Driving support device

Abstract

To reduce a collision risk between an own vehicle and a target.SOLUTION: A drive support device according to the present invention includes: an acquisition part that acquires target information which is information on a target existing in a periphery of the own vehicle from a prescribed sensor; a determination part that determines whether the target exists in an outer area which is an area outside a prescribed area including a travel planned route of the own vehicle on the basis of the target information; a detection part that detects the target in the prescribed area on the basis of the target information; and a calculation part that calculates a collision risk degree on the basis of a relative speed of the target relative to the own vehicle when the target is detected in the prescribed area by the detection part.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a driving support device that supports the driving of a vehicle.

Background Art

[0002] Conventionally, in a vehicle (such as a passenger car), an object (such as another vehicle or a pedestrian) existing around the host vehicle is detected based on sensor data (such as camera image data), and when the object enters a predetermined area including the planned travel route, there is a technique for calculating the collision risk based on the relative speed of the object with respect to the host vehicle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described conventional technology, the movement amount of the object after it enters a predetermined area including the planned travel route is calculated, and the relative speed of the object is calculated based on the movement amount. Therefore, it takes time to calculate the collision risk, and there are problems such as a situation where it may not be possible to avoid a collision between the host vehicle and the object at the time when the collision risk is calculated.

[0005] Therefore, an object of the present invention is to provide a driving support device that can reduce the collision risk between the host vehicle and an object.

Means for Solving the Problems

[0006] In order to solve the above problems, the driving support device of the present invention includes an acquisition unit that acquires target information, which is information on targets existing around the host vehicle, from a predetermined sensor, a determination unit that determines whether or not the target exists in an outer region, which is a region outside a predetermined region including the planned travel route of the host vehicle, based on the target information, a detection unit that detects the target in the predetermined region based on the target information, and a calculation unit that calculates a collision risk degree based on the relative speed of the target with respect to the host vehicle when the target is detected in the predetermined region by the detection unit.

[0007] According to this configuration, since the collision risk degree is calculated based on the relative speed of the target with respect to the host vehicle immediately after the target enters the predetermined region, the collision risk between the host vehicle and the target can be reduced.

[0008] Further, when the host vehicle is traveling, the predetermined region is defined by a length in the moving direction corresponding to the vehicle speed of the host vehicle and a length in the vehicle width direction of the host vehicle corresponding to the distance in the moving direction from the host vehicle, and when the target is detected in the predetermined region by the detection unit, the calculation unit calculates the collision risk degree based on a value obtained by adding a predetermined relative speed to the relative speed of the target with respect to the host vehicle.

[0009] According to this configuration, by calculating the collision risk degree based on a value obtained by adding a predetermined relative speed to the relative speed of the target with respect to the host vehicle, the collision risk between the host vehicle and the target can be further reduced.

Effects of the Invention

[0010] According to the present invention, since the collision risk degree is calculated based on the relative speed of the target with respect to the host vehicle immediately after the target enters the predetermined region, the collision risk between the host vehicle and the target can be reduced.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

MODE FOR CARRYING OUT THE INVENTION

[0012] Hereinafter, embodiments of a driving support system including a driving support device of the present invention will be described with reference to the accompanying drawings.

[0013] FIG. 1 is a block diagram showing the configuration of a driving support system 1 according to the first embodiment. The driving support system 1 is mounted on a host vehicle C1 (FIG. 2) and is a system that supports the driving of the host vehicle C1 by a driver. The driving support system 1 has a collision warning function, a primary braking function (a gentle braking function), and a secondary braking function (a strong braking function) as driving support functions for avoiding a collision between the host vehicle C1 and a target object (other vehicles C2, C3, a pedestrian M, etc. in FIG. 2) or reducing damage caused by the collision.

[0014] The collision warning function warns (notifies) the driver of the possibility of a collision using an alarm 26 (details will be described later). The primary braking function decelerates the host vehicle C1 at a primary target deceleration by automatic braking in order to prompt the driver to take a collision avoidance action. The secondary braking function decelerates the host vehicle C1 at a secondary target deceleration greater than the primary target deceleration by automatic braking for collision avoidance and reduction of collision damage.

[0015] The driving support system 1 includes an ECU (Electronic Control Unit). The ECU 11 is provided with a microcomputer (microcontroller) 12. The microcomputer 12 has a built-in CPU 13 and a memory 14. In addition to the ECU 11, a plurality of ECUs for controlling each part are mounted on the host vehicle C1, and the ECU 11 is connected so as to enable two-way communication with other ECUs by means of the CAN (Controller Area Network) communication protocol.

[0016] The host vehicle C1 is also equipped with a camera 21 (an example of a predetermined sensor). The camera 21 is, for example, a stereo camera capable of continuously capturing still images at a predetermined frame rate. The camera 21 is installed at a position where it can capture a wide angle around the host vehicle C1. For example, four cameras 21 are installed so as to capture the front, rear, left, and right of the host vehicle C1, respectively.

[0017] The camera 21 extracts, for example, target pixels corresponding to the same target object in each image captured by the image sensor from a pair of image data input from the left and right eye image sensors, detects the amount of displacement of the positions of the target pixels between the pair of images, and calculates the distance to the same target object based on the principle of triangulation. The output signal of the camera 21 is input to the ECU 11.

[0018] The host vehicle C1 is further provided with a vehicle speed sensor 22, a steering angle sensor 23, and a yaw rate sensor 24. The vehicle speed sensor 22 outputs, as a detection signal, a pulse signal synchronized with the rotation of a rotating body (e.g., a drive shaft) that rotates as the host vehicle C1 travels. The steering angle sensor 23 outputs a detection signal corresponding to the steering angle (absolute steering angle) with respect to the steering angle midpoint of the steering mechanism (e.g., the steering wheel) of the host vehicle C1. The steering angle takes a positive value when the steering mechanism is turned to the right from the steering angle midpoint (the state where the steering wheel is turned to the right side), and a negative value when it is turned to the left (the state where the steering wheel is turned to the left side). The yaw rate sensor 24 outputs a detection signal corresponding to the yaw rate, which is the rotational angular velocity around the vertical axis passing through the center of gravity of the host vehicle C1. The detection signals of the vehicle speed sensor 22, the steering angle sensor 23, and the yaw rate sensor 24 are input to the ECU 11.

[0019] The host vehicle C1 is equipped with a hydraulic braking system. The braking system includes a brake pedal, a brake booster, a master cylinder, a brake actuator 25, brakes provided on each wheel, and the like. The brake pedal is arranged at a position convenient for a driver sitting in the driver's seat to step on with the right foot. When the brake pedal is stepped on, the stepping force input to the brake pedal is transmitted to the brake booster. In the brake booster, the negative pressure generated in the intake system of the engine is utilized, and the stepping force of the brake pedal is amplified by the pressure difference between the negative pressure and the atmospheric pressure.

[0020] The force amplified by the brake booster is transmitted from the brake booster to the master cylinder, and a hydraulic pressure corresponding to that force is generated from the master cylinder. The hydraulic pressure of the master cylinder is transmitted to the brake actuator 25, and hydraulic pressure is supplied from the brake actuator 25 to the wheel cylinders of the brakes provided on each wheel, and braking force is applied to the wheels from each brake by that hydraulic pressure. Further, the brake actuator 25 incorporates an electric pump, and when the automatic brake is activated, the electric pump is driven by electric power from the battery, and the hydraulic pressure generated by the electric pump is supplied to each wheel cylinder.

[0021] In addition, the host vehicle C1 is equipped with an alarm 26. The alarm 26 outputs various alarms, and the alarms may be output by light, sound, or voice.

[0022] Next, with reference to FIG. 2 as well, the ECU 11 will be described in detail. FIG. 2 is a diagram showing an example of the positional relationship between the host vehicle C1 and targets (vehicles C2, C3, pedestrian M) in the first embodiment. In this example, the case of the host vehicle C1 traveling backward is taken as an example. However, the present invention is not limited to this, and is also applicable when the host vehicle C1 is traveling forward.

[0023] During the travel of the host vehicle C1, a predetermined area (area R2) is defined by the length in the moving direction corresponding to the vehicle speed of the host vehicle C1 (A: for example, "vehicle speed (m / s) × 3" (m)), and the length in the vehicle width direction of the host vehicle C1 corresponding to the distance in the moving direction from the host vehicle C1 (B: for example, "1 + distance (m) × 1.1" (m)). Also, the horizontal length C in the rectangular area R is a predetermined value (for example, 9 (m)).

[0024] The ECU 11 (acquisition unit) acquires target information (such as position information), which is information on targets existing around the host vehicle C1, from the camera 21.

[0025] In addition, the ECU 11 (determination unit) determines whether or not a target exists in an outer area (area R1), which is an area outside a predetermined area (area R2) including the planned travel route of the host vehicle C1, based on the target information. In the example of FIG. 2, the targets are the vehicles C2, C3, and the pedestrian M, but the vehicles C2, C3 are stopped, and hereinafter, the pedestrian M will mainly be described as an example of a target.

[0026] In addition, in the captured image by the camera 21, a part of the body of the pedestrian M may be hidden by the vehicle C2. However, if a part of the body such as the feet of the pedestrian M is included in the captured image, not only the presence of the pedestrian M can be recognized, but also the position of the pedestrian M and the calculation of the distance from the host vehicle C1 to the pedestrian M can be performed. In addition, the recognition that the detected target is a human body can be realized by, for example, image recognition technology such as pattern matching.

[0027] In addition, immediately after the pedestrian M walks and enters the region R2 from the region R1, the ECU11 (detection unit) detects the pedestrian M in the region R2 based on the target information.

[0028] In addition, when the pedestrian M is detected in the region R2, the ECU11 (calculation unit) calculates the collision risk based on the relative speed and distance of the pedestrian M with respect to the host vehicle C1 (the distance to the pedestrian M. The same applies hereinafter). That is, since the ECU11 has recognized the position of the pedestrian M since the pedestrian M was present in the region R1, immediately after detecting the pedestrian M in the region R2, the relative speed of the pedestrian M with respect to the host vehicle C1 can be calculated, and the collision risk is calculated based on the relative speed and the distance. For example, if the relative speeds are the same, the shorter the distance, the greater the collision risk. Also, for example, if the distances are the same, the greater the relative speed, the greater the collision risk.

[0029] FIG. 3 is a flowchart showing the processing by the driving support system 1 of the first embodiment. First, in step S1, the ECU11 acquires target information around the host vehicle C1 from the camera 21. The acquisition of this target information is executed, for example, at a cycle of 50 ms.

[0030] Next, in step S2, the ECU11 determines whether or not a target exists in the outer region (region R1) based on the target information. If Yes, it proceeds to step S3, and if No, it returns to step S1. For example, assuming that it is determined that the pedestrian M exists in the region R1, it proceeds to step S3.

[0031] In step S3, the ECU 11 determines whether or not an object has been detected in a predetermined area (area R2). If Yes, it proceeds to step S4; if No, it returns to step S1. For example, assuming that a pedestrian M has been detected in area R2, it proceeds to step S4.

[0032] In step S4, the ECU 11 calculates a collision risk based on the relative speed and distance of the pedestrian M with respect to the host vehicle C1. The collision risk is calculated in three levels: "low" collision risk, "medium" collision risk, and "high" collision risk, for example, according to the distance from the host vehicle C1 to the pedestrian M and the like.

[0033] Next, in step S5, the ECU 11 performs processing according to the collision risk calculated in step S4. For example, when the collision risk is "low", it executes a collision warning function to warn the driver of the possibility of a collision.

[0034] Also, when the collision risk is "medium", it executes a primary braking function and decelerates the host vehicle C1 at a primary target deceleration by automatic braking in order to prompt the driver to take collision avoidance action.

[0035] Also, when the collision risk is "high", it executes a secondary braking function and decelerates the host vehicle C1 at a secondary target deceleration (> primary target deceleration) by automatic braking in order to avoid a collision and reduce collision damage.

[0036] Thus, according to the first embodiment, since the collision risk is calculated based on the relative speed of the object with respect to the host vehicle C1 immediately after the object enters the predetermined area, the collision risk between the host vehicle C1 and the object can be reduced. For example, in a parking lot where there are many obstacles such as parked vehicles during the running of the host vehicle C1, a more effective pedestrian collision damage reduction system can be realized.

[0037] (Second Embodiment) Next, the second embodiment will be described. Descriptions of matters similar to those of the first embodiment will be omitted as appropriate. When a target is detected in a predetermined area, the ECU 11 (calculation unit) calculates the collision risk based on the value obtained by adding a predetermined relative speed (for example, about 1 m / s) to the relative speed of the target with respect to the host vehicle C1, and the distance.

[0038] FIG. 4 is a flowchart showing the processing by the driving support system 1 according to the second embodiment. Steps S1 to S3 are the same as steps S1 to S3 in FIG. 3.

[0039] After step S3, in step S4a, the ECU 11 calculates the collision risk based on the value obtained by adding a predetermined relative speed to the relative speed of the pedestrian M with respect to the host vehicle C1, and the distance. Step S5 is the same as step S5 in FIG. 3.

[0040] According to this configuration, by calculating the collision risk based on the value obtained by adding a predetermined relative speed to the relative speed of the target with respect to the host vehicle C1, the collision risk between the host vehicle C1 and the target can be further reduced.

[0041] For example, when a pedestrian M who was not detected in the area R1 (FIG. 2) is suddenly detected in the area R2 (FIG. 2), even when the relative speed of the pedestrian M has not been calculated immediately after that, the collision risk can be calculated based on the value obtained by adding a predetermined relative speed (for example, about 1 m / s). Thereby, the damage reduction effect can be further enhanced.

[0042] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalent scope.

[0043] In addition, the program executed by the ECU 11 of the present embodiment can be provided by recording it on a recording medium readable by a computer device such as a CD (Compact Disc)-ROM (Read Only Memory), flexible disk (FD), CD-R (Recordable), DVD (Digital Versatile Disk) in an installable format or an executable format. Further, the program may be provided or distributed via a network such as the Internet.

[0044] In addition, the target object is not limited to pedestrians and other vehicles, but is generally any moving object such as a bicycle, motorcycle, or animal (such as a dog or cat).

[0045] In addition, the sensor for detecting the object is not limited to a camera, and other sensors using electromagnetic waves, ultrasonic waves, etc. may also be used.

[0046] In addition, in the second embodiment, the predetermined relative speed to be further added to the relative speed of the object is not limited to a constant value, and may be, for example, a value that varies according to the distance from the host vehicle C1 (for example, the smaller the distance from the host vehicle C1, the larger the value).

[0047] In addition, in the embodiment, when the predetermined relative speed cannot be calculated, the distance from the host vehicle C1 to the pedestrian M may be subtracted (for example, subtracted by 1 m).

Explanation of Signs

[0048] 1... Driving support system, 11... ECU, 12... Microcomputer, 13... CPU, 14... Memory, 21... Camera, 22... Vehicle speed sensor, 23... Steering angle sensor, 24... Yaw rate sensor, 25... Brake actuator, 26... Alarm

Claims

1. An acquisition unit that acquires target information, which is information on a target existing around the host vehicle, from a predetermined sensor; A determination unit that determines whether or not the target exists in an outer region, which is a region outside a predetermined region including a planned travel route of the host vehicle, based on the target information; A detection unit that detects the target in the predetermined region based on the target information; A calculation unit that calculates a collision risk level based on a relative speed of the target with respect to the host vehicle when the target is detected in the predetermined region by the detection unit. The driving support device is provided with: The calculation unit calculates the collision risk level based on a value obtained by adding a predetermined relative speed to the relative speed of the target with respect to the host vehicle when the target is detected in the predetermined region by the detection unit.

2. The driving support device according to claim 1, wherein the predetermined region is defined according to the vehicle speed of the host vehicle when the host vehicle is traveling.

3. The driving support device according to claim 1 or claim 2, wherein the predetermined region is defined by a length in a moving direction corresponding to the vehicle speed of the host vehicle and a length in a vehicle width direction of the host vehicle corresponding to a distance in the moving direction from the host vehicle when the host vehicle is traveling.

4. The driving support device according to claim 1 or claim 2, wherein the predetermined region is defined so as to widen in the vehicle width direction of the host vehicle as the distance from the host vehicle increases.

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