Conflict avoidance support device

Abstract

In the present invention, a collision with a second oncoming vehicle is avoided even when a host vehicle has already entered a first oncoming lane, and, after having avoiding a collision with the second oncoming vehicle, having a collision with a first oncoming vehicle is also avoided. Specifically, when there is a possibility of the host vehicle colliding with the second oncoming vehicle, a collision with the second oncoming vehicle is avoided without stopping the host vehicle by using a braking force or deceleration that is less than the braking force or deceleration necessary to stop the host vehicle in front of the second oncoming lane, and, after avoiding a collision with the second oncoming vehicle, it is possible to avoid a collision with the first vehicle without stopping the host vehicle in the first oncoming lane by canceling the braking force or deceleration instructed to the host vehicle, allowing secondary damage to be minimized.

Description

[Technical Field]

[0001] The present invention relates to a collision avoidance assistance device that assists vehicle driving operations to avoid collisions with surrounding objects or to reduce damage caused by collisions. [Background technology]

[0002] An example of a collision avoidance support device for an oncoming vehicle traveling in the opposite lane when the vehicle turns right at an intersection is the technology described in Patent Document 1. The collision avoidance support device described in Patent Document 1 determines the possibility of the vehicle colliding with the oncoming vehicle based on the path of the vehicle turning right and the position of the oncoming vehicle, and if it determines that there is a possibility of a collision, it applies the brakes to avoid a collision with the oncoming vehicle.

[0003] Just before the vehicle passes through an intersection and switches to straight-ahead driving, there is a high possibility that the vehicle may erroneously judge the possibility of a collision with an oncoming vehicle on the right turn. Therefore, in Patent Document 1, the direction of the vehicle when the vehicle switches its turn signal to the on state is used as a reference, and the deflection angle, which is the angle of change in the direction of the vehicle as it turns in the direction of the on turn signal, is suppressed from operating collision avoidance control when it is equal to or greater than a threshold value. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-165253 Summary of the Invention [Problem to be solved by the invention]

[0005] In the collision avoidance assistance device, when there is an oncoming vehicle (hereinafter referred to as the first oncoming vehicle) traveling in the oncoming lane closest to the vehicle (hereinafter referred to as the first oncoming lane) and an oncoming vehicle (hereinafter referred to as the second oncoming vehicle) traveling in the oncoming lane further back from the vehicle (hereinafter referred to as the second oncoming lane), if the collision avoidance assistance device determines that the vehicle has already entered the first oncoming lane and there is a possibility of collision only with the second oncoming vehicle that is closer to the vehicle than the first oncoming vehicle, if the threshold value compared with the deflection angle is small, the device will prevent the braking action for the second oncoming vehicle, thereby preventing a collision with the second oncoming vehicle.

[0006] On the other hand, if the threshold value compared with the deflection angle is increased, the vehicle will stop before entering the second oncoming lane by applying the brakes, avoiding a collision with the second oncoming vehicle. However, if the brakes are applied at the above timing, the vehicle will stop in the first oncoming lane, which could result in the first oncoming vehicle hitting the side of the vehicle, with which there was no possibility of a collision after avoiding a collision with the second oncoming vehicle, which could lead to secondary damage.

[0007] Therefore, if the vehicle has already entered the first oncoming lane, it is difficult for the collision avoidance assistance device to avoid a collision with the first oncoming vehicle while also avoiding a collision with the second oncoming vehicle.

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a collision avoidance assistance device that can avoid a collision with a second oncoming vehicle even when the host vehicle has already entered a first oncoming lane, and also avoid being hit by the first oncoming vehicle after avoiding the collision with the second oncoming vehicle. Specifically, the present invention aims to provide a collision avoidance assistance device that can avoid a collision with the second oncoming vehicle without stopping the host vehicle by applying a braking force or deceleration that is smaller than the braking force or deceleration required for the host vehicle to stop just before the second oncoming lane when there is a possibility of the host vehicle colliding with the second oncoming vehicle, and can avoid a collision with the first vehicle without stopping the host vehicle in the first oncoming lane and prevent secondary damage by releasing the braking force or deceleration instructed to the host vehicle after avoiding the collision with the second oncoming vehicle. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention is configured as follows: That is, the present invention includes a surrounding environment recognition unit that detects information about targets around the host vehicle, a collision prediction unit that calculates a time to collision that is a time until a collision occurs between the host vehicle and one of the targets approaching the host vehicle when the host vehicle crosses an oncoming lane, a control determination unit that calculates a timing to decelerate the host vehicle by a first deceleration if the time to collision is equal to or less than a braking operation determination threshold, and an oncoming lane situation determination unit that determines whether the oncoming lane has two or more lanes based on an input from the surrounding environment recognition unit and distinguishes vehicles traveling in two of the oncoming lanes, and the oncoming lane situation determination unit determines a lane that is closer to the host vehicle as seen from the host vehicle as a first driving lane and determines whether the first driving lane is a lane that is closer to the host vehicle than the oncoming lane. The vehicle traveling is defined as the first traveling vehicle, the lane of the oncoming lane that is further back from the host vehicle is defined as the second traveling lane, and the vehicle traveling in the second traveling lane is defined as the second traveling vehicle, and the collision prediction unit calculates a second collision margin time, which is the time until the host vehicle and the second traveling vehicle collide, based on the result of the oncoming lane situation judgment unit, and calculates a predicted passing time, which is the time required for the second traveling vehicle to pass through an intersection area between the predicted path of the second traveling vehicle and the predicted path of the host vehicle, and the control judgment unit sets the deceleration for slowing down the host vehicle to a second deceleration that is smaller than the first deceleration based on the second collision margin time and the predicted passing time. [Effects of the Invention]

[0010] According to the present invention, the host vehicle avoids a collision with a second oncoming vehicle, while also avoiding being hit by the first oncoming vehicle after avoiding the collision with the second oncoming vehicle. Specifically, when there is a possibility that the host vehicle will collide with the second oncoming vehicle, the host vehicle avoids a collision with the second oncoming vehicle without stopping the host vehicle by applying a braking force or deceleration that is smaller than the braking force or deceleration required for the host vehicle to stop in front of the second oncoming vehicle lane, and after avoiding the collision with the second oncoming vehicle, the host vehicle avoids a collision with the first vehicle without stopping in the first oncoming vehicle lane, thereby preventing secondary damage.

[0011] Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating an example of the configuration of a vehicle equipped with an embodiment of a collision avoidance support device to which the present invention is applied; [Figure 2] 1 is a functional block diagram of an embodiment of a collision avoidance assistance device to which the present invention is applied; [Figure 3] 3 is an example of a flowchart of collision avoidance assistance in an embodiment of a collision avoidance assistance device to which the present invention is applied. [Figure 4] An example of free space calculation. [Figure 5] 10 shows an example of the positions of the host vehicle 10 and the second oncoming vehicle according to the predicted overlap rate. [Figure 6] 10 is an example of a second collision region according to a predicted overlap rate. [Figure 7] 10 is an example of a flowchart for determining whether to perform second control. [Figure 8] 10 shows an example of the positions of the host vehicle 10 and the first oncoming vehicle according to the first oncoming lane crossing time and the first time to collision. [Figure 9] 10 shows an example of the positions of the host vehicle 10 and the second oncoming vehicle according to the predicted collision position arrival time and the total time for passing through the second collision area. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings used to explain the embodiments, parts having the same functions are designated by the same reference numerals, and repeated description thereof may be omitted.

[0014] 1 is a schematic diagram of a vehicle equipped with an embodiment of a collision avoidance support device according to the present invention. The collision avoidance support device is mounted on a vehicle (host vehicle) 10 and supports the vehicle 10 in avoiding collision with an obstacle around the vehicle 10. The vehicle 10 is composed of a front camera 2F (hereinafter sometimes simply referred to as camera 2) mounted on the front of the vehicle, radar 3, a right front wheel speed sensor 5FR that detects the wheel speed of a right front wheel 4FR, a right rear wheel speed sensor 5RR that detects the wheel speed of a right rear wheel 4RR, a left rear wheel speed sensor 5RL that detects the wheel speed of a left rear wheel 4RL, a left front wheel speed sensor 5FL that detects the wheel speed of a left front wheel 4FL, a steering angle sensor 6, a yaw rate sensor 7, a meter 8, a buzzer 9, a collision avoidance support device 11, a braking control device 12, etc.

[0015] The front camera 2F is equipped with a lens and an imaging element, and is appropriately positioned so as to capture images of the environment surrounding the vehicle 10. The captured images of the front camera 2F are transmitted to the collision avoidance support device 11, where they are processed. The collision avoidance support device 11 identifies the object type of the object (hereinafter referred to as the "object" as appropriate) around the vehicle 10 based on the captured images transmitted from the front camera 2F. Examples of object types include automobiles, pedestrians, motorcycles, roads, lane lines such as white and yellow lines, traffic signals, traffic signs, and obstacles. In this embodiment, one camera 2 is disposed to capture images of the environment surrounding the vehicle 10, but multiple cameras may also be disposed. The camera 2 may be a monocular camera or a stereo camera, and the type of camera and the functions of the camera may be changed as necessary.

[0016] The radars 3 are installed at the four corners of the vehicle 10. Each radar 3 measures the position and speed of targets around the vehicle 10 by, for example, emitting electromagnetic waves and receiving reflected waves from surrounding targets, and transmits the measurement results to the collision avoidance support device 11. The radar 3 may be, for example, a millimeter-wave radar or a laser radar, or an ultrasonic sensor instead of a radar. Furthermore, a combination of multiple sensors may be used to measure the speed and position of a target. In this embodiment, as an example, a combination of the camera 2 and the radar 3 is used as a means for acquiring information about targets around the vehicle 10. However, for example, a LIDAR may be used instead of the radar 3, or multiple sensors may be used. Furthermore, the number and installation locations of the radars 3 may be changed as needed.

[0017] A right front wheel 4FR, a right rear wheel 4RR, a left rear wheel 4RL, and a left front wheel 4FL are disposed on the front, rear, left, and right sides of the vehicle body of the host vehicle 10. A right front wheel speed sensor 5FR, a right rear wheel speed sensor 5RR, a left rear wheel speed sensor 5RL, and a left front wheel speed sensor 5FL are provided for each of the wheels 4FR, 4RR, 4RL, and 4FL. Each wheel speed sensor 5FR, 5RR, 5RL, and 5FL detects its own wheel speed and transmits the detected wheel speeds to the collision avoidance assistance device 11. The collision avoidance assistance device 11 calculates the speed of the host vehicle 10 based on the information on each wheel speed. Hereinafter, unless otherwise specified, the right front wheel 4FR, right rear wheel 4RR, left rear wheel 4RL, and left front wheel 4FL will be referred to as wheels 4, and the right front wheel speed sensor 5FR, right rear wheel speed sensor 5RR, left rear wheel speed sensor 5RL, and left front wheel speed sensor 5FL will be referred to as wheel speed sensors 5.

[0018] The steering angle sensor 6 is a sensor that detects the rotation angle (steering angle) of the steering wheel of the vehicle 10 , and the steering angle detected by the steering angle sensor 6 is transmitted to the collision avoidance assistance device 11 .

[0019] The yaw rate sensor 7 detects the yaw rate of the host vehicle 10 , and the yaw rate detected by the yaw rate sensor 7 is transmitted to the collision avoidance assistance device 11 .

[0020] For example, when the collision avoidance support device 11 determines that there is a high possibility of a collision between the vehicle 10 and a target, the meter 8 displays a warning image to notify the driver of the high possibility of a collision. In this embodiment, the meter 8 is provided as an example of a means for displaying a warning image, but instead of the meter 8, for example, a part of a car navigation system may be used, or an image may be displayed using a head-up display.

[0021] The buzzer 9 sounds a warning sound to notify the driver of the high possibility of collision when, for example, the collision avoidance assistance device 11 determines that there is a high possibility of collision between the vehicle 10 and a target. In this embodiment, the buzzer 9 is provided as an example of a means for sounding a warning sound, but instead of the buzzer 9, for example, a part of a car navigation system may be used, or the warning sound may be sounded from a speaker.

[0022] The collision avoidance support device 11 is configured to be capable of performing a collision avoidance support operation to avoid a collision between the host vehicle 10 and a target or to reduce damage caused by the collision. The collision avoidance support device 11 is configured to be capable of outputting control signals for activating the meter 8, the buzzer 9, and the braking control device 12 based on information received from the above-mentioned multiple sensors. In this embodiment, the collision avoidance support device 11 is configured as, for example, an ECU (Electronic Control Unit) mounted on the host vehicle 10, and assists in any or all of the following to realize the collision avoidance support operation: displaying a warning screen on the meter 8, sounding an alarm on the buzzer 9, and automatically activating the brakes via the braking control device 12.

[0023] The braking control device 12 controls the braking device of the host vehicle 10. The braking control device 12 is a component that can adjust the braking force of the braking device in response to a control signal output from the collision avoidance assistance device 11, and includes brake actuators such as a hydraulic pump and a valve unit.

[0024] Fig. 2 shows the internal functional block configuration of the collision avoidance assistance device 11 shown in Fig. 1. Such functional blocks are realized by hardware, software, or a combination of these.

[0025] As shown in FIG. 2, the collision avoidance support device 11 includes a vehicle information recognition unit 201, a surrounding environment recognition unit 202, an intersection crossing prediction unit 203 for the host vehicle, an oncoming lane situation determination unit 204, a collision prediction unit 205, and a collision determination unit 206.

[0026] The vehicle information recognition unit 201 calculates information about the host vehicle 10, such as the turning radius and acceleration of the host vehicle 10, to be used by the intersection crossing prediction unit 203, the collision prediction unit 205, and the collision determination unit 206, based on the speed of the host vehicle 10 acquired from the wheel speed sensor 5 and the yaw rate of the host vehicle 10 acquired from the yaw rate sensor 7. The yaw rate may also be acquired from the steering angle of the host vehicle 10 acquired from the steering angle sensor 6.

[0027] The surrounding environment recognition unit 202 determines the type of object (e.g., vehicle, bicycle, pedestrian) based on the obstacle information acquired from the camera 2 and radar 3, and standardizes the current position and speed information of the object into a format and coordinate system used by the collision avoidance support device 11. In the present embodiment, the coordinate system used, for example, has the center of the front end of the vehicle 10 as the origin, and determines the position and speed of the object with the overall length of the vehicle 10 as the longitudinal direction and the overall width as the lateral direction. When the same object is detected by the above-mentioned multiple sensors, the current position and speed of the object may be determined taking into account errors in the front-rear and left-right directions of the camera 2 and radar 3. Furthermore, the unit 202 calculates target information required for the oncoming lane situation determination unit 204 and the collision prediction unit 205, such as the acceleration of the object.

[0028] In addition to the above, the surrounding environment recognition unit 202 acquires the position and angle of oncoming lanes and the number of lanes from the conditions of the road on which the vehicle is traveling and the conditions of oncoming lanes acquired from the camera 2.

[0029] The intersection crossing prediction unit 203 determines whether the vehicle 10 is turning right or left at the intersection based on information about the vehicle 10 and information calculated by the vehicle information recognition unit 201, and determines whether the vehicle 10 is entering the first oncoming lane based on the positional relationship of the oncoming lane obtained by the surrounding environment recognition unit 202.

[0030] The oncoming lane condition determination unit 204 is composed of an oncoming vehicle determination unit 204A and a free space detection unit 204B.

[0031] The oncoming vehicle determination unit 204A determines whether there are multiple oncoming lanes (two or more lanes) based on the target position, target speed, target acceleration, and information related to the oncoming lane acquired from the surrounding environment recognition unit 202, and if there are multiple oncoming lanes, determines which oncoming lane the target is traveling in (distinguishes the vehicle traveling in the oncoming lane). The lane in front of the host vehicle 10 is determined as the first driving lane, and a vehicle traveling in the first oncoming lane is determined as the first oncoming vehicle (first traveling vehicle), and the lane in the farther side of the host vehicle 10 is determined as the second driving lane, and a vehicle traveling in the second oncoming lane is determined as the second oncoming vehicle (second traveling vehicle).

[0032] The free space detection unit 204B calculates (detects) a section in the first oncoming lane where there is no first oncoming vehicle (hereinafter referred to as a free space) from information about the road shape and the first oncoming lane.

[0033] The collision prediction unit 205 is composed of a collision prediction time calculation unit 205A and a collision area passing time calculation unit 205B.

[0034] The collision prediction time calculation unit 205A predicts the paths of the host vehicle 10, the first oncoming vehicle, and the second oncoming vehicle based on information about the host vehicle 10, the first oncoming vehicle, the second oncoming vehicle, and the road shape. Based on the predicted paths of the host vehicle 10, the first oncoming vehicle, and the second oncoming vehicle, it determines whether there is a possibility that the host vehicle 10 will collide with the first oncoming vehicle and the second oncoming vehicle, and calculates the time until a collision with the host vehicle 10 is predicted (hereinafter referred to as the time to collision). As a result, the collision prediction time calculation unit 205A calculates the time to collision, which is the time until a collision with a vehicle coming towards the host vehicle 10 among the targets detected by the surrounding environment recognition unit 202 when the host vehicle 10 crosses the oncoming lane (the time until a collision is predicted).

[0035] The collision area passing time calculation unit 205B calculates the area where a collision between the vehicle 10 and the second oncoming vehicle is predicted based on the time until a collision with the vehicle 10 is predicted, in other words, the intersection area between the predicted path of the second oncoming vehicle and the predicted path of the vehicle 10 (hereinafter referred to as the second collision area), and calculates the time required for the second oncoming vehicle to pass through the second collision area (intersection area) from its current position.

[0036] The collision determination unit 206 is made up of a collision avoidance operation determination unit 206A and a control instruction unit 206B.

[0037] Based on the calculation results of the collision prediction unit 205, the collision avoidance operation determination unit 206A issues a warning and requests braking to the first oncoming vehicle and the second oncoming vehicle.

[0038] The control instruction unit 206B requests the meter 8 to display a warning screen and requests the buzzer 9 to sound an alarm, based on the alarm activation request acquired from the collision avoidance operation determination unit 206A.

[0039] In addition to the above, the control instruction unit 206B outputs a control command value required to avoid collision with the target to the braking control device 12 based on the braking operation request acquired from the collision avoidance operation determination unit 206A. When the time to collision is equal to or less than the braking operation determination threshold, the control instruction unit 206B outputs a control command value to the braking control device 12 for decelerating the host vehicle 10 to avoid collision with the target. The control instruction unit 206B is capable of outputting a first deceleration or a first braking force and a second deceleration or a second braking force, the second deceleration being smaller than the first deceleration and the second braking force being smaller than the first braking force.

[0040] When outputting a control command value, the control instruction unit 206B switches between the first deceleration and the second deceleration or the first braking force and the second braking force in response to an operation request from the collision avoidance operation determination unit 206A.

[0041] 3 is an example of a flowchart for collision avoidance assistance in an embodiment of the present invention when a first oncoming lane and a second oncoming lane exist and the host vehicle 10 has already entered the first oncoming lane. The method for determining whether the host vehicle 10 has entered the first oncoming lane may be based on the positional relationship between the position of the oncoming lane and the host vehicle 10 acquired from the surrounding environment recognition unit 202, and is not limited to the method described in this embodiment.

[0042] In step S401 of FIG. 3, it is determined whether the host vehicle 10 is turning right or left at an intersection based on information from the vehicle information recognition unit 201. As an example of a determination method, it may be determined that the host vehicle 10 is turning right or left at an intersection based on the yaw rate, the turning radius, or both the yaw rate and the turning radius of the host vehicle 10. Alternatively, it may be determined that the host vehicle 10 is decelerating based on the speed information of the host vehicle 10. It may also be determined that the host vehicle 10 is traveling through an intersection based on road signs acquired from the camera 2. If it is determined in step S401 that the host vehicle 10 is turning right or left at an intersection, the process proceeds to step S402. If the host vehicle 10 is not turning right or left, the processes from step S401 onward are not performed. In this embodiment, collision avoidance assistance is performed when the host vehicle 10 is turning right or left. However, collision avoidance assistance may also be performed in a conventional manner even when the host vehicle 10 is not turning right or left. This step S401 is executed by the intersection crossing prediction unit 203.

[0043] In step S402, the free space in the first oncoming lane is calculated. When the oncoming lane situation determination unit 204 determines that a first oncoming vehicle is present, the free space is calculated based on information about the first oncoming vehicle acquired from the surrounding environment recognition unit 202. FIG. 4 shows the free space when the first oncoming vehicle is not detected (row (A) in FIG. 4), when the first oncoming vehicle is located far from the host vehicle 10 (row (B) in FIG. 4), and when the first oncoming vehicle is located close to the host vehicle 10 (row (C) in FIG. 4). In the figure, 1000 indicates a white line on the road, and an area 1001 surrounded by the white line 1000 indicates the first oncoming lane, and an area 1002 indicates the second oncoming lane. 10 indicates the host vehicle 10, and 11C indicates the first oncoming vehicle. An arrow 1010 indicates the travel path of the host vehicle 10. Area 1003 indicates the free space calculated in step S402, and the free space is an area in the first oncoming lane where no oncoming vehicles exist. 1004 indicates the length of the free space based on the current position of the host vehicle 10. As in FIG. 4(A), if the first oncoming vehicle cannot be detected, the vertical length 1004 of the free space may be set to the limit distance that the sensor can detect, or collision determination with the first oncoming vehicle may not be performed in step S402 and thereafter. As in FIG. 4(B) and FIG. 4(C), if the first oncoming vehicle can be detected, the vertical length of the free space may be calculated based on the current position of the host vehicle 10, and information about the free space may be used when determining a collision with the first oncoming vehicle in step S402 and thereafter. This step S402 is executed by the free space detection unit 204B of the oncoming lane condition determination unit 204.

[0044] In step S403, based on information regarding the host vehicle 10, the first oncoming vehicle, and the second oncoming vehicle and information regarding the free space calculated in step S402, it is determined whether or not there is a possibility of a collision between the host vehicle 10 and the first oncoming vehicle (hereinafter referred to as first collision determination), and whether or not there is a possibility of a collision between the host vehicle 10 and the second oncoming vehicle (hereinafter referred to as second collision determination). As an example of a method for the first collision determination, the positions of the host vehicle 10 and the first oncoming vehicle after a predetermined time are predicted, and if there is an area where the predicted positions of the host vehicle 10 and the first oncoming vehicle overlap with the host vehicle 10, it is determined that there is a possibility of a collision with the host vehicle 10. In the second collision determination, it is also determined that there is a possibility of a collision with the host vehicle 10 if there is an area where the predicted positions of the host vehicle 10 and the second oncoming vehicle overlap with the host vehicle 10.

[0045] When calculating the predicted position of the host vehicle 10 after a predetermined time, the predicted position may be calculated assuming that the behavior of the host vehicle 10 is a steady turn with constant speed and yaw rate, or the predicted position may be calculated taking into account changes in the acceleration and yaw rate of the host vehicle, and the method of calculating the predicted position of the host vehicle 10 is not limited to the method of this embodiment. When calculating the predicted positions of the first oncoming vehicle and the second oncoming vehicle after a predetermined time, the predicted positions may be calculated assuming that the behavior of the oncoming vehicles is uniform linear motion, or the predicted positions may be calculated taking into account the acceleration of the first oncoming vehicle and the second oncoming vehicle, and the method of calculating the predicted positions of the first oncoming vehicle and the second oncoming vehicle is not limited to the method of this embodiment.

[0046] If it is determined in the first collision determination that a collision with the host vehicle 10 will occur, the time that will pass until a collision between the host vehicle 10 and the first oncoming vehicle is predicted (hereinafter referred to as the first collision margin time) is calculated. Based on the first collision margin time, the position of the host vehicle 10 when a collision between the host vehicle 10 and the first oncoming vehicle is predicted (hereinafter referred to as the first collision margin position) and the position of the first oncoming vehicle (hereinafter referred to as the first oncoming vehicle collision margin position) are calculated.

[0047] If it is determined in the second collision determination that a collision with the host vehicle 10 will occur, the time that will pass until a collision between the host vehicle 10 and the second oncoming vehicle is predicted (hereinafter referred to as the second collision margin time) is calculated. Based on the second collision margin time, the position of the host vehicle 10 when a collision between the host vehicle 10 and the second oncoming vehicle is predicted (hereinafter referred to as the second collision margin position) and the position of the second oncoming vehicle (hereinafter referred to as the second oncoming vehicle collision margin position) are calculated.

[0048] If the first collision determination is not established when a first oncoming vehicle is present, the first time to collision is calculated as the time it takes for the first oncoming vehicle to reach the second predicted collision position from the current position.

[0049] In the above-described first collision determination, the determination is made based on information about the host vehicle 10 and the first oncoming vehicle, as an example, but the determination may also be made based on information about the free space. For example, in step S402, if the length of the free space is longer than a predetermined distance, it may be determined that there is no first oncoming vehicle that may collide with the host vehicle 10, and the first time to collision may be set to a large value, or the length of the free space may be set to the time required for the first oncoming vehicle to travel at a previously set maximum assumed speed.

[0050] If there is no second oncoming vehicle, the second time to collision is also set to a large value.

[0051] This step S403 is executed by the collision prediction time calculation unit 205A of the collision prediction unit 205.

[0052] In step S404, the process from step S404 onward is switched based on the result of the first collision determination. If it is determined that there is a possibility of a collision with the first oncoming vehicle as a result of the first collision determination, the process proceeds to step S409, and if it is determined that there is no possibility of a collision with the first oncoming vehicle, the process proceeds to step S405.

[0053] In step S405, the processing from step S405 onwards is switched based on the result of the second collision determination. If it is determined that there is a possibility of a collision with the second oncoming vehicle as a result of the second collision determination, the process proceeds to step S406. If it is determined that there is no possibility of a collision with the second oncoming vehicle, deceleration is not requested because there is no possibility of a collision with the first oncoming vehicle or the second oncoming vehicle.

[0054] When the host vehicle 10 is decelerating by the second deceleration or braking force, if the deceleration of the host vehicle 10 eliminates the possibility of a collision with the second oncoming vehicle (at the point when the possibility of a collision with the second oncoming vehicle becomes low), the request for the second deceleration or braking force is canceled. By canceling the request for the deceleration or braking force in the above case, the host vehicle 10 can quickly pass through the first oncoming lane without stopping, and is prevented from being hit by the first oncoming vehicle after avoiding a collision with the second oncoming vehicle.

[0055] In step S406, when it is determined that there is a possibility that the host vehicle 10 will collide with the second oncoming vehicle, the time that will pass until the second oncoming vehicle passes the second collision area (hereinafter referred to as the second collision area predicted passing time) is calculated based on the second collision predicted position and the second oncoming vehicle collision predicted position. This step S406 is executed by the collision area passing time calculation unit 205B of the collision prediction unit 205.

[0056] The second collision area is an intersection area between the predicted path of the second oncoming vehicle and the predicted path of the host vehicle 10, and the size of the second collision area is calculated based on the positional relationship between the second predicted collision position and the predicted collision position of the second oncoming vehicle, but in addition to the above, a margin distance may be set that takes into account the host vehicle speed, the speed of the second oncoming vehicle, or the detection accuracy of the sensor. The predicted second collision area passage time varies depending on the overlap ratio (hereinafter referred to as the predicted overlap ratio) between the host vehicle 10 and the second oncoming vehicle at the point where the collision between the host vehicle 10 and the second oncoming vehicle is predicted (second collision area), so the predicted second collision area passage time may be calculated based on the predicted overlap ratio.

[0057] Based on Figure 5, we will explain the case where the predicted overlap rate calculated in step S406 is large (column (A) of Figure 5) and the case where the predicted overlap rate is small (column (B) of Figure 5). The speeds of the host vehicle 10 and the second oncoming vehicle are the same in columns (A) and (B) of Figure 5, and the traveling trajectory of the host vehicle 10 is the same in columns (A) and (B). 12A indicates the current position of the host vehicle 10, and 12B indicate the current position of the second oncoming vehicle, with the second oncoming vehicle being closer to the host vehicle 10 in column (A) than in column (B).

[0058] Reference numeral 1110 indicates the host vehicle 10 at the second predicted collision position. Reference numerals 1112A and 1112B indicate the second predicted collision position with an oncoming vehicle. Reference numeral 1102 indicates the second collision area. As an example of a method for calculating the second collision area, the positions where the paths of the right and left sides of the host vehicle 10 and the path of the second oncoming vehicle intersect (points 1115 and 1116 in FIG. 5) are calculated from the positions of the right and left sides of the host vehicle 10 at the second predicted collision position, and a rectangle is formed with points 1115 and 1116 as vertices, parallel to the overall length and width directions of the second oncoming vehicle at the second predicted collision position with the oncoming vehicle.

[0059] Arrows 1101A and 1101B indicate the length of the second oncoming vehicle entering the second collision area, and the predicted overlap rate is the percentage of 1101A or 1101B relative to the overall length of the second oncoming vehicle in the second collision area. In Fig. 5, the host vehicle 10 collides with the second oncoming vehicle from the lower left to the upper right, but in the case where the host vehicle 10 collides perpendicularly with the second oncoming vehicle, for example, the overall length of the second oncoming vehicle in the second collision area is equal to the overall width of the host vehicle 10, and therefore the calculated predicted overlap rate is the percentage relative to the overall width of the host vehicle 10.

[0060] Based on FIG. 6, the calculation of the predicted second collision area passing time will be described in the case where the predicted overlap rate is large (column (A) of FIG. 5) and the case where the predicted overlap rate is small (column (B) of FIG. 5).

[0061] The definitions of 1110, 1112A, 1112B, 1101A, 1101B, 1115, and 1116 are the same as in FIG. 5. 1117 indicates the second oncoming vehicle when it passes through the second collision area. Lengths 1104A and 1104B indicate the distance required for all of the second oncoming vehicles to pass through the second collision area, and can be calculated based on the predicted overlap rate and the overall length of the second oncoming vehicle. The length from the front end of the second oncoming vehicle to point 1116 at the predicted collision position of the second oncoming vehicle is calculated from the predicted overlap rate, and the calculated length is added to the overall length of the second oncoming vehicle to calculate lengths 1104A and 1104B.

[0062] In step S406, the predicted time to pass through the second collision area is calculated based on the lengths of 1104A and 1104B. When calculating the predicted time to pass through the second collision area, the calculation may be performed assuming that the speed of the second oncoming vehicle is constant at its current speed, or the calculation may be performed taking into account the acceleration of the second traveling vehicle.

[0063] As shown in Figure 6, the travel distance (1104A and 1104B) required for all of the second oncoming vehicles to pass through the second collision area varies depending on the predicted overlap rate. Therefore, by calculating the predicted passing time of the second collision area based on the calculated predicted overlap rate, it is possible to calculate the predicted passing time of the second collision area according to the positional relationship and state of the vehicle 10 and the second oncoming vehicle.

[0064] In this embodiment, as an example, a case has been described in which the predicted passing time of the second collision area is calculated based on the calculated predicted overlap rate, but the predicted passing time of the second collision area may also be calculated using a method different from the method described in this embodiment.

[0065] In step S406, if the speed of the second oncoming vehicle is fast or if the distance from the host vehicle 10 to the second oncoming vehicle is long, it is assumed that the detection information, such as the speed and position of the second oncoming vehicle detected by the sensor, will contain a large error. If the second collision area predicted passage time calculated based on the information detected by the sensor is shorter than the second collision area predicted passage time calculated based on the actual position of the second oncoming vehicle, it may be erroneously determined that the second oncoming vehicle is passing through the second collision area, resulting in a collision with the second oncoming vehicle. Therefore, if the speed of the second oncoming vehicle is faster than a predetermined speed, or if the distance from the host vehicle 10 to the second oncoming vehicle is longer than a predetermined distance, or if both the speed of the second oncoming vehicle is faster than the predetermined speed and the distance from the host vehicle 10 to the second oncoming vehicle are longer than a predetermined distance, a predetermined time may be added to the second collision area predicted passage time to prevent the host vehicle 10 from colliding with the second oncoming vehicle.

[0066] The above-mentioned predetermined speed and predetermined distance may be variable depending on the speed and positional relationship between the host vehicle 10 and the second oncoming vehicle. In order to prevent the host vehicle 10 from colliding with the second oncoming vehicle due to the second oncoming vehicle decelerating after the host vehicle 10 activates the brakes using the collision avoidance assist device, the predicted second collision area passing time may be calculated taking into account the current deceleration of the second oncoming vehicle, or a margin time may be added to the predicted second collision area passing time in advance, taking into account that the second oncoming vehicle will decelerate at a constant deceleration.

[0067] In step S407, the time that will elapse until the host vehicle 10 reaches the second predicted collision position when decelerated by the second deceleration or braking force (hereinafter referred to as predicted collision position arrival time) is calculated from the current position and speed of the host vehicle 10. If the road distance to the second predicted collision position is longer than the distance that the host vehicle 10 travels before stopping by the second deceleration or braking force, the host vehicle 10 will stop before reaching the second predicted collision position, and therefore, in the above case, as an example, the predicted collision position arrival time is set to 0. This step S407 is executed by the collision prediction unit 205.

[0068] In step S408, based on the first collision margin time, the second collision area predicted passage time, and the collision predicted position arrival time, it is determined that a collision with the second oncoming vehicle can be avoided by the second deceleration or braking force, and that if the host vehicle 10 slows down by the second deceleration or braking force, it will not collide with the first oncoming vehicle (hereinafter referred to as the second control implementation determination).

[0069] If the second control execution determination is affirmative in step S408, the timing of application of the second deceleration or braking force is determined in step S410. If the second control execution determination is negative in step S408, the process proceeds to step S409, where the timing of application of the first deceleration or braking force is determined.

[0070] Steps S408 and after are executed by the collision determination unit 206.

[0071] FIG. 7 is an example of a flowchart of the second control execution determination.

[0072] In step S501, it is determined whether a collision can be avoided with the second deceleration or braking force depending on the state of the host vehicle 10 and the second oncoming vehicle.

[0073] If the speed of the host vehicle 10 is slower than the predetermined speed, collision avoidance using the second deceleration or braking force is not performed because there is a possibility that the host vehicle 10 will stop before reaching the second predicted collision position if it is decelerated by the second deceleration or braking force. In other words, when the vehicle speed of the host vehicle 10 is lower than the predetermined vehicle speed, the deceleration or braking force is not changed from the first deceleration or braking force to the second deceleration or braking force (switching from the first to the second deceleration or braking force is not performed). The predetermined speed may be set based on the current state of the host vehicle 10 and is not limited to the method described in this embodiment. One example of a method for setting the predetermined speed from the current state of the host vehicle 10 is to calculate the distance from the current position of the host vehicle 10 to reach the second predicted collision position (hereinafter referred to as the second distance) from the speed of the host vehicle 10 and the second time to collision, calculate the minimum speed of the host vehicle 10 required to travel the second distance without stopping if the host vehicle 10 is decelerated by the second deceleration or braking force, and set the minimum speed calculated by the above method as the predetermined speed. By setting the predetermined speed by the above method, it can be determined whether the host vehicle 10 will stop before reaching the second predicted collision position.

[0074] If the speed of the second oncoming vehicle is slower than a predetermined speed, the second oncoming vehicle may stop or turn right or left within the second collision area, so collision avoidance is not performed by using the second deceleration or braking force. In other words, when the speed of the second traveling vehicle is slower than a predetermined speed, the deceleration or braking force is not changed from the first deceleration or braking force to the second deceleration or braking force (switching from the first to the second deceleration or braking force is not performed).

[0075] In step S502, based on the second collision margin time and the second collision area predicted passage time and collision position predicted arrival time, it is determined whether the second oncoming vehicle will be able to pass through the second collision area before the host vehicle 10 if the host vehicle 10 decelerates due to the second deceleration or braking force.

[0076] The time required for the second oncoming vehicle to pass through the second collision area from its current position can be calculated as the sum of the second collision margin time, which is the time required for the second oncoming vehicle to reach the second collision area from its current position, and the predicted second collision area passage time, which is the time required for the second oncoming vehicle to pass through the second collision area after reaching it (hereinafter referred to as the total time for passing through the second collision area).

[0077] If the predicted collision position arrival time is greater than the total time for passing through the second collision area, the second oncoming vehicle will have already passed through the second collision area when the host vehicle 10 reaches the second predicted collision position, and the process proceeds to step S503. On the other hand, if the predicted collision position arrival time is less than the total time for passing through the second collision area, the second oncoming vehicle will be in the second collision area (will not be able to pass through the second collision area) when the host vehicle 10 reaches the second predicted collision position, and therefore a collision with the second oncoming vehicle cannot be avoided by the second deceleration or braking force, and the host vehicle 10 is stopped in front of the second oncoming vehicle lane by the first deceleration or braking force to avoid a collision with the second oncoming vehicle.

[0078] In step S503, based on the first collision margin time and the time required for the host vehicle 10 to pass through the first oncoming lane when decelerated at the second deceleration or braking force (hereinafter referred to as the first oncoming lane passing time), it is determined whether a collision with the first oncoming vehicle can be avoided when the host vehicle 10 decelerates at the second deceleration or braking force.

[0079] The time to pass through the first oncoming lane is the sum of the time to reach the predicted collision position and the time required for the host vehicle 10 to pass the full length of the host vehicle 10 at the speed of the host vehicle 10 after the time to reach the predicted collision position when the host vehicle 10 is decelerated by the second deceleration or braking force.

[0080] 8 shows the positional relationship between the host vehicle 10 and the first oncoming vehicle when the host vehicle 10 decelerates at the second deceleration or braking force and passes through the first oncoming lane in the case where the first oncoming lane passing time is shorter than the first collision margin time (column (A) of FIG. 8) and in the case where the first oncoming lane passing time is longer than the first collision margin time (column (B) of FIG. 8). The speeds of the host vehicle 10 and the first oncoming vehicle are the same in columns (A) and (B) of FIG. 8.

[0081] Reference numeral 10 indicates the current position of the vehicle 10. Reference numerals 11A and 11B indicate the current positions of the first oncoming vehicle in cases (A) and (B), with the first oncoming vehicle being closer to the vehicle 10 in row (B) than in row (A). The definitions of 1000, 1001, and 1002 are the same as in FIG. 5.

[0082] 1231 is a coordinate system with the origin at the center of the front end of the first oncoming vehicle 11A and 11B, and the longitudinal position is defined as the full length direction of the first oncoming vehicle, and the lateral position is defined as the full width direction. The longitudinal position of 1231 is defined as being forward of the first oncoming vehicle, and the lateral position is defined as being to the left of the first oncoming vehicle.

[0083] The dotted line in 1210 indicates the vertical position of the second predicted collision position in the coordinate system in 1231. 1211A and 1211B indicate the position of the first oncoming vehicle in the cases of rows (A) and (B) when the host vehicle 10 passes through the first oncoming lane. 1210A and 1210B indicate the position of the host vehicle 10 in the cases of rows (A) and (B) after the first collision margin time.

[0084] As shown in column (A) of FIG. 8, when the first oncoming lane crossing time is shorter than the first time to collision, the first oncoming vehicle passes the longitudinal position of the second predicted collision position in the coordinate system 1231 after the host vehicle 10 passes through the first oncoming lane. Therefore, when the host vehicle 10 is decelerated with the second deceleration or braking force, the host vehicle 10 and the first oncoming vehicle will not collide, and collision avoidance by the second deceleration or braking force is possible. On the other hand, as shown in column (B) of FIG. 8, when the first oncoming lane crossing time is longer than the first time to collision, the first oncoming vehicle reaches the longitudinal position of the second predicted collision position in the coordinate system 1231 before the host vehicle 10 passes through the first oncoming lane. When the host vehicle 10 is decelerated with the second deceleration or braking force, the host vehicle 10 will collide with the first oncoming vehicle. Therefore, in the above case, the host vehicle 10 is stopped in front of the second oncoming lane with the first deceleration or braking force.

[0085] If there is no first oncoming vehicle, the first time to collision is set to a large value, and therefore a second deceleration or braking force is required (column (A) in FIG. 8).

[0086] In step S409, a threshold value for determining the activation timing of collision avoidance assistance using the first deceleration or braking force (hereinafter referred to as the first braking operation determination threshold value) is calculated, and it is determined that the host vehicle 10 has reached the activation timing of the first deceleration or braking force from the first collision margin time and the second collision margin time. The first braking operation determination threshold value is calculated by calculating the distance required for the host vehicle 10 to stop using the first deceleration or the first braking force, and the calculated distance is set as the time that will elapse when the host vehicle 10 is currently traveling.

[0087] If the first time to collision is equal to or less than the first braking operation determination threshold, a first deceleration or braking force is requested in order to stop the host vehicle 10 before it collides with the first oncoming vehicle.

[0088] If the second collision margin time is equal to or less than the first braking operation determination threshold, a first deceleration or braking force is requested so that the host vehicle 10 stops before colliding with the second oncoming vehicle, and the host vehicle 10 stops in the first oncoming lane.

[0089] In step S410, if the second control execution determination is established, it is determined whether the timing has arrived for the host vehicle 10 to start deceleration by the second deceleration or braking force. The predicted collision position arrival time is compared with the total time for passing through the second collision area to determine whether the timing has arrived for starting deceleration.

[0090] Even if the second deceleration or braking force is requested at the timing when the second control implementation determination is established, the host vehicle 10 can avoid a collision with the first oncoming vehicle while avoiding a collision with the second oncoming vehicle, but the second deceleration or braking force may also be requested after a predetermined time has elapsed from the above timing.

[0091] FIG. 9 shows the position of the second oncoming vehicle when the host vehicle 10 reaches the second collision area in two cases: when the host vehicle 10 starts decelerating at the timing when the second control execution determination is established (column (A) of FIG. 9); and when the host vehicle 10 starts decelerating at the timing when a predetermined time has elapsed since the timing when the second control execution determination is established and the predicted collision position arrival time becomes equal to the total time for passing through the second collision area (column (B) of FIG. 9). The speeds of the host vehicle 10 and the second oncoming vehicle in column (A) of FIG. 9 are the same as the speeds of the host vehicle 10 and the second oncoming vehicle in column (B). 10A and 10B indicate the current positions of the host vehicle 10 in columns (A) and (B), respectively, with 10B being closer to the second oncoming vehicle than 10A. 12C indicates the current position of the second oncoming vehicle, which is the same position in columns (A) and (B). 1000, 1001, and 1002 are defined as in FIG. 5. 1310A indicates the position of the host vehicle 10 when the host vehicle 10 reaches the second collision area when it decelerates from position 10A at a second deceleration or braking force. 1310B indicates the position of the host vehicle 10 when it reaches the second collision area when it decelerates from position 10B at a second deceleration or braking force. 1312A indicates the position of the second oncoming vehicle when it reaches the second collision area when it decelerates from position 10A at a second deceleration or braking force. 1312B indicates the position of the second oncoming vehicle when it reaches the second collision area when it decelerates from position 10B at a second deceleration or braking force.

[0092] As shown in column (A) of FIG. 9, because the predicted collision position arrival time is longer than the total time for passing through the second collision area, when the host vehicle 10 reaches the second collision area, the second oncoming vehicle has already passed through the second collision area, but when the host vehicle 10 reaches the second collision area, the second oncoming vehicle is at a position away from the host vehicle 10. In the case of column (B) of FIG. 9, because the first oncoming lane passing time is equal to the first marginal time to collision, the second oncoming vehicle passes through the second collision area when the host vehicle 10 reaches the second collision area. Compared to the case of column (A), in the case of column (B), the host vehicle 10 starts to decelerate when the distance from the host vehicle 10 to the second oncoming vehicle is shorter, which improves the accuracy of the sensor's recognition of the second oncoming vehicle and the accuracy of predicting the paths of the host vehicle 10 and the second oncoming vehicle. Therefore, the case of column (B) can suppress excessive operation more effectively.

[0093] Therefore, the predetermined time from the time when the second control execution determination is made to the time when the second deceleration or braking force is requested may be adjustable based on the state of the vehicle 10 and the second oncoming vehicle, and if adjustment is possible as described above, it is adjusted within a range where the time to reach the predicted collision position does not become longer than the total time to pass through the second collision area.

[0094] In step S411, based on the result of the first braking operation determination in step S409 and the result of the second braking operation determination in step S410, the deceleration or braking force (deceleration command value) requested by the collision avoidance assistance device 11 from the brake control device 12 is determined. Since deceleration or braking force is not requested simultaneously from the first braking operation determination and the second braking operation determination, if the host vehicle 10 is not applying the brakes, the deceleration or braking force requested by the first braking operation determination or the second braking operation determination is requested of the brake control device 12.

[0095] If the second oncoming vehicle also decelerates when the host vehicle 10 is decelerating at the second deceleration or braking force, the host vehicle 10 may reach the second collision area before the second oncoming vehicle passes through the second collision area, resulting in a collision with the second oncoming vehicle. Therefore, in step S411, if deceleration of the second oncoming vehicle is detected while the host vehicle 10 is decelerating at the second deceleration or braking force, the host vehicle 10 may stop in front of the second oncoming vehicle lane and avoid a collision with the second oncoming vehicle by requesting a deceleration greater than the first deceleration or a braking force greater than the first braking force.

[0096] By requesting a second deceleration or precision force when the second control execution determination is established, the host vehicle 10 can pass through the intersection without stopping in the first oncoming lane after avoiding a collision with the second oncoming vehicle, thereby avoiding a collision with the first oncoming vehicle and preventing secondary damage.

[0097] In the present embodiment, as an example, a case has been described in which a collision with the first oncoming vehicle is avoided while avoiding a collision with a second oncoming vehicle with which there is a possibility of collision when the host vehicle 10 has already entered the first oncoming lane, but when the host vehicle 10 has not entered the first oncoming lane, a collision between the second oncoming vehicle and the first oncoming vehicle may be avoided by a method different from that of the present embodiment. As an example of collision avoidance assistance for a second oncoming vehicle with which there is a possibility of collision when the host vehicle 10 has not entered the first oncoming lane, a request may be made to the host vehicle 10 to decelerate or apply braking force so that the host vehicle 10 can stop in front of the first oncoming lane, thereby avoiding a collision between the second oncoming vehicle and the first oncoming vehicle.

[0098] In this embodiment, as an example, a case has been described in which the brakes are applied to a single vehicle that may collide with the vehicle 10 to avoid a collision, but if there are multiple targets that may collide with the vehicle 10, it is also possible to ensure that the vehicle stops in front of the target that is most likely to collide with the vehicle 10 first among the multiple targets that may collide with the vehicle 10.

[0099] In this embodiment, as an example, a method for avoiding a collision when there are a first oncoming lane and a second oncoming lane and there is a possibility of a collision with the second oncoming vehicle has been described. However, if there is only the first oncoming lane and there is a possibility of a collision with the first oncoming vehicle, the host vehicle 10 may request a first deceleration or braking force at a timing when it can stop just before the first oncoming lane, or the collision may be avoided by a conventional method.

[0100] As described above, the collision avoidance support device 11 of this embodiment includes a surrounding environment recognition unit 202 that detects information about targets around the host vehicle, a collision prediction unit 205 that calculates a time to collision which is a time until a collision (a time until a collision is predicted) with a vehicle among the targets that is moving towards the host vehicle when the host vehicle crosses an oncoming lane, a control determination unit (collision determination unit 206) that calculates a timing to decelerate the host vehicle by a first deceleration when the time to collision is equal to or less than a braking operation determination threshold, and an oncoming lane situation determination unit 204 that determines whether the oncoming lane has two or more lanes based on an input from the surrounding environment recognition unit 202 and distinguishes vehicles traveling in two of the oncoming lanes, and the oncoming lane situation determination unit 204 determines a lane that is closer to the host vehicle as seen from the host vehicle as a first traveling lane, and determines whether a vehicle traveling in the first traveling lane is traveling in the oncoming lane. The vehicle approaching the host vehicle is designated as a first traveling vehicle (first oncoming vehicle), the lane of the oncoming lane that is further back from the host vehicle is designated as a second traveling lane, and the vehicle traveling in the second traveling lane is designated as a second traveling vehicle (second oncoming vehicle), and the collision prediction unit 205 calculates a second collision margin time, which is the time until the host vehicle and the second traveling vehicle collide, based on the result of the oncoming lane situation determination unit 204, and calculates a predicted passing time (second collision area predicted passing time), which is the time required for the second traveling vehicle to pass through an intersection area (second collision area) between the predicted path of the second traveling vehicle and the predicted path of the host vehicle, and the control determination unit (collision determination unit 206) sets the deceleration for decelerating the host vehicle to a second deceleration that is smaller than the first deceleration, based on the second collision margin time and the predicted passing time (second collision area predicted passing time) (step S502).

[0101] The collision prediction unit 205 calculates a first collision margin time, which is the time until the host vehicle and the first traveling vehicle collide (longer than the second collision margin time), and the control determination unit (collision determination unit 206) sets the deceleration to a second deceleration that is smaller than the first deceleration, taking into account the first collision margin time (step S503).

[0102] When the vehicle speed of the host vehicle is lower than a predetermined vehicle speed, the control determination unit (collision determination unit 206) does not change the deceleration from the first deceleration to the second deceleration (step S501).

[0103] When the vehicle speed of the second traveling vehicle is lower than a predetermined vehicle speed, the control determination unit (collision determination unit 206) does not change the deceleration from the first deceleration to the second deceleration (step S501).

[0104] The collision prediction unit 205 calculates a predicted overlap rate, which is the ratio of overlap between the host vehicle and the second traveling vehicle in the intersection area (second collision area) between the predicted path of the second traveling vehicle and the predicted path of the host vehicle, and calculates the predicted passing time (second collision area predicted passing time) based on the predicted overlap rate.

[0105] The vehicle has a free space detection unit 204B that detects a free space, which is a space in the first driving lane where no obstacles exist, and the collision prediction unit 205 calculates the first collision margin time between the vehicle and the first driving vehicle based on information about the free space.

[0106] The control determination unit (collision determination unit 206) cancels the request for the second deceleration when the possibility of a collision with the second traveling vehicle becomes low.

[0107] When the host vehicle is decelerating at the second deceleration, the deceleration of the host vehicle is increased (more than the second deceleration or the first deceleration) based on the vehicle speed of the second traveling vehicle (when deceleration is detected).

[0108] According to this embodiment, the host vehicle avoids a collision with the second oncoming vehicle, and also avoids being hit by the first oncoming vehicle after avoiding the collision with the second oncoming vehicle. Specifically, when there is a possibility that the host vehicle will collide with the second oncoming vehicle, the host vehicle avoids a collision with the second oncoming vehicle without stopping the host vehicle by applying a braking force or deceleration that is smaller than the braking force or deceleration required for the host vehicle to stop in front of the second oncoming vehicle lane, and after avoiding the collision with the second oncoming vehicle, the host vehicle avoids a collision with the first vehicle without stopping in the first oncoming vehicle lane, and secondary damage can also be prevented.

[0109] It should be noted that the present invention is not limited to the above-described embodiment and includes various modifications. For example, the above-described embodiment has been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment having all of the described configurations.

[0110] Furthermore, the above-mentioned configurations, functions, processing units, processing means, etc. may be realized in part or in whole in hardware, for example by designing them as integrated circuits, or may be realized in software by a processor interpreting and executing a program that realizes each function.

[0111] Information such as programs, tables, and files that realize each function can be stored in a storage device such as a memory, a hard disk, or an SSD (Solid State Drive), or in a recording medium such as an IC card, an SD card, or a DVD.

[0112] In addition, the control lines and information lines shown are those that are considered necessary for explanation, and do not necessarily represent all the control lines and information lines that are necessary for implementation. In reality, it can be assumed that almost all components are interconnected. [Explanation of symbols]

[0113] 2 Cameras 3. Radar 4 wheels 5 Wheel speed sensor 6 Steering angle sensor 7 Yaw rate sensor 8 meters 9 Buzzer 10 Vehicle 11 Collision avoidance support device 12 Braking control device 201 Vehicle Information Recognition Unit 202 Surrounding Environment Awareness Department 203 Vehicle intersection crossing prediction unit 204 Oncoming Lane Situation Judgment Unit 204A Oncoming vehicle judgment unit 204B Free space detector 205 Collision Prediction Department 205A Collision prediction time calculation unit 205B Collision area transit time calculation unit 206 Collision determination unit (control determination unit) 206A Collision avoidance operation determination unit 206B Control instruction section 1000 White Line 1001 1st Oncoming Lane 1002 2nd Oncoming Lane

Claims

1. a surrounding environment recognition unit that detects information about targets around the vehicle; a collision prediction unit that calculates a time to collision, which is a time until a collision between the host vehicle and a vehicle among the targets that is moving toward the host vehicle when the host vehicle crosses an oncoming lane; a control determination unit that calculates a timing to decelerate the host vehicle at a first deceleration when the time to collision is equal to or less than a braking operation determination threshold; an oncoming lane situation determination unit that determines whether the oncoming lanes include two or more lanes based on an input from the surrounding environment recognition unit and distinguishes vehicles traveling in two of the oncoming lanes, the oncoming lane situation determination unit defines a lane of the oncoming lanes closer to the host vehicle as a first driving lane, and a vehicle traveling in the first driving lane as a first driving vehicle; and defines a lane of the oncoming lanes further from the host vehicle as a second driving lane, and a vehicle traveling in the second driving lane as a second driving vehicle; the collision prediction unit calculates a second collision margin time, which is a time until a collision between the host vehicle and the second traveling vehicle, based on a result of the oncoming lane situation determination unit, and calculates a predicted passing time, which is a time required for the second traveling vehicle to pass through an intersection area between a predicted path of the second traveling vehicle and the host vehicle; The collision avoidance support device is characterized in that the control determination unit sets the deceleration at which the host vehicle is decelerated to a second deceleration that is smaller than the first deceleration based on the second collision margin time and the predicted passing time.

2. the collision prediction unit calculates a first collision margin time, which is a time until a collision occurs between the host vehicle and the first traveling vehicle; 2. The collision avoidance assist device according to claim 1, wherein the control determination unit sets the deceleration to a second deceleration that is smaller than the first deceleration, taking into account the first time to collision.

3. 2. The collision avoidance support device according to claim 1, wherein the control determination unit does not change the deceleration from the first deceleration to the second deceleration when the vehicle speed is lower than a predetermined vehicle speed.

4. 2. The collision avoidance support device according to claim 1, wherein the control determination unit does not change the deceleration from the first deceleration to the second deceleration when the vehicle speed of the second traveling vehicle is lower than a predetermined vehicle speed.

5. 2. The collision avoidance support device according to claim 1, wherein the collision prediction unit calculates a predicted overlap rate, which is a ratio of overlap between the host vehicle and the second traveling vehicle in an intersection area between the predicted path of the second traveling vehicle and the predicted path of the host vehicle, and calculates the predicted passing time based on the predicted overlap rate.

6. a free space detection unit that detects a free space that is a space in the first driving lane where no obstacles exist, 2. The collision avoidance assist device according to claim 1, wherein the collision prediction unit calculates a first time to collision between the host vehicle and the first traveling vehicle based on the information about the free space.

7. 2. The collision avoidance assist device according to claim 1, wherein the control determination unit cancels the request for the second deceleration when the possibility of a collision with the second traveling vehicle becomes low.

8. 2. The collision avoidance assist device according to claim 1, wherein when the host vehicle is decelerating at the second deceleration, the deceleration of the host vehicle is increased based on the vehicle speed of the second traveling vehicle.

Images