Driving support device

Abstract

To provide a driving support device which can accurately estimate a risk of a collision with an object which can exist in a detected dead angle region according to a time change of the dead angle region.SOLUTION: A driving support device supports driving of an own vehicle on the basis of a risk existing around the own vehicle. The driving support device includes: a dead angle region calculation section which specifies a dead angle region at a prescribed time and calculates a time change of the dead angle region accompanying traveling of the own vehicle; and a risk estimation section which assumes an object which can exist in the dead angle region specified at the prescribed time and estimates a potential risk of a collision between the own vehicle and the object which can exist in the dead angle region on the basis of the time change of the dead angle region specified at the prescribed time and an assumption operation within the dead angle region of the assumed object.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a driving assistance device that supports the driving of a vehicle so as to avoid collisions with surrounding obstacles.

Background Art

[0002] In recent years, for the purpose of mainly reducing traffic accidents and driving load, the practical application of vehicles equipped with driving assistance functions and autonomous driving functions such as autonomous emergency braking (AEB) and adaptive cruise control (ACC) has been promoted. For example, based on information detected by various sensors such as an external camera and LiDAR (Light Detection and Ranging) provided on the host vehicle, an obstacle existing around the host vehicle is detected, and a device that supports the driving of the host vehicle so as to avoid a collision between the host vehicle and the obstacle is known. However, among traffic accidents, there are events that are difficult to avoid when preparatory actions such as deceleration are not taken in advance assuming an accident, such as a sudden jump from a blind spot area.

[0003] On the other hand, for example, Patent Document 1 discloses a technique for foreseeably avoiding a potential risk in consideration of the occurrence of a potential risk that is not detected by the host vehicle, such as a sudden jump from a blind spot area, on the planned travel route of the host vehicle. Specifically, Patent Document 1 discloses a driving assistance device that starts automatic deceleration control when a braking operation or a steering operation of the driver is detected after detecting a blind spot area seen from the vehicle in the traveling direction of the vehicle, or when a predetermined time has elapsed. Patent Document 1 also describes presenting to the driver the risk of a pedestrian or a bicycle jumping out from the blind spot area when the blind spot area is detected.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the blind spot area seen from the host vehicle decreases as the host vehicle moves forward, it is considered that when the area of the blind spot area becomes equal to or less than a predetermined value, there is no potential risk or the content of the potential risk is limited. For example, as the blind spot area decreases, the types of objects that can exist in the blind spot area may be limited to smaller ones, or the speed at which an object that can exist in the decreasing blind spot area jumps onto the trajectory of the host vehicle may be limited according to the moving speed of the object. In Patent Document 1, since such a change in the blind spot area is not considered, even when there is no potential risk or the content of the potential risk can be limited, the vehicle is controlled based on the initially calculated potential risk. Therefore, even in a situation where it is clear that there is no potential risk in the blind spot area, there is a risk that the control after the potential risk such as acceleration control cannot be shifted until it is determined by a sensor or the like that there is no object in the blind spot area.

[0006] The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide a driving support device capable of accurately estimating the risk of collision with an object that may exist in a blind spot area according to the time change of the detected blind spot area.

Means for Solving the Problems

[0007] In order to solve the above problems, according to an aspect of the present disclosure, there is provided a driving support device that supports the driving of a host vehicle based on risks existing around the host vehicle, the driving support device including: a blind spot area calculation unit that specifies a blind spot area at a predetermined time and calculates a time change of the blind spot area as the host vehicle moves forward; and a risk estimation unit that assumes an object that may exist in the blind spot area specified at the predetermined time and estimates a potential risk of collision between the host vehicle and an object that may exist in the blind spot area based on the time change of the blind spot area specified at the predetermined time and the assumed behavior of the object in the blind spot area.

Advantages of the Invention

[0008] As described above, according to the present disclosure, it is possible to accurately estimate the risk of collision with an object that may exist in the blind spot area according to the time change of the detected blind spot area.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

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Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0010] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present disclosure will be described in detail. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0011] <1. Overall Configuration of Vehicle> First, an example of the overall configuration of a vehicle equipped with a driving assistance device according to an embodiment of the present disclosure will be described.

[0012] FIG. 1 is a schematic diagram showing a configuration example of a vehicle 1 equipped with a driving assistance device 50. The vehicle 1 shown in FIG. 1 is configured as a four-wheel drive vehicle that transmits the driving torque output from a driving power source 9 that generates the driving torque of the vehicle to the left front wheel 3LF, the right front wheel 3RF, the left rear wheel 3LR, and the right rear wheel 3RR (hereinafter, collectively referred to as "wheel 3" when no particular distinction is required). The driving power source 9 may be an internal combustion engine such as a gasoline engine or a diesel engine, may be a driving motor, or may be provided with both an internal combustion engine and a driving motor.

[0013] Note that the vehicle 1 may be, for example, an electric vehicle equipped with two driving motors, a front-wheel driving motor and a rear-wheel driving motor, or an electric vehicle equipped with a driving motor corresponding to each wheel 3. Further, when the vehicle 1 is an electric vehicle or a hybrid electric vehicle, the vehicle 1 is equipped with a secondary battery that stores electric power supplied to the driving motor, and a generator such as a motor or a fuel cell that generates electric power to be charged to the battery.

[0014] Vehicle 1 includes, as devices used for driving control of Vehicle 1, a driving power source 9, an electric steering device 15, and brake devices 17LF, 17RF, 17LR, 17RR (hereinafter, collectively referred to as "brake device 17" when no particular distinction is required). The driving power source 9 outputs driving torque that is transmitted to the front-wheel drive shaft 5F and the rear-wheel drive shaft 5R via a transmission (not shown), a front-wheel differential mechanism 7F, and a rear-wheel differential mechanism 7R. The driving of the driving power source 9 and the transmission is controlled by a vehicle control unit 41 configured to include one or more electronic control units (ECUs: Electronic Control Unit).

[0015] An electric steering device 15 is provided on the front-wheel drive shaft 5F. The electric steering device 15 includes an electric motor and a gear mechanism (not shown) and adjusts the steering angles of the left front wheel 3LF and the right front wheel 3RF by being controlled by the vehicle control unit 41. During manual driving, the vehicle control unit 41 controls the electric steering device 15 based on the steering angle of the steering wheel 13 by the driver. Also, during autonomous driving, the vehicle control unit 41 controls the electric steering device 15 based on the set driving trajectory.

[0016] The brake devices 17LF, 17RF, 17LR, 17RR apply braking force to the front, rear, left, and right drive wheels 3LF, 3RF, 3LR, 3RR, respectively. The brake device 17 is configured as, for example, a hydraulic brake device, and a predetermined braking force is generated by controlling the hydraulic pressure supplied to each brake device 17 by the vehicle control unit 41. When Vehicle 1 is an electric vehicle or a hybrid electric vehicle, the brake device 17 is used in combination with regenerative braking by the driving motor.

[0017] The vehicle control unit 41 includes one or more electronic control units that control the driving of a driving force source 9 that outputs the driving torque of the vehicle 1, an electric steering device 15 that controls the steering angle of a steering wheel or a steered wheel, and a brake device 17 that controls the braking force of the vehicle 1. The vehicle control unit 41 may have a function of controlling the driving of a transmission that shifts the output output from the driving force source 9 and transmits it to the wheels 3. The vehicle control unit 41 is configured to be able to acquire information transmitted from the driving assistance device 50 and is configured to be able to execute automatic driving control of the vehicle 1.

[0018] In addition, the vehicle 1 includes front cameras 31LF and 31RF, a rear camera 31R, a vehicle state sensor 35, a GPS (Global Positioning System) sensor 37, and an HMI (Human Machine Interface) 43. Note that in this embodiment, the rear camera 31R may be omitted.

[0019] The front cameras 31LF and 31RF and the rear camera 31R constitute surrounding environment sensors for acquiring information on the surrounding environment of the vehicle 1. The front cameras 31LF and 31RF and the rear camera 31R capture the front or rear of the vehicle 1 and generate image data. The front cameras 31LF and 31RF and the rear camera 31R include imaging elements such as CCD (Charged-Coupled Devices) or CMOS (Complementary Metal-Oxide-Semiconductor), and transmit the generated image data to the driving assistance device 50. In the vehicle 1 shown in FIG. 1, the front cameras 31LF and 31RF are configured as a stereo camera including a pair of left and right cameras, and the rear camera 31R is configured as a so-called monocular camera, but each may be either a stereo camera or a monocular camera.

[0020] In addition to the front cameras 31LF and 31RF and the rear camera 31R, the vehicle 1 may be provided with cameras on the side mirrors 11L and 11R, for example, to capture images of the left rear or right rear. Additionally, the vehicle 1 may be equipped with one or more sensors, such as a LiDAR (Light Detection And Ranging), a radar sensor such as a millimeter-wave radar, or an ultrasonic sensor, as ambient environment sensors for acquiring information about the surrounding environment.

[0021] The vehicle state sensor 35 consists of at least one sensor for detecting the operating state and behavior of the vehicle 1. The vehicle state sensor 35 includes, for example, at least one of a steering angle sensor, an accelerator position sensor, a brake stroke sensor, a brake pressure sensor, or an engine speed sensor, and detects the operating state of the vehicle 1, such as the steering angle of the steering wheel or the steering wheel, the accelerator opening, the brake operation amount, or the engine speed. Further, the vehicle state sensor 35 includes, for example, at least one of a vehicle speed sensor, an acceleration sensor, or an angular velocity sensor, and detects the behavior of the vehicle, such as the vehicle speed, longitudinal acceleration, lateral acceleration, or yaw rate. The vehicle state sensor 35 transmits a sensor signal containing the detected information to the driving assistance device 50.

[0022] The GPS sensor 37 receives satellite signals from GPS satellites. The GPS sensor 37 transmits the position information of the vehicle 1 on the map data included in the received satellite signals to the driving assistance device 50. Instead of the GPS sensor 37, an antenna for receiving satellite signals from another satellite system for specifying the position of the vehicle 1 may be provided.

[0023] The HMI 43 is driven by the driving assistance device 50 and presents various information to the driver by means such as image display and voice output. The HMI 43 includes, for example, a display device provided in the instrument panel and a speaker provided in the vehicle. The display device may be the display device of the navigation system. Further, the HMI 43 may include a HUD (Head-Up Display) that performs display on the front window by superimposing the scenery around the own vehicle 1.

[0024] <2. Driving Support Device> Next, the driving support device 50 according to the present embodiment will be specifically described.

[0025] (2-1. Configuration Example) FIG. 2 is a block diagram showing a configuration example of the driving support device 50 according to the present embodiment. The driving support device 50 is connected to the surrounding environment sensor 31, the vehicle state sensor 35, and the GPS sensor 37 directly or via communication means such as CAN (Controller Area Network) and LIN (Local Inter Net). Further, the vehicle control unit 41 and the HMI 43 are connected to the driving support device 50. Note that the driving support device 50 is not limited to an electronic control device mounted on the vehicle 1, and may be a terminal device such as a smartphone or a wearable device.

[0026] The driving support device 50 includes a control unit 51, a storage unit 53, and an accumulated blind spot area database 55. The control unit 51 is configured to include one or more processors such as a CPU (Central Processing Unit) and various peripheral components. A part or all of the control unit 51 may be configured with updatable components such as firmware, or may be a program module executed according to instructions from a CPU or the like.

[0027] The storage unit 53 is composed of a storage element such as a RAM or a ROM. However, the type and number of the storage unit 53 are not particularly limited. The storage unit 53 stores a computer program executed by the control unit 51, various parameters used for arithmetic processing, detection data, arithmetic results, and other information. The accumulated blind spot area database 55 is a database configured by a storage element such as a RAM or a ROM, or a storage medium such as an HDD, a CD, a DVD, an SSD, a USB flash drive, or a storage device, and stores information on the accumulated blind spot area calculated by the control unit 51.

[0028] (2-2. Functional Configuration) Next, the functional configuration of the control unit 51 of the driving support device 50 will be described. The control unit 51 includes a surrounding environment detection unit 61, a blind spot area calculation unit 63, a risk estimation unit 65, a driving condition setting unit 67, and a notification control unit 69. Each of these units is a function realized by the execution of a computer program by one or more processors such as a CPU. However, part or all of the surrounding environment detection unit 61, the blind spot area calculation unit 63, the risk estimation unit 65, the driving condition setting unit 67, and the notification control unit 69 may be configured by hardware.

[0029] (Surrounding Environment Detection Unit) The surrounding environment detection unit 61 detects the surrounding environment of the host vehicle 1 based on the detection data transmitted from the surrounding environment sensor 31. Specifically, the surrounding environment detection unit 61 performs image processing on the image data transmitted from the front cameras 31LF and 31RF, and uses object detection technology to detect surrounding vehicles, people, bicycles, and other obstacles existing around the host vehicle 1. In addition, the surrounding environment detection unit 61 calculates the positions of surrounding vehicles, people, etc. seen from the host vehicle 1, the distances from the host vehicle 1 to surrounding vehicles, people, etc., and the relative speeds of surrounding vehicles, people, etc. with respect to the host vehicle 1.

[0030] (Blind Spot Area Calculation Unit) The blind spot area calculation unit 63 specifies the blind spot area at a predetermined time and calculates the time change of the blind spot area as the host vehicle 1 progresses. The blind spot area seen from the host vehicle 1 changes as the host vehicle 1 progresses. That is, when there is a blind spot area seen from the host vehicle 1 at a certain time, as the host vehicle 1 progresses, a part of the blind spot area gradually enters the field of view, so the area of the initially specified blind spot area gradually decreases as the host vehicle 1 progresses. The blind spot area calculation unit 63 specifies the blind spot area caused by the shielding object when a shielding object is detected in front of the host vehicle 1, and calculates the area (cumulative blind spot area) that continues to be maintained as the blind spot area excluding the area (blind spot elimination area) that enters the field of view as time passes.

[0031] For example, the blind spot area calculation unit 63 detects an occlusion based on the detection result by the surrounding environment detection unit 61. Examples of the occlusion typically include parked vehicles, buildings such as side walls and fences, but are not limited to these occlusions. Further, the blind spot area calculation unit 63 may detect an occlusion or a blind spot area using the information on the position of the host vehicle 1 on the map data acquired via the GPS sensor 37 and the road information in front of the traveling direction.

[0032] The blind spot area calculation unit 63 may calculate the temporal change of the overhead two-dimensional blind spot area viewed from above the host vehicle 1 or the occlusion, or may calculate the temporal change of the two-dimensional blind spot area viewed from the host vehicle 1. The overhead two-dimensional blind spot area viewed from above the host vehicle 1 or the occlusion is defined in the lateral direction and the depth direction viewed from the host vehicle 1, and the two-dimensional blind spot area viewed from the host vehicle 1 is defined in the lateral direction and the height direction viewed from the host vehicle 1. In the present embodiment, the blind spot area calculation unit 63 calculates the cumulative blind spot area defined in the lateral direction and the depth direction viewed from the host vehicle 1, and the cumulative blind spot area defined in the lateral direction and the height direction viewed from the host vehicle 1.

[0033] The calculated cumulative blind spot area is sequentially stored in the blind spot area database 55 until the host vehicle 1 passes by the side of the occlusion. Thereby, the change of the cumulative blind spot area with the passage of time can be tracked.

[0034] (Risk estimation unit) The risk estimation unit 65 assumes an object that may exist in the blind spot area specified at a predetermined time (hereinafter, also referred to as "potential risk target"), and based on the temporal change of the blind spot area and the assumed movement of the potential risk target within the blind spot area, estimates the potential risk of collision between the host vehicle 1 and the potential risk target that may exist in the blind spot area. The assumed potential risk target is an object not detected by the surrounding environment sensor 31 of the host vehicle 1, and the risk estimation unit 65 does not have to assume an object whose other part appears in the detection range of the surrounding environment sensor 31 even if a part thereof exists in the blind spot area. Further, the assumed potential risk target is an object that may intrude from the blind spot area into the traveling direction of the host vehicle 1, and a stationary object does not have to be assumed.

[0035] Potential risk objects that may exist in the blind spot area or cumulative blind spot area specified at a specific time can be hypothesized according to the size of the blind spot area or cumulative blind spot area. For example, when the size of the top-down two-dimensional blind spot area is large, there may be objects such as pedestrians, bicycles, and automobiles in the blind spot area. For example, when the blind spot area or cumulative blind spot area is 5 m in the lateral direction and 10 m in the depth direction as seen from the host vehicle 1, types of potential risk objects may include pedestrians, bicycles, motorcycles, tricycles, automobiles, etc. On the other hand, when the size or width of the top-down two-dimensional blind spot area or cumulative blind spot area is small, although there may be pedestrians in the blind spot area or cumulative blind spot area, the possibility of the existence of bicycles, motorcycles, etc. is low. Also, when the size or width of the top-down two-dimensional blind spot area or cumulative blind spot area is small, there may be a possibility of the existence of bicycles, motorcycles, etc. only in a specific direction.

[0036] Also, when the height of the blind spot area or cumulative blind spot area is high, there may be objects such as pedestrians including adults and children, bicycles, motorcycles, tricycles, etc. in the blind spot area or cumulative blind spot area. On the other hand, when the height of the blind spot area or cumulative blind spot area is low, although there may be children or tricycles in the blind spot area or cumulative blind spot area, the possibility of the existence of adults, bicycles, motorcycles, etc. is low. Therefore, when an obstacle is detected in front of the host vehicle 1 and the blind spot area is specified, the risk estimation unit 65 hypothesizes the presence, position, and orientation of potential risk objects that may exist in the blind spot area based on the area and shape of the blind spot area defined in the lateral and depth directions as seen from the host vehicle 1, and the area and shape of the blind spot area defined in the lateral and height directions as seen from the host vehicle 1.

[0037] Further, the risk estimation unit 65 sets a potential risk target that may exist in the cumulative blind spot area and an intrusion speed of the potential risk target into the front of the host vehicle 1 based on the change in the area of the cumulative blind spot area as the host vehicle 1 travels. Specifically, as the area of the cumulative blind spot area decreases, the types of potential risk targets that may exist in the blind spot area are more limited. Also, on the premise that it is a potential risk target that is still not detected by the surrounding environment sensor 31 of the host vehicle while the area of the cumulative blind spot area decreases as the host vehicle 1 travels, the set speed range of the potential risk target and the set trajectory of the potential risk target within the cumulative blind spot area are more limited. The set speed range of the potential risk target can be replaced with the intrusion speed of the potential risk target into the front of the host vehicle 1, and the set trajectory of the potential risk target is used for determining the intrusion position of the potential risk target into the front of the host vehicle 1.

[0038] The risk estimation unit 65 estimates potential risks based on potential risk targets that may exist within the blind spot area or the cumulative blind spot area, the set speed range of the potential risk targets, and the set trajectory of the potential risk targets. The lower the possibility that a potential risk target intrudes from the blind spot area into the front of the host vehicle 1, the lower the estimated potential risk. Specifically, the potential risk relatively decreases as the cumulative blind spot area decreases as the host vehicle 1 moves. For example, when the cumulative blind spot area is 2 m in the lateral direction and 1 m in the depth direction as viewed from the host vehicle 1, the types of potential risk targets that may exist are limited to bicycles and pedestrians. Also, since the potential risk target remains in the cumulative blind spot area, the potential risk target is almost stationary, and the assumed intrusion speed is slow.

[0039] Therefore, the area where the assumed potential risk object may enter in front of the host vehicle 1, that is, the variation in the jump-out distance and the intrusion position is small, and even if the potential risk object intrudes in front of the host vehicle 1, the area where it can collide with the host vehicle 1 is small. Thus, the potential risk is estimated to be relatively low. On the other hand, if the area where the assumed potential risk object may enter in front of the host vehicle 1 is large and the area where it can collide with the host vehicle 1 when the potential risk object intrudes in front of the host vehicle 1 is large, the potential risk is estimated to be relatively high. For example, the risk estimation unit 65 may set the potential risk in multiple stages according to the area of the region where the host vehicle 1 can collide when the potential risk object intrudes in front of the host vehicle 1.

[0040] After the shielding object is detected and the blind spot area is detected at a predetermined time, the risk estimation unit 65 repeatedly assumes potential risk objects that may exist in the blind spot area and estimates the potential risk of collision between the assumed potential risk objects and the host vehicle 1 until the host vehicle 1 passes by the side of the shielding object. The risk estimation unit 65 estimates the potential risk for each of the multiple potential risk objects that can be assumed.

[0041] (Driving condition setting unit) Basically, the driving condition setting unit 67 sets the driving conditions of the host vehicle 1 so as to avoid collisions with obstacles existing in front of the host vehicle 1 in the traveling direction. For example, during the automatic driving of the host vehicle 1, the driving condition setting unit 67 sets a driving trajectory that can avoid collisions between the host vehicle and the obstacle, and sets a target steering angle for the host vehicle 1 to travel along the driving trajectory. For example, the driving condition setting unit 67 sets the driving trajectory of the host vehicle 1 using the risk potential, which is an index indicating the possibility of the host vehicle 1 colliding with pedestrians, surrounding vehicles, and other obstacles. In this case, the risk potential is set such that the closer the distance to the obstacle, the higher the collision risk, and the driving condition setting unit 67 sets the driving trajectory so that the host vehicle 1 travels on a trajectory with a smaller collision risk. Also, when the risk potential is set such that the lower the vehicle speed, the smaller the collision risk, the driving condition setting unit 67 may reduce the collision risk by setting the driving trajectory and the vehicle speed.

[0042] Also, in the present embodiment, until the host vehicle 1 passes by the side of an obstacle that causes a blind spot area, the driving condition setting unit 67 sets the driving conditions so that the host vehicle 1 travels on a trajectory where the potential risk becomes smaller along with the collision risk becoming smaller. Specifically, when it is determined based on the potential risk estimated by the risk estimation unit 65 that the potential risk object may collide with the host vehicle 1, the driving condition setting unit 67 sets the travel trajectory so that the distance between the host vehicle 1 and the obstacle increases. Further, when the potential risk cannot be sufficiently reduced only by changing the travel trajectory, the driving condition setting unit 67 may reduce the potential risk by changing the travel trajectory or, alternatively, by decelerating the host vehicle 1 instead of changing the travel trajectory.

[0043] The driving condition setting unit 67 sets a target steering angle and a target acceleration / deceleration based on the set travel trajectory and vehicle speed, and transmits information on the target steering angle and the target acceleration / deceleration to the vehicle control unit 41. The vehicle control unit 41 controls the travel of the host vehicle 1 based on the acquired information on the target steering angle and the target acceleration / deceleration. At this time, the driving condition setting unit 67 may set the target steering angle and the target acceleration / deceleration so as not to exceed a preset upper limit value of the steering angular velocity or the upper limit value of the acceleration / deceleration. Thereby, the travel of the host vehicle 1 is controlled so that sudden steering or sudden deceleration does not occur, and the discomfort of the occupants of the host vehicle 1 can be reduced.

[0044] Further, when the potential risk no longer exists while the driving condition setting unit 67 is setting the driving conditions so that the potential risk becomes smaller, the driving condition setting process for reducing the potential risk is terminated even before the host vehicle 1 passes by the side of the obstacle that caused the blind spot area. Thereby, before it is detected by the surrounding environment sensor 31 of the host vehicle 1 that there is no object in the blind spot area, the driving mode of the host vehicle 1 can be shifted to the mode after passing by the side of the obstacle. Therefore, it is possible to reduce the risk that the user feels annoyance, such as the host vehicle 1 not accelerating even though it is clear that there is no object that may collide with the host vehicle 1 in the blind spot area.

[0045] (Notification control unit) The notification control unit 69 notifies the occupants of the host vehicle 1 by controlling the driving of the HMI 43. In the present embodiment, the notification control unit 69 notifies the occupants of the host vehicle 1 of the presence of a potential risk of collision with a potential risk object that the host vehicle 1 may be present in the blind spot area. The notification control unit 69 notifies the presence of the potential risk by outputting a warning sound or voice, or by performing image display or text display. The content of the notification is not particularly limited, and a certain warning sound or voice may be output, or image display or text display may be performed, or the position or intrusion speed at which a potential risk object intrudes from the blind spot area into the front of the host vehicle 1 may be notified.

[0046] In addition, after the presence of the potential risk is detected and the notification process is started, when the potential risk no longer exists, the notification control unit 69 stops the notification process even before the host vehicle 1 passes by the side of the shielding object that caused the blind spot area. Thereby, unnecessary notifications are stopped when it is clear that there is no object that may collide with the host vehicle 1 in the blind spot area, and the possibility that the user feels annoyance can be reduced.

[0047] (3. Operation of the driving support device) Subsequently, an example of the operation of the driving support device according to the present embodiment will be described with reference to a flowchart.

[0048] FIGS. 3 to 5 are flowcharts showing an example of the operation of the driving support device 50. First, when a system including the driving support device 50 is activated (step S11), the surrounding environment detection unit 61 of the control unit 51 acquires detection data transmitted from the surrounding environment sensor 31, and detects the surrounding environment of the host vehicle 1 based on the detection data (step S13). In the present embodiment, the surrounding environment detection unit 61 detects at least other vehicles, persons, buildings, traffic signs, white lines, etc. existing in front of the host vehicle 1 in the traveling direction based on the detection data transmitted from the surrounding environment sensor 31.

[0049] Next, the blind spot area calculation unit 63 of the control unit 51 determines whether there is an obstacle that can cause a blind spot in front of the traveling direction of the host vehicle 1 (step S15). For example, the blind spot area calculation unit 63 calculates the size, position, and relative speed of each object detected by the surrounding environment detection unit 61 with respect to the host vehicle 1, and determines whether there is an object that can cause a blind spot area when viewed from the host vehicle 1. For example, when the lateral width, height, and depth of the object are each equal to or greater than a preset dimension, the object exists within a preset distance from the planned travel trajectory of the host vehicle 1, and the relative speed is equal to or less than a preset speed threshold, the blind spot area calculation unit 63 determines that the object corresponds to an obstacle.

[0050] If it is determined that there is no obstacle that can cause a blind spot (S15 / No), the process returns to step S13, and the surrounding environment detection process (step S13) and the determination process of the presence or absence of an obstacle (step S15) are repeated. On the other hand, if it is determined that there is an obstacle that can cause a blind spot (S15 / Yes), the blind spot area calculation unit 63 executes a process of calculating the cumulative blind spot area X (step S17).

[0051] FIG. 4 is a flowchart showing the cumulative blind spot area calculation process. First, the blind spot area calculation unit 63 acquires information on the size, position, and relative speed of the object determined to be an obstacle (step S41). Next, the blind spot area calculation unit 63 calculates the current blind spot area x(t) caused by the obstacle as seen from the host vehicle 1 based on the size of the obstacle and the positional relationship between the obstacle and the host vehicle 1 (step S43). For example, the blind spot area calculation unit 63 specifies, among the areas surrounded by a plurality of straight line groups passing through the installation positions of the front cameras 31FL and 31RF provided on the host vehicle 1 and a plurality of points on the contour of the obstacle as seen from the host vehicle 1, the area located on the back side of the obstacle as seen from the host vehicle 1. The specified blind spot area x(t) is obtained as an area in the lateral direction, height direction, and depth direction as seen from the host vehicle 1. Note that after the obstacle is detected, the blind spot area calculation unit 63 repeatedly calculates the blind spot area x(t) at an appropriate processing interval until the host vehicle 1 passes by the side of the obstacle or until it is determined that there is no potential risk.

[0052] Next, the blind spot area calculation unit 63 compares the calculated current blind spot area x(t) with the cumulative blind spot area X(t - Δt) stored in the cumulative blind spot area database 55 up to the previous time (step S45). The blind spot area calculation unit 63 specifies a blind spot elimination area y that does not overlap with the current blind spot area (t) among the cumulative blind spot areas X(t - Δt) up to the previous time.

[0053] Next, the blind spot area calculation unit 63 updates the cumulative blind spot area X(t) to calculate the current cumulative blind spot area X(t) (step S47). Thereby, among the blind spot areas x(t) specified when an obstacle is detected by the host vehicle 1, the blind spot elimination area y that has entered the field of view of the host vehicle 1 as the host vehicle 1 moves forward is removed, and the cumulative blind spot area X(t) that is continuously maintained as a blind spot area is calculated.

[0054] Next, the blind spot area calculation unit 63 stores the calculated cumulative blind spot area X(t) in the cumulative blind spot area database 55 (step S49). Thereby, when calculating the cumulative blind spot area X(t) after the next time, the cumulative blind spot area X(t-Δt) until then can be referred to. In addition, at the time of the first blind spot area calculation process after it is determined that there is an obstacle that causes the blind spot area x, the calculated blind spot area x(t) is stored as the cumulative blind spot area X(t).

[0055] The blind spot area calculation unit 63 repeatedly executes the cumulative blind spot area calculation process at a predetermined processing interval until the host vehicle 1 passes by the side of the obstacle or until there is no potential risk.

[0056] Returning to FIG. 3, after the calculation process of the cumulative blind spot area X(t) by the blind spot area calculation unit 63 is executed in step S17, the risk estimation unit 65 of the control unit 51 executes a process of calculating the potential risk of collision between the potential risk target object that may exist in the cumulative blind spot area X(t) and the host vehicle 1 (step S19).

[0057] FIG. 5 is a flowchart showing the potential risk calculation process. First, the risk estimation unit 65 assumes a potential risk target object that may exist in the cumulative blind spot area X(t) calculated in step S17 (step S51). Specifically, the risk estimation unit 65 assumes a potential risk target object that may exist according to the size of the cumulative blind spot area X(t). As described above, an object that may enter in front of the host vehicle 1 is assumed as the potential risk target object. For example, the risk estimation unit 65 assumes the type, position, and orientation of the potential risk target object that may exist in the cumulative blind spot area X(t) based on the area and shape of the cumulative blind spot area X(t) viewed in a top-down two-dimensional manner, and the area and shape of the cumulative blind spot area X(t) including the element in the height direction of the obstacle viewed from the host vehicle 1.

[0058] The risk estimation unit 65 assumes a plurality of potential risk objects that may exist in the cumulative blind spot area X(t). In this case, objects of the same type may be assumed at different positions, or objects of different types may be assumed at the same or different positions. Also, in order not to assume an object that has no risk of colliding with the host vehicle 1, a potential risk object may be assumed in the cumulative blind spot area X(t) within a range where the distance from the shielding object is set in advance. In this case, the distance from the shielding object may be set longer as the vehicle speed of the host vehicle 1 or the relative speed of the host vehicle 1 with respect to the shielding object is higher.

[0059] Next, the risk estimation unit 65 sets the trajectory in the cumulative blind spot area X(t) of the potential risk object that may exist in the cumulative blind spot area X(t) based on the change in the area and shape of the cumulative blind spot area X(t) as the host vehicle 1 moves forward (step S53). For example, the risk estimation unit 65 can set the trajectory of each potential risk object by connecting the positions of the same type of potential risk objects that may exist in the cumulative blind spot area X(t) calculated at each time while the area and shape of the cumulative blind spot area X(t) change. The trajectory to be set may be only a trajectory in a direction in which the potential risk object can enter in front of the host vehicle 1. In order to prevent an increase in the load of the arithmetic processing, the trajectory to be set may be only a straight-line trajectory. The risk estimation unit 65 sets one or more trajectories for each of all the assumed potential risk objects. The shorter the area or width of the cumulative blind spot area X(t) is, the shorter the length of the settable trajectory becomes.

[0060] Next, the risk estimation unit 65 sets the speed of a potential risk target that may exist in the cumulative blind spot area X(t) based on changes in the area and shape of the cumulative blind spot area X(t) as the host vehicle 1 moves (step S55). For example, the risk estimation unit 65 sets, as the speed of the potential risk target, the speed obtained by dividing the length of the trajectory set in step S53 by the time it takes for the potential risk target to move on the trajectory. The time it takes for the potential risk target to move on the trajectory can be obtained as the sum of the processing intervals from the time when the potential risk target is assumed to be at the starting point of the trajectory to the time when the potential risk target is assumed to be at the ending point of the trajectory. In this embodiment, after it is determined that there is an occlusion and the blind spot area x is detected, no new potential risk target is assumed while the host vehicle 1 is moving, and a potential risk target that may continuously exist in the cumulative blind spot area X(t) is assumed from the moment the blind spot area x is detected. Therefore, basically, the shorter the set trajectory length is, the lower the set speed becomes.

[0061] Next, the risk estimation unit 65 estimates the potential risk of the potential risk target colliding with the host vehicle 1 based on the potential risk target that may exist in the cumulative blind spot area X(t), the set speed range of the potential risk target, and the set trajectory of the potential risk target (step S57). Basically, as the cumulative blind spot area X(t) decreases as the host vehicle 1 moves, the potential risk becomes relatively lower. For example, as the cumulative blind spot area X(t) decreases, the objects that may exist in the cumulative blind spot area X(t) are limited to relatively small objects. Also, the speed of the potential risk target assumed to continue staying in the cumulative blind spot area X(t) with a decreasing area becomes lower. Therefore, even if the potential risk target invades in front of the host vehicle 1, the area where it can collide with the host vehicle 1 is small, so the potential risk is estimated to be relatively low. On the other hand, when the area where the potential risk target can collide with the host vehicle 1 is large when the potential risk target invades in front of the host vehicle 1, the potential risk is estimated to be relatively high.

[0062] In this embodiment, the risk estimation unit 65 sets potential risks in multiple levels according to the area of the region where a potential risk target may collide with the host vehicle 1 when the potential risk target enters in front of the host vehicle 1. For example, the risk estimation unit 65 sets a higher potential risk as the area of the region where the potential risk target can enter within the passing region (passing range) of the host vehicle 1, which is set based on the current vehicle speed, acceleration / deceleration, and steering angle of the host vehicle 1, is larger.

[0063] Returning to FIG. 3, after the potential risk is calculated in step S19, the driving condition setting unit 67 determines whether a potential risk target existing in the cumulative blind spot region X(t) may collide with the host vehicle 1 (step S21). For example, the driving condition setting unit 67 determines whether a potential risk target may collide with the host vehicle 1 based on the time-series passing points when the host vehicle 1 travels along the current travel trajectory and the intrusion position and time when it is assumed that the potential risk target intrudes onto the travel trajectory of the host vehicle 1. Specifically, the driving condition setting unit 67 can determine that a potential risk target may collide with the host vehicle 1 if the distance between the passing point of the host vehicle 1 and the intrusion position of the potential risk target is within a predetermined distance set in advance at any time. Instead of determining whether a potential risk target may collide with the host vehicle 1, it may also be determined whether the potential risk estimated in step S19 is less than a preset risk value.

[0064] When it is determined that a potential risk target may collide with the host vehicle 1 (S21 / Yes), at least one of the following processes is executed: the notification control unit 69 notifies the occupant of the host vehicle 1 of the existence of the potential risk of colliding with a potential risk target that may exist in the blind spot region (notification process), or the driving condition setting unit 67 performs a process to avoid a collision with the potential risk target (avoidance process) (step S23).

[0065] For example, the notification control unit 69 notifies the presence of a potential risk by outputting a warning sound or voice, or by performing image display or text display. The content of the notification is not particularly limited, and a certain warning sound or voice may be output, or image display or text display may be performed, or the position or intrusion speed at which a potential risk object intrudes from a blind spot area into the front of the host vehicle 1 may be notified.

[0066] Also, the driving condition setting unit 67 avoids a collision with a potential risk object by setting a driving trajectory so that the distance between the host vehicle 1 and the shielding object increases. As the distance between the host vehicle 1 and the shielding object increases, the area of the region where the host vehicle 1 may collide when the potential risk object intrudes in front of the host vehicle 1 becomes smaller, so the potential risk becomes smaller. Also, when the driving condition setting unit 67 cannot avoid a collision with a potential risk object only by changing the driving trajectory, it may change the driving trajectory or, alternatively, instead of changing the driving trajectory, decelerate the host vehicle 1 to avoid a collision with the potential risk object. The driving condition setting unit 67 sets a target steering angle and a target acceleration / deceleration based on the set driving trajectory and vehicle speed, and transmits information on the target steering angle and the target acceleration / deceleration to the vehicle control unit 41. The vehicle control unit 41 controls the running of the host vehicle 1 based on the acquired information on the target steering angle and the target acceleration / deceleration.

[0067] After the notification process or the avoidance process is executed in step S23, the blind spot area calculation unit 63 determines whether the host vehicle 1 has passed by the side of the shielding object that caused the blind spot area x (step S25). For example, when the shielding object that has been detected in front of the host vehicle 1 so far is no longer detected based on the ambient environment information detected by the ambient environment detection unit 61, the blind spot area calculation unit 63 determines that the host vehicle 1 has passed by the side of the shielding object. The blind spot area calculation unit 63 may store the position of the detected shielding object on the map data, and determine that the host vehicle 1 has passed by the side of the shielding object when the host vehicle 1 passes through the position.

[0068] When it is not determined that the host vehicle 1 has passed by the side of the obstacle (S25 / No), the process returns to step S17, and the processes of the above-described steps are repeated. On the other hand, when it is determined that the host vehicle 1 has passed by the side of the obstacle (S25 / Yes), the driving condition setting unit 67 shifts to the process after passing by the side of the obstacle (step S27). For example, the driving condition setting unit 67 starts a process of returning the travel trajectory that has been expanding the distance between the host vehicle 1 and the obstacle to a reference position such as the center of the road, or accelerating the host vehicle 1 to return to the reference vehicle speed.

[0069] On the other hand, in step S21 above, when it is not determined that the potential risk target object may collide with the host vehicle 1 (S21 / No), the driving condition setting unit 67 shifts to the process after passing by the side of the obstacle regardless of whether the host vehicle 1 has passed by the side of the obstacle (step S27). Thereby, when it is clear that there is no object in the dead angle region x even before passing by the side of the obstacle, the travel trajectory or the vehicle speed can be quickly restored, and the annoyance felt by the occupant of the host vehicle 1 can be reduced.

[0070] After shifting to the process after passing by the side of the obstacle in step S27, it is determined whether or not the system of the host vehicle 1 including the driving support device 50 has stopped (step S29). When the system has not stopped (S29 / No), the process returns to step S13, and the processes of the above-described steps are repeated. On the other hand, when the system has stopped (S29 / Yes), the operation of the driving support device 50 is stopped.

[0071] As described above, the driving assistance device 50 according to the present embodiment identifies the dead angle area x at a predetermined time when detecting an obstacle that causes a dead angle area in front of the traveling direction of the host vehicle 1, and calculates the cumulative dead angle area X indicating the temporal change of the dead angle area x accompanying the subsequent traveling of the host vehicle 1. Further, based on the change in the cumulative dead angle area X, the driving assistance device 50 sets the type, position, trajectory, and speed of a potential risk object that may exist in the cumulative dead angle area X, and estimates the potential risk of the potential risk object colliding with the host vehicle 1. As a result, when a dead angle area is detected, rather than performing uniform avoidance control, it is possible to change the traveling trajectory or decelerate according to the potential risk. Further, when it is clear that there is no object in the dead angle area, even before the obstacle is no longer detected by the surrounding environment sensor 31 of the host vehicle 1, the process immediately shifts to the process after passing by the side of the obstacle. Therefore, the annoyance felt by the occupant of the host vehicle 1 can be reduced.

[0072] <4. Application Examples> The driving assistance device 50 according to the present embodiment has been described so far. Hereinafter, some examples of driving scenes to which the driving assistance device 50 according to the present embodiment is applied will be described.

[0073] (4-1. First Application Example) FIGS. 6 to 8 are diagrams for explaining the first application example, and are explanatory diagrams showing a driving scene in which the host vehicle 1 passes by the side of the parked vehicle 2.

[0074] FIG. 6 shows an overhead two-dimensional dead angle area. At time t, the dead angle area calculation unit 63 detects the parked vehicle 2 as an obstacle in front of the host vehicle 1, and identifies the dead angle area x(t) seen from the host vehicle 1 caused by the parked vehicle 2. The dead angle area calculation unit 63 sets the dead angle area x(t) identified when detecting the parked vehicle 2 as the cumulative dead angle area X(t).

[0075] As the host vehicle 1 moves forward, the blind spots x(t + Δt) and x(t + 2Δt) at respective times t + Δt and t + 2Δt change. For this reason, at respective times t + Δt and t + 2Δt, a part of the blind spot x(t) detected at time t gradually enters the field of view as seen from the host vehicle 1, and the blind spot elimination area y gradually expands with the passage of time. The blind spot area calculation unit 63 sets, at respective times t + Δt and t + 2Δt, the blind spot areas that overlap the blind spot areas x(t) and x(t + Δt) detected up to the previous times t and t + Δt as the cumulative blind spot areas X(t + Δt) and X(t + 2Δt). That is, the cumulative blind spot area X(t + Δt) at time t + Δt is the area where the cumulative blind spot area X(t) at time t and the blind spot area x(t + Δt) at time t + Δt overlap, and the cumulative blind spot area X(t + 2Δt) at time t + 2Δt is the area where the cumulative blind spot area X(t + Δt) at time t + Δt and the blind spot area x(t + 2Δt) at time t + 2Δt overlap. The cumulative blind spot area X(t + 2Δt) at time t + 2Δt can also be said to be the area where the blind spot area x(t) at time t, the blind spot area x(t + Δt) at time t + Δt, and the blind spot area x(t + 2Δt) at time t + 2Δt overlap.

[0076] The risk estimation unit 65 assumes, at the time t when the shielding object is detected, potential risk objects that may exist in the cumulative blind spot area X(t). In the example shown in FIG. 6, pedestrians 3 are assumed at two locations in the cumulative blind spot area X(t) at time t, but other potential risk objects such as bicycles and automobiles can be assumed according to the area of the cumulative blind spot area X(t). Further, the risk estimation unit 65 assumes, at respective times t + Δt and t + 2Δt, potential risk objects that may exist in the cumulative blind spot areas X(t + Δt) and X(t + 2Δt). However, if it is assumed that the pedestrians 3 that have not been detected by the host vehicle 1 also at the previous times t and t + Δt are the potential risk objects, the potential risk objects that can be assumed in the cumulative blind spot areas X(t + Δt) and X(t + 2Δt) are limited to pedestrians and bicycles.

[0077] Further, the risk estimation unit 65 sets the speeds and trajectories of the potential risk objects assumed in the cumulative blind spots X(t), X(t+Δt), and X(t+2Δt) at times t, t+Δt, and t+2Δt, respectively. The cumulative blind spot X(t) at time t is the first detected blind spot X(t), and since the movement of the potential risk objects before that cannot be predicted, various variations of the speeds and trajectories of the potential risk objects in the cumulative blind spot X(t) at time t can be assumed. On the other hand, in the cumulative blind spots X(t+Δt) and X(t+2Δt) at times t+Δt and t+2Δt, assuming that the potential risk objects have not been detected by the host vehicle 1 at times t and t+Δt until then, the speeds and trajectories of the potential risk objects in the cumulative blind spots X(t+Δt) and X(t+2Δt) are limited.

[0078] FIG. 7 shows an example assuming a bicycle 4 as the potential risk object. The bicycle 4 can be assumed to have a relatively higher speed than a pedestrian. Also, since the length of the bicycle 4 is larger than the width of the pedestrian, the position and orientation of the bicycle 4 that can be assumed to move toward the traveling direction of the host vehicle 1 are more limited than those of the pedestrian. For example, the area of the cumulative blind spot X(t+2Δt) at time t+2Δt in FIG. 7 can assume the bicycle 4, but the area of the cumulative blind spot X(t+2Δt) at time t+2Δt in FIG. 6 cannot assume the bicycle 4. Therefore, the area of the passing area in front of the host vehicle 1 where the bicycle 4 can enter is relatively small. Also, although the area of the cumulative blind spot X(t+2Δt) at time t+2Δt in FIG. 7 can assume the bicycle 4, since it is clear that the bicycle 4 has continued to stay in the cumulative blind spot X(t+2Δt) continuously after time t, the bicycle 4 is almost stationary, and even if it enters in front of the host vehicle 1, its entry speed is estimated to be slow. Therefore, at time t+2Δt, the potential risk of the host vehicle 1 colliding with the bicycle 4 is estimated to be small.

[0079] As described above, the driving support device 50 according to the present embodiment accurately estimates the potential risk of the host vehicle 1 colliding with a potential risk target object by assuming the presence or absence of a potential risk target object that may exist in the cumulative blind spot area X(t) and the intrusion position and intrusion speed of the host vehicle 1 into the front based on the change in the cumulative blind spot area X(t) indicating the temporal change of the blind spot area x(t) specified at a predetermined time. Thereby, it is possible to appropriately change the driving trajectory or decelerate according to the potential risk. Further, before the host vehicle 1 passes by the side of the parked vehicle 2, it is determined by the risk estimation unit 65 that there is no potential risk, and the timing to accelerate the host vehicle 1 or return the driving trajectory to the original can be advanced.

[0080] Furthermore, FIG. 8 shows the change in the cumulative blind spot area X considering the height direction of the shielding object (parked vehicle 2). When comparing the blind spot areas x(t), x(t+Δt), x(t+Δ2t) in the height direction of the parked vehicle 2 at each time, the cumulative blind spot areas X(t+Δt), X(t+2Δt) become smaller compared to the case of comparing the two-dimensional overhead blind spot areas x(t), x(t+Δt), x(t+Δ2t) shown in FIGS. 6 and 7 at each time. Specifically, when considering the height direction of the parked vehicle 2, as the host vehicle 1 advances, the space above the bonnet of the parked vehicle 2 gradually comes into view. The portion of the bonnet where this upper space becomes the blind spot elimination area y has a small size in the height direction, so a potential risk target object cannot be assumed. Therefore, among the cumulative blind spot areas X(t+Δt), X(t+2Δt), the area where a potential risk target object can be assumed is more restricted than the cumulative blind spot areas X(t+Δt), X(t+2Δt) shown only in the two-dimensional overhead view in FIGS. 6 and 7. That is, the timing at which it is determined by the risk estimation unit 65 that there is no potential risk can be advanced, and the timing to accelerate the host vehicle 1 or return the driving trajectory to the original can be further advanced.

[0081] (4-2. Second application example) FIG. 9 is a diagram for explaining a second application example, and is an explanatory diagram showing a driving scene in which when the host vehicle 1 is traveling in the left lane of a three-lane road, the speed of the preceding vehicle 5 traveling in the center lane is slower than the speed of the host vehicle 1, and the host vehicle 1 overtakes the preceding vehicle 5 and moves in front of the preceding vehicle 5.

[0082] FIG. 9 shows an overhead two-dimensional blind spot area. At time t, when the blind spot area calculation unit 63 detects the preceding vehicle 5 as an obstacle in the center lane in front of the host vehicle 1, it specifies the blind spot area x(t) seen from the host vehicle 1 caused by the preceding vehicle 5. When the blind spot area calculation unit 63 recognizes the preceding vehicle 5 as a vehicle to be overtaken, the specified blind spot area x(t) is set as the cumulative blind spot area X(t). Further, as the host vehicle 1 moves forward, the blind spot areas x(t+Δt) and x(t+2Δt) at times t+Δt and t+2Δt respectively change. For this reason, at times t+Δt and t+2Δt respectively, a part of the blind spot area x(t) detected at time t gradually enters the field of view seen from the host vehicle 1, and the blind spot elimination area y gradually expands over time. The blind spot area calculation unit 63 calculates the cumulative blind spot areas X(t+Δt) and X(t+2Δt) at times t+Δt and t+2Δt respectively.

[0083] At the time t when the obstacle is detected, the risk estimation unit 65 assumes a potential risk object that may exist in the cumulative blind spot area X(t). In the example shown in FIG. 9, in order to assume a potential risk object existing in the right lane deeper than the center lane as seen from the host vehicle 1, no assumption is made for pedestrians, bicycles, etc., and another vehicle 6 traveling in the right lane is assumed.

[0084] Further, the risk estimation unit 65 sets the speeds and trajectories of the potential risk objects assumed in the cumulative blind spot areas X(t), X(t+Δt), and X(t+2Δt) at times t, t+Δt, and t+2Δt, respectively. In the example shown in FIG. 9, at times t+Δt and t+2Δt, although the blind spot elimination area y gradually expands on the front side of the blind spot area x(t) specified at time t, no other vehicle 6 has appeared in the blind spot elimination area y. Therefore, since it is clear that the assumed speed of the other vehicle 6 is relatively slow compared to the vehicle speeds of the host vehicle 1 and the preceding vehicle 5, it is determined that the possibility of the other vehicle 6 changing lanes in front of the preceding vehicle 5 is low.

[0085] In the example shown in FIG. 9, simply considering the presence or absence of the blind spot area, until it is confirmed by the surrounding environment sensor 31 of the host vehicle 1 that there is no shielding object that causes the blind spot area, that is, until it is confirmed that the overtaking of the preceding vehicle 5 is completed, a notification indicating that lane change is dangerous is issued. On the other hand, in the driving support device 50 according to the present embodiment, based on the change in the cumulative blind spot area X(t) indicating the time change of the blind spot area x(t) as the host vehicle 1 progresses, the host vehicle 1 can accurately estimate the potential risk of colliding with another vehicle 6 that changes lanes (invades) in front of the preceding vehicle 5 in the center lane from the right lane. As a result, it is determined by the risk estimation unit 65 that there is no potential risk before the host vehicle 1 overtakes the preceding vehicle 5, and the timing to complete the overtaking of the preceding vehicle 5 by the host vehicle 1 or to stop the notification that lane change is dangerous can be advanced.

[0086] <5. Summary> As described above, the driving support device 50 according to the present embodiment identifies the blind spot area x(t) at a predetermined time t, and calculates the cumulative blind spot areas X(t), X(t+Δt), X(t+2Δt) indicating the temporal change of the blind spot area x(t) accompanying the progress of the host vehicle 1 at each time t, t+Δt, t+2Δt. Further, the driving support device 50 assumes potential risk objects that may exist in the calculated cumulative blind spot areas X(t), X(t+Δt), X(t+2Δt), and based on the cumulative blind spot areas X(t), X(t+Δt), X(t+2Δt) and the assumed actions of the potential risk objects within the cumulative blind spot areas X(t), X(t+Δt), X(t+2Δt), estimates the potential risk of collision between the host vehicle 1 and the potential risk objects. Thereby, not simply determining whether or not there is a blind spot area as viewed from the host vehicle 1, but rather accurately estimating the potential risk of collision with potential risk objects that may exist in the blind spot area.

[0087] Therefore, when the driving support device 50 notifies the occupant of the host vehicle 1 of the existence of a potential risk, even before the host vehicle 1 passes by the side of an obstacle (parked vehicle 2 or preceding vehicle 5) that caused the blind spot area, the notification can be stopped when the potential risk no longer exists. Thereby, unnecessary notifications are stopped when it is clear that there are no objects that may collide with the host vehicle 1 in the blind spot area, and the risk that the user feels annoyed can be reduced.

[0088] Further, when the driving support device 50 controls the automatic driving of the host vehicle 1, even before the host vehicle 1 passes by the side of an obstacle (parked vehicle 2 or preceding vehicle 5) that caused the blind spot area, the setting of the driving conditions for reducing the potential risk can be terminated when the potential risk no longer exists. Thereby, the risk that the user feels annoyed can be reduced, such as the host vehicle 1 not accelerating even though it is clear that there are no objects that may collide with the host vehicle 1 in the blind spot area.

[0089] In addition, in the driving support device 50 according to the present embodiment, based on the change in the cumulative blind spot area indicating the change in the area of the blind spot area, the speed and trajectory of the potential risk target within the cumulative blind spot area, or the intrusion speed of the potential risk target into the front of the host vehicle 1 are set, and the potential risk is estimated. Thereby, according to the area of the region where the assumed potential risk target can intrude into the passing region of the host vehicle 1, the potential risk of collision between the host vehicle 1 and the potential risk target can be accurately estimated, and the accuracy of the driving support control can be improved.

[0090] In addition, in the driving support device 50 according to the present embodiment, not only the two-dimensional overhead blind spot area defined in the lateral and depth directions viewed from the host vehicle 1, but also the blind spot area in the height direction of the shielding object is considered to estimate the potential risk. Therefore, an assumption about an object that may exist in the blind spot area can be made accurately, the potential risk of collision between the host vehicle 1 and the potential risk target can be accurately estimated, and the accuracy of the driving support control can be improved.

[0091] As described above, the preferred embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, but the present disclosure is not limited to such examples. It is obvious that those having ordinary knowledge in the technical field to which the present disclosure pertains can come up with various modification examples or correction examples within the scope of the technical idea described in the claims, and it is naturally understood that these also belong to the technical scope of the present disclosure.

[0092] For example, in the above embodiment, the larger the area of the region where the potential risk target can intrude into the passing region (passing range) of the host vehicle 1, the higher the potential risk is set, but the present disclosure is not limited to such an example. For example, the potential risk may be set according to the type and number of potential risk targets that can be assumed in the cumulative blind spot area and the magnitude of the intrusion speed of the host vehicle 1 forward.

[0093] A computer program applicable to a driving support device that supports driving of the host vehicle based on risks present around the host vehicle, the computer program causing a processor to identify a blind spot area at a predetermined time and calculate a temporal change in the blind spot area as the host vehicle progresses, assume an object that may exist in the blind spot area identified at the predetermined time, and estimate a potential risk of collision between the host vehicle and the object that may exist in the blind spot area based on the temporal change in the blind spot area identified at the predetermined time and the assumed behavior of the object within the blind spot area. A recording medium storing the computer program also belongs to the technical scope of the present disclosure.

Explanation of Signs

[0094] 1…Vehicle (host vehicle), 2…Parked vehicle, 3…Pedestrian, 4…Bicycle, 5…Leading vehicle, 6…Other vehicle, 31…Surrounding environment sensor, 50…Driving support device, 51…Control unit, 55…Cumulative blind spot area database, 61…Surrounding environment detection unit, 63…Blind spot area calculation unit, 65…Risk estimation unit, 67…Driving condition setting unit, 69…Notification unit

Claims

1. In a driving support device that supports the driving of the host vehicle based on risks existing around the host vehicle, a dead angle area calculation unit that identifies a dead angle area at a predetermined time and calculates a temporal change in the area of the dead angle area as the host vehicle moves forward; a risk estimation unit that assumes an object that may exist in the dead angle area identified at the predetermined time, and estimates a potential risk of collision between the host vehicle and the object that may exist in the dead angle area based on the temporal change in the area of the dead angle area identified at the predetermined time and the assumed movement of the object within the dead angle area; A driving support device comprising:

2. The risk estimation unit sets the object that may exist in the dead angle area and the intrusion speed of the object into the front of the host vehicle based on the temporal change in the area of the dead angle area, and estimates the potential risk. The driving support device according to claim 1.

3. The risk estimation unit obtains the object that may exist in the dead angle area, a set speed range of the object within the dead angle area, and a set trajectory of the object based on the temporal change in the area of the dead angle area, and estimates the potential risk. The driving support device according to claim 1 or 2.

4. Comprising a notification control unit that notifies the occupant of the host vehicle, The notification control unit starts notification when the potential risk exists, and stops notification when the potential risk no longer exists even before the host vehicle passes by the side of an obstacle that caused the dead angle area. The driving support device according to any one of claims 1 to 3.

5. Comprising a driving condition setting unit that sets the driving conditions of the host vehicle, The driving condition setting unit sets the driving conditions so that the potential risk is reduced when the potential risk exists, and ends the setting of the driving conditions for reducing the potential risk when the potential risk no longer exists even before the host vehicle passes by the side of an obstacle that caused the dead angle area. The driving support device according to any one of claims 1 to 4.

Images