JP2020160690A - Video recording device and video recording method - Google Patents

Abstract

To provide a video recording device and video recording method that can specify a situation where tailgating driving was performed after the fact.SOLUTION: The video recording device includes: a recording unit that records vehicle neighborhood video generated by a first camera installed at a predetermined position of a vehicle; an event detection unit that detects a first event occurred in the vehicle; a tailgating detection unit that detects tailgating driving that the vehicle suffers as a second event based on the vehicle neighborhood video; a protection period setting unit that, in a case where the event detection unit detects the first event, sets a first protection period based on a detection time of the first event, and in a case where the tailgating detection unit detects the second event, sets a second protection period longer than the first protection period based on a detection time of the second event; and a protection unit that protects video generated in each of the first protection period and the second protection period set by the protection time setting unit in the vehicle neighborhood video.SELECTED DRAWING: Figure 2

Description

The present invention relates to a video recording device and a video recording method.

A running vehicle may be extremely close to other vehicles. Such an act of another vehicle is one of high-risk acts called driving. Patent Document 1 discloses a drive recorder that records an image of another vehicle that has been driven by driving when it is driven by another vehicle.

However, there was room for improvement in recording the vehicle surrounding image so that the situation in which the road rage was performed can be identified after the fact.

JP-A-2018-112892

An object of the present invention is to provide a video recording device and a video recording method capable of ex post facto identification of a situation in which a driving operation is performed.

The image recording device according to the present invention includes a recording unit that records a vehicle peripheral image of the surroundings of the vehicle generated by a first camera installed at a predetermined position of the vehicle, and a first image generated by the vehicle. An event detection unit that detects an event, a fan detection unit that detects the fan driving received by the vehicle as a second event based on the captured vehicle peripheral image, and the event detection unit detects the first event. If so, the first protection period is set based on the detection time of the first event, and when the fan detection unit detects the second event, the first protection period is based on the detection time of the second event. Generated in each of the first protection period and the second protection period set by the protection time setting unit in the protection period setting unit that sets a longer second protection period and the vehicle peripheral image recorded by the recording unit. It is provided with a protection unit that protects the image.

The present invention can record an image capable of ex post facto identification of the situation of a vehicle that has been driven by a fan.

It is the schematic of the vehicle equipped with the image recording apparatus according to Embodiment 1 of this invention. It is a functional block diagram which shows the structure of the image recording apparatus according to Embodiment 1 of this invention. It is a flowchart which shows the outline of the operation of the image recording apparatus according to Embodiment 1 of this invention. It is a flowchart for demonstrating the operation of the fanning detection part. It is a figure which shows the positional relationship between own vehicle and other vehicle at the time of fanning detection. This is an example of an image of another vehicle photographed at time T1. This is an example of an image of another vehicle photographed at time T2. It is a figure explaining an example of the operation of the protection period setting part. It is a functional block diagram which shows the structure of the image recording apparatus by 2nd Embodiment of this invention. It is a figure explaining one operation of an interval acquisition part and time correction part. It is a figure explaining one operation of an interval acquisition part and time correction part. It is a figure explaining one operation of an interval acquisition part and time correction part. It is a functional block diagram which shows the structure of the image recording apparatus according to the 3rd Embodiment of this invention. It is an example of the time change of the relative distance D and the relative speed V when it is not detected as a driving operation. It is an example of the time change of the relative distance D and the relative velocity V when a high fanning intensity is detected. It is an example of the time change of the relative distance D and the relative velocity V when a high fanning intensity is detected. This is an example of correction of the second protection period. This is an example of correction of the second protection period. This is an example of correction of the second protection period.

[Embodiment 1]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated. The present invention is not limited to the embodiments shown below. In addition, these examples of implementation are merely examples, and the present invention can be implemented in a form in which various modifications and improvements have been made based on the knowledge of those skilled in the art.

FIG. 1 shows a video recording system 100 equipped with a video recording device according to an embodiment of the present invention. As shown in FIG. 1, the video recording system 100 is mounted on the own vehicle 1. The video recording system 100 includes a camera 10, a video recording device 20, a sensor unit 30, an operation unit 40, and a communication bus 50. Although each component of the video recording system 100 is described using a solid line for the sake of explanation, it is actually arranged inside the own vehicle 1.

In the following description, the direction with respect to the own vehicle 1 is defined as follows in combination with the description in FIG. The "forward" of the vehicle is the straight-ahead direction of the own vehicle 1. The "rear" of the own vehicle 1 is the opposite direction of the "front". That is, the direction used in the following description corresponds to the generally used front-rear direction when the person sitting in the driver's seat is facing the traveling direction through the windshield.

The camera 10 is installed at a predetermined position of the own vehicle 1 and generates a vehicle peripheral image in which an image of the surroundings of the own vehicle 1 is captured. The camera 10 is, for example, a digital video camera having an image sensor and a lens. The camera 10 has a wide-angle lens having a wide angle of view in order to take a wide image of the periphery of the own vehicle 1 with one camera.

In FIG. 1, the camera 10a is a front camera installed in front of the own vehicle 1 and mainly taking a picture of the front of the own vehicle 1. The camera 10b is a rear camera installed behind the own vehicle 1 and mainly taking a picture of the rear of the own vehicle 1. The own vehicle 1 may be equipped with one camera 10 or three or more cameras 10.

The camera 10 is connected to the video recording device 20 via the communication bus 50. The camera 10 outputs the generated vehicle peripheral image to the image recording device 20.

The image recording device 20 records and protects the vehicle peripheral image generated by the camera 10. Details will be described later.

The sensor unit 30 detects various states of the own vehicle 1. The sensor unit 30 has, for example, an acceleration sensor. The sensor unit 30 is connected to the video recording device 20 via the communication bus 50. The sensor unit 30 detects various states of the own vehicle 1 with an acceleration sensor or the like, and outputs sensor signals corresponding to the detected states to the video recording device 20.

The operation unit 40 is mounted on the own vehicle 1 and receives a user's operation on the video recording device 20. The operation unit 40 has, for example, a touch panel, a push button switch, and the like. The operation unit 40 is connected to the video recording device 20 via the communication bus 50. The operation unit 40 receives an operation by the user and outputs an operation signal corresponding to the accepted operation to the video recording device 20.

The communication bus 50 connects functional blocks such as the sensor unit 30 and the operation unit 40 with the video recording device 20 by wire. For the communication bus 50, for example, CAN (Controller Area Network) or LIN (Local Interconnect Network) is used. When the video recording device 20, the sensor unit 30, and the operation unit 40 are arranged at a relatively short distance from each other, the communication bus may include, for example, I2C (Inter-Integrated Circuit) or SPI (Serial Peripheral Interface). May be used. The video recording device 20, the sensor unit 30, and the operation unit 40 may perform wireless communication by WiFi (Wireless Fidelity), Bluetooth (registered trademark), or the like.

The video recording device 20, the sensor unit 30, and the operation unit 40 may be configured as an integrated device. The camera 10 is attached to the own vehicle 1 separately from the integrated device, and is connected to the integrated device by wire or wirelessly. Such a configuration may be used.

<1.1. Configuration of video recording device>
Next, the configuration of the video recording device 20 according to the first embodiment will be described with reference to FIG. FIG. 2 is a functional block diagram of the video recording device 20. The video recording device 20 includes an event detection unit 210, an acquisition unit 220, a recording unit 230, a fanning detection unit 240, a protection period setting unit 250, a protection unit 260, and a storage unit 270.

The video recording device 20 is, for example, a microcomputer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output port, and the like.

The CPU of the microcomputer executes each functional block included in the video recording device 20 by reading and executing a program stored in the ROM, for example. It should be noted that at least one or all of each functional block may be configured by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

The event detection unit 210 detects the first event for the vehicle. The details of the first event will be described later. The event detection unit 210 is connected to the sensor unit 30 and the operation unit 40 via the communication bus 50. The event detection unit 210 notifies the protection period setting unit 250 that the first event has been detected.

The acquisition unit 220 acquires the vehicle peripheral image generated by the camera 10 from the camera 10, and outputs the acquired vehicle peripheral image to the fan detection unit 240 and the recording unit 230. When the camera is analog, the acquisition unit 220 may have an AD converter (Analog to Digital converter) (not shown). The AD converter acquires the vehicle peripheral image by digitally converting the analog signal. The vehicle peripheral image is a moving image including a plurality of image frames. That is, the acquisition unit 220 acquires a video frame at a predetermined frame rate, and outputs the acquired video frame to the fanning detection unit 240 and the recording unit 230. The frame rate is, for example, 1/60 second.

The recording unit 230 records the vehicle peripheral image acquired by the acquisition unit 220. The recording unit 230 encodes the vehicle peripheral image and records it in the storage unit 270. Specifically, the recording unit 230 encodes the vehicle peripheral image using an image compression method such as MPEG (Moving Picture Expert Group).

The fanning detection unit 240 detects the fanning driving received by the vehicle as a second event based on the vehicle peripheral image acquired by the acquisition unit 220. The fanning detection unit 240 notifies the protection period setting unit 250 that the detected second event has been detected.

The protection period setting unit 250 sets a protection period for specifying the vehicle peripheral image to be protected among the vehicle peripheral images recorded by the recording unit 230. Specifically, when the event detection unit 210 detects the first event, the protection period setting unit 250 sets the first protection period based on the detection time of the first event. Further, the protection period setting unit 250 sets a second protection period longer than the first protection period based on the detection time of the second event when the fanning detection unit 240 detects the second event. The protection period setting unit 250 outputs the set protection period to the protection unit 260.

The protection unit 260 protects the vehicle peripheral image recorded in the recording unit 270 based on the first protection period and the second protection period set by the protection period setting unit 250. Specifically, the protection unit 260 protects the vehicle peripheral image generated by the camera 10 in each of the first protection period and the second protection period set by the protection period setting unit 250. The protection unit 260 records the protection information related to the protection of the image around the vehicle as the image protection information in the storage unit 270. The protection information includes a first protection period and a second protection period set by the protection period setting unit 250.

The storage unit 270 is a non-volatile storage device, and stores the vehicle peripheral image recorded by the recording unit 230 and the image protection information recorded by the protection unit 260. The storage unit 270 includes a video recording area 271 which is a ring buffer for recording video around the vehicle and a management area 272 for recording video protection information. The storage unit 270 is composed of, for example, a semiconductor storage device such as a flash memory or an SD card (Secure Digital Card), or a magnetic storage device such as an HDD (Hard Disk Drive).

<1.2. Operation of video recording device>
The outline of the operation of the video recording device 20 will be described with reference to FIG. FIG. 3 is a flowchart showing an outline of the video recording process of the video recording device 20.

The video recording device 20 repeatedly executes this flowchart at a predetermined cycle during the period when the ignition signal of the own vehicle 1 is ON. The video recording device 20 may repeatedly execute this flowchart at a predetermined cycle while the power switch of the video recording device 20 is turned on by the user's operation. The predetermined cycle is, for example, a 1/60 second cycle equal to the frame rate of the vehicle peripheral image generated by the camera 10.

When the ignition signal of the own vehicle 1 is turned off, the video recording device 20 stops the processing of this flowchart. The video recording device 20 may stop the processing of this flowchart when the power switch of the video recording device 20 is turned off by the user's operation.

The video recording device 20 records the vehicle peripheral image acquired by the acquisition unit 210 in the image storage area 271 of the storage unit 270 (step S101). The video storage area 271 is a ring buffer. The video storage area 271 includes an overwriteable area and a protected area, and the video recording device 20 records the vehicle peripheral image in the overwriteable area. When the entire area of the overwritable area is used, the video recording device 20 overwrites the newly acquired vehicle peripheral image on the vehicle peripheral image recorded most in the overwriteable area.

The video recording device 20 determines whether or not at least one of the first event and the second event has been detected (step S102).

Specifically, when the event detection unit 210 receives a sensor signal indicating an acceleration larger than a predetermined threshold value from the sensor unit 30, it determines that the first event has been detected. The predetermined threshold value is used to determine whether or not the driver of the own vehicle 1 has applied a sudden brake. Further, when the event detection unit 210 receives an operation signal indicating a predetermined operation from the operation unit 40, the event detection unit 210 determines that the first event has been detected.

When the fanning detection unit 240 detects the fanning operation, it determines that the second event has been detected.

When both the first event and the second event are not detected (step S102: No), the video recording device 20 ends the process.

On the other hand, when at least one of the first event and the second event is detected (step S102: Yes), the video recording device 20 determines whether or not the detected event is the first event (step S103).

When the detected event is the first event (step S103: Yes), the video recording device 20 sets the first protection period as the protection period (step S104a).

When the detected event is the second event (step S103: No), the video recording device 20 sets the second protection period as the protection period (step S104b). The length of the second protection period is longer than the length of the first protection period.

When the protection period is set (after step S104a and step S104b), the video recording device 20 protects the vehicle peripheral image based on the set protection period (step S105). The video recording device 20 newly changes the overwriteable area in the video recording area 271 in which the vehicle peripheral image generated in the set protection period is recorded to the protection area. Details will be described later.

As described above, the video recording device 20 protects the vehicle peripheral image generated during the second protection period when the vehicle is driven by driving. In addition, the length of the second protection period when receiving a fanning operation is set longer than the first protection period which is protected in the case of sudden braking or the like.

As a result, the video recording device 20 can record a video that can identify the situation of the vehicle that has been driven in a hurry after the fact.

The detection of the first event by the event detection unit 210 will be described in detail. As described above, the detection is performed based on the first event, the sensor signal received from the sensor unit 30, and the operation signal corresponding to the user's operation received from the operation unit 40.

When the event detection unit 210 receives a sensor signal whose acceleration exceeds a predetermined threshold value, it determines that the first event has been detected. A predetermined threshold value is set for each of the front-rear direction, the left-right direction, and the up-down direction of the own vehicle 1. For example, the front-back threshold is used to detect sudden braking and sudden acceleration. The threshold value in the left-right direction is used to detect a sharp turn of the own vehicle 1. The vertical threshold value is used to detect the rollover, capsizing, etc. of the own vehicle 1. The event detection unit 210 may use the threshold value in at least one of these three directions.

When the event detection unit 210 receives a predetermined operation signal for the video recording device 20 from the operation unit 40, the event detection unit 210 detects the first event. Specifically, the event detection unit 210 determines that the first event has been detected when it receives an operation signal indicating that a button instructing image protection is pressed.

The event detection unit 210 outputs to the protection period setting unit 250 whether or not the first event has been detected.

Next, the overwriteable area and the protected area set in the video recording area 271 will be described. The recording unit 230 records the encoded vehicle peripheral image in the overwriteable area of the image recording area 271 of the storage unit 270. The video recording area 271 includes an overwriteable area and a protected area. Which of the areas to be recorded corresponds to is identified by referring to the video protection information recorded in the management area 272.

First, the recording unit 230 records the vehicle peripheral image in the unrecorded area of the image recording area 271. The unrecorded area is an overwriteable area.

Next, consider the case where there is no unrecorded area in the video recording area 271. The video recording area 271 is used as a ring buffer. Therefore, when all the areas of the video recording area 271 are used, the recording unit 230 transmits the vehicle peripheral image generated this time to the area in which the vehicle peripheral image having the oldest recording time is recorded among the overwriteable areas. Overwrite and record.

The recording unit 230 does not overwrite the protected area designated by the video protection information in the video recording area 271. The recording unit 230 overwrites the vehicle peripheral image generated this time on an overwriteable area different from the protected area.

As a result, the vehicle peripheral image recorded in the protected area is protected without being overwritten by the recording unit 230.

Next, the detection of the second event by the fan detection unit 240 will be described in detail. The operation of the fan detection unit 240 will be described with reference to FIG. FIG. 4 is a flowchart showing the operation of the fan detection unit 240.

First, the fanning detection unit 240 acquires the vehicle peripheral image from the acquisition unit 220 (step S201).

Next, the fanning detection unit 240 detects the target vehicle for detecting whether or not the fanning driving is being performed from the acquired vehicle peripheral image (step S202). The target vehicle is another vehicle running following the own vehicle. The fan detection unit 240 detects the target vehicle by using pattern matching. A known method other than pattern matching may be used. Further, the detection of the image corresponding to the target vehicle may be performed instead of the detection of the target vehicle itself. For example, the shadow of the target vehicle falling on the following road surface may be detected.

The fanning detection unit 240 determines whether or not the target vehicle is driving in a fanning manner based on the inter-vehicle distance D between the target vehicle and the own vehicle (step S203). Specifically, when the distance between the target vehicle and the own vehicle is short, the fanning detection unit 240 determines that the target vehicle is driving in a fanning manner. Whether or not the inter-vehicle distance is short is determined by whether or not the inter-vehicle distance is smaller than the predetermined threshold distance Dth.

The detection of the driving operation will be described in detail with reference to FIG. FIG. 5 is a diagram showing the positional relationship between the own vehicle 1 and the target vehicle 2 at times T1 and T2.

At time T1, the inter-vehicle distance D between the own vehicle 1 and the target vehicle 2 is the distance D1. As shown in the figure, the inter-vehicle distance is the distance between the rear end of the vehicle (in this case, the own vehicle 1) and the front end of the following vehicle (in this case, the target vehicle 2). Since the distance D1 is longer than the threshold distance Dth at the time T1, the fanning detection unit 240 determines that the target vehicle 2 is not driving the fanning at the time T1.

On the other hand, at time T2, the inter-vehicle distance between the own vehicle 1 and the target vehicle 2 is a distance D2 shorter than the distance D1. Since the distance D2 is shorter than the threshold distance Dth at the time T2, the fan detection unit 240 determines that the target vehicle 2 is driving the fan at the time T2.

That is, as shown in FIG. 5, when the target vehicle 2 travels behind the own vehicle 1 in a region which is behind the rear end surface of the own vehicle 1 and closer to the own vehicle 1 than the threshold distance Dth. In addition, the fanning detection unit 240 determines that the target vehicle 2 is driving the fanning.

The fanning detection unit 240 actually detects the fanning driving without directly obtaining the inter-vehicle distance D. The fanning detection unit 240 determines whether or not the target vehicle 2 is traveling in the proximity region Ap where the inter-vehicle distance D is smaller than the threshold distance Dth, and determines whether or not the target vehicle 2 is traveling, and whether or not the vehicle is driving. To judge. Specifically, when the target vehicle is shown in the area corresponding to the proximity region Ap in the vehicle peripheral image, the fanning detection unit 240 determines that the target vehicle 2 is driving in a fanning manner.

The determination of the inter-vehicle distance will be described with reference to FIGS. 6 and 7. FIG. 6 is a vehicle peripheral image PIC1 generated by the camera 10a at time T1. FIG. 7 is a vehicle peripheral image PIC2 generated at time T2. The own vehicle 1 and the target vehicle 2 are shown in the vehicle peripheral images PIC1 and PIC2 at any time.

The fanning detection unit 240 sets the distance reference line Lth and the fanning detection area Ath on the vehicle peripheral image. The distance reference line Lth corresponds to the threshold distance Dth in the vehicle peripheral image. Further, the fanning detection region Ath is a region corresponding to the proximity region Ap in the vehicle peripheral image. The distance reference line Lth is calculated based on the threshold distance Dth, the mounting position of the camera, the mounting direction, and the distortion of the camera optical system. In the vehicle peripheral images PIC1 and PIC2, the distance reference line Lth extends in the lateral direction in the vehicle peripheral image and is arranged below the center line that equally divides the vehicle peripheral image vertically. The fanning detection area Ath is set as an area below the distance reference line Lth in the vehicle peripheral image.

When the target vehicle 2 is partially reflected in the fan detection area Ath, the fan detection unit 240 determines that the inter-vehicle distance D between the vehicle 1 and the target vehicle 2 is smaller than Dth, and the target vehicle 2 is driven by the fan. Is determined to be performed.

In the vehicle peripheral image PIC1 (see FIG. 6) generated at time T1, the target vehicle 2 is located above the distance reference line Lth, and the target vehicle 2 is not reflected in the fanning detection area Ath. Therefore, the fanning detection unit 240 determines that the inter-vehicle distance D is smaller than the threshold distance Dth, and determines that the target vehicle 2 is not driving in the fanning.

In the vehicle peripheral image PIC2 (see FIG. 7) generated at time T2, the lower end of the target vehicle 2 is located below the distance reference line Lth, and the target vehicle 2 is reflected in the fanning detection area Ath. Therefore, the fanning detection unit 240 determines that the inter-vehicle distance D is smaller than the threshold distance Dth, and determines that the target vehicle 2 is driving in a fanning manner.

In the vehicle peripheral images PIC1 and PIC2, the distance reference line Lth is shown as a straight line, but this is not the case. The distance reference line Lth may be a curved line reflecting distortion of the optical system or the like.

Further, it may be set as a predetermined area instead of being divided by the distance reference line Lth. For example, the fanning detection area Ath may be set only in the lane in which the own vehicle 1 travels. As a result, it is possible to suppress erroneous detection of vehicles in adjacent lanes.

Returning to FIG. 4, when the inter-vehicle distance D between the target vehicle and the own vehicle is smaller than the threshold distance Dth (step S203: Yes), the fan detection unit 240 sets the fan detection state to "detection" (step S204a). ). When the inter-vehicle distance D is equal to or greater than the threshold distance Dth (step S203: No), the fan detection unit 240 sets the fan detection state to "not detected" (step S204b).

Next, it is determined whether or not the fanning detection state has changed from "undetected" to "detected" (step S205). When it is determined that the fanning detection state has not changed (step S205: No), the fanning detection unit 240 ends the process. When the fanning detection state changes from "not detected" to "detection" (step S205: Yes), the fanning detection unit 240 determines that the second event has been detected (step S206), and ends the process.

As described above, the fanning detection unit 240 according to the present embodiment determines that the second event has been detected when the fanning detection state changes from "detected" to "not detected". This is because it is considered useful to protect the image around the vehicle before it is fanned in order to identify the state of the fanned driving after the fact.

It should be noted that the second event may be detected even when the fanning detection state changes from "detected" to "undetected". For example, when there is a margin in the free space of the storage unit 270, the fanning detection unit may detect the change from "detection" to "undetected" in the fanning detection state by performing a second event.

Next, with reference to FIG. 8, the protection period used for protecting the image around the vehicle will be described in detail. FIG. 8 is a diagram showing the setting of the protection period for each of the first event and the second event.

Consider the case where the event detection unit 210 detects the first event. In this case, the protection period setting unit 250 sets the first protection period P1 based on the detection time T1r of the first event. The first protection period P1 is a period from the start time T1s to the end time T1e, and includes the detection time T1r of the first event. The protection period setting unit 250 sets the start time T1s to be a time earlier than the detection time T1r by a predetermined time, and sets the time after a predetermined time from the detection time T1e of the first event to the end time T1e. The predetermined time used for setting the start time T1s and the predetermined time used for setting the end time T1e may be the same or different.

Next, consider the case where the fan detection unit 240 detects the second event. In this case, the protection period setting unit 250 sets the second protection period P2 based on the detection time T2r of the second event. The second protection period P2 is longer than the first protection period P1. The second protection period P2 is a period from the start time T2s to the end time T2e, and includes the detection time T2r of the second event. The protection period setting unit 250 sets the start time T2s to be a time earlier than the detection time T2r of the second event by a predetermined time, and sets the time after a predetermined time from the detection time T2r to the end time T2e. The predetermined time used for setting the start time T2s and the predetermined time used for setting the end time T2e may be the same or different.

At this time, the time from the start time T2s to the detection time T2r in the second protection period P2 is longer than the time from the start time T1s to the detection time T1r in the first protection period P1. This makes it possible to identify the situation before the driving is detected after the fact.

When recording a first event indicating the occurrence of a sudden braking or a sharp turn, the period including the first event is often set to about several tens of seconds.

On the other hand, in order to identify the state of the driving operation after the fact, it is preferable to protect the past image for a long time in units of several minutes from the timing when the driving operation is determined. This is because it is possible to confirm how the target vehicle to be driven by the road rage behaves before the road rage.

The protection unit 260 protects the image generated by the camera 10 in the protection period set by the protection period setting unit 250 among the vehicle peripheral images recorded in the storage unit 270. Specifically, the protection unit 260 specifies an address range indicating an area in which the vehicle peripheral image to be protected is recorded based on the protection period set by the protection period setting unit 250, and the image including the specified address range. The protection information is stored in the storage unit 270.

Specifically, the address range includes at least a protection start address and a protection end address. In the video recording area 271, the area from the protection start address to the protection end address is identified as a protection area. The protection unit 260 refers to the video recording area 271 and acquires the area of the video recording area 271 in which the vehicle peripheral image generated by the camera 10 is recorded during the protection period. The protection unit 260 generates video protection information based on the start address and end address of the area. The protection unit 260 records the generated video protection information in the management area 272 of the storage unit 270, and updates the video protection information in the management area 272. As a result, the area of the video recording area 271 that records the vehicle peripheral image set as the protection area in the protection period setting unit 250 this time is newly changed from the overwriteable area to the protected area and excluded from the overwriteable area.

<1.3. Effect of video recording device>
Next, the effect of the video recording device according to the first embodiment will be described.

The video recording device 20 according to the first embodiment detects the first event that occurs in the vehicle, and detects the driving that the vehicle receives as the second event based on the captured vehicle peripheral image.

When the video recording device 20 detects the first event, the first protection period is set based on the detection time of the first event, and when the second event is detected, the detection time of the second event is set. Based on this, a second protection period longer than the first protection period is set.

The video recording device 20 protects the video generated in each of the first protection period and the second protection period set by the protection time setting unit.

As a result, the video recording device 20 can record a video that can identify the situation of the vehicle that has been driven in a hurry after the fact. In addition, an appropriate protection period can be set according to the event type, and the video recording device 20 can efficiently use the storage unit 270.

Further, the video recording device 20 sets the time from the start time of the second protection period to the detection time of the second event longer than the time from the start time of the first protection period to the detection time of the first event.

As a result, the video recording device 20 can protect the state of the vehicle before it is detected as a road rage for a long time, and can record a video that makes it easier to identify the situation of the vehicle that has performed the road rage after the fact. it can.

<Modification example>
A modified example of the first embodiment will be described.

The recording unit may record the vehicle peripheral image by dividing it into files of a predetermined size. For example, the recording unit can divide and record the vehicle peripheral image so that the recording time per file is 20 minutes. In this case, the protection unit 260 may prohibit overwriting of all files including the protection period.

For example, assume that the protection period is 1 minute and the file partition size is every 20 minutes. In this assumption, if the protection period is all included in one file, the protection unit prohibits overwriting of one file including the protection period. The protection department prohibits the overwriting of two files including the protection period.

[Embodiment 2]
<2.1. Configuration of video recording device>
Next, the configuration of the video recording device 20 according to the second embodiment of the present invention will be described with reference to FIG. The description of the configuration overlapping with the first embodiment will be omitted. FIG. 9 is a functional block diagram of the video recording device 20. The video recording device 20 according to the second embodiment further includes an interval acquisition unit 310 and a time correction unit 320.

The recording unit 230 according to the second embodiment acquires the fanning detection state from the fanning detection unit 240, and records the acquired fanning detection state in the storage unit 270 together with the vehicle peripheral image.

The protection period setting unit 250 according to the second embodiment outputs the set protection period to the interval acquisition unit 310.

The interval acquisition unit 310 acquires the time interval between the protection period set when the previous event occurred and the time when the current event occurs. The details of the acquisition time interval will be described later. The interval acquisition unit 310 outputs the acquired time interval and the protection period set based on this event to the time correction unit 320.

The time correction unit 320 corrects the start time of the protection period set based on the current event based on the time interval acquired by the interval acquisition unit 310. The time correction unit 320 outputs the corrected protection period to the protection unit 260.

<2.2. Operation and effect of video recording device>
Next, the operations of the interval acquisition unit 310 and the time correction unit 320 will be described with reference to FIGS. 10A to 10C.

(Correction pattern 1)
In the correction pattern 1, when the first event is detected after setting one protection period, the interval acquisition unit 310 acquires the time interval from the end time of the one protection period to the detection time of the first event. ..

This will be specifically described with reference to FIG. 10A. FIG. 10A is an example in which the protection period is corrected by two events detected in the near time.

The video recording device 20 sets a predetermined protection period as one protection period when the previous event is detected (protection period at the time of the previous event). In the correction pattern 1, the previous event may be either the first event or the second event. The protection period at the time of the previous event ends at time Te.

After that, the event detection unit 210 detects the first event at time T1r. At this time, the protection period setting unit 250 sets the first protection period P1. The first protection period P1 is a period from the start time T1s to the end time T1e, and includes the detection time T1r of the first event. The operation up to this point is the same as that of the first embodiment.

The interval acquisition unit 310 refers to the storage unit 270 and acquires the end time Te of the protection period at the time of the previous event. Next, the interval acquisition unit 310 acquires the time interval ΔT based on the end time Te and the first event detection time T1r this time. Specifically, ΔT = T1r-Te.

Next, when the time interval ΔT acquired by the interval acquisition unit is shorter than the predetermined first threshold time by Tth1, the time correction unit 320 sets the start time of the first protection period set by the protection time setting unit 250. The end time Te of the protection period at the time of the event is corrected.

Specifically, when the time interval ΔT is smaller than the first threshold time Tth1, the time correction unit 320 makes the start time T1s of the first protection period coincide with the end time Te of the protection period at the time of the previous event.

In the correction pattern 1, when the detection of the first event is repeated in a short time, the image around the vehicle can be protected in a continuous manner without being scattered. Therefore, it becomes easy to identify the situation at the time of the event after the fact.

(Correction pattern 2)
In the correction pattern 2, the interval acquisition unit 310 acquires the time interval of the two transition times from the detected state of the fanning operation to the undetected state of the fanning operation as the fanning detection interval.

This will be specifically described with reference to FIG. 10B. FIG. 10B is an example in which the protection period is corrected by continuously detecting the second event. The video recording device 20 sets a second protection period when the second event is detected last time (protection period at the time of the second event last time). In addition, the recording unit 230 according to the second embodiment records the fanning detection state in the storage unit 270 in association with the time. The protection period at the time of the previous second event ends at time Te. At the transition time TeA after the previous second event detection, the fanning detection state shifts from the “detected” state to the “undetected” state.

After that, the fanning detection unit 240 detects the second event at time T2r. At this time, the protection period setting unit 250 sets the second protection period from the start time T2s including the detection time T2r to the end time T2e as the protection period.

The interval acquisition unit 310 refers to the storage unit 270 and acquires the transition time TeA. Next, the interval acquisition unit 310 acquires the time interval ΔT based on the transition time TeA and the second event detection time T2r this time. Specifically, ΔT = T2r-TeA.

Next, when the time interval ΔT is smaller than the second threshold time Tth2, the time correction unit 320 corrects so that the start time T2s of the second protection period becomes Te. The second threshold time Tth2 is longer than the first threshold time Tth1.

As a result, in the correction pattern 2, the video recording device 20 can continuously protect the vehicle peripheral video so as not to be scattered when the detection of the second event is repeated in a short time. Further, as compared with the case of the first event, in the case of the fanning operation, the time interval in which the fanning is repeated is often longer. Therefore, by making the second threshold time longer than the first threshold time, it is possible to record an image that makes it easy to identify the situation of the driving operation after the fact.

(Correction pattern 3)
FIG. 10C is a diagram illustrating time correction when the second event is detected. Since the operation of the interval acquisition unit 310 is the same as that of the correction pattern 2, the description thereof will be omitted.

When the time interval ΔT is smaller than the second threshold time Tth2, the time correction unit 320 corrects so that the start time T2s of the second protection period becomes the transition time TeA. If the transition time TeA is before the previous protection period end time Te, the time correction unit 320 corrects the start time T2s so that the end time Te becomes the end time Te.

In the correction pattern 3, unlike the correction pattern 2, the image around the vehicle is not protected during a part of the period in which the vehicle is in the “detection” state. This is because if it is known that the vehicle is in the “detection” state, it can be estimated that the vehicle has been continuously driven even if there is no image. If the own vehicle 1 has been continuously driven for a long time, the protection period corrected based on the correction pattern 2 may become long. In the correction pattern 3, the storage unit 270 can be used more efficiently while recording an image that can identify the situation of the vehicle that has been driven in a hurry after the fact.

In the figure, the transition time TeA is later than the end time Te, but the opposite is also possible. In this case, the time correction unit 320 corrects the start time T2s so that the start time T2s matches the end time Te.

[Embodiment 3]
<3.1. Configuration of video recording device>
Next, the configuration of the video recording device 20 according to the third embodiment of the present invention will be described with reference to FIG. The description of the configuration overlapping with the first embodiment will be omitted. FIG. 13 is a functional block diagram of the video recording device 20. The video recording device 20 according to the third embodiment further includes a fanning intensity detecting unit 410.

The acquisition unit according to the third embodiment further outputs the acquired vehicle peripheral image to the fanning strength calculation unit 410.

The fanning strength calculation unit 410 calculates the fanning strength with respect to the vehicle based on the image around the vehicle. The fanning strength is an index of the viciousness of the fanning driving. Specifically, the fanning intensity calculation unit 410 calculates the fanning intensity based on at least one time change amount of the distance and speed of the target vehicle shown in the vehicle peripheral image. The fanning strength calculation unit 410 outputs the calculated fanning strength to the protection period setting unit 250.

The protection period setting unit 250 according to the third embodiment corrects the protection period based on the fan strength calculated by the fan strength detection unit 410. Specifically, the protection period setting unit 250 corrects the protection period so that the larger the fan strength calculated by the fan strength detection unit 410, the longer the protection period. The protection period setting unit 250 outputs the corrected protection period to the protection unit 260.

<3.2. Operation of video recording device>
The fanning strength calculation unit 410 calculates the fanning strength with respect to the vehicle based on the image around the vehicle. Specifically, the fanning intensity detecting unit 410 first detects the target vehicle for which the fanning intensity is calculated based on the vehicle peripheral image acquired by the acquiring unit 220. The target vehicle is detected by using pattern matching or the like as in the case of the fan detection unit 240.

Next, the fanning strength detection unit 410 detects the distance and speed of the target vehicle. Specifically, the fanning strength detection unit 410 detects the distance between the own vehicle and the target vehicle and the relative speed of the target vehicle with respect to the own vehicle.

The inter-vehicle distance detects the foot of a perpendicular line drawn from the tip of the target vehicle to the road surface in the image around the vehicle. Specifically, it is calculated from the position where the lower end of the bumper of the target vehicle is shown on the image.

The relative speed is calculated based on the time change of the inter-vehicle distance obtained above and the time change of the speed of the own vehicle. Specifically, the fanning strength detection unit 410 calculates the amount of movement of the own vehicle based on the own vehicle speed at the time of the previous fanning strength detection processing, the own vehicle speed at the time of the current processing, and the processing interval time between the previous time and the current time. To do. Next, the fanning strength detection unit 410 calculates the amount of movement of the target vehicle from the inter-vehicle distance between the previous processing and the current processing. The fanning strength calculation unit 410 calculates the relative speed of the target vehicle with respect to the own vehicle based on the movement amount of the own vehicle, the movement amount of the target vehicle, and the processing interval time.

Next, the calculation of the fanning strength will be described with reference to FIGS. 12A to 12C. 12A to 12C are examples of the inter-vehicle distance and the relative speed when calculating the fanning strength.

FIG. 12A is an example of the inter-vehicle distance and the relative speed when the driving is not detected as a driving. Specifically, the target vehicle is in a situation where it is chasing with a safe inter-vehicle distance. In such a situation, the inter-vehicle distance and relative speed of the target vehicle are substantially constant with respect to time, and the time change is small. In such a case, the fanning strength is set to zero.

FIG. 12B is an example of the inter-vehicle distance and the relative speed when a high vibration strength is calculated. Specifically, the target vehicle is in a situation where the target vehicle closes the inter-vehicle distance at a high relative speed and then follows after a narrow inter-vehicle distance. In this case, since the time change of the distance is particularly large, a high fanning strength is calculated.

Further, in FIG. 12B, the time change of the distance is larger in the pattern shown by the solid line than in the pattern shown by the dotted line. It can be said that the solid line pattern shortens the inter-vehicle distance compared to the dotted line pattern. In other words, the solid line pattern is considered to be a malicious running pattern with a stronger intention to "fan" than the dotted line pattern. Therefore, the fanning intensity calculation unit 410 calculates a fanning intensity higher in the case of a pattern such as a solid line having a large amount of time change in distance than in a pattern such as a dotted line having a small amount of time change in distance. That is, the fanning strength calculation unit 410 calculates the higher fanning strength as the amount of time change of the distance increases.

FIG. 12C is an example of the inter-vehicle distance and the relative speed when a high vibration strength is calculated. Specifically, the target vehicle is in a situation where it repeatedly approaches and separates from its own vehicle. In this case, although there is a time change in the distance, a high fanning intensity is calculated because the time change in the relative velocity is large.

Further, in FIG. 12C, the time change of the relative velocity is larger in the pattern shown by the solid line than in the pattern shown by the dotted line. It can be said that the solid line pattern repeats approaching and separating in a shorter cycle than the dotted line pattern. In other words, the solid line pattern is considered to be a malicious running pattern with a stronger intention to "fan" than the dotted line pattern. Therefore, the fanning strength calculation unit 410 calculates that in the case of a pattern such as a solid line having a large amount of time change in relative velocity, the fanning intensity is higher than that in a pattern such as a dotted line having a small amount of time change in relative velocity. That is, the fanning strength calculation unit 410 calculates the higher fanning strength as the amount of change in relative velocity over time increases.

The protection period setting unit 250 according to the third embodiment corrects the protection period based on the fan strength calculated by the fan strength detection unit 410. Specifically, the protection period setting unit 250 corrects the protection period so that the larger the fan strength calculated by the fan strength detection unit 410, the longer the protection period.

In the first embodiment, the protection period setting unit 250 sets the second protection period as the protection period when the fanning detection unit 240 detects the second event. In the first embodiment, the length of the second protection period assumes a predetermined fixed value set in advance. In the present embodiment, the protection period setting unit 250 corrects the second protection period based on the fan strength calculated by the fan strength calculation unit 410.

(Correction pattern A)
In the correction pattern A, when the protection period setting unit 250 sets the second protection period, the second protection period is also corrected. This will be specifically described with reference to FIG. 13A. First, as in the first embodiment, when the second event is detected in the fanning detection unit 240, the protection period setting unit 250 sets the second protection period P2. Next, the protection period setting unit 250 corrects the start time T2s and the end time T2e of the second protection period based on the agitation strength. In the correction pattern A, the higher the fanning intensity, the earlier the start time T2s is corrected. For example, in the second event detection time, when the fanning intensity is larger than a predetermined threshold value, the previously set protection start time T2s is corrected to a later correction start time T2s'. The correction start time T2s'is set to a time earlier than the start time T2s for a predetermined fixed time. Specifically, for example, 2 minutes ago. Further, the higher the fanning intensity, the more past the time may be corrected. That is, the higher the fanning intensity, the longer the state of the target vehicle performed in the past than the fanning detection time T2r is protected.

(Correction pattern B)
In the correction pattern B, the protection period setting unit 250 corrects the second protection period after the fact.

For example, consider the running pattern shown by the solid line in FIG. 12C. In FIG. 12C, the target vehicle is driving in a driving pattern with a high driving strength at an inter-vehicle distance closer than the threshold distance Dth. That is, at the time T2r when the second event is detected, the fanning intensity is not so high, but after the second event is detected, a high fanning intensity may be exhibited. In such a case, the correction pattern A that corrects based on the fanning intensity at the second event detection time T2r may not be able to protect the traveling pattern having a high fanning intensity.

Therefore, when a high fanning intensity is calculated even though the event detection has not been performed, the protection period setting unit corrects the second protection period as in the correction pattern B shown in FIG. 13B. This will be specifically described with reference to FIG. 13B. First, when the second event is detected, the protection period setting unit 250 sets the second protection period in consideration of the correction by the correction pattern A. After that, the protection period setting unit 250 corrects the second protection period during the period in which the fanning detection state continues in the "detection" state even if the second event is not detected. Specifically, after the second event is detected, the protection period setting unit 250 corrects the protection end time T2e so that the higher the fanning intensity at the current processing time, the later the protection end time T2e. When the fanning strength is greater than the threshold strength at the current processing time, the protection period setting unit 250 corrects the protection end time T2e to T2e'before the current processing time. That is, the higher the fanning intensity, the longer the state of the target vehicle performed after the fanning detection time T2r is protected.

Further, the protection period setting unit 250 may additionally protect a period in which the fanning strength is higher than a predetermined threshold value. In this case, as shown in FIG. 13C, the second protection period may be configured to include a plurality of periods instead of one continuous period.

<3.3. Effect of video recording device>
The video recording device 20 according to the third embodiment further includes a fan strength calculation unit 410 that calculates the fan strength with respect to the vehicle based on the captured vehicle peripheral image. The protection time setting unit 250 corrects the second protection time based on the calculated agitation strength.

As a result, the length of the protection period can be changed according to the driving condition of the target vehicle.

In addition, the fanning strength calculation unit 410 calculates the fanning strength based on at least one time change amount of the distance and speed of the target vehicle.

As a result, it is possible to accurately quantify and calculate the maliciousness of the driving.

Further, the protection time setting unit 250 corrects so that the larger the calculated agitation strength, the longer the second protection time.

As a result, in a situation where it is highly likely that the vehicle is undergoing a strong road rage after the fact, it is possible to protect the image of the state of the road rage for a long time.

<Modification example>
The video recording device 20 may be connected to a microphone and record audio data acquired by the microphone together with a vehicle peripheral image. In that case, the voice data generated during the second protection period may be protected.

If you are driving in a hurry, you may be honked by voice, such as a horn. Therefore, it is preferable that voice is also protected. On the other hand, in the first protection period, which is protected by an event for the vehicle, it is often less necessary to leave the sound. Therefore, the storage unit 270 can be used efficiently by protecting the voice data in the second protection period.

Further, in the above description, the vehicle peripheral image generated by the rear camera has been used as an example, but the description is not limited to this. The fanning detection unit 240 and the fanning intensity detecting unit 410 may perform processing based on the images of the front camera and the side camera.

For example, when detection is performed using a front camera, it is possible to detect driving in which the distance between vehicles is reduced from the front to stop the vehicle.

Further, in this case, when the second event is detected by any one camera, it is preferable to protect the images generated by all the other cameras.

As a result, it is possible to record the state of the entire surroundings of the vehicle other than the target vehicle. As a result, it is possible to record an image in which it is possible to more accurately identify the situation of the vehicle that has been driven by driving.

Further, the fanning detection unit 240 detects the fanning driving by image recognition of the image around the vehicle, but this is not the case. The inter-vehicle distance actually measured using a distance detection device such as a radar, LiDAR (Light Detection and Ranging), or ultrasonic sonar may be used.

Although the embodiment of the present invention has been described above, the above-described embodiment is merely an example for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented within a range that does not deviate from the gist thereof.

1 Own vehicle 10 Camera 20 Video recording system 30 Sensor unit 40 Operation unit 50 Communication bus 210 Event detection unit 220 Acquisition unit 230 Recording unit 240 Fan detection unit 250 Protection period setting unit 260 Protection unit 270 Storage unit 100 Video recording system

Claims (11)

A recording unit that records a vehicle peripheral image of the surroundings of the vehicle generated by a first camera installed at a predetermined position of the vehicle, and a recording unit.
An event detection unit that detects the first event that occurs in the vehicle, and
A fan detection unit that detects the fan driving received by the vehicle as a second event based on the captured image of the surroundings of the vehicle.
When the event detection unit detects the first event, the first protection period is set based on the detection time of the first event, and when the fanning detection unit detects the second event, the second event. A protection period setting unit that sets a second protection period longer than the first protection period based on the event detection time, and a protection period setting unit.
Of the vehicle peripheral images recorded by the recording unit, a protection unit that protects the images generated in each of the first protection period and the second protection period set by the protection time setting unit, and
A video recording device equipped with. The image according to claim 1, wherein the time from the start time of the second protection period to the detection time of the second event is longer than the time from the start time of the first protection period to the detection time of the first event. Recording device. When the first event is detected by the event detection unit after the protection time setting unit sets one protection period, the time interval from the end time of the one protection period to the detection time of the first event is set. Interval acquisition part to acquire and
When the time interval acquired by the interval acquisition unit is shorter than the predetermined first threshold time, the start time of the first protection period set by the protection time setting unit is set to the end time of the one protection period. The image recording device according to claim 2, further comprising a time correction unit for correction. The time from the transition time when the fanning detection unit shifts from the detection state of the fanning operation to the undetected state of the fanning operation after the previous detection of the second event to the time when the fanning detection unit detects a new fanning operation. An interval acquisition unit that acquires the fanning detection interval, and
When the fanning detection interval acquired by the interval acquisition unit is shorter than the predetermined second threshold time, the start time of the second protection period is set to the protection set by the protection time setting unit at the time of the previous detection of the second event. The image recording apparatus according to claim 2 or 3, further comprising a time correction unit that corrects to the end time of the period. Interval acquisition unit that acquires the time from the transition time when the fanning detection unit shifts from the detection state of the fanning operation to the undetected state of the fanning operation to the time when the fanning detection unit detects a new fanning operation as the fanning detection interval. When,
Claim 2 to further include a time correction unit that corrects the start time of the second protection period to the transition time when the fanning detection interval acquired by the interval acquisition unit is shorter than the predetermined second threshold time. The image recording apparatus according to any one of 4. Further provided with a fanning strength calculation unit for calculating the fanning strength with respect to the vehicle based on the captured vehicle peripheral image.
The image recording device according to any one of claims 1 to 5, wherein the protection time setting unit corrects the second protection time based on the calculated agitation strength. The fanning strength calculation unit
The image recording device according to claim 6, wherein the fanning intensity is calculated based on at least one time change amount of the distance and speed of the target vehicle shown in the photographed vehicle peripheral image. The protection time setting unit
The image recording apparatus according to any one of claims 6 to 7, wherein the larger the calculated agitation strength is, the longer the second protection time is corrected. The recording unit records voice data acquired by a microphone mounted on the vehicle, and records the voice data.
The protection unit protects the voice data generated in the second protection period among the voice data recorded by the recording unit.
The image recording apparatus according to any one of claims 1 to 8. The image around the vehicle is
Includes a plurality of images produced by the plurality of cameras including the first camera.
The protection unit
The image recording device according to any one of claims 1 to 9, which protects the plurality of images. A recording process for recording a vehicle peripheral image of the surroundings of the vehicle generated by a first camera installed at a predetermined position of the vehicle, and
An event detection process that detects the first event that occurs in the vehicle, and
A fan detection step of detecting the fan driving received by the vehicle as a second event based on the captured vehicle surrounding image, and a fan detection step.
When the first event is detected in the event detection step, the first protection period is set based on the detection time of the first event, and when the second event is detected in the fanning detection step, the second event is detected. A protection period setting step of setting a second protection period longer than the first protection period based on the detection time of the event, and a protection period setting step.
Among the vehicle peripheral images recorded in the recording process, a protection step for protecting the images generated in each of the first protection period and the second protection period set in the protection time setting process, and
Video recording method including.

Images