Driving support device

Abstract

To provide a driving support device capable of reliably recognizing a pre-signal while enabling reduction of a facility cost.SOLUTION: A driving support device performs: recognizing at least one between a display mode of a traffic light (7 or 8) in front of a vehicle 1 and description contents of an auxiliary sign 9 based on a photographed image by a camera which is mounted on the vehicle 1 so as to photograph the front of the vehicle 1; and executing driving support processing to notify a driver of the vehicle 1 of the recognition information as driving support information. The driving support device prohibits the execution of the driving support processing when it is recognized that the traffic light (7 or 8) exists in front of the vehicle 1 based on the photographed image and also it is determined that the recognized traffic light (7 or 8) is a notice traffic light 8 based on at least one among the display mode of the recognized traffic light (7 or 8), the description contents of the auxiliary sign 9, and a curvature of an arrangement place of the traffic light (7 or 8) in front of the vehicle 1 on a road.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a driving assistance device for a vehicle. [Background technology]

[0002] For example, Patent Document 1 states that "When multiple traffic lights can be seen from the lane in which the vehicle is traveling, there is a risk that the driver will mistakenly recognize traffic lights other than those corresponding to the lane in which the vehicle is traveling as traffic lights for the lane in which the vehicle is traveling, so driving assistance is provided by making the driver aware of the traffic lights that they should look at."

[0003] Furthermore, Figure 9 and paragraphs 0032-0033 of Patent Document 1 state that "Vehicle 30 in this embodiment does not stop in front of traffic light 69, which is a warning signal light (the position of vehicle 34), but can stop at the correct stopping position in front of traffic light 68 (the position of vehicle 36)." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-125388 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned Patent Document 1, it is necessary to "pre-store in the storage unit 56 the position information of the points where the traffic lights 62 and 64 are present as traffic light location information 566," which is costly.

[0006] In view of the above circumstances, an object of the present invention is to provide a driving assistance device that can reduce equipment costs and ensure that a warning signal is recognized. [Means for solving the problem]

[0007] The present invention is a driving assistance device that is mounted on a vehicle and recognizes at least one of the display form of a traffic light ahead of the vehicle and the contents of an auxiliary sign based on an image captured by a camera that captures an image ahead of the vehicle, and executes a driving assistance process that notifies the driver of the vehicle of the recognized information as driving assistance information.The device is characterized in that if it recognizes that there is a traffic light ahead of the vehicle based on the captured image, and if it determines that the recognized traffic light is a warning traffic light based on at least one of the display form of the recognized traffic light, the contents of the auxiliary sign, and the curvature of the road where the traffic light is installed ahead of the vehicle, it prohibits the execution of the driving assistance process.

[0008] The warning signal is information to inform the driver of a vehicle that "the original traffic light is ahead." Generally, when a road has a curve of a certain curvature or more just before the location of the original traffic light, it is difficult for the driver of the vehicle to see the original traffic light from a distance, so a warning signal or auxiliary sign is installed just before the location of the original traffic light to indicate the presence of the warning signal.

[0009] The auxiliary sign is a sign that, in addition to the letters indicating the warning signal, also lists traffic rules such as "large vehicles are not allowed" or "school route."

[0010] According to this configuration, when the traffic light recognized in the image captured by the camera is a warning traffic light, the execution of the driving assistance process can be prohibited, thereby preventing inappropriate driving assistance that would stop the vehicle before the warning traffic light.

[0011] Furthermore, the above configuration is not a large-scale configuration like that of Patent Document 1, which "uses the vehicle 30 and the server 50 connected to the vehicle 30 via the Internet INT and communication carrier BS to stop the vehicle 30 at the correct stopping position in front of the actual traffic light 68, rather than stopping the vehicle 30 in front of the traffic light 69, which is a warning signal light," and there is no need to "pre-store information about the warning signal and information about the location of the warning traffic light in the memory unit 56 of the server 50," as in Patent Document 1, so it is possible to reduce the equipment costs of the driving assistance device of the present invention.

[0012] The driving assistance device may be configured to include a camera that captures images in front of the vehicle and a control unit that executes the driving assistance processing, and the vehicle may be configured to include a notification unit that notifies the driving assistance information.

[0013] According to this configuration, by specifying the configuration of the vehicle's onboard equipment and the driving assistance device, it is made clear that the equipment and configuration are simple, making it possible to reduce the manufacturing costs of the vehicle's onboard equipment and the driving assistance device.

[0014] Further, in the driving assistance device, the control unit can include a first determination unit that determines whether or not there is a traffic light ahead of the vehicle based on the captured image; a second determination unit that, if the first determination unit makes a positive determination, determines whether or not there is an auxiliary sign ahead of the vehicle based on the captured image; a third determination unit that, if the second determination unit makes a positive determination, determines whether or not the characters of the auxiliary sign include a warning signal; a fourth determination unit that, if the third determination unit makes a negative determination, determines whether the traffic light ahead of the vehicle has two yellow lights flashing alternately; a fifth determination unit that, if the fourth determination unit makes a negative determination, determines whether the location of the traffic light ahead of the vehicle is on a curve with a predetermined curvature or more; a first management unit that, if the second determination unit or the fifth determination unit makes a negative determination, determines that the traffic light ahead of the vehicle is not a warning traffic light and allows the driving assistance processing to be executed; and a second management unit that, if any of the third to fifth determination units makes a positive determination, determines that the traffic light ahead of the vehicle is a warning traffic light and prohibits the execution of the driving assistance processing.

[0015] According to this configuration, it is clear that the processing executed by the control unit is simplified, and therefore it is possible to reduce the manufacturing cost of the driving assistance device. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a driving assistance device that can reduce equipment costs and can reliably recognize warning signals. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram schematically illustrating a configuration of an embodiment of a driving assistance device according to the present invention. [Figure 2] 4 is a flowchart used to explain the operation of the driving assistance device. [Figure 3] FIG. 1 is an explanatory diagram showing an example of a road on which normal traffic lights and warning traffic lights are installed. DETAILED DESCRIPTION OF THE INVENTION

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0019] 1 to 3 show an embodiment of the present invention. A driving assistance device 2 is mounted on a vehicle 1.

[0020] The vehicle 1 is equipped with at least a notification unit 11. The notification unit 11 can be, for example, at least one of a video display device for outputting text related to driving assistance and an audio output device (a speaker that is standard equipment in the vehicle 1 or a speaker that can be added later) for outputting audio related to driving assistance.

[0021] The image display device may be a display such as a meter that is standard equipment on the vehicle 1, or a retrofitted display, but if the vehicle 1 is already equipped with a car navigation system, it is also possible to use the display of that car navigation system.

[0022] The driving assistance device 2 provides the driver of the vehicle 1 with information for assisting driving, and includes at least a camera 21 and a control unit 22.

[0023] The camera 21 is an imaging device that captures images (still images and moving images) of the front, and is, for example, a video camera with a built-in imaging element (CCD: Charge-Coupled Device, CMOS: Complementary Metal-Oxide-Semiconductor).

[0024] The control unit 22 performs an analysis process on the image captured by the camera 21 to recognize at least one of the display form of the traffic light (7 or 8) ahead of the vehicle 1 and the written content (e.g., characters) of the auxiliary sign 9, and executes driving assistance processing according to the recognition result. A known method can be adopted as the specific method for the analysis process by the control unit 22.

[0025] The driving assistance process recognizes the original display form of the traffic light 7, and provides information for assisting the driving of the vehicle 1 (referred to as driving assistance information) to the driver of the vehicle 1 according to the recognition result. In the driving assistance process by the control unit 22, a necessary command is issued to an in-vehicle control unit (not shown) to cause the notification unit 11 of the vehicle 1 to notify the driving assistance information.

[0026] In addition, when the control unit 22 recognizes that there is a traffic light (7 or 8) ahead of the vehicle 1 based on the image captured by the camera 21, and determines that the recognized traffic light (7 or 8) is a warning traffic light 8, it prohibits the execution of the driving assistance processing.

[0027] The control unit 22 of the driving assistance device 2 is made up of a known electronic control unit (ECU) and includes a central processing unit (CPU), a non-volatile storage device (Read Only Memory: ROM), a temporary storage device (Random Access Memory: RAM), etc. The ROM stores various control programs and maps to be referenced when executing the various control programs. The CPU executes arithmetic processing based on the various control programs and maps stored in the ROM. The RAM is a memory that temporarily stores the results of calculations by the CPU, data input from each sensor, etc.

[0028] Next, the operation of the driving support device 2 will be described with reference to the flowchart shown in FIG.

[0029] First, in step S1, it is determined whether or not a traffic light (7 or 8) is present on the road 5 based on information received from the vehicle 1 (images captured by the camera 21 mounted on the vehicle 1).

[0030] In this step S1, by performing an analysis process on the image captured by the camera 21, it is possible to recognize the road 5, the actual traffic light 7, the warning traffic light 8, the auxiliary sign 9, the curve 6 with a curvature greater than a predetermined value, etc. in the captured image.

[0031] If the determination in step S1 is affirmative, the process proceeds to step S2. In step S2, it is determined whether or not an auxiliary sign 9 is present ahead of the vehicle 1 on the road 5. In step S2, the presence or absence of the auxiliary sign 9 and the contents of the auxiliary sign 9 (e.g., text) are recognized based on the image captured by the camera 21.

[0032] If the determination in step S2 is affirmative, it is determined in step S3 whether or not the contents (for example, characters) of the auxiliary sign 9 ahead of the vehicle 1 include the character string "warning signal."

[0033] If the determination in step S3 is negative, the process proceeds to step S4. In step S4, it is determined whether the display mode of the traffic light (7 or 8) recognized in step S1 is, for example, "two yellow lights flashing alternately." The determination criterion in step S4 may be any display mode that is not a display mode that should normally be displayed on the traffic light 7, and it may be, for example, "flashing yellow."

[0034] If the determination in step S4 is negative, the process proceeds to step S5, where it is determined whether the location of the traffic light (7 or 8) recognized in step S1 is on a curve 6 with a curvature equal to or greater than a predetermined value.

[0035] If a negative determination is made in step S2 or step S5, it is determined in step S6 that the traffic light (7 or 8) ahead of the vehicle 1 is not the warning traffic light 8, and the execution of the driving assistance process is permitted. After this, the flow chart is terminated.

[0036] Furthermore, if an affirmative determination is made in any one of steps S3 to S5, it is determined that the traffic light (7 or 8) ahead of the vehicle 1 is a warning traffic light 8, and the execution of the driving assistance process is prohibited. After this, the flowchart ends.

[0037] In the flowchart of Figure 2, step S1 corresponds to the first judgment unit described in the claims, step S2 corresponds to the second judgment unit described in the claims, step S3 corresponds to the third judgment unit described in the claims, step S4 corresponds to the fourth judgment unit described in the claims, step S5 corresponds to the fifth judgment unit described in the claims, step S6 corresponds to the first management unit described in the claims, and step S7 corresponds to the second management unit described in the claims.

[0038] Incidentally, when the location of the warning traffic light 8 and auxiliary sign 9 is on a curve 6 with a curvature equal to or greater than a predetermined value, as in the case of road 5 shown in Figure 3, it is difficult for the driver of vehicle 1 to see the actual traffic light 7 before the curve 6, and if a traffic light (7 or 8) is present on such a curve 6, it can be said that it is difficult to determine whether the traffic light (7 or 8) is the actual traffic light 7 or the warning traffic light 8. Therefore, if the driving assistance device 2 determines that the traffic light (7 or 8) on the curve 6 is the actual traffic light 7, it will provide driving assistance to stop vehicle 1 in a position before the traffic light (7 or 8) on the curve 6, as shown by the dashed dotted line in Figure 3, which can be said to be inappropriate.

[0039] However, in the case of the road 5 described above, the driving assistance device 2 of this embodiment will make a positive determination in step S5 of the flowchart shown in Fig. 2 based on the image of the curve 6 with a curvature equal to or greater than the predetermined value, and will therefore determine in step S7 that the traffic light (7 or 8) at the curve 6 is the warning traffic light 8, prohibiting the execution of the driving assistance process. This will prevent inappropriate driving assistance from being provided, such as stopping the vehicle 1 before the warning traffic light 8, thereby making it possible to avoid a situation in which a following vehicle would rear-end the vehicle if the vehicle were to be stopped due to the inappropriate driving assistance.

[0040] Moreover, the driving assistance device 2 of this embodiment has a simple configuration that can be mounted on the vehicle 1, and is not a large-scale configuration like the above-mentioned Patent Document 1, which "uses the vehicle 30 and the server 50 connected to the vehicle 30 via the Internet INT and the communication carrier BS to stop the vehicle 30 at the correct stopping position in front of the actual traffic light 68, rather than stopping the vehicle 30 in front of the traffic light 69, which is a warning signal light." Furthermore, there is no need to "pre-store information about the warning signal and information about the location of the warning traffic light in the memory unit 56 of the server 50," as in the above-mentioned Patent Document 1, so it is possible to reduce the equipment costs of the driving assistance device 2 of the present invention.

[0041] As described above, according to the driving assistance device 2 of one embodiment of the present invention, it is possible to reduce equipment costs and also to reliably recognize the warning traffic light 8.

[0042] The present invention is not limited to the above-described embodiments, but can be modified as appropriate within the scope of the claims and the equivalents thereof.

[0043] (1) In the above embodiment, an example is given in which "steps S2, S3, S4, and S5 in FIG. 2 are used" to make a determination as to whether to allow or prohibit the execution of the driving assistance processing, but the present invention is not limited to this.

[0044] For example, although not shown, it is possible to eliminate steps S2 to S4 in FIG. 2 and move to step S5 if a positive determination is made in step S1.

[0045] Also, for example, although not shown, it is possible to eliminate steps S2, S3, and S5 in FIG. 2 and proceed to step S4 if a positive judgment is made in step S1, and proceed to step S6 if a negative judgment is made in step S4.

[0046] Furthermore, although not shown, it is possible to eliminate step S5 in FIG. 2 and move to step S6 if a negative determination is made in step S4.

[0047] (2) In the above embodiment, for example, although not shown, the vehicle 1 may use, in addition to the camera 21, other devices, such as millimeter wave radar, a GPS (Global Positioning System) device, an acceleration sensor, and a vehicle speed sensor, as devices required to recognize the locations of the original traffic lights 7, warning traffic lights 8, and auxiliary signs 9 installed on the road 5, the display format of the original traffic lights 7 and warning traffic lights 8, and the contents of the auxiliary signs 9.

[0048] The millimeter-wave radar transmits millimeter waves (electromagnetic waves with a wavelength of 1 to 10 millimeters) toward an object and receives the reflected waves to detect the distance to the object. The GPS device detects positioning information related to the vehicle's position (e.g., latitude, longitude, altitude). The acceleration sensor detects the acceleration of the vehicle 1 (longitudinal acceleration, lateral acceleration, vertical acceleration, etc.). The vehicle speed sensor detects the traveling speed (vehicle speed) of the vehicle 1.

[0049] In recent years, the acceleration sensor and the vehicle speed sensor have been installed as standard equipment on the vehicle 1, and the outputs from these sensors can be used for driving assistance processing.

[0050] (3) In the above embodiment, the driving assistance device 2 is provided with the camera 21, but the present invention is not limited to this.

[0051] For example, although not shown, if the vehicle 1 is equipped with a camera, the on-board camera can be used instead of the camera 21 of the driving assistance device 2. [Industrial Applicability]

[0052] The present invention can be suitably used in a driving assistance device that provides driving assistance information to a driver of a vehicle. [Explanation of symbols]

[0053] 1 Vehicle, 11 Notification unit, 2 Driving assistance device, 21 Camera, 22 Control unit, 5 Road, 6 Curve, 7 Original traffic light, 8 Warning signal, 9 Auxiliary sign.

Claims

1. A driving assistance device that is mounted on a vehicle and recognizes at least one of a display form of a traffic light and a description of an auxiliary sign ahead of the vehicle based on an image captured by a camera that captures an image ahead of the vehicle, and that executes a driving assistance process to notify a driver of the vehicle of the recognized information as driving assistance information, A driving assistance device characterized by prohibiting the execution of the driving assistance processing when it recognizes that there is a traffic light ahead of the vehicle based on the captured image, and when it determines that the recognized traffic light is a warning traffic light based on at least one of the display form of the recognized traffic light, the content of the auxiliary sign, and the curvature of the road where the traffic light is installed ahead of the vehicle.

2. The driving assistance device according to claim 1 is a camera that captures an image of a scene ahead of the vehicle; and a control unit that executes the driving assistance process; The driving assistance device is characterized in that the vehicle is provided with a notification unit that notifies the driving assistance information.

3. The driving assistance device according to claim 2, The control unit includes a first determination unit that determines whether or not there is a traffic light ahead of the vehicle based on the captured image; a second determination unit that determines whether or not an auxiliary sign is present ahead of the vehicle based on the captured image when the first determination unit makes a positive determination; a third determination unit that determines whether or not a warning signal is included in the characters of the auxiliary sign when the second determination unit makes a positive determination; a fourth determination unit that determines whether or not a traffic light ahead of the vehicle is flashing two yellow lights alternately when a negative determination is made by the third determination unit; and a fifth determination unit that determines whether or not a location of a traffic signal ahead of the vehicle is on a curve with a curvature equal to or greater than a predetermined value when a negative determination is made by the fourth determination unit; a first management unit that determines that the traffic light ahead of the vehicle is not a warning traffic light and permits execution of the driving assistance process when a negative determination is made by the second determination unit or the fifth determination unit; A driving assistance device characterized by including a second management unit that, when a positive judgment is made by any of the third to fifth judgment units, determines that the traffic light ahead of the vehicle is a warning traffic light and prohibits the execution of the driving assistance processing.

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