Information processing device, information processing method, and information processing program

Abstract

To provide an information processing device that determines an aggressive driving behavior with high accuracy.SOLUTION: An information processing device 100 includes: an image acquisition part 11; a U-shape detection part 15; and an aggressive driving determination part 17. The image acquisition part 11 acquires an image captured behind a vehicle. The U-shape detection part 15 detects a horizontal line related to a vehicle body and both vertical lines of the vehicle body included in the image acquired by the image acquisition part 11. The aggressive driving determination part 17 determines that a driving state of a following vehicle corresponds to aggressive driving, based on at least a distance between the following vehicle identified from the horizontal line and the vertical lines detected by the U-shape detection part 15 and an own vehicle.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an information processing device, an information processing method, and an information processing program. [Background technology]

[0002] Tailgating generally refers to the act of forcing a vehicle in front to give way, and is a highly dangerous act that involves driving abnormally close to another vehicle.

[0003] By recording such behavior in an image recording device such as a drive recorder in the vehicle being tailgated, it is possible to deal with any trouble that may occur, such as a rear-end collision. Since typical drive recorders do not automatically detect tailgating, it is necessary to manually save the footage. However, it is difficult to operate manually when the vehicle is being tailgated.

[0004] There is a technology in which a driving assistance device determines whether another vehicle is tailgating the driver's own vehicle based on an image captured by an imaging means, and further determines whether the tailgating state is continuing.If it determines that the tailgating state is continuing, it provides information about the other vehicle to the driver of the driver's own vehicle (for example, Patent Technical Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-112892 Summary of the Invention [Problem to be solved by the invention]

[0006] However, because the conventional technology uses only horizontal lines to determine whether a driver is tailgating, it can erroneously determine whether the driver is tailgating. For example, horizontal lines on the road, such as deceleration lines or distance confirmation lines, can lead to the driver being mistakenly determined to be tailgating by a following vehicle that is not tailgating, or to the driver being tailgating by a following vehicle that does not exist. Thus, the problem that the present invention aims to solve is, for example, the problem of erroneous determination of tailgating that occurs in the conventional technology described above. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the invention described in claim 1 is characterized by having an image acquisition unit that acquires an image taken of the rear of the vehicle, a U-shaped detection unit that detects horizontal lines related to the vehicle body contained in the image and both vertical lines of the vehicle body, and a tailgating judgment unit that judges tailgating based on at least the distance between the following vehicle identified based on the horizontal lines and both vertical lines detected by the U-shaped detection unit and the vehicle itself.

[0008] The invention described in claim 11 is an information processing method executed by an information processing device, characterized in that it includes an image acquisition process for acquiring an image of the rear of a vehicle, a U-shaped detection process for detecting horizontal lines related to the vehicle body contained in the image and both vertical lines of the vehicle body, and a tailgating determination process for determining whether tailgating is occurring based on at least the distance between the vehicle and a following vehicle identified based on the horizontal lines and both vertical lines detected by the U-shaped detection process.

[0009] The invention described in claim 12 is characterized in that the computer executes an image acquisition step of acquiring an image of the rear of the vehicle, a U-shaped detection step of detecting horizontal lines related to the vehicle body contained in the image and both vertical lines of the vehicle body, and a tailgating determination step of determining whether tailgating is occurring based on at least the distance between the vehicle and a following vehicle identified based on the horizontal lines and both vertical lines detected by the U-shaped detection step. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an example of a functional configuration diagram of an image recording apparatus including an information processing apparatus according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of an object detection process performed by an image recording device including an information processing device according to an embodiment. [Figure 3] FIG. 3 is a diagram showing an example of a following vehicle detection process performed by an image recording device including an information processing device according to an embodiment. [Figure 4] FIG. 4 is a diagram showing an example of a road rage determination process performed by an image recording device including an information processing device according to an embodiment. [Figure 5] FIG. 5 is a flowchart showing an example of a tailgating determination process performed by an image recording device including an information processing device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] An information processing device according to one embodiment of the present invention will be described below. In the information processing device according to one embodiment of the present invention, a U-shaped detection unit detects a following vehicle from a U-shaped line formed by a horizontal line formed by the road surface and the vehicle body and two vertical lines of the vehicle body, and a distance calculation unit calculates the distance between the vehicle and the following vehicle based on the U-shaped line. Then, a tailgating determination unit determines tailgating based on the distance calculated by the distance calculation unit. With this aspect, by detecting a following vehicle using the U-shaped line and determining tailgating based on the distance between the vehicle and the following vehicle, erroneous determination of tailgating can be reduced and tailgating can be determined with high accuracy.

[0012] In addition, the tailgating determination unit determines that tailgating is not occurring when the distance between the two vertical lines of the vehicle body is decreasing. With this configuration, even if a following vehicle is detected within a predetermined distance due to a temporary decrease in the inter-vehicle distance, it can be determined that the following vehicle is moving away, and an alarm can be prevented from being issued.

[0013] The U-shaped detection unit determines whether the change in the length of the pair of left and right vertical lines changes in accordance with the distance, and excludes U-shaped shapes that do not change in accordance with the distance from the detection target. This prevents the erroneous detection of objects other than the following vehicle as U-shaped shapes, and prevents the erroneous determination of tailgating.

[0014] The distance calculation unit calculates the distance between the vehicle and the following vehicle based on the position of the horizon formed by the road surface and the vehicle body and the installation position of the camera. In this manner, tailgating can be determined based on the distance between the vehicle and the following vehicle.

[0015] Furthermore, an information processing method according to one embodiment of the present invention is an information processing method executed by an information processing device that determines tailgating, in which a U-shaped detection process detects a following vehicle from a U-shaped line formed by a horizontal line formed by the road surface and the vehicle body and two vertical lines of the vehicle body, and a distance calculation process calculates the distance between the vehicle and the following vehicle based on the U-shaped line. Then, a tailgating determination process determines tailgating based on the distance calculated by the distance calculation process. According to this aspect, by detecting a following vehicle using the U-shaped line and determining tailgating, erroneous determination of tailgating can be reduced and tailgating can be determined with high accuracy.

[0016] In addition, an information processing program according to one embodiment of the present invention causes a computer to execute a U-shaped detection step of detecting a following vehicle from a U-shaped line formed by a horizontal line formed by the road surface and the vehicle body and two vertical lines of the vehicle body, a distance calculation step of calculating the distance between the vehicle and the following vehicle based on the U-shaped line, and a tailgating driving determination step of determining tailgating driving based on the distance calculated by the distance calculation step. In this manner, by detecting a following vehicle using the U-shaped line and determining tailgating driving, it is possible to reduce erroneous determinations of tailgating driving and determine tailgating driving with high accuracy.

[0017] [Example] An image recording device including an information processing device according to an embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of a functional configuration diagram of an image recording device including an information processing device according to an embodiment. Image recording device 1 is, for example, a drive recorder installed in a mobile object such as an automobile.

[0018] As shown in FIG. 1, the image recording device 1 includes a speed information acquisition unit 2, a camera 3, an acceleration sensor 4, an operation unit 5, a display 6, an internal memory 7, an external memory 8, and a control unit 10.

[0019] The speed information acquisition unit 2 is connected to, for example, the vehicle's ECU (Electronic Control Unit) via wired or wireless communication and acquires information on the vehicle's traveling speed (traveling speed). That is, the speed information acquisition unit 2 functions as a traveling speed acquisition unit that acquires the traveling speed of a moving object. Note that the speed information acquisition unit 2 is not limited to acquiring information on the vehicle's traveling speed from the vehicle, but may also have a function to detect the vehicle's own position using a GPS (Global Positioning System) or the like, and calculate and acquire the traveling speed from the travel distance per unit time.

[0020] The camera 3 is a device that captures images of the area behind the vehicle. In this embodiment, the camera 3 captures still images or moving images. The camera 3 is attached to a location that can capture images of the area behind the vehicle. For example, it is preferable to attach the camera 3 to the rear end of the vehicle body or the rear end of the passenger compartment. However, the camera 3 may be attached to, for example, the windshield, as long as it can capture images of an area that can detect other vehicles approaching from behind the vehicle. When the camera 3 is attached to the rear end of the vehicle body or the rear end of the passenger compartment, the camera 3 may be configured separately from the operation unit 5, display 6, etc., and connected by a cable or the like.

[0021] The acceleration sensor 4 detects the acceleration applied to the image recording device 1, i.e., the acceleration of the vehicle. If the acceleration detected by the acceleration sensor 4 is equal to or greater than a predetermined value, it is determined that an impact has been applied to the vehicle, and under control of the control unit 10, the images recorded in the internal memory 7 are recorded as event recordings in the holding area of ​​the external memory 8. When the images are recorded as event recordings in the holding area, they are retained without being erased by overwriting or the like.

[0022] The operation unit 5 is an interface for accepting various operations on the image recording device 1. For example, the operation unit 5 includes an operation button, a remote controller, a power switch, and the like.

[0023] The display 6 is configured by, for example, a liquid crystal display. The display 6 can display images captured by the camera 3, images recorded in the external memory 8, etc. The display 6 also displays alarm information.

[0024] The internal memory 7 is a storage area that functions as an image buffer or the like for temporarily storing images captured by the camera 3. The internal memory 7 may be a volatile memory or a non-volatile memory.

[0025] Images temporarily stored in the internal memory 7 are transferred to and recorded in the external memory 8 under the control of the control unit 10. That is, the external memory 8 functions as a recording unit that records images captured behind the moving object. The external memory 8 is a storage medium such as an SD card, and is attached to a slot or the like (not shown). Therefore, the external memory 8 is removable. The external memory 8 has a non-holding area and a holding area. The non-holding area is an area where images transferred from the internal memory 7 are recorded, but once all images in that area are recorded, the oldest images are overwritten. The holding area is an area used during the event recording described above, and is not overwritten.

[0026] The control unit 10 is realized using a CPU (Central Processing Unit), NP (Network Processor), FPGA (Field Programmable Gate Array), etc., and executes processing programs stored in memory. As shown in Fig. 1, the control unit 10 has an image acquisition unit 11, a curve detection unit 12, an object detection unit 13, a horizon determination unit 14, a U-shaped detection unit 15, a distance calculation unit 16, a road rage determination unit 17, and an alarm unit 18. Each unit of the control unit 10 will be described below.

[0027] The image acquisition unit 11 acquires an image. For example, the image acquisition unit 11 acquires an image captured by the camera 3. Here, the image acquired by the image acquisition unit 11 may be a still image or a moving image.

[0028] The curve detection unit 12 detects whether the host vehicle is traveling around a curve. For example, the curve detection unit 12 detects whether the host vehicle is traveling around a curve from a change in acceleration detected by the speed information acquisition unit 2, which is an acceleration sensor.

[0029] When the curve detection unit 12 detects that the host vehicle is traveling around a curve, the object detection unit 13 detects an object in the image captured by the camera 3 whose position relative to the camera 3 does not change. For example, the object detection unit 13 detects a horizontal line in the image captured by the camera 3 whose position relative to the camera 3 does not change as a heating wire. Specifically, the object detection unit 13 detects a rear defogger provided on the rear window, which is a horizontal line that appears in the image captured by the camera 3, as a heating wire. Furthermore, for example, the object detection unit 13 detects a figure or the like in the image captured by the camera 3 whose position relative to the camera 3 does not change as a sticker, cargo, or the like.

[0030] The horizon determination unit 14 determines whether or not a situation exists in which the horizon formed by the road surface and the vehicle body can be detected. For example, the horizon determination unit 14 determines that a situation exists in which the horizon formed by the road surface and the vehicle body can be detected from the image acquired by the image acquisition unit 11. Alternatively, for example, the horizon determination unit 14 determines that a situation exists in which the horizon formed by the road surface and the vehicle body cannot be detected from the image acquired by the image acquisition unit 11.

[0031] Furthermore, the horizon determination unit 14 determines whether or not the situation allows for the detection of a horizon formed by the road surface and the vehicle body, based on the luminance. For example ... value (cd / m 2 ) is equal to or less than a predetermined value, it is determined that the situation is not such that the horizon formed by the road surface and the vehicle body can be detected. Note that when determining whether the situation is such that the horizon formed by the road surface and the vehicle body can be detected, the horizon determination unit 14 may select any range, such as the entire screen or the road surface portion, or may set any brightness value as the threshold value.

[0032] Furthermore, the horizon determination unit 14 determines whether or not the situation allows for detection of the horizon formed by the road surface and the vehicle body based on the solar altitude. For example, the horizon determination unit 14 determines that the situation allows for detection of the horizon formed by the road surface and the vehicle body because the solar altitude is 70°. Alternatively, for example, the horizon determination unit 14 determines that the situation does not allow for detection of the horizon formed by the road surface and the vehicle body because the solar altitude is 10°. Note that the horizon determination unit 14 may set any threshold value for the solar altitude when determining whether or not the situation allows for detection of the horizon formed by the road surface and the vehicle body.

[0033] Furthermore, the horizon determination unit 14 determines, based on the time, whether or not the situation allows for detection of the horizon formed by the road surface and the vehicle body. For example, the horizon determination unit 14 determines that the situation allows for detection of the horizon formed by the road surface and the vehicle body because the current time is 13:00. Alternatively, for example, the horizon determination unit 14 determines that the situation does not allow for detection of the horizon formed by the road surface and the vehicle body because the current time is 18:00. Note that the horizon determination unit 14 may set any threshold value for the time when determining whether or not the situation allows for detection of the horizon formed by the road surface and the vehicle body.

[0034] The above-mentioned elements such as brightness, solar altitude, and time are merely examples, and the elements used in the actual determination are not limited to those mentioned above. The horizon determination unit 14 may use elements that are suitable for the purpose, such as location information and weather information, to determine whether or not the situation is such that the horizon formed by the road surface and the vehicle body can be detected.

[0035] The U-shaped detection unit 15 detects a following vehicle from a U-shaped line formed by a horizontal line between the road surface and the vehicle body and two vertical lines of the vehicle body. For example, the U-shaped detection unit 15 detects a following vehicle from an upward U-shaped line formed by a concave line including a line intersecting the boundary line between the vehicle body and the ground.

[0036] Here, the "upward U" refers to a shape consisting of a concave line that includes a line that intersects with the boundary line between the vehicle body and the ground. Therefore, the upward U shape includes shapes such as the katakana character U rotated approximately 90 degrees clockwise and the letter U.

[0037] Furthermore, when the horizon determination unit 14 determines that the situation is such that the horizontal line formed by the road surface and the vehicle body can be detected, the U-shaped detection unit 15 detects the following vehicle from the U-shaped line formed by the horizontal line formed by the road surface and the vehicle body and both vertical lines of the vehicle body, and when the horizon determination unit 14 determines that the situation is not such that the horizontal line formed by the road surface and the vehicle body can be detected, the U-shaped detection unit 15 detects the following vehicle from the upward U-shaped line formed by a concave line including a line that intersects with the boundary line between the vehicle body and the ground.

[0038] Also, for example, when the horizon determination unit 14 determines that the situation is not such that it is possible to detect the horizontal line formed by the road surface and the vehicle body, the U-shaped detection unit 15 detects a downward U-shaped shape formed by the horizontal line included in the vehicle body and both vertical lines of the vehicle body.

[0039] Here, the downward U-shape refers to an upward U-shape that is turned upside down. Therefore, downward U-shapes include the katakana U-shape rotated approximately 90 degrees counterclockwise and the alphabet U-shape turned upside down.

[0040] Furthermore, the U-shaped detection unit 15 detects a U-shaped line formed by the horizontal line formed by the boundary line between the windshield and the body of the vehicle, and both vertical lines of the vehicle, as a horizontal line included in the vehicle body. For example, the U-shaped detection unit 15 detects a U-shaped line formed by the horizontal line at the bottom of the windshield formed by the boundary line between the windshield and the hood of the vehicle, and both vertical lines of the vehicle body.

[0041] Furthermore, the U-shaped detection unit 15 determines whether the change in the length of the pair of left and right vertical lines changes in response to the distance, and excludes U-shaped shapes that do not change in response from the detection target. For example, if the length of the pair of left and right vertical lines becomes shorter even though the distance between the host vehicle and the following vehicle is shortening, the U-shaped detection unit 15 determines that the U-shaped shape does not change in response to the change in distance, and excludes it from the detection target.

[0042] Furthermore, for example, if the length of the pair of left and right vertical lines increases even though the distance between the vehicle and the following vehicle is increasing, the U-shape detection unit 15 determines that the U-shape does not change in response to the change in distance and excludes it from the detection target.

[0043] In addition, when the object detection unit 13 detects a horizontal line whose relative position with the camera does not change, the U-shaped detection unit 15 detects a following vehicle from a U-shaped line that is not a horizontal line detected by the object detection unit 13 but is made up of at least one of a horizontal line formed by the road surface and the vehicle body or a horizontal line included in the vehicle body and both vertical lines of the vehicle body.

[0044] For example, when the object detection unit 13 detects a rear defogger provided on the rear window as a heating wire, which is a horizontal line that appears in the image captured by the camera 3, the U-shaped detection unit 15 detects the following vehicle by an upward U-shaped or downward U-shaped portion without using the horizontal line of the heating wire. In other words, the U-shaped detection unit 15 excludes the heating wire from the following vehicle detection processing so as not to erroneously detect it as part of the vehicle body, etc.

[0045] Distance calculation unit 16 calculates the distance between the host vehicle and the following vehicle based on the U-shaped curve. For example, distance calculation unit 16 calculates the distance between the host vehicle and the following vehicle from the position of the horizon formed by the road surface and the vehicle body and the installation position of camera 3. For example, distance calculation unit 16 calculates the distance between the host vehicle and the following vehicle using trigonometric functions based on information on the coordinates of the horizon formed by the road surface and the vehicle body in the image captured by camera 3.

[0046] Furthermore, the distance calculation unit 16 calculates the distance between the host vehicle and the following vehicle from the distance between both vertical lines of the vehicle body based on a predetermined vehicle width. For example, the distance calculation unit 16 calculates the distance between the host vehicle and the following vehicle from the distance between both vertical lines of the vehicle body based on an assumed vehicle width of 1800 mm. Specifically, the distance calculation unit 16 assumes that the vehicle width of the following vehicle is 1800 mm, measures how many pixels the 1800 mm vehicle width is captured in the image, and calculates the distance between the host vehicle and the following vehicle. Note that the vehicle width of the following vehicle used by the distance calculation unit 16 when calculating the distance may be set as appropriate.

[0047] The tailgating determination unit 17 determines tailgating based on the distance calculated by the distance calculation unit 16. For example, the tailgating determination unit 17 determines tailgating when the distance between the vehicle and the following vehicle calculated by the distance calculation unit 16 is equal to or less than a predetermined value. Specifically, the tailgating determination unit 17 determines tailgating when the distance between the vehicle and the following vehicle is equal to or less than 3 m. The predetermined distance at which the tailgating determination unit 17 determines tailgating may be set appropriately or may be changed depending on the speed.

[0048] Furthermore, for example, the tailgating determination unit 17 determines that tailgating has occurred when the distance between the vehicle and the following vehicle calculated by the distance calculation unit 16 remains below a predetermined value for a predetermined period of time. Specifically, the tailgating determination unit 17 determines that tailgating has occurred when the distance between the vehicle and the following vehicle remains below 10 m for one minute. Here, the predetermined distance or predetermined period for the tailgating determination unit 17 to determine that tailgating has occurred may be set appropriately or may be changed depending on the speed.

[0049] Furthermore, for example, the tailgating determination unit 17 determines that tailgating is not occurring when the distance between the two vertical lines on the vehicle body is getting smaller. For example, even if the distance between the host vehicle and the following vehicle calculated by the distance calculation unit 16 is equal to or less than a predetermined value, the tailgating determination unit 17 determines that tailgating is not occurring when the distance between the host vehicle and the following vehicle is getting smaller. In other words, the tailgating determination unit 17 determines that tailgating is occurring when the distance between the host vehicle and the following vehicle calculated by the distance calculation unit 16 is equal to or less than a predetermined value and the distance between the two vertical lines on the following vehicle's body is not getting smaller.

[0050] When the tailgating determination unit 17 determines that tailgating is occurring, the warning unit 18 issues a warning using the display 6, etc. For example, when the tailgating determination unit 17 determines that tailgating is occurring, the warning unit 18 warns the driver by displaying on the display 6 a message such as "The following vehicle is tailgating."

[0051] [Object detection processing] Next, the object detection process will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of the object detection process performed by an image recording device equipped with an information processing device according to the embodiment, and shows an image of the rear of the vehicle captured by an image recording device 1 installed on the vehicle. Fig. 2(1) shows the rear window of the vehicle. The multiple horizontal lines on the rear window in Fig. 2(1) are heating wires that function as a rear defogger.

[0052] First, the curve detection unit 12 detects that the host vehicle is traveling around a curve from changes in acceleration detected by the speed information acquisition unit 2, which is an acceleration sensor. Then, when the object detection unit 13 detects that the host vehicle is traveling around a curve, it detects, as heating wires, horizontal lines in the image captured by the camera 3 whose relative position with respect to the camera 3 does not change. For example, the object detection unit 13 detects, as heating wires, horizontal lines whose relative position with respect to the camera 3 does not change when traveling around a curve, and excludes the horizontal lines detected as heating wires without taking them into consideration in the following vehicle detection process.

[0053] [U-shaped detection process] Next, the U-shaped detection process will be described with reference to Fig. 3. Fig. 3 shows an example of a following vehicle detection process performed by an image recording device equipped with an information processing device according to an embodiment. First, Fig. 3(1) is an illustration showing brightness, solar altitude, and current time, which are examples of elements used to determine whether the horizon formed by the road surface and the vehicle body can be detected. The horizon determination unit 14 determines whether the situation allows detection of the horizon formed by the road surface and the vehicle body based on elements such as brightness, solar altitude, and current time.

[0054] Next, Fig. 3(2) shows the detection of a following vehicle using the horizontal line formed by the road surface and the vehicle body. In Fig. 3(1), when the horizon determination unit 14 determines that the situation allows the detection of the horizontal line formed by the road surface and the vehicle body, the U-shaped detection unit 15 uses the horizontal line formed by the road surface and the vehicle body, that is, detects the following vehicle using the upward U-shaped line.

[0055] In this case, the U-shaped detection unit 15 first detects the horizontal line formed by the road surface and the vehicle body. Next, the U-shaped detection unit 15 detects a pair of vertical lines on the vehicle body. The U-shaped detection unit 15 then detects the following vehicle based on the upward U-shaped line formed by the horizontal line formed by the road surface and the vehicle body and the vertical lines on the vehicle body.

[0056] 3(3) shows the detection of a following vehicle without using the horizontal line formed by the road surface and the vehicle body. In FIG. 3(1), when the horizon determination unit 14 determines that the situation is not such that the horizontal line formed by the road surface and the vehicle body can be detected, the U-shaped detection unit 15 detects the following vehicle without using the horizontal line formed by the road surface and the vehicle body, that is, by the downward U-shaped line.

[0057] In this case, the U-shaped detection unit 15 first detects the horizontal line included in the vehicle. Next, the U-shaped detection unit 15 detects a pair of vertical lines on the vehicle body. The U-shaped detection unit 15 then detects the following vehicle based on the downward U-shaped line formed by the horizontal line included in the vehicle body and the vertical lines on the vehicle body.

[0058] [Tailgating driving detection processing] Next, the tailgating determination process will be explained using Fig. 4. Fig. 4 is a diagram for explaining the tailgating determination process by an image recording device equipped with an information processing device according to the embodiment. First, Fig. 4(1) shows the vehicle equipped with the image recording device 1. Next, Fig. 4(2) shows the following vehicle. Finally, Fig. 4(3) is a line showing the distance at which tailgating is determined by the tailgating determination unit 17 to be tailgating.

[0059] First, the distance between the host vehicle and the following vehicle is calculated by the distance calculation unit 16. When the U-shaped detection unit 15 detects the following vehicle in Fig. 4(2) using an upward U-shaped mark, the distance calculation unit 16 calculates the distance between the host vehicle in Fig. 4(1) and the following vehicle in Fig. 4(2) from the position of the horizon formed by the road surface and the vehicle body and the installation position of the camera 3.

[0060] On the other hand, when the U-shaped detection unit 15 detects the following vehicle in Figure 4(2) using a downward U-shaped mark, the distance calculation unit 16 calculates the distance between the vehicle in Figure 4(1) and the following vehicle in Figure 4(2) from the distance between both vertical lines of the vehicle body based on a predetermined vehicle width.

[0061] Then, the tailgating determination unit 17 determines whether tailgating is occurring based on the distance between the host vehicle and the following vehicle calculated by the distance calculation unit 16. For example, the tailgating determination unit 17 determines that tailgating is occurring when the following vehicle in FIG. 4(2) crosses the line in FIG. 4(3) and approaches the host vehicle in FIG. 4(1). Also, for example, the tailgating determination unit 17 determines that tailgating is occurring when the following vehicle in FIG. 4(2) crosses the line in FIG. 4(3) and approaches the host vehicle in FIG. 4(1) for a predetermined period of time.

[0062] Furthermore, for example, even if the following vehicle in Figure 4(2) crosses the line position in Figure 4(3) and approaches the own vehicle in Figure 4(1), the tailgating determination unit 17 determines that it is not tailgating if the following vehicle in Figure 4(2) moves away from the own vehicle in Figure 4(1).

[0063] [flowchart] Next, detection of tailgating by the image recording device 1 configured as described above will be described with reference to the flowchart in Fig. 5. Fig. 5 is a flowchart showing an example of tailgating determination processing by an image recording device equipped with an information processing device according to the embodiment. The flowchart in Fig. 5 is mainly executed by the control unit 10. Furthermore, this flowchart can be configured as a program executed by a CPU possessed by the control unit 10, thereby making it an information processing program.

[0064] First, the image acquisition unit 11 acquires an image of the rear of the vehicle (step S101). For example, the image acquisition unit 11 acquires an image of the rear of the vehicle body captured by the camera 3.

[0065] Next, if there is an object whose position relative to the camera 3 does not change when the vehicle is going around a curve (step S102 "YES"), the object detection unit 13 does not take the object into consideration when detecting a following vehicle (step S103). For example, when the curve detection unit 12 detects that the vehicle is going around a curve using the speed information acquisition unit 2, which is an acceleration sensor, the object detection unit 13 detects the rear defogger provided on the rear window, which is a horizontal line whose position relative to the camera 3 does not change, as an electric heating wire and excludes it from the detection of a following vehicle.

[0066] Then, the horizon determination unit 14 determines whether or not the situation allows the detection of the horizon formed by the road surface and the vehicle body (step S104). For example, the horizon determination unit 14 determines whether or not the situation allows the detection of the horizon formed by the road surface and the vehicle body based on the brightness, solar altitude, time, etc.

[0067] Here, if the horizon determination unit 14 determines that the situation is such that the horizon formed by the road surface and the vehicle body can be detected (step S104 "YES"), the U-shaped detection unit 15 detects the following vehicle using the horizon formed by the road surface and the vehicle body (step S105).

[0068] For example, if the horizon determination unit 14 determines that the current time is 13:00 and that the horizontal line formed by the road surface and the vehicle body can be detected, the U-shaped detection unit 15 detects the following vehicle using the horizontal line formed by the road surface and the vehicle body. For example, the U-shaped detection unit 15 detects the following vehicle from the upward U-shaped line formed by the horizontal line formed by the road surface and the vehicle body and both vertical lines of the vehicle body.

[0069] On the other hand, if the horizon determination unit 14 determines that the situation is not such that the horizon formed by the road surface and the vehicle body can be detected (step S104 "NO"), the U-shaped detection unit 15 detects the following vehicle without using the horizon formed by the road surface and the vehicle body (step S106).

[0070] For example, if the horizon determination unit 14 determines that the current time is 18:00 and that the situation is not such that the horizon formed by the road surface and the vehicle body can be detected, the U-shaped detection unit 15 detects the following vehicle without using the horizontal line formed by the road surface and the vehicle body. For example, the U-shaped detection unit 15 detects the following vehicle from a downward U-shaped line formed by the horizontal line included in the vehicle body and both vertical lines of the vehicle body.

[0071] Then, the U-shaped detection unit 15 determines whether the change in the length of the pair of vertical lines corresponds to the distance (step S107). If there is no corresponding change (step S107 "NO"), the U-shaped detection unit 15 excludes the U-shaped object from the detection target (step S108). For example, if the length of the left and right pair of vertical lines becomes shorter even though the distance between the host vehicle and the following vehicle is shortening, the U-shaped detection unit 15 determines that the U-shaped object does not change in response to the change in distance, and excludes it from the detection target.

[0072] Then, distance calculation unit 16 calculates the distance between the host vehicle and the following vehicle based on the U-shape (step S109). For example, distance calculation unit 16 calculates the distance between the host vehicle and the following vehicle from the position of the horizontal line formed by the road surface and the vehicle body and the installation position of camera 3. Also, for example, distance calculation unit 16 calculates the distance between the host vehicle and the following vehicle from the distance between both vertical lines of the vehicle body based on a predetermined vehicle width.

[0073] The tailgating determination unit 17 determines whether the distance calculated by the distance calculation unit 16 is equal to or less than a predetermined value (step S110). For example, if the distance between the host vehicle and the following vehicle calculated by the distance calculation unit 16 is not equal to or less than a predetermined value (step S110 "NO"), the tailgating determination unit 17 does not determine that tailgating is occurring. On the other hand, if the distance between the host vehicle and the following vehicle calculated by the distance calculation unit 16 is equal to or less than a predetermined value (step S110 "YES"), the tailgating determination unit 17 further determines whether the distance between the vertical lines of the vehicle bodies is becoming smaller (step S111).

[0074] Here, if the distance between the vertical lines of the vehicle body is not small (step S111 "NO"), the tailgating determination unit 17 determines that tailgating is occurring (step S112). Next, the warning unit 18 issues a warning using the display 6 or the like (step S113). For example, the warning unit 18 warns the driver by displaying on the display 6 a message such as "The following vehicle is tailgating."

[0075] On the other hand, when the distance between the vertical lines of both vehicle bodies is small (step S111 "YES"), the tailgating determination unit 17 determines that tailgating is not occurring (step S114).

[0076] [others] Although one example of an embodiment of the present invention has been described above, the present invention is not limited to the above example. In other words, a person skilled in the art can implement various modifications in accordance with conventionally known knowledge without departing from the gist of the present invention. As long as such modifications still include the information processing device of the present invention, they are of course included in the scope of the present invention. [Explanation of symbols]

[0077] 1 Image recording device 2 Speed ​​information acquisition section 3 Camera 4. Accelerometer 5 Control section 6. Display 7. Internal memory 8. External Memory 10 Control Unit 11 Image acquisition unit 12 Curve detection unit 13 Object detection unit 14 Horizontal line determination section 15 U-shaped detector 16 Distance calculation unit 17. Tailgating Determination Department 18 Alarm section

Claims

1. an image acquisition unit that acquires an image of the rear of the vehicle; a U-shaped detection unit that detects horizontal lines related to a vehicle body included in the image and both vertical lines of the vehicle body; a tailgating determination unit that determines tailgating based on at least the distance between the vehicle and a following vehicle identified based on the horizontal line and both vertical lines detected by the U-shaped detection unit; An information processing device comprising:

2. a horizon determination unit that determines whether or not a horizon formed by a road surface and a vehicle body included in the image can be detected; The U-shaped detection unit When the horizon determining unit determines that the situation allows the detection of a horizontal line formed by the road surface and the vehicle body, it detects a U-shape formed by the horizontal line formed by the road surface and the vehicle body and both vertical lines of the vehicle body, and when the horizon determining unit determines that the situation does not allow the detection of a horizontal line formed by the road surface and the vehicle body, it detects a U-shape formed by the horizontal line included in the vehicle body and both vertical lines of the vehicle body.

1. An information processing device comprising:

3. The U-shaped detection unit As the horizontal lines included in the vehicle body, a horizontal line formed by the boundary line between the windshield of the vehicle body and the body of the vehicle body, and a U-shape formed by both vertical lines of the vehicle body are detected.

3. The information processing apparatus according to claim 2, wherein:

4. 4. The information processing device according to claim 3, further comprising a distance calculation unit that calculates the distance between the subject vehicle and a following vehicle from the distance between both vertical lines of the vehicle body based on a predetermined vehicle width.

5. 3. The information processing apparatus according to claim 2, wherein the horizon determining unit determines whether or not a situation exists in which a horizon formed by the road surface and the vehicle body can be detected, based on brightness.

6. 3. The information processing apparatus according to claim 2, wherein the horizon determining unit determines whether or not the situation allows detection of the horizon formed by the road surface and the vehicle body based on the solar altitude.

7. 3. The information processing apparatus according to claim 2, wherein the horizon determining unit determines, based on time, whether or not a situation exists in which the horizon formed by the road surface and the vehicle body can be detected.

8. a curve detection unit that detects that the vehicle is traveling on a curve; an object detection unit that detects an object in the image whose relative position with respect to a camera that captures the image does not change when the curve detection unit detects that the host vehicle is traveling around a curve; 2. The information processing apparatus according to claim 1, further comprising:

9. The information processing apparatus according to claim 8 , wherein the object detection unit detects a horizontal line of the object as a heating wire.

10. the object detection unit detects a horizon that does not change in relative position with respect to the camera, The U-shaped detection unit Detect a horizontal line other than that detected by the object detection unit, which is a U-shaped line formed by at least one of a horizontal line formed by the road surface and the vehicle body included in the image, or a horizontal line included in the vehicle body, and both vertical lines of the vehicle body.

9. The information processing apparatus according to claim 8,

11. An information processing method executed by an information processing device, an image acquisition step of acquiring an image of the rear of the vehicle; a U-shaped detection step of detecting horizontal lines related to a vehicle body included in the image and both vertical lines of the vehicle body; a tailgating determination step of determining tailgating based on at least the distance between the following vehicle identified based on the horizontal line and both vertical lines detected in the U-shaped detection step and the subject vehicle; An information processing method comprising:

12. an image acquisition step of acquiring an image of the rear of the vehicle; a U-shaped detection step of detecting horizontal lines and both vertical lines of a vehicle body included in the image; a tailgating driving determination step of determining tailgating driving based on at least a distance between the following vehicle identified based on the horizontal line and both vertical lines detected in the U-shaped detection step and the subject vehicle; An information processing program characterized by causing a computer to execute the above.

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