JP2010146477A - Drive recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive recorder for efficiently performing recording of image information or the like to a recording medium having a limited recording capacity. <P>SOLUTION: The drive recorder (2) includes: a compression processing part (13) which performs compression of information taken by an imaging means (3); and a control part (10) which controls to steadily record the information taken by the imaging means to a recording medium (4) by compressing the information at a predetermined compression ratio with the compression processing part and to record, when a predetermined condition is established, the information taken by the imaging means to the recording medium. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drive recorder, and more particularly to a drive recorder for efficiently recording video information and the like on a recording medium having a limited recording capacity.

  2. Description of the Related Art Conventionally, a so-called drive recorder has been proposed that records an image around a vehicle with a camera installed in the vehicle and records the surrounding image and vehicle speed when an impact is applied to the vehicle, such as a collision or sudden braking. ing. By providing the drive recorder in the vehicle, when an accident occurs, the recorded information can be analyzed to verify the cause of the accident. Further, the information recorded by the drive recorder can be used to improve the driver's awareness of safe driving, and the video recording the daily driving situation can be used for safe driving guidance and the like.

  There has been disclosed a drive recorder that cyclically records video captured by an in-vehicle camera and records video recorded at the time of an accident on another recording medium (see, for example, Patent Documents 1 and 2).

  There is also known a drive recorder provided with a plurality of cameras and configured to record imaging information from a specific camera according to the impact level (right turn of acceleration, left turn of acceleration) detected by the impact detection means. (For example, refer to Patent Document 3).

JP-A 63-16785 Japanese Patent Laid-Open No. 06-237463 JP 2006-321424 A

  For example, when a heavy truck and a light vehicle collide, the drive recorder attached to the truck has a small impact and it may be difficult to detect acceleration. As described above, there is a problem that video information is not recorded when the impact is small even in a situation where video information is desired to be acquired. However, even if the impact is small, if all the video information is recorded, there is a problem that it becomes impossible to immediately record on a recording medium having a limited recording capacity.

  Therefore, an object of the present invention is to provide a drive recorder that can solve the above-described problems.

  It is another object of the present invention to provide a drive recorder that can efficiently record video information and the like on a recording medium having a limited recording capacity.

  In order to solve the above-described problems, in the drive recorder according to the present invention, in the drive recorder that records information captured by the imaging unit on a recording medium, a compression processing unit that compresses the information captured by the imaging unit, and a compression The information picked up by the image pickup means by the processing unit is compressed at a predetermined compression rate and steadily recorded on the recording medium, and the information picked up by the image pickup means is recorded on the recording medium when a predetermined recording condition is satisfied. It has the control part which controls as follows.

  In the drive recorder according to the present invention, in constant recording, information is compressed and recorded on a recording medium at a high compression rate, and when a predetermined recording condition is satisfied, the information is compressed at a low compression rate to be a recording medium. Information for steady recording can be recorded on the recording medium for a long time, and detailed and clear information can be recorded on the recording medium in an important period where there is a possibility of a serious accident or the like.

  A drive recorder according to the present invention will be described below with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to these embodiments, but extends to the invention described in the claims and equivalents thereof.

  First, information recording in the drive recorder will be described.

  FIG. 1 is a diagram showing an example in which a drive recorder 2 is mounted on a vehicle 1.

  A drive recorder 2 is installed in the vehicle 1 and connected to a camera 3 that captures the front of the vehicle 1. Video information from the camera 3 is cyclically recorded in the RAM 12 in the drive recorder 2. When a predetermined recording condition is satisfied, the video information recorded in the RAM 12 is recorded in the memory card 4. Even if the predetermined recording condition is not satisfied, the video information recorded in the RAM 12 is constantly recorded in the memory card 4 with a high compression rate and a low image quality. The predetermined recording condition means a case where an impact is applied to the vehicle 1 due to the occurrence of an accident or the like, and details will be described later.

  In addition to the video information, the drive recorder 2 acquires operation information including vehicle speed information and the like, and cyclically records it in the RAM 12 in the drive recorder 2. The operation information is recorded on the memory card 4 together with the video information. Details of the operation information will be described later.

  FIG. 2 is a diagram illustrating an example in which the drive recorder 2 is installed in the vehicle 1.

  The drive recorder 2 is electrically connected to the camera 3. The camera 3 is attached to the front glass surface on the back side of the vehicle interior mirror, photographs the front of the vehicle, and transmits video information to the drive recorder 2. In FIGS. 1 and 2, only the drive recorder 2 and one camera 3 are connected, but it is also possible to connect a plurality of cameras such as for the rear of the vehicle, for the side, or for the inside of the vehicle.

  FIG. 3 is a diagram illustrating an example of the appearance of the playback device.

  Video information, operation information, and the like recorded on the memory card 4 are reproduced by a reproduction device 400 configured by a personal computer or the like. The memory card 4 is inserted into an I / F connected to a personal computer, and video information, operation information, and the like are read. The playback device 400 can play back video information and the like recorded on the memory card 4.

  FIG. 4 is a block diagram showing an electrical configuration of the drive recorder 2.

  The drive recorder 2 can be configured separately from the camera 3 as an apparatus dedicated to video recording as shown in FIG. 2, but may be configured integrally with being housed in the same housing as the camera 3. . Moreover, it can also be comprised as one function of a vehicle-mounted navigation apparatus.

  The camera 3 is configured to photograph the front of the vehicle 1 and output an analog video signal 500. For example, a CCD image sensor (Charge Coupled Device Image Sensor) or a CMOS image sensor (Complementary Metal Oxide Semiconductor Image) is used as a two-dimensional image sensor. Sensor).

  The memory card 4 is a recording medium removable from the drive recorder 2, and an SD card (Secure Digital Memory Card) which is a programmable non-volatile semiconductor memory card is used. However, other removable memory cards such as a CF card (Compact Flash Card) and a memory stick may be used. In this example, the memory card 4 is used as a removable recording medium. However, the present invention is not necessarily limited to this, and a removable hard disk or the like can also be used.

  The acceleration sensor 5 is configured by a so-called G sensor (Gravity Accelerative Sensor) that detects the magnitude of an impact applied to the vehicle 1 as a gravitational acceleration. It is made of a semiconductor that generates a current based on the gravitational acceleration when it receives an impact, detects the magnitude of the gravitational acceleration in the longitudinal direction and the lateral direction of the vehicle, and outputs gravitational acceleration information 505 to the CPU 10.

  The photographing switch (photographing SW) 6 is attached to the main body of the drive recorder 2, and transmits a push-down signal 506 to the electrically connected CPU 10 when operated by the user. Thereby, the CPU 10 controls to record the video information on the assumption that a recording condition described later is satisfied.

  The vehicle speed sensor 7 includes a magnetic sensor or an optical sensor that outputs the rotation of a rotor provided on the wheel shaft of the vehicle 1 as a rotation pulse signal 507. The CPU 10 calculates the speed information of the vehicle 1 by calculating the number of wheel rotations per unit time from the pulse signal received from the vehicle speed sensor 7.

  A CPU (Central Processing Unit) 10 operates as a control device of the drive recorder 2 and is configured by a microcomputer or the like. Based on the control program 16, the CPU 10 executes control of each part of the drive recorder 2 and data calculation processing.

  The image IC 11 converts the video signal 500 input from the camera 3 into a digital signal, and creates and outputs video information 501. For example, the image IC 11 is composed of JPEG-IC (Joint Photographic coding Experts Group-Integrated Circuit), and creates still image data in JPEG format. In this case, the JPEG-IC outputs, for example, video information 501 of 640 × 480 pixels and 30 frames / second to a RAM (Random Access Memory) 12.

  The RAM 12 continuously records the uncompressed video information 501 converted by the image IC 11 for 40 seconds (30 × 40 = 1200 frames) cyclically. The RAM 12 also circulates and records operation information, which will be described later, linked to each still image data. For example, an SDRAM (Synchronous Dynamic Random Access Memory) is used for the RAM 12. Since SDRAM is designed to operate in synchronization with the CPU clock, it has a short I / O waiting time, and can be accessed faster than conventional DRAM (Dynamic Random Access Memory). This is because it is suitable for the control for processing the video data at a high speed. Note that the recording capacity of the RAM 12 is merely an example, and the present invention is not limited to this. The RAM 12 outputs information 502 including video information and operation information recorded in a cyclic manner to the compression processing circuit 13.

  In accordance with the control signal 504 from the CPU 10, the compression processing circuit 13 performs processing of changing the compression rate of video information output from the RAM 502 and / or thinning out predetermined video information and operation information. Recording information 503 is output to the interface (I / F) 14. Details of the processing of the compression processing circuit 13 will be described later.

  The interface (I / F) 14 configures a so-called slot portion of the memory card 4 provided in the drive recorder 2. The I / F 14 transfers the recording information 503 output from the compression processing circuit 13 to the inserted memory card 4.

  The nonvolatile ROM 15 records a control program 16 and the like for controlling the hardware resources constituting the drive recorder 2 in an integrated manner. A mask ROM may be used as the non-volatile ROM 15, but writing and erasing of a program can be performed by using a flash memory which is a programmable non-volatile semiconductor memory, an EEPROM (Erasable Programmable Read Only Memory), a ferroelectric memory, or the like. It becomes possible.

  The control program 16 is recorded in the nonvolatile ROM 15 and read by the CPU 10 when the drive recorder 2 is activated, and functions as a program for controlling each part and for data calculation processing.

  FIG. 5 is a block diagram showing an electrical configuration of the playback device 400.

  The interface (I / F) 411 constitutes a so-called slot portion of the memory card 4 provided in the playback device 400. The I / F 411 transfers video information, operation information, and the like recorded in the memory card 4 to the playback device 400 side.

  The RAM 414 is used for temporarily recording data when the CPU 410 performs image processing of video information transferred from the memory card 4 and information processing of operation information. For example, an SDRAM is used as the RAM 412.

  The nonvolatile ROM 415 records a control program 416 and the like for comprehensively controlling the hardware resources constituting the playback device 400. For the nonvolatile ROM 415, for example, an EEPROM, a ferroelectric memory, or the like is used.

  The control program 416 is recorded in the non-volatile ROM 415 and is read by the CPU 410 when the playback device 400 is activated, and functions as a program for control of each unit and data calculation processing.

  The CPU 410 operates as a control device for the playback device 400 and is configured by a microcomputer or the like. Based on the control program 416, the CPU 410 executes control of each part of the playback device 400, data calculation processing, and the like.

  The operation unit 430 includes a keyboard, a mouse, and the like, and is used as means for performing an operation input to the CPU 410 when the user operates the playback device 400.

  The display unit 440 includes a liquid crystal display device or the like, and is used to display video information, operation information, and the like recorded on the memory card 4 as appropriate.

  The map information recording unit 450 is composed of a recording medium such as a hard disk or a DVD, and records map information including road information and speed limit information.

  The card information recording unit 460 is configured by a recording medium such as a hard disk, and is used for recording video information, operation information, and the like recorded on the memory card 4.

  Next, a recording procedure for video information and operation information in the drive recorder 2 will be described. There are two types of recording in the drive recorder 2; recording when a predetermined recording condition is satisfied and constant recording (steady recording).

  The case where the recording condition is satisfied means the following three cases.

1. “G detection”: When the acceleration sensor 5 detects gravitational acceleration equal to or greater than a predetermined threshold. Specifically, when the gravitational acceleration in the front-rear direction of the vehicle 1 is Gy and the gravitational acceleration in the left-right direction of the vehicle 1 is Gx, the CPU 10 outputs the absolute value (Gx ² + Gy ²⁾ of the combined gravitational acceleration output from the acceleration sensor 5. ) 0 ^{- 5} was detected every 10 ms, the value of the threshold value or more acceleration, when it is detected continuously threshold duration or more, it is determined that the recording condition is established. Although the threshold acceleration can be set to 0.40 G and the threshold duration can be set to 100 milliseconds, these values are merely examples and are not limited to these.

    2. “Shooting SW”: When the shooting SW 6 is operated.

    3. “Speed trigger”: When a speed difference within a predetermined period of the vehicle 1 detected from the vehicle speed sensor 7 is equal to or greater than a threshold value. Specifically, when traveling at 60 km / h or more and the deceleration for one second becomes 14 km / h or more, it is determined that the recording condition is satisfied.

  Note that the above three recording conditions are examples, and other conditions can be used as the recording conditions.

  The operation information is the following information.

1. Gravity acceleration information (Gy, Gx) detected from the acceleration sensor 5.
2. Speed information detected from the vehicle speed sensor 7.
3. Date and time information output from the CPU 10.

  The three pieces of operation information are examples and are not limited to these.

  FIG. 6 is a diagram illustrating an example of using the recording area of the memory card 4.

  The recording area 100 of the memory card 4 includes a first area 101 in which recording information 503 is recorded when a recording condition is satisfied, a second area 102 in which recording information 503 is recorded constantly, and another area 103. Assigned. In the other area 103, the management program and management data of the memory card 6, the unique ID of the memory card 6, the ID (or name data) of the user (for example, taxi crew) who uses the memory card 6, etc. Is recorded.

  When a taxi company or the like operates and manages a plurality of vehicles and attaches the drive recorder 2 to all the vehicles, the recording conditions are established in the first area 101 in consideration of the operation status of the vehicles. In this case, the recording information 503 preferably has a recording capacity capable of recording at least 10 to 20 events, and the second area 102 preferably has a recording capacity capable of recording the recording information 503 by continuous recording for at least 8 hours. .

  FIG. 7 is a diagram illustrating an example of a recording method to the memory card.

  As described above, the image IC 11 outputs the video information 501 of 640 × 480 pixels, 30 frames / second to the RAM 12, and the RAM 12 cyclically stores the input video information for 40 seconds. The RAM 12 is also set to record operation information corresponding to each still image data. Information 502 including video information and operation information is output from the RAM 12 to the compression processing circuit 13 at a predetermined timing.

  FIG. 7 shows an example of a recording method to the memory card 4 from time T0 to time T4, and it is assumed that the recording condition is satisfied at time T2.

  When the recording condition is satisfied at time T2, the compression processing circuit 13 responds to a control signal 504 from the CPU 10 to 20 from 12 seconds before the recording condition is satisfied (time T1) to 8 seconds after the recording condition is satisfied (time T3). The video information and the operation information corresponding to the high frame rate (30 frames / second) for one second are compressed at a low compression rate (for example, 2 kbps) and recorded in the memory card 4 as the recording information 503. Output to. As a result, still image data of 30 × 20 = 600 frames from time T1 to T3 is recorded in the first area 101 of the memory card 4 with high image quality. Note that, when the recording condition is satisfied, it is not always necessary to compress and record the video information or the like on the memory card 4, and control may be performed so that the information is recorded on the memory card 4 without being compressed.

  On the other hand, in the constant recording, the compression processing circuit 13 first changes the video information from the high frame rate (30 frames / second) to the low frame rate (10 frames / second) according to the control signal 504 from the CPU 10. After that, video information at a low frame rate (10 frames / second) and operation information corresponding thereto are compressed at a high compression rate (for example, 500 kbps) and recorded in the memory card 4 with a variable compression rate. As described above, the recording information 503 is output to the IF 14. Thus, still image data at times T0 to T4 is always recorded in the second area 102 of the memory card 4 with low image quality.

  As described above, in continuous recording, video information is compressed and recorded in the memory card 4 at a low frame rate and a high compression rate, and when a predetermined recording condition is satisfied, a high frame rate and a low compression rate (or no compression). ), The video information is compressed and recorded on the memory card 4, so that information for steady recording can be recorded on the recording medium for a long time, and detailed and clear in an important period where there is a possibility of a serious accident or the like. Information can be recorded on a recording medium. That is, in the constant recording, the video information and the like are compressed and recorded on the recording medium at the first compression rate, but when the recording condition is satisfied, the second compression lower than the first compression rate. Video information and the like are compressed and recorded on a recording medium at a rate (including uncompressed).

  Note that the frame rate, the recording time, the compression rate, and the like are only examples when the above-described recording conditions are satisfied and when recording is always performed, and the present invention is not limited to these.

  In the above-described example shown in FIG. 7, recording is always performed (time T0 to T4), and recording is performed when the recording condition is satisfied (time T1 to T3). However, at times T1 to T3, recording due to the establishment of the recording condition and recording due to constant recording overlap. Therefore, in order to efficiently use the recording capacity of the memory card 4, the times T1 to T3 may be set not to always record.

  In the above-described example, when the recording condition is satisfied, the recording information 503 having a high frame rate and a high compression rate is recorded on the memory card 4 as compared with the case of the constant recording. You may make it record by.

  Furthermore, in the above-described example, the resolution (for example, 640 × 480) of the video signal output from the camera 3 is constant. However, it is also possible to use an imaging device of a type whose resolution can be changed as the camera 3 and to control the resolution to be changed by a control signal from the CPU 10. That is, in the case of continuous recording, a video signal with a low resolution (eg, 320 × 240) is output, and the resolution is changed to a high resolution (eg, 640 × 480) only when the recording condition is satisfied. To control. In the example of FIG. 7, when the recording condition is satisfied at time T2, the resolution of the camera 3 is changed to high resolution immediately after that, and high-resolution video information is recorded for the period from time T2 to T3. You can do that. By setting in this way, video information can be recorded with a smaller amount of data during constant recording.

  Further, in the above-described example, the recording is performed in a predetermined area of the memory card 4 when the recording condition is satisfied and when the recording is always performed, and when each area is full, no further recording can be performed. It was. However, it is preferable that the latest information is recorded on the memory card 4 by overwriting the oldest information when each area becomes full.

  FIG. 8 is a diagram showing a flow of an operation example of the memory card 4.

  First, the user inserts the memory card 4 into the I / F 414 of the playback device 400 and initializes the card (S1). In the initialization of the card, the data previously recorded on the memory card 4 is erased by the CPU 410, and formatting such as allocation of the first area 102 to the third area 103 as shown in FIG. 7 is performed. Further, in the third area 103, the unique ID of the memory card 4, the ID of the user (for example, a taxi crew member) using the memory card 4, or the name data is recorded.

  Next, the user reads the initialized memory card 4 at the start of operation (for example, when the taxi crew starts day shift work (7:45 to 17:15)). No. 2 I / F 14 and information recording is started (S2). Accordingly, when one of the two recording conditions described above is satisfied, the video information and the operation information are recorded in the first area 101 of the memory card 4, and the video information and the operation information by the constant recording are stored in the memory card 4. Recorded in the second area 102.

  Next, the user pulls out the memory card 6 inserted into the I / F 14 of the drive recorder 2 of the vehicle 1 at the end of the operation (for example, when the taxi manager ends the day shift work), and Inserted into the I / F 414, the recorded video information and operation information are transferred to the card information recording unit 460 of the playback device and recorded (S3), and the series of processing ends. In addition, the transfer of the data recorded on the memory card 4 to the playback device 400 is in principle performed for one operation unit of one vehicle. However, one memory card 4 may be used for a plurality of vehicles or used for a plurality of operations.

  On the playback device 400 side, the CPU 410 includes the video information and operation information when the recording conditions recorded in the memory card 4 are satisfied, and the video information and operation information recorded at all times, the ID of the read memory card, the user's The ID and the reading date / time data are added and recorded in the card information recording unit 460. Thereafter, the video information and the operation information recorded in the card information recording unit 460 can be reproduced on the display unit 440 by a predetermined operation of the operation unit 430 by the operator of the reproduction apparatus 400.

It is a figure which shows the example which mounted the drive recorder in the vehicle. It is a figure which shows the example which has arrange | positioned the drive recorder etc. in the vehicle. It is a figure which shows the example of an external appearance of a reproducing | regenerating apparatus. It is a block diagram which shows the electric constitution of a drive recorder. It is a block diagram which shows the electric constitution of a reproducing | regenerating apparatus. It is a figure which shows the usage example of the recording area of a memory card. It is a figure which shows an example of the recording method. It is the figure which showed the flow of the operation example of a memory card.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Drive recorder 3 Camera 4 Memory card 5 Acceleration sensor 6 Shooting switch 7 Vehicle speed sensor 10 CPU
11 Image IC
12 RAM
13 Compression processing circuit 14 IF
15 Non-volatile ROM,
16 Control program 18 Indicator light 400 Playback device 410 CPU
430 Operation unit 440 Display unit 450 Map information recording unit 460 Card information recording unit

Claims (3)

In a drive recorder that records information captured by an imaging unit on a recording medium,
A compression processing unit that compresses information captured by the imaging unit;
The information picked up by the image pickup means by the compression processing unit is compressed at a predetermined compression rate and steadily recorded on the recording medium, and the information picked up by the image pickup means when the predetermined recording condition is satisfied is recorded on the recording medium. A control unit controlling to record,
The drive recorder characterized by having.   The control unit steadily records information captured by the imaging unit on a recording medium at a low frame rate, and records information captured by the imaging unit on a recording medium at a high frame rate when a predetermined recording condition is satisfied. The drive recorder according to claim 1, wherein the drive recorder is controlled to record.   The control unit steadily records information captured at a low resolution by the imaging unit on a recording medium, and records information captured at a high resolution by the imaging unit on a recording medium when a predetermined recording condition is satisfied. The drive recorder according to claim 1 or 2, which is controlled as follows.

Images