JP5692894B2 - Drive recorder and video recording method of drive recorder - Google Patents

Description

  The present invention relates to a drive recorder and a video recording method thereof, and more particularly to a drive recorder that stores video information taken before and after an impact or the like occurs in a vehicle and a video recording method thereof.

  Drive recorders that continuously record information related to vehicle conditions, such as video around the vehicle and speed history, are widely used as an effective means of analyzing the situation at the time of a car accident due to a collision, mainly by transportation companies. It has been adopted. The drive recorder incorporates a CCD (Charge Coupled Device) camera (hereinafter referred to as a camera), an acceleration sensor, a card-like recording medium, etc., and constantly records images of the vehicle and surroundings from the viewpoint of the driver. doing.

  In addition, a drive recorder in which a plurality of cameras are installed so as to capture and record images related to all areas around the vehicle, such as not only the front but also the rear, right side, and left side, has been put into practical use.

  On the other hand, the recording medium of a drive recorder has a limited capacity due to the cost and the size of the drive recorder. Therefore, various ideas have been proposed so far to selectively and efficiently record the necessary video. (For example, see Patent Document 1 or Patent Document 2).

  For example, Patent Document 1 discloses an in-vehicle image recording apparatus that records on a recording medium by changing the resolution and frame rate of video captured by a camera in accordance with the speed of the vehicle. Further, Patent Document 2 discloses a drive recorder that has a plurality of cameras, but records only a video shot by any one of the arbitrarily selected cameras as a required video on a recording medium.

  According to the in-vehicle image recording apparatus disclosed in Patent Document 1, video is recorded with high image quality by increasing the resolution and frame rate only when necessary, so that the storage capacity of the recording medium can be saved. Further, according to the drive recorder disclosed in Patent Document 2, since only one video is selected and recorded among videos taken by a plurality of cameras, the storage capacity is smaller than when all videos are recorded. Significant savings.

JP-A-2006-270175, pages 7 to 13 FIG. JP, 2008-242913, A 4th page-9th page

  However, the in-vehicle image recording device disclosed in Patent Document 1 is intended to save storage capacity for video shot by one camera, and is suitable for video shot by a plurality of cameras. It did not disclose a means for saving storage capacity. In addition, the drive recorder disclosed in Patent Document 2 has a problem in that even if information useful for cause analysis of a collision or the like is included in a video captured by an unselected camera, the video is not recorded.

  Since the original purpose of installing multiple cameras in the drive recorder is to understand the situation around the vehicle in a collision, etc. in more detail, even if the degree of contribution to the cause analysis etc. is low, all images are possible Is preferably recorded.

  Therefore, the above problem is expected to be able to achieve both proper recording of video information and saving of storage capacity by adjusting the image quality of videos taken by a plurality of cameras.

  Specifically, if it is determined that the most useful information is included and the video of the selected camera is recorded with a higher quality than the standard, the video shot by the camera that was not selected is recorded with a lower quality than the standard. It is expected that video information can be recorded without omission while suppressing an increase in the amount of data to be recorded as much as possible.

  The present invention has been made in view of the above-described circumstances, and its purpose is to simultaneously record a video of a camera selected based on an external signal input and determined to contain the most useful information with high image quality. Another object of the present invention is to provide a drive recorder that can achieve both proper recording of video information and saving of storage capacity by recording low-quality video shot by a camera that has not been selected.

In order to achieve the object described above, the drive recorder according to the present invention is characterized by the following (1) .
(1) The drive recorder of the present invention is a drive recorder that records videos taken by a plurality of cameras that respectively shoot front and rear and left and right of a vehicle .
Based on an external signal, select at least one camera from the plurality of cameras,
The video shot by the selected at least one camera is recorded at a higher bit rate or frame rate or lower compression rate than the standard,
Record the video shot by the camera not selected at a lower bit rate or frame rate or higher compression rate than the standard ,
The external signal corresponding to the camera for photographing the front of the vehicle is a speed signal representing the speed of the vehicle, and the external signal corresponding to the camera for photographing the left and right of the vehicle is an input signal from a blinker. The external signal corresponding to the camera that captures the rear of the vehicle is a back signal indicating that the vehicle is moving backward, and allows a plurality of cameras to be selected .

According to the drive recorder configured as described in (1) above, images from all cameras can be recorded on a recording medium, and a limited storage area can be efficiently used to increase the recordable time. it is Ru can.

In order to achieve the object described above, the video recording method of the drive recorder according to the present invention is characterized by the following ( 2 ).
( 2 ) A video recording method for a drive recorder that records videos taken by a plurality of cameras that respectively shoot front and rear and left and right of the vehicle ,
Selecting at least one camera from the plurality of cameras based on an external signal;
Recording video captured by the selected at least one camera at a higher bit rate or frame rate or lower compression rate than the reference;
It is seen containing a step of the image captured by the not selected camera is recorded at a low bit rate or frame rate or high compression ratio than the standard, and
The external signal corresponding to the camera for photographing the front of the vehicle is a speed signal representing the speed of the vehicle, and the external signal corresponding to the camera for photographing the left and right of the vehicle is an input signal from a blinker. The external signal corresponding to the camera that captures the rear of the vehicle is a back signal indicating that the vehicle is moving backward, and allows a plurality of cameras to be selected .

According to the video recording method of the drive recorder having the configuration ( 2 ) above, video from all cameras can be recorded on the recording medium, and the limited storage area can be used efficiently and recorded. The time can be lengthened.

  According to the drive recorder and the image recording method of the drive recorder of the present invention, the video determined to be necessary for the cause analysis of the collision or the like is recorded with high quality, while the other video is recorded with low quality. The recorded video information can be recorded without omission while saving the storage capacity of the recording medium.

  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.

It is a schematic diagram which shows the apparatus example of the camera of the drive recorder in embodiment of this invention. It is a block diagram which shows schematic structure of the drive recorder in embodiment of this invention. It is a flowchart which shows the video recording operation | movement procedure of the drive recorder in embodiment of this invention.

  Hereinafter, a drive recorder according to an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing an example of a camera of a drive recorder according to an embodiment of the present invention. The drive recorder according to the present embodiment includes four cameras at positions where the front (camera A11), right (camera B12), left (camera C13), and rear (camera D14) of a vehicle such as a large truck can be appropriately photographed. doing.

  Next, FIG. 2 is a block diagram showing a schematic configuration of the drive recorder in the embodiment of the present invention. The drive recorder 100 mainly includes a camera A11, a camera B12, a camera C13, a camera D14, a CPU (Central Processing Unit) 30, a storage unit 40, an SDRAM (Synchronous Dynamic Random Access Memory) 50, an external signal input unit 60, and the like. Composed.

  Cameras A11 to D14 are CCD cameras that are capable of photographing the four directions of the front, right side, left side, and rear of the vehicle, and shoot images of each region. The cameras A11 to D14 are connected to the CPU 30 via the interfaces 21 to 24, respectively.

  The CPU 30 is a control unit that performs overall control of the operation of the drive recorder 100, and controls various operations such as individual recording operations of images captured by the four cameras. Specifically, in the case where the video once stored in the storage unit 40 described later from four cameras is recorded with high image quality (a frame rate or a bit rate or a lower compression rate than the reference), Recording to the SDRAM 50 at a bit rate or compression rate. On the other hand, when recording with low image quality (lower frame rate or bit rate or higher compression rate than the standard), the CPU 30 lowers the frame rate or bit rate (that is, performs thinning) or increases the compression rate to the SDRAM 50. Record.

  The storage unit 40 plays a role as temporary storage (buffer) for storing the video captured by the cameras A11 to D14 in the SDRAM 50. The SDRAM 50 is a readable / writable recording medium, and the video stored in the storage unit 40 is recorded at a predetermined interval. The storage area of the SDRAM 50 is sequentially recorded with video until the capacity is full, but after that, a new video is overwritten, so the old recording is sequentially erased.

  The external signal input unit 60 detects external signal inputs such as a speed signal 61, a back signal 62, a right winker 63, and a left winker 64, and transmits them to the CPU 30. As will be described later, the CPU 30 selects a camera that records video with high image quality in accordance with the type of external signal input.

  Next, the video recording operation of the conventional drive recorder 100 having the above configuration will be described.

  FIG. 3 is a flowchart showing a video recording operation procedure of the drive recorder in the embodiment of the present invention. First, when the drive recorder 110 starts a video recording operation (step S101), the CPU 30 determines whether or not the input signal level from the external signal input unit 60 related to the cameras A11 to D14 is Hi (step S102). ). If the input level of the external signal is Hi, the CPU 30 changes the bit rate or frame rate or compression rate of the corresponding camera and switches to a mode for recording video with high image quality (step S103).

  In the drive recorder of the present embodiment, the frame rate or bit rate or compression rate that the camera A11 to camera D14 normally shoot is set as the frame rate or bit rate or compression rate in the high image quality mode. In the SDRAM 50, the video temporarily stored in the storage unit 40 is recorded as it is.

  For example, if there is a signal input from the left winker 64 to the external signal input unit 60, it can be seen that the vehicle is about to turn left, so the CPU 30 records the video image taken by the camera C13 installed on the left side of the vehicle with high image quality. Switch to the mode you want. When turning left, accidents involving motorcycles entering from the left rear of the vehicle are likely to occur, so if you record video information on the left side of the vehicle with high image quality, a more detailed cause analysis will occur It is because it can do.

  Next, the CPU 30 determines whether or not the input signal level from the external signal input unit 60 is Lo (step S104). When the input level of the external signal is Lo, the CPU 30 returns the bit rate or frame rate or compression rate of the corresponding camera to the initial value, and switches to the mode for recording the video with the original image quality (low image quality) (step S105). ).

  In the drive recorder of the present embodiment, a lower predetermined frame rate or bit rate or higher predetermined compression rate than that normally taken by the camera A11 to camera D14 is set to a frame rate or bit rate or compression rate in the low image quality mode. Therefore, the CPU 30 performs the image quality reduction processing on the video temporarily stored in the storage unit 40, and the processed video is stored in the SDRAM 50.

  For example, when the signal input of the left winker 62 in the external signal input unit 60 drops from Hi to Lo, it can be seen that the left turn of the vehicle has ended, so the CPU 30 captures an image captured by the camera C13 installed on the left side of the vehicle. Switch to a low-quality recording mode. For example, in a situation where the vehicle goes straight after the left turn, the usefulness of the video information on the left side is lower than that at the time of the left turn.

  When the recording mode is switched to the normal image quality (low image quality) in step S105, the process returns to step S102 and the above procedure is repeated.

  As described above, in the drive recorder according to the embodiment of the present invention, when the input of the speed signal 61 becomes Hi, the camera A11 installed for front photographing is selected as a camera for recording in the high image quality mode, and the others are low in image quality. The camera is determined to record in the mode. When the input of the back signal 62 becomes Hi, the camera D14 installed for rearward shooting is selected as a camera for recording in the high image quality mode, and the others are determined as cameras for recording in the low image quality mode. Further, when the signal input of the right winker 63 becomes Hi, the camera B12 installed for right-side shooting is selected as a camera for recording in the high image quality mode, and the others are determined as cameras for recording in the low image quality mode. Further, when the signal input of the left winker 64 becomes Hi, the camera C13 installed for the left photographing is selected as a camera for recording in the high image quality mode, and the other is determined as the camera for recording in the low image quality mode.

  That is, even for cameras that are not selected by external signal input, all images captured by these cameras with low image quality are recorded in the SDRAM 50. For this reason, video information can be recorded without omission within the shooting range of the installed camera, regardless of the direction of the accident. In addition, since the image quality is kept low, the required storage capacity can be reduced and the recording medium can be used efficiently.

  Here, the setting of the difference between the high image quality and the low image quality will be specifically described. In the drive recorder according to the embodiment of the present invention, the standard for high image quality and low image quality is determined depending on whether the vehicle is traveling at high speed or low speed. For example, when shooting a front image of a vehicle that is traveling at a speed of 60 km / h or higher, the frame rate or bit rate or compression rate of the image is sufficient to use the image for cause analysis of an accident or the like. To calculate. The calculated predetermined frame rate or bit rate or compression rate is set as the frame rate or bit rate or compression rate in the “high quality mode”. On the other hand, when a front image of a vehicle traveling at a speed of less than 60 km / h is taken, a frame rate or a bit rate or a compression rate of the image sufficient to use the image for cause analysis of an accident or the like is experimentally calculated. The calculated predetermined frame rate or bit rate or compression rate is set as the frame rate or bit rate or compression rate in the “low image quality mode”. By recording video with high image quality when traveling at high speed, necessary information can be collected without omission.

  In the drive recorder according to the embodiment of the present invention, the high image quality and low image quality standards can be determined depending on whether the vehicle is traveling at night or during daytime. For example, when shooting a front image of a vehicle that is traveling under conditions where the brightness around the vehicle is less than the standard (nighttime) with a predetermined brightness as a reference, the image is sufficient to use for the cause analysis of an accident, etc. Experimentally calculate the frame rate or bit rate or compression rate of the correct video. The calculated predetermined frame rate or bit rate or compression rate is set as the frame rate or bit rate or compression rate in the “high quality mode”. On the other hand, when shooting a front image of a vehicle that is running under conditions where the brightness around the vehicle is higher than the standard (daytime), the frame rate or bit rate of the image is sufficient to use the image for cause analysis of an accident or the like. Alternatively, the compression ratio is experimentally calculated. The calculated predetermined frame rate or bit rate or compression rate is set as the frame rate or bit rate or compression rate in the “low image quality mode”. Necessary information can be collected without omission by recording images with high image quality during night driving.

  In the present embodiment, an example in which only one of the signal inputs to the external signal input unit 60 is Hi has been described. However, the present invention is not limited to this example. It is good also as a structure which records simultaneously the image | video of both cameras B12 which image | photograph the right side with high image quality.

  As described above, the drive recorder according to the embodiment of the present invention equipped with a plurality of cameras records the video selected according to some condition with high image quality, and records all other video with low image quality. Therefore, it is possible to achieve both high image quality of necessary video information and reduction in storage capacity.

  The drive recorder according to the present invention can achieve both proper recording of video information taken by all cameras and saving of storage capacity by recording necessary video with high image quality and other video with low image quality. It is useful in a drive recorder having a plurality of cameras.

11 Camera A
12 Camera B
13 Camera C
14 Camera D
30 CPU
40 storage unit 50 SDRAM
60 External signal input unit 100 Drive recorder

Claims (2)

In a drive recorder that records video taken by a plurality of cameras that shoot front and rear and left and right of the vehicle ,
Based on an external signal, select at least one camera from the plurality of cameras,
The video shot by the selected at least one camera is recorded at a higher bit rate or frame rate or lower compression rate than the standard,
Record the video shot by the camera not selected at a lower bit rate or frame rate or higher compression rate than the standard ,
The external signal corresponding to the camera for photographing the front of the vehicle is a speed signal representing the speed of the vehicle, and the external signal corresponding to the camera for photographing the left and right of the vehicle is an input signal from a blinker. The external signal corresponding to the camera that captures the rear of the vehicle is a back signal indicating that the vehicle is moving backward, and allows a plurality of cameras to be selected. Drive recorder. A video recording method of a drive recorder that records video shot by a plurality of cameras that respectively shoot front and rear and left and right of a vehicle ,
Selecting at least one camera from the plurality of cameras based on an external signal;
Recording video captured by the selected at least one camera at a higher bit rate or frame rate or lower compression rate than the reference;
It is seen containing a step of the image captured by the not selected camera is recorded at a low bit rate or frame rate or high compression ratio than the standard, and
The external signal corresponding to the camera for photographing the front of the vehicle is a speed signal representing the speed of the vehicle, and the external signal corresponding to the camera for photographing the left and right of the vehicle is an input signal from a blinker. The external signal corresponding to the camera that captures the rear of the vehicle is a back signal indicating that the vehicle is moving backward, and allows a plurality of cameras to be selected. A video recording method for a drive recorder.

Images