Vehicle collision avoidance support device

Abstract

A vehicle collision avoidance support device is provided that can prevent a collision between a vehicle and a moving object when the moving object is decelerated during the execution of steering avoidance control. The vehicle collision avoidance support device (10) is configured to execute steering avoidance control when an index value indicating the likelihood of a collision between the vehicle (100) and an object (200) in front of the vehicle is greater than a predetermined index value. The steering avoidance control is a control that sets an avoidance path within the lane in which the vehicle is traveling that can avoid a collision between the vehicle and the object and forcibly steers the vehicle so that the vehicle travels along the avoidance path. When the object is a moving object moving in the same direction as the vehicle, the vehicle collision avoidance support device terminates the steering avoidance control when the deceleration of the moving object is greater than a predetermined deceleration during the execution of the steering avoidance control.

Description

Technical Field

[0001] The present invention relates to a vehicle collision avoidance support device. Background Art

[0002] A vehicle collision avoidance support device is known that, when a vehicle (host vehicle) is likely to collide with an object in front of the vehicle, executes forced braking control to forcibly stop the vehicle and avoid collision with the object. Furthermore, a vehicle collision avoidance support device is also known that, when it is predicted that collision with the object cannot be avoided even by forcible braking of the vehicle, executes steering avoidance control to forcibly steer the vehicle so that the vehicle avoids the object and avoids collision with the object (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-43262 Summary of the Invention

[0006] Conventional vehicle collision avoidance support devices, when executing steering avoidance control, set a path for the vehicle to avoid an object (an avoidance path) and forcibly steer the vehicle to follow the avoidance path. However, if the object ahead of the vehicle is a preceding vehicle, such as a moving object moving in the same direction as the vehicle, and the object decelerates after the vehicle begins traveling along the avoidance path, the object may move backward relative to the vehicle onto or near the avoidance path. If steering avoidance control is continued while the object is moving backward relative to the vehicle onto or near the avoidance path, the vehicle may collide with the object.

[0007] An object of the present invention is to provide a vehicle collision avoidance support device capable of preventing a collision between a vehicle and a moving object that the vehicle is trying to avoid colliding with when the vehicle is decelerating during execution of steering avoidance control.

[0008] The vehicle collision avoidance support device according to the present invention is configured to execute steering avoidance control when an index value indicating the likelihood of a collision between the host vehicle and an object located ahead of the host vehicle exceeds a predetermined index value. The steering avoidance control is configured to establish an avoidance path within the lane in which the host vehicle is traveling that can avoid a collision between the host vehicle and the object, and to forcibly steer the host vehicle so that the host vehicle travels along the avoidance path. Furthermore, if the object is a moving object moving in the same direction as the host vehicle, the vehicle collision avoidance support device according to the present invention is configured to terminate the steering avoidance control when the deceleration of the moving object exceeds a predetermined deceleration during the execution of the steering avoidance control.

[0009] If a moving object that the host vehicle is trying to avoid decelerates, the moving object may retreat relative to the host vehicle onto or near the avoidance path. If steering avoidance control is continued even after the moving object has retreated relative to the host vehicle onto or near the avoidance path, the host vehicle may collide with the moving object. According to the present invention, if the moving object decelerates during the execution of steering avoidance control and the deceleration of the moving object exceeds a predetermined deceleration, steering avoidance control is terminated. This prevents the host vehicle from colliding with the moving object due to the deceleration of the moving object.

[0010] In the vehicle collision avoidance support device according to the present invention, the avoidance path is set in consideration of the relative speed of the own vehicle with respect to the moving object when the index value becomes equal to or greater than the predetermined index value, for example.

[0011] When a moving object decelerates, the relative speed of the host vehicle relative to the moving object increases. Therefore, when setting an avoidance path based on the relative speed of the host vehicle relative to the moving object when the index value exceeds a predetermined index value, whether the host vehicle will collide with the moving object while traveling along the avoidance path is highly correlated with whether the moving object is decelerating. According to the present invention, when setting an avoidance path based on the relative speed of the host vehicle relative to the moving object, steering avoidance control is discontinued when the deceleration of the moving object exceeds the predetermined deceleration, thereby preventing the host vehicle from colliding with the moving object.

[0012] Alternatively, the index value may be, for example, a predicted arrival time, which is the estimated time required for the host vehicle to reach the object. In this case, the shorter the predicted arrival time, the larger the index value. Furthermore, the predicted arrival time is determined based on the distance between the host vehicle and the object and the relative speed of the host vehicle relative to the object. Furthermore, the steering avoidance control is executed when the predicted arrival time becomes less than or equal to a predetermined predicted arrival time corresponding to the predetermined index value.

[0013] To prevent unnecessary initiation of steering avoidance control while executing it, it is effective to determine the timing for initiating steering avoidance control based on the time it takes for the vehicle to reach an object. According to the present invention, steering avoidance control is initiated using the estimated time it takes for the vehicle to reach the object (predicted arrival time) as an indicator. Therefore, steering avoidance control can be executed while preventing unnecessary initiation of steering avoidance control.

[0014] The components of the present invention are not limited to the embodiments of the present invention described below with reference to the drawings. Other objects, other features, and additional advantages of the present invention will be readily apparent from the description of the embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 1 is a diagram showing a vehicle collision avoidance assistance device according to an embodiment of the present invention and a vehicle (own vehicle) equipped with the vehicle collision avoidance assistance device.

[0016] Figure 2 (A) is a diagram showing the dividing lines that define the lane in which the vehicle is traveling. Figure 2 (B) is a diagram showing the yaw angle of the own vehicle, Figure 2 (C) is also a diagram showing the yaw angle of the own vehicle.

[0017] Figure 3 (A) is a diagram showing the driving range of the vehicle. Figure 3 (B) is a diagram showing a situation where an object (vehicle) exists within the driving range of the vehicle. Figure 3 (C) is a diagram showing a recommended avoidance path for the vehicle to avoid an object (vehicle). Figure 3 (D) is a diagram showing a target avoidance path that the vehicle travels to avoid an object (vehicle).

[0018] Figure 4 (A) is a diagram showing a situation where the steering of the vehicle (avoidance steering) for causing the vehicle to travel along the avoidance path has started. Figure 4 (B) is a diagram showing a situation where the evasive steering is in progress after the evasive steering has started. Figure 4 (C) is a diagram showing a state where the steering avoidance control is terminated.

[0019] Figure 5 (A) is a diagram showing a situation where the steering of the vehicle (avoidance steering) for causing the vehicle to travel along the avoidance path has started. Figure 5 (B) is a diagram showing a situation that may occur when, after the avoidance steering starts, the object (preceding vehicle) in front of the own vehicle decelerates and moves backward relative to the own vehicle to the vicinity of the avoidance path, and the avoidance steering (steering avoidance control) is continued.

[0020] Figure 6 This is a time chart showing changes in the deceleration and other factors of the target moving object when the steering avoidance control is performed and the steering avoidance control is completed without interruption.

[0021] Figure 7 This is a time chart showing changes in the deceleration and other factors of the target moving object when steering avoidance control is performed and then terminated midway.

[0022] Figure 8 This is a flowchart showing a routine executed by the vehicle collision avoidance support device according to the embodiment of the present invention.

[0023] Description of Reference Numerals

[0024] 10: Vehicle collision avoidance support device;

[0025] 21: driving device;

[0026] 22: Braking device;

[0027] 23: Steering gear;

[0028] 68: forward information detection device;

[0029] 90: ECU;

[0030] 100: own vehicle;

[0031] 200: Object;

[0032] 200tgt: object;

[0033] 200M: moving objects;

[0034] 200Mtgt: object moves;

[0035] R: avoidance path;

[0036] Rrec: recommended avoidance path;

[0037] Rtgt: Target avoidance path. DETAILED DESCRIPTION

[0038] Hereinafter, a vehicle collision avoidance support device according to an embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 As shown, a vehicle collision avoidance assistance device 10 according to an embodiment of the present invention is mounted on a host vehicle 100 .

[0039] ECU

[0040] like Figure 1 As shown, the vehicle collision avoidance support device 10 includes an ECU 90. ECU stands for Electronic Control Unit. ECU 90 primarily includes a microcomputer. The microcomputer includes a CPU, ROM, RAM, nonvolatile memory, and an interface. The CPU implements various functions by executing instructions, programs, or routines stored in the ROM.

[0041] <Drive device, etc.>

[0042] Furthermore, the vehicle 100 is equipped with a drive device 21 , a brake device 22 , and a steering device 23 .

[0043] Drive unit

[0044] The drive device 21 is a device that outputs driving force applied to the vehicle 100 to drive the vehicle 100, and is, for example, an internal combustion engine or a motor. The drive device 21 is electrically connected to the ECU 90. The ECU 90 can control the driving force output from the drive device 21 by controlling the operation of the drive device 21.

[0045] Braking system

[0046] The brake device 22 is a device that outputs a braking force applied to the vehicle 100 to brake the vehicle 100, and is, for example, a brake device. The brake device 22 is electrically connected to the ECU 90. The ECU 90 can control the braking force output from the brake device 22 by controlling the operation of the brake device 22.

[0047] <Steering gear>

[0048] The steering device 23 is a device that outputs a steering force applied to the vehicle 100 for steering the vehicle 100, and is, for example, a power steering device. The steering device 23 is electrically connected to the ECU 90. The ECU 90 can control the steering force output from the steering device 23 by controlling the operation of the steering device 23.

[0049] <Sensors, etc.>

[0050] Furthermore, the vehicle 100 is equipped with an accelerator pedal operation amount sensor 61 , a brake pedal operation amount sensor 62 , a steering angle sensor 63 , a steering torque sensor 64 , a vehicle speed sensor 65 , a longitudinal acceleration sensor 66 , a lateral acceleration sensor 67 and a forward information detection device 68 .

[0051] <Accelerator pedal operation amount sensor>

[0052] The accelerator pedal operation amount sensor 61 is electrically connected to the ECU 90. The accelerator pedal operation amount sensor 61 detects the operation amount of the accelerator pedal 31 and transmits information about the detected operation amount to the ECU 90. Based on this information, the ECU 90 obtains the operation amount of the accelerator pedal 31 as the accelerator pedal operation amount AP. The ECU 90 calculates the required driving force PDreq based on the accelerator pedal operation amount AP and the vehicle speed V100 of the vehicle 100. The required driving force PDreq is the driving force required to be output by the drive device 21.

[0053] <Brake pedal operation amount sensor>

[0054] The brake pedal operation amount sensor 62 is electrically connected to the ECU 90. The brake pedal operation amount sensor 62 detects the operation amount of the brake pedal 32 and transmits the detected operation amount information to the ECU 90. Based on this information, the ECU 90 obtains the operation amount of the brake pedal 32 as the brake pedal operation amount BP. Based on the brake pedal operation amount BP, the ECU 90 calculates the required braking force PBreq. The required braking force PBreq is the braking force required to be output by the brake device 22.

[0055] Steering angle sensor

[0056] The steering angle sensor 63 is electrically connected to the ECU 90. The steering angle sensor 63 detects the rotation angle of the steering wheel 33 of the vehicle 100 relative to the neutral position of the steering wheel 33 and transmits information about the detected rotation angle to the ECU 90. Based on this information, the ECU 90 obtains the rotation angle of the steering wheel 33 of the vehicle 100 relative to the neutral position as the steering angle SA.

[0057] Steering torque sensor

[0058] The steering torque sensor 64 is electrically connected to the ECU 90. The steering torque sensor 64 detects the torque input by the driver to the steering shaft 34 via the steering wheel 33 and transmits information about the detected torque to the ECU 90. Based on this information, the ECU 90 obtains the torque input by the driver to the steering shaft 34 via the steering wheel 33 as the driver input torque TQdr.

[0059] <Vehicle speed sensor>

[0060] The vehicle speed sensor 65 is electrically connected to the ECU 90. The vehicle speed sensor 65 detects the rotational speed of each wheel of the vehicle 100 and transmits information on the detected rotational speed of each wheel to the ECU 90. Based on this information, the ECU 90 obtains the running speed of the vehicle 100 as the vehicle speed V100.

[0061] Furthermore, the ECU 90 calculates the torque (assist steering torque TQas) applied from the steering device 23 to the steering shaft 34 based on the acquired steering angle SA, the driver input torque TQdr, and the vehicle speed V100. The assist steering torque TQas is the torque applied to the steering shaft 34 to assist the driver's steering operation of the steering wheel 33.

[0062] Longitudinal acceleration sensor

[0063] The longitudinal acceleration sensor 66 is electrically connected to the ECU 90. The longitudinal acceleration sensor 66 detects the longitudinal acceleration of the vehicle 100 and transmits the detected acceleration information to the ECU 90. Based on this information, the ECU 90 obtains the longitudinal acceleration of the vehicle 100 as the longitudinal acceleration Gx.

[0064] Lateral acceleration sensor

[0065] The lateral acceleration sensor 67 is electrically connected to the ECU 90. The lateral acceleration sensor 67 detects the lateral acceleration of the vehicle 100 and transmits the detected acceleration information to the ECU 90. Based on this information, the ECU 90 obtains the lateral acceleration of the vehicle 100 as the lateral acceleration Gy.

[0066] <Forward Information Detection Device>

[0067] The forward information detection device 68 is a device that detects information in front of the own vehicle 100 and includes, for example, a camera, a radar sensor (millimeter wave radar, etc.), an ultrasonic sensor (clearance sonar), a laser radar (LiDAR), etc.

[0068] The front information detection device 68 is electrically connected to the ECU 90 . The front information detection device 68 detects information in front of the vehicle 100 and transmits the detected information (front information I_F) to the ECU 90 .

[0069] The ECU 90 can detect an object 200 existing in front of the own vehicle 100 based on the front information I_F. In addition, when the ECU 90 detects such an object 200, it can obtain "the distance between the object 200 and the own vehicle 100 (object distance D200)", "the relative speed dV of the own vehicle 100 with respect to the object 200", and "the moving direction of the object 200" based on the front information I_F. Furthermore, the ECU 90 can identify "the left dividing line LML and the right dividing line LMR (refer to the lane LN) that defines the driving lane of the own vehicle 100" based on the front information I_F. Figure 2 (A))” or “the end of the road on which the own vehicle 100 is traveling (the so-called road end)”.

[0070] Then, the ECU 90 obtains the yaw angle YA based on the recognized left and right dividing lines LML and LMR or the road end. Figure 2 As shown in (B) and (C), the yaw angle YA is the angle between the lane extension direction line LLN (a line indicating the direction in which the lane LN extends) and the center front-rear line L100 of the vehicle (a line extending along the front-rear direction of the vehicle 100 at the center of the width direction of the vehicle 100).

[0071] <Overview of the Operation of the Vehicle Collision Avoidance Support System>

[0072] Next, the operation of the vehicle collision avoidance support device 10 will be briefly described. While the vehicle 100 is traveling, the vehicle collision avoidance support device 10 determines whether there are objects ahead of the vehicle 100 in its travel direction based on the forward information I_F. In this example, the objects are vehicles, people, bicycles, guardrails, and the like.

[0073] Furthermore, when there is an object ahead of the own vehicle 100 in the direction of travel and there is a high possibility that the own vehicle 100 will collide with the object, the vehicle collision avoidance support device 10 determines whether there is space laterally of the object for the own vehicle 100 to avoid the object, and when such space exists, utilizes the space to perform steering avoidance control for steering the own vehicle 100 in a manner that causes the own vehicle 100 to avoid the object.

[0074] In addition, the vehicle collision avoidance support device 10 can be configured to first issue an alarm to notify the driver of the own vehicle 100 that the own vehicle 100 may collide with an object before starting the steering avoidance control. If the driver still does not perform an operation to avoid the collision of the own vehicle 100 with the object (operation of the accelerator pedal 31, operation of the brake pedal 32, and operation of the steering wheel 33), forced braking of the own vehicle 100 is performed to stop the own vehicle 100. If, despite this, the own vehicle 100 is still likely to collide with the object, steering avoidance control is executed.

[0075] Furthermore, when there is no object ahead of the host vehicle 100 in the direction of travel, or when there is an object ahead of the host vehicle 100 in the direction of travel but the probability of collision between the host vehicle 100 and the object is low, the vehicle collision avoidance support device 10 performs normal driving control. In this normal driving control, when the required driving force PDreq is greater than zero, the operation of the drive device 21 is controlled so that the required driving force PDreq is output from the drive device 21. When the required braking force PBreq is greater than zero, the operation of the braking device 22 is controlled so that the required braking force PBreq is output from the braking device 22. When the auxiliary steering torque TQas is greater than zero, the operation of the steering device 23 is controlled so that the auxiliary steering torque TQas is output from the steering device 23.

[0076] Steering avoidance control

[0077] Next, the steering avoidance control will be described.

[0078] The vehicle collision avoidance support device 10 determines whether or not there is an object 200 within the vehicle driving range A100 based on the front information I_F while the vehicle 100 is driving. Figure 3 As shown in (A), the host vehicle driving range A100 is a range centered on the driving route R100 of the host vehicle 100 and having a width equal to the width of the host vehicle 100. The driving route R100 of the host vehicle 100 is the route that the host vehicle 100 travels when the host vehicle 100 maintains the steering angle SA at that time.

[0079] When the vehicle collision avoidance assistance device 10 determines that an object 200 exists within the host vehicle's driving range A100, it obtains the distance between the object 200 and the host vehicle 100 (object distance D200) and the relative speed dV of the host vehicle 100 with respect to the object 200 based on the forward information I_F. The vehicle collision avoidance assistance device 10 then calculates a predicted time of arrival TTC (= D200 / dV) by dividing the object distance D200 by the relative speed dV. The predicted time of arrival TTC is the estimated time required for the host vehicle 100 to reach the object 200. While the vehicle collision avoidance assistance device 10 determines that the object 200 exists within the host vehicle's driving range A100, it obtains the predicted time of arrival TTC at a predetermined calculation cycle CYC.

[0080] When the relative speed dV is constant, the closer the vehicle 100 is to the object 200, the shorter the predicted arrival time TTC. Figure 3 As shown in (B), when the predicted time to arrival (TTC) decreases to a predetermined time (predetermined predicted time to arrival (TTCth)) as the host vehicle 100 approaches the object 200, the vehicle collision avoidance support device 10 determines that the steering avoidance condition has been met. Specifically, the vehicle collision avoidance support device 10 uses the predicted time to arrival (TTC) as an index value indicating the likelihood of a collision between the host vehicle 100 and the object 200. When this index value exceeds a predetermined index value, the device determines that the likelihood of a collision between the host vehicle 100 and the object 200 is high. Therefore, in this example, the shorter the predicted time to arrival (TTC), the greater the index value indicating the likelihood of a collision between the host vehicle 100 and the object 200.

[0081] When the steering avoidance condition is satisfied, the vehicle collision avoidance support device 10 starts steering avoidance control. When starting steering avoidance control, the vehicle collision avoidance support device 10 first determines whether the driver has operated the steering wheel 33 in a direction in which the vehicle 100 can avoid the object 200 and pass.

[0082] When the vehicle collision avoidance support device 10 determines that the driver has operated the steering wheel 33 in a direction in which the vehicle 100 can avoid the object 200 and pass through, the vehicle collision avoidance support device 10 will be as follows: Figure 3 As shown in (C), a recommended path for the host vehicle 100 to travel while avoiding the object 200 is set as the recommended avoidance path Rrec.

[0083] In this example, the vehicle collision avoidance assistance device 10 sets a path that enables the own vehicle 100 to travel in a manner that allows the own vehicle 100 to avoid the object 200 and pass through the own lane LN (that is, the own vehicle 100 will not travel outside the own lane LN) as the recommended avoidance path Rrec.

[0084] Furthermore, in order to forcibly steer the host vehicle 100 so that it travels along the recommended avoidance path Rrec, thereby avoiding a collision between the host vehicle 100 and the object 200, it is preferable to set the recommended avoidance path Rrec in accordance with the relative speed dV of the host vehicle 100 with respect to the object 200. Therefore, the vehicle collision avoidance assistance device 10 sets the recommended avoidance path Rrec in consideration of the relative speed dV of the host vehicle 100 with respect to the object 200.

[0085] Furthermore, in this example, the vehicle collision avoidance assistance device 10 sets the path corresponding to the driver's operation of the steering wheel 33 as the recommended avoidance path Rrec. More specifically, if the driver turns the steering wheel 33 to the right, the vehicle collision avoidance assistance device 10 sets the path passing the right side of the object 200 as the recommended avoidance path Rrec. If the driver turns the steering wheel 33 to the left, the vehicle collision avoidance assistance device 10 sets the path passing the left side of the object 200 as the recommended avoidance path Rrec.

[0086] After setting the recommended avoidance path Rrec, the vehicle collision avoidance assistance device 10 performs steering of the vehicle 100 (first avoidance steering or auxiliary steering) by increasing or decreasing the auxiliary steering torque TQas based on the driver input torque TQdr so that the vehicle 100 does not deviate from the recommended avoidance path Rrec by more than a predetermined distance Δy. Specifically, the vehicle collision avoidance assistance device 100 performs the first avoidance steering, controlling the auxiliary steering torque TQas so that the vehicle 100 does not deviate from the recommended avoidance path Rrec by more than a predetermined distance. Therefore, this first avoidance steering is achieved by controlling the auxiliary steering torque TQas in consideration of the driver input torque TQdr, rather than ignoring the driver input torque TQdr.

[0087] Furthermore, the vehicle collision avoidance support device 10 may decelerate the vehicle 100 by reducing the driving force applied to the vehicle 100 or limiting it to a certain value or less, or by applying a braking force to the vehicle 100 in conjunction with the first avoidance steering.

[0088] On the other hand, when the steering avoidance condition is satisfied and the steering avoidance control is started, if the vehicle collision avoidance support device 10 determines that the driver has not operated the steering wheel 33 in a direction in which the vehicle 100 can avoid the object 200, the vehicle collision avoidance support device 10 will Figure 3 As shown in (D), a path for the host vehicle 100 to travel while avoiding the object 200 is set as the target avoidance path Rtgt.

[0089] In this example, the vehicle collision avoidance assistance device 10 sets a path that enables the own vehicle 100 to travel in a manner that allows the own vehicle 100 to avoid the object 200 and pass through the own lane LN (that is, the own vehicle 100 will not travel outside the own lane LN) as the target avoidance path Rtgt.

[0090] Furthermore, in order to forcibly steer the host vehicle 100 so that it travels along the target avoidance path Rtgt, thereby avoiding a collision between the host vehicle 100 and the object 200, it is preferable to set the target avoidance path Rtgt in accordance with the relative speed dV of the host vehicle 100 with respect to the object 200. Therefore, the vehicle collision avoidance assistance device 10 sets the target avoidance path Rtgt in consideration of the relative speed dV of the host vehicle 100 with respect to the object 200.

[0091] After setting the target avoidance path Rtgt, the vehicle collision avoidance support device 10 performs steering of the vehicle 100 (second avoidance steering or automatic steering) by controlling the auxiliary steering torque TQas so that the vehicle 100 travels along the target avoidance path Rtgt. Therefore, this second avoidance steering is achieved by controlling the auxiliary steering torque TQas so that the vehicle 100 travels along the target avoidance path Rtgt while ignoring the driver input torque TQdr.

[0092] Furthermore, the vehicle collision avoidance support device 10 may decelerate the vehicle 100 by reducing the driving force applied to the vehicle 100 or limiting it to a certain value or less, or by applying a braking force to the vehicle 100 together with the second avoidance steering.

[0093] When Figure 4 When the avoidance path R (recommended avoidance path Rrec or target avoidance path Rtgt) is set as shown in (A) and avoidance steering (first avoidance steering or second avoidance steering) is started, Figure 4 As shown in (B), the vehicle 100 is steered so as to travel along the avoidance path R. Figure 4 Avoid collision with object 200 as shown in (C).

[0094] Furthermore, the vehicle collision avoidance assistance device 10 does not perform evasive steering (first evasive steering or second evasive steering) if the recommended avoidance path Rrec or target avoidance path Rtgt cannot be set due to reasons such as "the width of the host lane LN is narrow, and there is no space to the side of the object 200 for the host vehicle 100 to avoid the object 200" or "the left side dividing line LML or the right side dividing line LMR of the host vehicle 100 cannot be recognized." In other words, the vehicle collision avoidance assistance device 10 does not perform evasive steering if the prohibition condition that the recommended avoidance path Rrec or the target avoidance path Rtgt cannot be set is satisfied.

[0095] Furthermore, as the prohibition conditions, conditions C1 to C21 described below may be appropriately adopted.

[0096] Condition C1 is a condition in which the evasive steering (the first evasive steering or the second evasive steering) cannot be performed due to a reason such as an abnormality in a device (for example, the steering device 23) for performing the evasive steering.

[0097] Condition C2 is a condition where, when the vehicle collision avoidance support device 10 is configured to execute automatic braking control (PCS), the automatic braking control cannot be executed due to a malfunction in the equipment (e.g., the brake device 22) that implements the automatic braking control. Automatic braking control is a control that forcibly brakes the vehicle 100 to stop before the collision with the object when there is a high probability that the vehicle 100 will collide with the object in front of it.

[0098] Condition C3 is a condition where, when the vehicle collision avoidance support device 10 is configured to execute vehicle stability control (VSC), the vehicle stability control cannot be executed due to a malfunction in a device (e.g., the brake device 22) for executing the vehicle stability control. For example, the vehicle stability control stabilizes the driving behavior of the vehicle 100 by adjusting the driving force PD applied to the drive wheels of the vehicle 100 or individually adjusting the braking force PB applied to each wheel of the vehicle 100 when the driving behavior of the vehicle 100 becomes unstable due to steering of the vehicle 100.

[0099] Condition C4 is a condition that, when the vehicle collision avoidance support device 10 is configured to be able to execute automatic braking control (PCS), the host vehicle 100 can be stopped before the host vehicle 100 collides with the object 200 by the automatic braking control.

[0100] Condition C5 is a condition that, when the vehicle collision avoidance support device 10 is configured to be able to execute automatic braking control (PCS) and has previously executed the automatic braking control, the time elapsed from the end time point of the automatic braking control is within a predetermined time.

[0101] Condition C6 is a condition that, when the steering avoidance control has been previously executed, the time elapsed from the end time point of the steering avoidance control is within a predetermined time period.

[0102] Condition C7 is a condition that the turn signal lamp of the host vehicle 100 is operating (flashing).

[0103] Condition C8 is a condition where, when object 200 is a leading vehicle and the recommended avoidance path Rrec or target avoidance path Rtgt passes to the left of the leading vehicle, the left turn signal indicator of the leading vehicle is operating (flashing). The vehicle collision avoidance assistance device 10 can determine whether the left turn signal indicator of the leading vehicle is operating (flashing) based on the front information I_F. Furthermore, the leading vehicle is a vehicle traveling in the same direction as the host vehicle 100, in the host lane LN (the lane in which the host vehicle 100 is traveling).

[0104] Condition C9 is a condition where, when object 200 is a leading vehicle and the recommended avoidance path Rrec or target avoidance path Rtgt passes through the right side of the leading vehicle, the right turn signal indicator of the leading vehicle is operating (flashing). The vehicle collision avoidance assistance device 10 can determine whether the right turn signal indicator of the leading vehicle is operating (flashing) based on the front information I_F.

[0105] Condition C10 is a condition that the accelerator pedal operation amount AP is equal to or greater than a predetermined accelerator pedal operation amount APth.

[0106] Condition C11 is a condition that the brake pedal operation amount BP is equal to or greater than a predetermined brake pedal operation amount BPth.

[0107] Condition C12 is a condition that the vehicle speed V100 of the own vehicle 100 is not within the predetermined range Rv.

[0108] Condition C13 is a condition that the relative speed dV of the object 200 with respect to the own vehicle 100 is not within the predetermined range Rdv.

[0109] Condition C14 is a condition that the lateral acceleration Gy is equal to or greater than a predetermined lateral acceleration Gy_th.

[0110] Condition C15 is a condition that the longitudinal acceleration Gx is a positive value and its absolute value is equal to or greater than a predetermined value Gx_th.

[0111] Condition C16 is a condition that the longitudinal acceleration Gx is a negative value and its absolute value is equal to or greater than a predetermined value Gx_th.

[0112] Condition C17 is a condition that the host vehicle 100 is traveling on a curve. The vehicle collision avoidance support device 10 can determine whether the host vehicle 100 is traveling on a curve based on the front information I_F.

[0113] Condition C18 is a condition that the distance between the left dividing line LML and the right dividing line LMR of the host vehicle 100 (inter-dividing line distance) is greater than or equal to a predetermined distance. The vehicle collision avoidance assistance device 10 can obtain the inter-dividing line distance based on the front information I_F.

[0114] Condition C19 is a condition that the recommended avoidance path Rrec or the target avoidance path Rtgt intersects the longitudinal centerline of the object 200. The vehicle collision avoidance support device 10 can determine whether the recommended avoidance path Rrec or the target avoidance path Rtgt intersects the longitudinal centerline of the object 200 based on the front information I_F.

[0115] Condition C20 is a condition that the object 200 is moving across the recommended avoidance path Rrec or the target avoidance path Rtgt. The vehicle collision avoidance assistance device 10 can determine whether the object 200 is moving across the recommended avoidance path Rrec or the target avoidance path Rtgt based on the front information I_F.

[0116] Condition C21 is a condition that, although the recommended avoidance path Rrec or the target avoidance path Rtgt can be set, the recommended avoidance path Rrec or the target avoidance path Rtgt is a route along which it is predicted that the host vehicle 100 cannot travel.

[0117] End of Steering Avoidance Control

[0118] After the vehicle collision avoidance support device 10 begins evasive steering (first evasive steering or second evasive steering), it monitors whether a termination condition, in which the absolute value of the yaw angle YA becomes less than or equal to a predetermined yaw angle YAth, has been met. The vehicle collision avoidance support device 10 continues evasive steering (steering avoidance control) until the termination condition is met. On the other hand, the vehicle collision avoidance support device 10 terminates evasive steering (steering avoidance control) when the termination condition is met.

[0119] Furthermore, when the vehicle collision avoidance support device 10 is configured to execute steering avoidance control while braking the vehicle 100 to stop the vehicle 100, the steering avoidance control (avoidance steering) may be terminated when the vehicle 100 stops.

[0120] <Canceling Steering Avoidance Control>

[0121] When the object 200 (target object 200tgt) that the host vehicle 100 is to avoid collision with by the steering avoidance control is an object 200 (target moving object 200Mtgt) such as a preceding vehicle moving in the same direction as the traveling direction of the host vehicle 100, Figure 5 As shown in (A), after the vehicle collision avoidance support device 10 sets the avoidance path R (recommended avoidance path Rrec or target avoidance path Rtgt) and starts the avoidance steering (first avoidance steering or second avoidance steering), if the target moving object 200Mtgt decelerates, the target moving object 200Mtgt may move backward relative to the own vehicle 100 onto the avoidance path R or near the avoidance path R. For example, Figure 5 As shown in FIG. 2(B), if the avoidance steering is continued when the target moving object 200Mtgt is relatively retreating to the vicinity of the avoidance path R with respect to the own vehicle 100, the own vehicle 100 may collide with the target moving object 200Mtgt.

[0122] Therefore, when the target object 200tgt is the moving object 200M (target moving object 200Mtgt), the vehicle collision avoidance support device 10 obtains the deceleration GxM of the target moving object 200Mtgt based on the front information I_F after the avoidance steering (the first avoidance steering or the second avoidance steering) starts, and terminates the steering avoidance control when the deceleration GxM becomes greater than the predetermined deceleration GxMth.

[0123] Therefore, after the avoidance steering is started, if the deceleration GxM of the target moving object 200Mtgt does not become equal to or greater than the predetermined deceleration GxMth before the termination condition is satisfied, Figure 6 As shown, the vehicle collision avoidance support device 10 ends the steering avoidance control when the end condition is satisfied.

[0124] exist Figure 6 In the example shown, the steering avoidance condition is met at time t60, and steering avoidance control begins. Then, at time t61, the deceleration GxM of the target moving object 200Mtgt increases and reaches zero at time t62. However, during this period, the deceleration GxM of the target moving object 200Mtgt does not exceed the predetermined deceleration GxMth, so steering avoidance control continues. Then, at time t63, when the termination condition is met, steering avoidance control ends.

[0125] On the other hand, if the deceleration GxM of the target moving object 200Mtgt becomes equal to or greater than the predetermined deceleration GxMth during the period from the start of the avoidance steering to the satisfaction of the termination condition, then Figure 7As shown, the vehicle collision avoidance assistance device 10 terminates the steering avoidance control. Specifically, if the termination condition is met and the deceleration GxM of the target moving object 200Mtgt becomes greater than or equal to the predetermined deceleration GxMth, the vehicle collision avoidance assistance device 10 terminates the steering avoidance control.

[0126] exist Figure 7 In the example shown, the steering avoidance condition is satisfied at time t70 and the steering avoidance control is started. Then, at time t71, when the deceleration GxM of the target moving object 200Mtgt becomes equal to or greater than the predetermined deceleration GxMth, the suspension condition is satisfied and the steering avoidance control is suspended.

[0127] As described above, when the mobile object 200M (target mobile object 200Mtgt) with which the host vehicle 100 is intended to avoid a collision decelerates, the target mobile object 200Mtgt may retreat relative to the host vehicle 100 onto or near the avoidance path R. If steering avoidance control is continued even after the target mobile object 200Mtgt has retreated relative to the host vehicle 100 onto or near the avoidance path R, the host vehicle 100 may collide with the target mobile object 200Mtgt. According to the vehicle collision avoidance support device 10, if the target mobile object 200Mtgt decelerates during the execution of steering avoidance control and the deceleration GxM of the target mobile object 200Mtgt exceeds the predetermined deceleration GxMth, the steering avoidance control is terminated. This prevents the host vehicle 100 from colliding with the target mobile object 200Mtgt due to the deceleration of the target mobile object 200Mtgt.

[0128] Furthermore, the vehicle collision avoidance support device 10 may be configured to terminate the steering avoidance control when the driver input torque TQdr becomes equal to or greater than a predetermined large torque TQth during execution of the steering avoidance control.

[0129] <Specific Operations of the Vehicle Collision Avoidance Support System>

[0130] Next, the specific operation of the vehicle collision avoidance support device 10 will be described. The CPU of the ECU 90 of the vehicle collision avoidance support device 10 executes the following operation every time a predetermined time has passed. Figure 8 Therefore, when the predetermined timing is reached, the CPU starts Figure 8 The process starts at step 800 and proceeds to step 805 to determine whether the value of the steering avoidance condition flag Xst is "1." The steering avoidance condition flag Xst is a flag whose value is set to "1" when the steering avoidance condition is satisfied.

[0131] If the CPU determines "yes" in step 805, the process proceeds to step 810 to determine whether the driver input torque TQdr is greater than zero. If the CPU determines "yes" in step 810, the process proceeds to step 815 to set the recommended avoidance path Rrec. Next, the CPU proceeds to step 820 to determine whether the recommended avoidance path Rrec can be set.

[0132] If the CPU determines "yes" in step 820, it proceeds to step 825 and starts the first evasive steering. The CPU then proceeds to step 845. On the other hand, if the CPU determines "no" in step 820, it proceeds directly to step 845. In this case, the first evasive steering is not started.

[0133] If the CPU determines "No" in step 810, the process proceeds to step 830 to set the target avoidance path Rtgt. The CPU then proceeds to step 835 to determine whether the target avoidance path Rtgt can be set. If the CPU determines "Yes" in step 835, the process proceeds to step 840 to initiate the second evasive steering. The CPU then proceeds to step 845. On the other hand, if the CPU determines "No" in step 835, the process proceeds directly to step 845. In this case, the second evasive steering is not initiated.

[0134] When the CPU advances the process to step 845 , it sets the value of the steering avoidance condition flag Xst to “0.” Next, the CPU advances the process to step 850 .

[0135] If the CPU makes a “No” determination in step 805 , the CPU directly proceeds to step 850 .

[0136] When the CPU advances the process to step 850, it determines whether the abort condition is met. If the CPU determines "yes" in step 850, the CPU advances the process to step 855. If evasive steering (the first evasive steering or the second evasive steering) is currently being executed, the CPU aborts the steering avoidance control by aborting the evasive steering. The CPU then advances the process to step 860. On the other hand, if the CPU determines "no" in step 850, the CPU directly advances the process to step 860. In this case, if evasive steering (the first evasive steering or the second evasive steering) is currently being executed, the evasive steering is not aborted and continues.

[0137] When the CPU advances the processing to step 860, it determines whether the termination condition is met. If the CPU determines "yes" in step 860, it advances the processing to step 865, and when evasive steering (the first evasive steering or the second evasive steering) is being executed, it ends the steering avoidance control by ending the evasive steering being executed. Then, the CPU advances the processing to step 895 and temporarily ends this routine. On the other hand, if the CPU determines "no" in step 860, it directly advances the processing to step 895 and temporarily ends this routine. At this time, when evasive steering (the first evasive steering or the second evasive steering) is being executed, the evasive steering being executed is not ended and is continued.

[0138] The above is the specific operation of the vehicle collision avoidance assistance device 10 .

[0139] In addition, the present invention is not limited to the above-described embodiment, and various modifications can be adopted within the scope of the present invention.

Claims

1. A vehicle collision avoidance support device, The vehicle collision avoidance support device is configured to execute steering avoidance control when an index value indicating the degree of possibility of a collision between the own vehicle and an object existing in front of the own vehicle becomes equal to or greater than a predetermined index value. The steering avoidance control is configured to set an avoidance path within the lane in which the own vehicle is traveling that can avoid a collision between the own vehicle and the object, and to perform avoidance steering control forcibly steering the own vehicle so that the own vehicle travels along the avoidance path. The avoidance path is a path that allows the host vehicle to avoid the object and pass through while allowing the host vehicle to travel within the lane in which the host vehicle is traveling. The steering avoidance control is a control for performing the avoidance steering and reducing the driving force applied to the own vehicle. Furthermore, when the object is a moving object moving in the same direction as the own vehicle, the steering avoidance control is stopped when the deceleration of the moving object becomes equal to or greater than a predetermined deceleration during the execution of the steering avoidance control.

2. The vehicle collision avoidance support device according to claim 1, The avoidance path is set in consideration of a relative speed of the own vehicle with respect to the moving object when the index value becomes equal to or greater than the predetermined index value.

3. The vehicle collision avoidance support device according to claim 1 or 2, The index value is the estimated time required for the vehicle to reach the object, that is, the predicted arrival time. The shorter the predicted arrival time, the greater the index value. The predicted arrival time is obtained based on the distance between the own vehicle and the object and the relative speed of the own vehicle with respect to the object. The steering avoidance control is executed when the predicted arrival time becomes equal to or shorter than a predetermined predicted arrival time corresponding to the predetermined index value.

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