Driving assistance device and driving assistance method

Abstract

To suppress delay of detection of a predetermined target in front of a vehicle.SOLUTION: A driving assistance device 100 performs driving assistance of a vehicle when a predetermined target is present in a driving assistance area set in front of the vehicle. When setting change of area of a driving assistance area is possible and setting change of the area of the driving assistance area when a crosswalk is detected in front of the vehicle in an enlargement direction is possible, the driving assistance device 100 is configured to enlarge the area of the driving assistance area so as to spread outward of the vehicle so as to include the entire area of the driving assistance area when the crosswalk is detected.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a driving assistance device and a driving assistance method. [Background technology]

[0002] Patent Document 1 discloses a conventional obstacle detection device that, when a crosswalk is present within an obstacle detection area set in front of the vehicle, changes the shape of the obstacle detection area to accommodate the shape of the crosswalk. Specifically, when a crosswalk is present within the obstacle detection area set in front of the vehicle, this conventional obstacle detection device expands the left and right width of the obstacle detection area on the crosswalk to match the left and right width of the crosswalk. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-271766 Summary of the Invention [Problem to be solved by the invention]

[0004] However, on a crosswalk, there are multiple white lines extending in the front-to-back direction that make up the crosswalk, and these lines are interspersed with the silhouettes of pedestrians. This makes it relatively difficult to detect pedestrians on a crosswalk, and as a result, there is a risk that pedestrian detection will be delayed.

[0005] The present invention has been made in view of the above-mentioned problems, and has as its object to suppress delays in detecting a predetermined target ahead of the vehicle. [Means for solving the problem]

[0006] In order to solve the above problems, a driving assistance device according to one aspect of the present invention, which provides driving assistance to a vehicle when a specified target is present in a driving assistance area set in front of the vehicle, is configured so that the area of ​​the driving assistance area can be changed, and if the area of ​​the driving assistance area can be changed in an expanding direction when a crosswalk is detected in front of the vehicle, the area of ​​the driving assistance area is expanded so as to extend outward from the vehicle so as to encompass the entire area of ​​the driving assistance area when the crosswalk is detected.

[0007] Furthermore, a driving assistance device method according to one aspect of the present invention, which provides driving assistance for a vehicle when a specified target is present in a driving assistance area set in front of the vehicle, is capable of changing the area size of the driving assistance area, and if the area size of the driving assistance area can be changed in an expanding direction when a crosswalk is detected in front of the vehicle, expands the area size of the driving assistance area so that it extends outward from the vehicle to encompass the entire area of ​​the driving assistance area when the crosswalk is detected. [Effects of the Invention]

[0008] According to these aspects of the present invention, the driving assistance area is expanded when a pedestrian crossing is detected, thereby making it possible to prevent delays in detecting a predetermined target. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a driving assistance device according to an embodiment of the present invention; [Figure 2A] FIG. 2 is a diagram showing an example of a driving assistance area set on the right front side of the vehicle; [Figure 2B] FIG. 2 is a diagram showing an example of a driving assistance area set on the left front side of the vehicle; [Figure 3] 4 is a flowchart illustrating setting control of a driving assistance area according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, like components are designated by like reference numerals.

[0011] FIG. 1 is a schematic diagram of a driving assistance device 100 according to an embodiment of the present invention.

[0012] The driving assistance device 100 includes a surrounding sensor 1, a vehicle sensor 2, an HMI (Human Machine Interface) 3, an actuator 4, and a control device 5. The surrounding sensor 1, the vehicle sensor 2, the HMI 3, the actuator 4, and the control device 5 are each communicatively connected via an in-vehicle network 7 that complies with a standard such as a controller area network.

[0013] The surrounding sensor 1 is a sensor for generating surrounding data that represents the situation around a vehicle (hereinafter referred to as "host vehicle") for which driving assistance is provided by the driving assistance device 100. In this embodiment, the surrounding sensor 1 includes one or more external cameras 11 for capturing images of the surroundings of the host vehicle, including the area ahead of the host vehicle.

[0014] The external camera 11 captures the surroundings of the vehicle at a predetermined frame rate (for example, 10 [Hz] to 40 [Hz]) and generates a surrounding image showing the surroundings of the vehicle. Every time the external camera 11 generates a surrounding image, it transmits the generated surrounding image to the control device 5 as surrounding data.

[0015] Instead of or in addition to the external camera 11, a distance measurement sensor that measures the distance to a target such as a vehicle or a pedestrian present around the vehicle may be provided as the surrounding sensor 1. Examples of distance measurement sensors include a LiDAR (Light Detection And Ranging) that emits radar light and measures distance based on the reflected light, and a millimeter wave radar sensor that emits radio waves and measures distance based on the reflected waves.

[0016] The vehicle sensor 2 is a sensor for generating vehicle data representing the status of the vehicle. In this embodiment, the vehicle sensor 2 includes a speed sensor 21 that generates speed data indicating the traveling speed of the vehicle, and a positioning sensor 22 that generates current position data indicating the current position of the vehicle, such as latitude and longitude. However, the vehicle sensor 2 is not limited to these sensors. The vehicle sensor 2 transmits each acquired data to the control device 5 as vehicle data.

[0017] The HMI 3 is a user interface for exchanging information between the vehicle and its occupants. The HMI 3 includes an output device 31 for notifying the vehicle occupant through the vehicle occupant's bodily senses (for example, sight, hearing, touch, etc.), and an input device 32 for the vehicle occupant to perform input operations and response operations. In this embodiment, the output device 31 includes displays (for example, a meter display, a center display, a head-up display, etc.) 311 and a speaker 312, and the input device 32 includes a touch panel 321 and a microphone 322.

[0018] The HMI 3 displays information (e.g., text information or image information) corresponding to a display signal received from the control device 5 on a display 311, and outputs sound corresponding to a sound signal from a speaker 312. The HMI 3 also transmits data input by a vehicle occupant via a panel or voice input (hereinafter referred to as "occupant input data") to the control device 5 via the input device 32.

[0019] The HMI 3 may be pre-installed in the vehicle, or may be a terminal such as a smartphone owned by the vehicle occupant. In the latter case, for example, information may be exchanged between the vehicle and the vehicle occupant's terminal by short-range wireless communication, or information may be exchanged indirectly via communication between the vehicle occupant's terminal and an external server (not shown).

[0020] The actuator 4 is a device used for driving control of the host vehicle. In this embodiment, the actuator 4 includes an acceleration actuator 41 (for example, at least one of an engine and a motor) that controls acceleration of the host vehicle, a brake actuator 42 (for example, a hydraulic actuator) that controls braking of the host vehicle, and a steering actuator 43 (for example, a steering motor) that controls steering of the host vehicle.

[0021] The control device 5 is an ECU (Electronic Control Unit) including a communication unit 51, a storage unit 52, and a processing unit 53.

[0022] The communication unit 51 includes an interface circuit for connecting the control device 5 to the in-vehicle network 7. The communication unit 51 supplies various data received from the sensors 1 and 2, the HMI 3, etc. to the processing unit 53. The communication unit 51 also outputs various signals output from the processing unit 53 to the HMI 3, the actuator 4, etc.

[0023] The storage unit 52 has a storage medium such as a hard disk drive (HDD), a solid disk drive (SSD), or a semiconductor memory, and stores various computer programs and data used for processing by the processing unit 53.

[0024] The processing unit 53 has one or more central processing units (CPUs) and their peripheral circuits, and executes various computer programs stored in the storage unit 52. The processing unit 53 is, for example, a processor. The processing unit 53 may further include other arithmetic circuits such as a logic unit, a numerical calculation unit, or a graphics processing unit. The processing unit 53 executes processing in accordance with the computer programs, thereby functioning as a feature detection unit 61, a target detection unit 62, and a driving assistance unit 63, and operates as functional units (modules) that realize predetermined functions. In the following description, when processing is described using each of the functional units 61 to 63 as the subject, it indicates that the processing unit 53 is executing a program that realizes each of the functional units 61 to 63.

[0025] The following describes the specific processing carried out by the control device 5. That is, the details of each of the functional units 61 to 63 realized by the processing unit 53 executing processing according to a program will be described.

[0026] The feature detection unit 61 detects features based on the surrounding data received from the surrounding sensor 1. In this embodiment, the feature detection unit 61 detects a crosswalk ahead based on the surrounding image received from the external camera 11. The feature detection unit 61 can detect a crosswalk ahead based on the surrounding image received from the external camera 11, for example, using an image recognition method such as pattern matching or semantic segmentation. When the feature detection unit 61 detects a crosswalk, it detects crosswalk data related to the crosswalk. The crosswalk data includes, for example, the distance to the crosswalk. The distance to the crosswalk can be detected based, for example, on the Y coordinate (ordinate) on the surrounding image where the crosswalk is detected, or the size of the crosswalk area extracted from the surrounding image by image recognition.

[0027] The feature detection unit 61 can also detect a crosswalk ahead by, for example, inputting the surrounding image received from the external camera 11 into a classifier that has been trained in advance to detect crosswalks. In this way, the method for detecting features is not particularly limited, and various known methods may be used for detection.

[0028] The target detection unit 62 detects targets present around the vehicle based on the surrounding data received from the surrounding sensor 1. The target detection unit 62, for example, sequentially inputs surrounding images received from the external camera 11 into a classifier to detect areas in the surrounding images where targets such as vehicles, motorcycles, pedestrians, traffic lights, and buildings are depicted, and the types of targets depicted in those areas. The classifier may be, for example, a convolutional neural network (CNN) having multiple convolution layers connected in series from the input side to the output side. The target detection unit 62 estimates the distance from the external camera 11 to the target using the standard target sizes stored in the memory unit 52 for each type of target and the size of the target detected in the surrounding images, and calculates the position and speed of the target by tracking the target detected in the surrounding images over time. Note that the target detection method is not limited to the above method, and various known detection methods may be used.

[0029] The driving assistance unit 63 provides driving assistance to the driver of the host vehicle when a predetermined target is present in a driving assistance area (see FIGS. 2A and 2B) set ahead of the host vehicle. The predetermined target is a moving object, such as a pedestrian or a motorcycle, that is moving toward the host vehicle and may be traveling on a crosswalk. The driving assistance unit 63 can provide driving assistance to the driver, for example, by issuing a notification to alert the driver or a notification urging the driver to slow down, via the HMI 3. Furthermore, the driving assistance unit 63 can also provide driving assistance to the driver, for example, by executing driving control of the host vehicle (for example, deceleration, steering avoidance, etc.) via the actuator 4, in addition to or instead of the notification via the HMI 3.

[0030] Hereinafter, the driving assistance provided by the driving assistance unit 63 will be described in more detail with reference to FIGS. 2A and 2B.

[0031] 2A and 2B are diagrams showing examples of driving assistance areas set on the right front side and the left front side of the vehicle.

[0032] 2A and 2B, the driving assistance areas set on the right front side and the left front side of the vehicle are symmetrical in shape, and the area of ​​the areas can be changed in stages or continuously according to the driver's preference. In this embodiment, the driving assistance areas can be changed in three stages: a first area, a second area, and a third area, in order of increasing area size.

[0033] The first area is a predetermined area on the right front side and the left front side of the vehicle. The second area is an area obtained by expanding the first area outward from the vehicle so as to encompass the entire first area. The third area is an area obtained by expanding the second area outward from the vehicle so as to encompass the entire second area.

[0034] The driving assistance area is initially set to the third area, which has the largest area size. The larger the area of ​​the driving assistance area, the earlier it is possible to detect predetermined targets present on the right and left front sides of the vehicle, but the frequency of driving assistance intervention increases accordingly. For this reason, some drivers may feel that the driving assistance area is too large and set the driving assistance area to the second or first area.

[0035] On the other hand, on a crosswalk, there are multiple white lines that extend forward and backward and are spaced apart, so the silhouettes of pedestrians are mixed in with the multiple white lines that make up the crosswalk. This makes it relatively difficult to detect pedestrians on a crosswalk in the first place, and as a result, there is a risk that pedestrian detection will be delayed.

[0036] Therefore, when a crosswalk is detected ahead, it is desirable to be able to detect pedestrians as early as possible. Therefore, in this embodiment, if the driving assistance area when a crosswalk is detected ahead is not the third area, the driving assistance area is temporarily changed to the third area.

[0037] 3 is a flowchart illustrating the setting control of the driving assistance area according to this embodiment, which is performed by the driving assistance unit 63 and, in turn, the control device 5. The control device 5 switches and executes this routine at a predetermined calculation period ΔT.

[0038] In step S1, the control device 5 determines whether or not a pedestrian crossing exists ahead based on the detection result of the feature detection unit 61. If a pedestrian crossing exists ahead, the control device 5 proceeds to the processing of step S2. On the other hand, if a pedestrian crossing does not exist ahead, the control device 5 ends the current processing.

[0039] In step S2, the control device 5 determines whether the crosswalk ahead is a crosswalk without a traffic light. If the crosswalk ahead is a crosswalk without a traffic light, the control device 5 proceeds to the processing of step S3. On the other hand, if the crosswalk ahead is a crosswalk with a traffic light, the control device 5 proceeds to the processing of step S4.

[0040] Whether the crosswalk ahead is a crosswalk without a traffic light can be determined, for example, based on the crosswalk detection result by the feature detection unit 61 and the traffic light detection result by the target detection unit 62. In this embodiment, if the target detection unit 62 does not detect a traffic light within a predetermined distance before or after the crosswalk detected by the feature detection unit 61, the control device 5 determines that the crosswalk is a crosswalk without a traffic light.

[0041] In this embodiment, the reason for determining whether a traffic light is installed at a crosswalk is as follows: Collision accidents with moving objects moving across a crosswalk are particularly likely to occur at crosswalks without traffic lights, and if the driving assistance area is expanded against the driver's will at a crosswalk with traffic lights, the frequency of unnecessary driving assistance interventions, such as providing driving assistance in response to pedestrians waiting at a traffic light, may increase, and the driver may find the driving assistance annoying.

[0042] In step S3, if the driving assistance area is not set to the third area, the control device 5 temporarily expands the driving assistance area. In this embodiment, the control device 5 temporarily changes the driving assistance area to the third area. The temporarily changed driving assistance area is returned to the original area, for example, when the vehicle passes a crosswalk.

[0043] In step S4, the control device 5 leaves the driving assistance area as it is currently set.

[0044] The driving assistance device 100 according to the present embodiment described above provides driving assistance for a vehicle when a predetermined target is present in a driving assistance area set in front of the vehicle. The driving assistance device is capable of changing the area setting of the driving assistance area, and if the area of ​​the driving assistance area can be changed in an enlarged direction when a crosswalk is detected in front of the vehicle, the driving assistance device is configured to enlarge the area of ​​the driving assistance area so that it expands outward from the vehicle to encompass the entire driving assistance area when the crosswalk is detected. The predetermined target is, for example, a moving object capable of crossing a crosswalk, such as a pedestrian, moving in the direction of the vehicle.

[0045] In this way, when a pedestrian crossing is detected ahead of the vehicle, the driving assistance area is expanded, which makes it possible to prevent delays in detecting specific targets that are the target of driving assistance, and as a result, it is also possible to prevent delays in the activation timing of driving assistance.

[0046] In particular, in this embodiment, the area of ​​the driving assistance area is expanded outward from the vehicle so as to encompass the entire area of ​​the driving assistance area when a crosswalk is detected. Therefore, for example, a specific target such as a pedestrian traveling on the sidewalk outside the crosswalk on the roadway, i.e., a specific target about to cross the crosswalk, may be captured within the driving assistance area. In this case, there is no need to detect the specific target on the crosswalk, so a decrease in detection accuracy can be suppressed. Therefore, delays in detecting the specific target can be suppressed.

[0047] Furthermore, the driving assistance device 100 according to this embodiment is configured to expand the area of ​​the driving assistance area to the maximum area that can be set when the area of ​​the driving assistance area when a crosswalk is detected ahead of the vehicle is not the largest among the settable area areas.

[0048] As a result, when a pedestrian crossing is detected ahead, the driving assistance area can be expanded to the maximum extent possible, thereby preventing delays in detecting specific targets that are the target of driving assistance.

[0049] In this embodiment, the crosswalks that are the target of driving assistance are those without traffic lights. This prevents unnecessary driving assistance from being provided, such as in response to a pedestrian waiting at a traffic light. This prevents the driver from feeling annoyed by the driving assistance.

[0050] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0051] For example, in the above embodiment, when a crosswalk is detected ahead, the driving assistance area is expanded to the maximum third area, but it may be expanded to a size smaller than the area when a crosswalk is detected ahead, rather than to the maximum.

[0052] Furthermore, for example, in the above embodiment, the computer program executed in the control device 5 may be provided in a form recorded on a computer-readable portable recording medium such as a semiconductor memory, a magnetic recording medium, or an optical recording medium. [Explanation of symbols]

[0053] 100 Driving assistance device

Claims

1. A driving assistance device that performs driving assistance for a vehicle when a predetermined target is present in a driving assistance area set in front of the vehicle, The area of ​​the driving assistance area can be changed, When the area size of the driving assistance area when a pedestrian crossing is detected ahead of the vehicle can be changed in an enlarged direction, the area size of the driving assistance area is configured to be enlarged so as to spread outward from the vehicle so as to encompass the entire area of ​​the driving assistance area when the pedestrian crossing is detected. Driving assistance device.

2. When a crosswalk is detected ahead of the vehicle, if the area of ​​the driving assistance area is not the largest among the settable area areas, the area of ​​the driving assistance area is expanded to the largest settable area area. The driving assistance device according to claim 1 .

3. The crosswalk is a crosswalk without a traffic light. The driving assistance device according to claim 1 or 2.

4. the predetermined target is a moving object that is moving toward the vehicle and is capable of traveling on a crosswalk, The driving assistance device according to claim 1 or 2.

5. A driving assistance method for a vehicle when a predetermined target is present in a driving assistance area set in front of the vehicle, the method comprising: The area of ​​the driving assistance area can be changed, If the area size of the driving assistance area when a crosswalk is detected ahead of the vehicle can be changed in an enlarged direction, the area size of the driving assistance area is enlarged so as to expand outward from the vehicle so as to encompass the entire area of ​​the driving assistance area when the crosswalk is detected. Driving assistance methods.

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