length upper limit value, the recording control unit excludes the data to be protected in the area where the first data is recorded. 2. The drive recorder according to claim 1, wherein the data having the oldest recorded time is searched for and deleted as unnecessary data. When the recording control unit secures the new empty area, the recording control unit excludes the data to be protected from the area where the second data or the third data selected is recorded. 2. The drive recorder according to claim 1 , wherein the oldest data is searched for and deleted as unnecessary data. The recording control unit records, on the recording medium, a plurality of types of image data captured by a plurality of in-vehicle cameras that capture at least different locations as the two or more types of recording target data. The drive recorder according to claim 1.

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