Vehicle collision avoidance assistance device

Abstract

The present invention provides a vehicle collision avoidance assistance device that can start collision avoidance control at a timing at which collision of the host vehicle with an object ahead can be more reliably avoided without causing the driver of the host vehicle to feel uncomfortable. A vehicle collision avoidance assistance device (10) is configured to implement collision avoidance control for avoiding collision of a host vehicle (100) with an object (200) ahead thereof. The vehicle collision avoidance assistance device determines a self collision avoidance possibility, which is a possibility that collision of the host vehicle with the object ahead thereof can be avoided by driving operation of the host vehicle performed by the driver of the host vehicle himself or herself, and sets the start timing of the collision avoidance control to a timing that is earlier than the start timing of the collision avoidance control in a case where the self collision avoidance possibility is determined to be present.

Description

TECHNICAL FIELD

[0001] The present application relates to a vehicle collision avoidance assistance device. BACKGROUND

[0002] A vehicle collision avoidance assistance device configured to implement collision avoidance control including forced steering control and forced braking control for avoiding collision of a host vehicle with an object ahead of the host vehicle is known (for example, refer to Patent Literature 1). The forced steering control is control for avoiding collision of the host vehicle with the object by forcibly steering the host vehicle even without steering wheel operation by a driver of the host vehicle, and the forced braking control is control for avoiding collision of the host vehicle with the object by forcibly applying braking force to the host vehicle even without brake pedal operation by the driver of the host vehicle.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2017-43262

[0006] The vehicle collision avoidance assistance device starts the collision avoidance control when the host vehicle approaches an object ahead of the host vehicle (an object ahead) and becomes a prescribed timing. In order to more reliably avoid collision of the host vehicle with the object ahead by the collision avoidance control, it is preferable that the start timing of the collision avoidance control be early. However, if the start timing of the collision avoidance control is too early, the collision avoidance control is started during a period in which the driver of the host vehicle considers that the host vehicle does not approach the object ahead to the extent that driving operation (for example, a depression operation of a brake pedal, a rotation operation of a steering wheel) for avoiding collision of the host vehicle with the object ahead must be started, and thus the driver can be given a sense of discomfort. Nonetheless, if the start timing of the collision avoidance control is too late, collision of the host vehicle with the object ahead can not be avoided even if the collision avoidance control is implemented. SUMMARY

[0007] An object of the present application is to provide a vehicle collision avoidance assistance device that can start collision avoidance control at a timing at which collision of a host vehicle with an object ahead can be more reliably avoided without giving a driver of the host vehicle a sense of discomfort.

[0008] The vehicle collision avoidance assistance device of the present application is configured to implement collision avoidance control for avoiding collision of the host vehicle with an object ahead thereof. In addition, the vehicle collision avoidance assistance device of the present application is configured to determine self collision avoidance possibility, which is the possibility that collision of the host vehicle with an object ahead thereof can be avoided by driving operation of the host vehicle performed by the driver of the host vehicle himself or herself, and set the start timing of the collision avoidance control to an earlier timing than the start timing of the collision avoidance control in the case where the self collision avoidance possibility is determined to be present.

[0009] According to the present application, in the case where there is no possibility that collision of the host vehicle with an object can be avoided by driving operation performed by the driver himself or herself, the collision avoidance control is started at a relatively early timing, and in the case where there is a possibility that collision of the host vehicle with an object can be avoided by driving operation performed by the driver himself or herself, the collision avoidance control is started at a relatively late timing. Thus, the collision avoidance control can be started at a timing at which collision of the host vehicle with an object can be more reliably avoided without causing the driver of the host vehicle to feel uncomfortable.

[0010] It should be noted that the vehicle collision avoidance assistance device of the present application can also be configured to implement forced steering control for avoiding collision of the host vehicle with an object ahead thereof by forcibly steering the host vehicle as the collision avoidance control.

[0011] According to the present application, the forced steering control can be started at a timing at which collision of the host vehicle with an object can be more reliably avoided without causing the driver of the host vehicle to feel uncomfortable.

[0012] In addition, the vehicle collision avoidance assistance device of the present application can also be configured to detect the holding state of the steering wheel of the host vehicle by the driver of the host vehicle, and determine the self collision avoidance possibility based on the holding state.

[0013] The holding state of the steering wheel by the driver is an effective index for determining the self collision avoidance possibility. According to the present application, the self collision avoidance possibility is determined based on the holding state of the steering wheel. Thus, the self collision avoidance possibility can be more appropriately determined.

[0014] In addition, the vehicle collision avoidance assistance device of the present application can also be configured to detect the presence or absence of holding of the steering wheel by the driver of the host vehicle as the holding state.

[0015] Whether or not the driver is holding the steering wheel is an effective index for determining the self-collision avoidance possibility. According to the present application, the self-collision avoidance possibility is determined based on whether or not the driver is holding the steering wheel. Thus, the self-collision avoidance possibility can be more appropriately determined.

[0016] Further, the vehicle collision avoidance assistance device of the present application can also be configured to detect a portion of the steering wheel held by the driver of the host vehicle as the holding state.

[0017] The portion of the steering wheel held by the driver is an effective index for determining the self-collision avoidance possibility. According to the present application, the self-collision avoidance possibility is determined based on the portion of the steering wheel held by the driver. Thus, the self-collision avoidance possibility can be more appropriately determined.

[0018] Further, the vehicle collision avoidance assistance device of the present application can also be configured to detect a state of alertness of the driver of the host vehicle, and determine the self-collision avoidance possibility based on the state of alertness.

[0019] The state of alertness of the driver is an effective index for determining the self-collision avoidance possibility. According to the present application, the self-collision avoidance possibility is determined based on the state of alertness of the driver. Thus, the self-collision avoidance possibility can be more appropriately determined.

[0020] Further, the vehicle collision avoidance assistance device of the present application can also be configured to detect a holding state of the steering wheel of the host vehicle by the driver of the host vehicle and a state of alertness of the driver of the host vehicle, determine the self-collision avoidance possibility based on the holding state and the state of alertness, respectively, and set the start timing of the collision avoidance control to an earlier timing than the start timing of the collision avoidance control in a case where the self-collision avoidance possibility is determined to be absent based on the state of alertness, as compared with a case where the self-collision avoidance possibility is determined to be absent based on the holding state.

[0021] It can be considered that the self-collision avoidance possibility is lower in a case where the self-collision avoidance possibility is absent due to the state of alertness of the driver, as compared with a case where the self-collision avoidance possibility is absent due to the holding state of the steering wheel by the driver. According to the present application, the collision avoidance control is started at an earlier timing in a case where the self-collision avoidance possibility is determined to be absent based on the state of alertness of the driver, as compared with a case where the self-collision avoidance possibility is determined to be absent based on the holding state of the steering wheel by the driver. Thus, the collision avoidance control can be started at a more appropriate timing.

[0022] Further, the vehicle collision avoidance assistance device of the present application can also be configured to detect a holding state of a steering wheel of the host vehicle by the driver of the host vehicle and a state of alertness of the driver of the host vehicle, determine the self-collision avoidance possibility based on the holding state and the state of alertness, respectively, and determine that there is no self-collision avoidance possibility even if it is determined based on the holding state that there is the self-collision avoidance possibility, in a case where it is determined based on the state of alertness that there is no self-collision avoidance possibility.

[0023] It can be considered that even in a scenario where it is determined based on the holding state of the steering wheel by the driver that there is the self-collision avoidance possibility, the self-collision avoidance possibility is low in a case where it is determined based on the state of alertness of the driver that there is no self-collision avoidance possibility. According to the present application, it is determined that there is no self-collision avoidance possibility even if it is determined based on the holding state of the steering wheel by the driver that there is the self-collision avoidance possibility, in a case where it is determined based on the state of alertness of the driver that there is no self-collision avoidance possibility. Thus, the collision avoidance control can be started at a more appropriate timing.

[0024] Further, the vehicle collision avoidance assistance device of the present application can also be configured to determine that there is no self-collision avoidance possibility in a case where it is determined based on the state of alertness that there is the self-collision avoidance possibility and it is determined based on the holding state that there is no self-collision avoidance possibility.

[0025] It can be considered that even if there is the self-collision avoidance possibility due to the state of alertness of the driver, the self-collision avoidance possibility is relatively low if there is no self-collision avoidance possibility due to the holding state of the steering wheel by the driver. According to the present application, it is determined that there is no self-collision avoidance possibility even if it is determined based on the state of alertness of the driver that there is the self-collision avoidance possibility, in a case where it is determined based on the holding state of the steering wheel by the driver that there is no self-collision avoidance possibility. Thus, the collision avoidance control can be started at a more appropriate timing.

[0026] The constituent elements of the present application are not limited to the embodiments of the present application described below with reference to the drawings. Other objects, other characteristics, and its incidental advantages will become further apparent from the description of the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a diagram showing a vehicle collision avoidance assistance device of an embodiment of the present application and a vehicle (host vehicle) in which the vehicle collision avoidance assistance device is mounted.

[0028] Figure 2 is a diagram showing a distance or the like between the host vehicle and an object (vehicle) in front of the host vehicle.

[0029] Figure 3 (A) is a diagram showing the predicted driving area of ​​this vehicle. Figure 3 (B) is a diagram showing a scenario where an object (vehicle) exists in the predicted driving area of ​​this vehicle.

[0030] Figure 4 (A) is a diagram showing a scenario where the vehicle approaches an object (vehicle) existing in the vehicle's predicted driving area. Figure 4 (B) is a diagram showing the avoidance path.

[0031] Figure 5 (A) is a diagram showing a scenario where the start timing of forced steering control has arrived. Figure 5 (B) is a diagram showing the target avoidance path in forced steering control.

[0032] Figure 6 Figure (A) is a diagram illustrating a scenario where the vehicle begins to turn along a target avoidance path through forced steering control. Figure 6 (B) is a diagram showing a scenario where the vehicle passes beside an object (vehicle) in front through forced steering control. Figure 6 (C) is a diagram showing a scenario where the forced steering control is terminated when the vehicle passes by an object (vehicle) in front.

[0033] Figure 7 This is a diagram showing the designated portion of the steering wheel of this vehicle.

[0034] Figure 8 (A) is a diagram showing a scenario where the start timing of the forced braking control has arrived. Figure 8 Figure (B) shows a scenario where braking force is applied to the vehicle through forced braking control. Figure 8 (C) is a diagram showing a scenario where the vehicle stops in front of an object (vehicle) and the forced braking control is terminated.

[0035] Figure 9 This is a flowchart illustrating the routines performed by the vehicle collision avoidance assist device according to an embodiment of the present invention.

[0036] Figure 10 This is a flowchart illustrating the routines performed by a vehicle collision avoidance assist device according to a first variation of an embodiment of the present invention.

[0037] Figure 11 This is a flowchart illustrating the routines performed by a vehicle collision avoidance assist device according to a second variation of an embodiment of the present invention.

[0038] Figure 12is a flowchart showing a routine executed by the vehicle collision avoidance assistance device of the embodiment, the first modification, and the second modification of the present application.

[0039] Figure 13 is a flowchart showing a routine executed by the vehicle collision avoidance assistance device of the embodiment, the first modification, and the second modification of the present application.

[0040] Explanation of Reference Numerals:

[0041] 10 vehicle collision avoidance assistance device, 35 steering wheel, 40 holding state detection device, 41 touch sensor, 60 surrounding information detection device, 61 radio wave sensor, 62 image sensor, 70 wakefulness state detection device, 71 driver monitoring camera, 90 ECU, 100 host vehicle, 200 front object. DETAILED DESCRIPTION

[0042] Hereinafter, a vehicle collision avoidance assistance device of an embodiment of the present application will be described with reference to the drawings. As shown in Figure 1 The vehicle collision avoidance assistance device 10 of the embodiment of the present application is mounted on the host vehicle 100.

[0043] <ECU>

[0044] The vehicle collision avoidance assistance device 10 is provided with an ECU 90. The ECU (Electric Control Unit) is an abbreviation of an electronic control unit. The ECU 90 is provided with a microcomputer as a main part. The microcomputer includes a CPU (Central Processing Unit), a ROM (Read-Only Memory), a RAM (Random Access Memory), a nonvolatile memory, and an interface, and the like. The CPU realizes various functions by executing instructions or programs or routines stored in the ROM.

[0045] <Driving Device, etc.>

[0046] Further, the host vehicle 100 is mounted with a driving device 21, a braking device 22, and a steering device 23.

[0047] <Driving Device>

[0048] The driving device 21 is a device that outputs a driving torque TQ D (driving force) imparted to the host vehicle 100 in order to make the host vehicle 100 travel, and is, for example, an internal combustion engine, a motor, or the like. The driving device 21 is electrically connected to the ECU 90. The ECU 90 can control the driving torque TQ D output from the driving device 21 by controlling the operation of the driving device 21.

[0049] Brake device

[0050] The brake device 22 is a device that outputs a brake torque TQ_B (braking force) that is given to the host vehicle 100 in order to brake the host 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 brake torque TQ_B output from the brake device 22 by controlling the operation of the brake device 22.

[0051] Steering device

[0052] The steering device 23 is a device that outputs a steering torque TQs (steering force) that is given to the host vehicle 100 in order to steer the host 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 torque TQs output from the steering device 23 by controlling the operation of the steering device 23.

[0053] Sensors and the like

[0054] Furthermore, the host vehicle 100 is equipped with an accelerator pedal 31, an accelerator pedal operation amount sensor 32, a brake pedal 33, a brake pedal operation amount sensor 34, a steering wheel 35, a steering shaft 36, a steering angle sensor 37, a steering torque sensor 38, a holding state detection device 40, a vehicle motion amount detection device 50, a surrounding information detection device 60, and a sober state detection device 70.

[0055] Accelerator pedal operation amount sensor

[0056] The accelerator pedal operation amount sensor 32 is a sensor that detects the operation amount of the accelerator pedal 31. The accelerator pedal operation amount sensor 32 is electrically connected to the ECU 90. The accelerator pedal operation amount sensor 32 transmits information on the detected operation amount of the accelerator pedal 31 to the ECU 90. The ECU 90 acquires the operation amount of the accelerator pedal 31 as an accelerator pedal operation amount AP on the basis of the information.

[0057] The ECU 90 acquires a requested drive torque TQ_D_req (requested driving force) by calculation on the basis of the accelerator pedal operation amount AP and the vehicle speed V100 of the host vehicle 100. The requested drive torque TQ_D_req is a drive torque TQ_D that is requested to be output by the drive device 21. The ECU 90 controls the operation of the drive device 21 in such a manner that the requested drive torque TQ_D_req is output.

[0058] Brake pedal operation amount sensor

[0059] The brake pedal operation amount sensor 34 is a sensor that detects the operation amount of the brake pedal 33. The brake pedal operation amount sensor 34 is electrically connected to the ECU 90. The brake pedal operation amount sensor 34 transmits information of the detected operation amount of the brake pedal 33 to the ECU 90. The ECU 90 acquires the operation amount of the brake pedal 33 as a brake pedal operation amount BP on the basis of the information.

[0060] The ECU 90 acquires a requested brake torque TQ_B_req (requested braking force) by calculation on the basis of the brake pedal operation amount BP. The requested brake torque TQ_B_req is a brake torque TQ_B requested to be output by the brake device 22. The ECU 90 controls the operation of the brake device 22 in such a manner that the requested brake torque TQ_B_req is output.

[0061] <Steering angle sensor>

[0062] The steering angle sensor 37 is a sensor that detects the rotation angle of the steering shaft 36 with respect to a neutral position. The steering angle sensor 37 is electrically connected to the ECU 90. The steering angle sensor 37 transmits information of the detected rotation angle of the steering shaft 36 to the ECU 90. The ECU 90 acquires the rotation angle of the steering shaft 36 as a steering angle θsteer on the basis of the information.

[0063] <Steering torque sensor>

[0064] The steering torque sensor 38 is a sensor that detects the torque input to the steering shaft 36 by the driver via the steering wheel 35. The steering torque sensor 38 is electrically connected to the ECU 90. The steering torque sensor 38 transmits information of the detected torque to the ECU 90. The ECU 90 acquires the torque input to the steering shaft 36 by the driver via the steering wheel 35 (driver input torque TQs_driver) on the basis of the information.

[0065] <Hold state detection device>

[0066] The hold state detection device 40 is a device that detects the hold state of the driver of the host vehicle 100 on the steering wheel 35, and is a touch sensor 41 provided to the steering wheel 35 in this example.

[0067] <Touch sensor>

[0068] The touch sensor 41 is a sensor that detects that the driver of the host vehicle 100 has touched the steering wheel 35. The touch sensor 41 is electrically connected to the ECU 90. When it is detected that the driver of the host vehicle 100 has touched the steering wheel 35, the touch sensor 41 transmits information (a signal) of the portion of the steering wheel 35 touched by the driver of the host vehicle 100 to the ECU 90. The ECU 90 can identify the portion of the steering wheel 35 touched by the driver of the host vehicle 100 on the basis of the information (the signal).

[0069] <VEHICLE MOVEMENT DETECTION DEVICE>

[0070] The vehicle movement detection device 50 is a device that detects the movement of the host vehicle 100, and in the present example, includes a vehicle speed detection device 51, a longitudinal acceleration sensor 52, a lateral acceleration sensor 53, and a yaw rate sensor 54.

[0071] <VEHICLE SPEED DETECTION DEVICE>

[0072] The vehicle speed detection device 51 is a device that detects the vehicle speed of the host vehicle 100, and is, for example, a wheel speed sensor. The vehicle speed detection device 51 is electrically connected to the ECU 90. The vehicle speed detection device 51 transmits information of the detected vehicle speed of the host vehicle 100 to the ECU 90. The ECU 90 acquires the vehicle speed V100 of the host vehicle 100 on the basis of the information.

[0073] The ECU 90 acquires the requested steering torque TQs_req by computation on the basis of the acquired steering angle θsteer, the driver input torque TQs_driver, and the vehicle speed V100. The requested steering torque TQs_req is a steering torque TQs requested to be output from the steering device 23. The ECU 90 controls the operation of the steering device 23 in such a manner that the requested steering torque TQs_req is output from the steering device 23. Note that, in the case of forced steering described later, the ECU 90 appropriately decides the steering torque TQs required for the host vehicle 100 to travel along the target avoidance path Rtgt, regardless of the steering angle θsteer and the like, as the requested steering torque TQs_req, and controls the operation of the steering device 23 in such a manner that the requested steering torque TQs_req is output.

[0074] <LONGITUDINAL ACCELERATION SENSOR>

[0075] The longitudinal acceleration sensor 52 is a sensor that detects the acceleration in the front-rear direction of the host vehicle 100. The longitudinal acceleration sensor 52 is electrically connected to the ECU 90. The longitudinal acceleration sensor 52 transmits information of the detected acceleration to the ECU 90. The ECU 90 acquires the acceleration in the front-rear direction of the host vehicle 100 as the longitudinal acceleration Gx on the basis of the information.

[0076] < Lateral acceleration sensor >

[0077] The lateral acceleration sensor 53 is a sensor that detects the acceleration in the lateral (width) direction of the host vehicle 100. The lateral acceleration sensor 53 is electrically connected to the ECU 90. The lateral acceleration sensor 53 transmits information on the detected acceleration to the ECU 90. The ECU 90 acquires the acceleration in the lateral direction of the host vehicle 100 as the lateral acceleration Gy on the basis of the information.

[0078] < Yaw rate sensor >

[0079] The yaw rate sensor 54 is a sensor that detects the yaw rate YR of the host vehicle 100. The yaw rate sensor 54 is electrically connected to the ECU 90. The yaw rate sensor 54 transmits information on the detected yaw rate YR to the ECU 90. The ECU 90 acquires the yaw rate YR of the host vehicle 100 on the basis of the information.

[0080] < Surrounding information detection device >

[0081] The surrounding information detection device 60 is a device that detects information on the surroundings of the host vehicle 100, and in the present example, is provided with the electric wave sensor 61 and the image sensor 62. The electric wave sensor 61 is, for example, a radar sensor (millimeter wave radar or the like). The image sensor 62 is, for example, a video camera. Note that the surrounding information detection device 60 can also be provided with an acoustic wave sensor such as an ultrasonic sensor (gap sonar), or a light sensor such as a laser radar (LiDAR).

[0082] < Electric wave sensor >

[0083] The electric wave sensor 61 is electrically connected to the ECU 90. The electric wave sensor 61 transmits electric waves, and receives electric waves (reflected waves) reflected by an object. The electric wave sensor 61 transmits information (sensing result) on the transmitted electric waves and the received electric waves (reflected waves) to the ECU 90. In other words, the electric wave sensor 61 senses an object present in the surroundings of the host vehicle 100, and transmits information (sensing result) on the sensed object to the ECU 90. The ECU 90 can acquire information on the object present in the surroundings of the host vehicle 100 (surrounding detection information I_D) on the basis of the information (electric wave information).

[0084] Note that in the present example, the object is a vehicle, an automatic two-wheeled vehicle, a bicycle, a person, or the like.

[0085] < Image sensor >

[0086] Image sensor 62 is also electrically connected to ECU 90. Image sensor 62 captures images of the surroundings of vehicle 100 and sends the captured image information to ECU 90. ECU 90 can use this information (image information) to obtain information related to the surroundings of vehicle 100 (surroundings detection information I_D).

[0087] like Figure 2 As shown, when an object (object 200) exists in front of the vehicle 100, the ECU 90 senses the object 200 based on the surrounding detection information I_D. It should be noted that the object 200 can be a vehicle, an autonomous two-wheeled vehicle, a bicycle, or a person, etc. Figure 2 The example shown is a vehicle.

[0088] When the ECU90 senses an object 200 in front, it can obtain, for example, the distance between the object 200 in front and the vehicle 100 (object distance D200) and the speed of the vehicle 100 relative to the object 200 in front (relative speed ΔV200) based on the surrounding detection information I_D.

[0089] Furthermore, the ECU90 identifies the left dividing line LM_L and the right dividing line LM_R of the lane (lane LN) that defines the driving lane of this vehicle 100 based on the surrounding detection information I_D. The ECU90 can determine the range of lane LN based on the identified left and right dividing lines LM (i.e., the left dividing line LM_L and the right dividing line LM_R).

[0090] <Awake State Detection Device>

[0091] The alertness detection device 70 is a device for detecting the conscious state of the driver of the vehicle 100, and in this example, it is a driver monitoring camera 71. The driver monitoring camera 71 is installed inside the passenger compartment of the vehicle 100 so as to face the driver of the vehicle 100 and capture his face.

[0092] <Driver monitoring camera>

[0093] The driver monitoring camera 71 is a camera that captures the face of the driver of the vehicle 100. The driver monitoring camera 71 is electrically connected to the ECU 90. The driver monitoring camera 71 sends the image information (image data) of the driver's face captured to the ECU 90. The ECU 90 can determine whether the driver of the vehicle 100's eyes are open (i.e., whether the driver of the vehicle 100 is awake) based on this information.

[0094] It should be noted that the ECU90 may also acquire the driver's body temperature, pulse and blood pressure, and other so-called vital data, and determine whether the driver of the vehicle 100 is conscious (i.e., whether the driver of the vehicle 100 is awake) based on the acquired vital data.

[0095] <Summary of the operation of vehicle collision avoidance assist device>

[0096] Next, a summary of the operation of the vehicle collision avoidance assist device 10 will be explained.

[0097] The vehicle collision avoidance assist device 10 performs processing to sense objects such as vehicles ahead of the vehicle 100 in its direction of travel based on surrounding detection information I_D while the vehicle 100 is in motion. During periods when no object is sensed ahead of the vehicle 100 in its direction of travel, the vehicle collision avoidance assist device 10 performs normal driving control.

[0098] Normal driving control is as follows: when the requested drive torque TQ_D_req (requested drive force) is greater than zero, the drive unit 21 is controlled to operate by outputting the requested drive torque TQ_D_req from the drive unit 21; when the requested braking torque TQ_B_req (requested braking force) is greater than zero, the brake unit 22 is controlled to operate by outputting the requested braking torque TQ_B_req from the brake unit 22; and when the requested steering torque TQs_req (requested steering force) is greater than zero, the steering unit 23 is controlled to operate by outputting the requested steering torque TQs_req from the steering unit 23.

[0099] When an object (object 200) is detected in front of the vehicle 100 in the direction of travel, the vehicle collision avoidance assist device 10 determines whether the object exists in the predicted driving area A100 based on the surrounding detection information I_D.

[0100] like Figure 3 As shown in (A), the predicted driving area A100 is an area with a width equal to the width of the vehicle 100, centered on the predicted driving route R100 of the vehicle 100. The predicted driving route R100 is the driving route that the vehicle 100 will travel in the future while maintaining the steering angle θsteer at that point in time. Therefore, Figure 3 The predicted driving route R100 shown in (A) is a straight line, but it can sometimes be a curve depending on the conditions.

[0101] The vehicle collision avoidance assist device 10 continues normal driving control when the sensed object 200 in front is not present in the predicted driving area A100.

[0102] On the other hand, when it is determined that the sensed object 200 in front exists within the predicted driving area A100, the vehicle collision avoidance assist device 10 determines the possibility (collision probability) of the vehicle 100 colliding with the object 200 in front.

[0103] In this example, the vehicle collision avoidance assist device 10 obtains the distance (object distance D200) between the object 200 in front and the vehicle 100, and determines the collision probability based on whether the obtained object distance D200 is below a predetermined distance (collision probability determination distance Dth).

[0104] <Obtaining the Avoidance Path>

[0105] When Figure 4 As shown in (A), when the vehicle 100 approaches the object 200 in front, and the distance between the object and D200 becomes shorter than the collision probability determination distance Dth, and the distance between the object and D200 is determined to be less than the collision probability determination distance Dth, the vehicle collision avoidance assist device 10 determines that the avoidance path acquisition condition Croute is met.

[0106] When the condition for obtaining the avoidance path, Croute, is met, the vehicle collision avoidance assist device 10 begins to obtain the avoidance path R based on the surrounding detection information I_D.

[0107] The avoidance path R is the path that the vehicle 100 travels to avoid a collision with the object 200 in front of it, such as... Figure 4 As shown in (B), this is the path that allows the vehicle 100 to travel within the lane LN and pass beside the object 200 in front.

[0108] It should be noted that, in Figure 4 In the example shown in (B), the avoidance path R is the path that passes through the right side of the object 200 in front. However, if there is space on the left side of the object 200 in front, allowing the vehicle 100 to travel within the lane LN and pass by the object 200 in front, sometimes the path that passes through the left side of the object 200 in front is also taken as the avoidance path R.

[0109] <Determination of the start timing of forced steering control>

[0110] Furthermore, if the distance between the object and D200 is below the collision probability determination distance Dth, and thus a collision is deemed possible, the vehicle collision avoidance assist device 10 determines that the forced steering start determination condition Cd_steer is met.

[0111] When the forced steering start determination condition Cd_steer is met, the vehicle collision avoidance assist device 10 determines the timing for starting forced steering control (forced steering start timing Ts_steer).

[0112] In this example, the vehicle collision avoidance assist device 10 determines the forced steering start timing Ts_steer based on the predicted arrival time TTC. The predicted arrival time TTC is the predicted time required for the vehicle 100 to reach the object 200 in front. The vehicle collision avoidance assist device 10 obtains the predicted arrival time TTC by dividing the object distance D200 by the relative speed ΔV200 (TTC = D200 / ΔV200).

[0113] When the vehicle collision avoidance assist device 10 determines that there is an object 200 in front within the predicted driving area A100, it acquires the object distance D200, relative speed ΔV200, and predicted arrival time TTC according to a specified calculation cycle.

[0114] The vehicle collision avoidance assist device 10 determines whether the predicted arrival time TTC has shortened to a predetermined time (collision determination time TTCth). It should be noted that when the relative speed ΔV200 is constant, the closer the vehicle 100 is to the object 200 in front, the shorter the predicted arrival time TTC will be.

[0115] The vehicle collision avoidance assist device 10 continues normal driving control during the period when the predicted arrival time TTC is longer than the collision determination time TTCth.

[0116] On the other hand, afterwards, when... Figure 5 As shown in (A), while maintaining a state where no collision avoidance steering wheel operation is performed by the driver of vehicle 100 (an operation applied to the steering wheel 35 to avoid a collision between vehicle 100 and object 200 in front), if vehicle 100 approaches object 200 and the predicted arrival time TTC shortens to the collision determination time TTCth, vehicle collision avoidance assist device 10 determines that if vehicle 100 continues to move as before, vehicle 100 will collide with object 200 in front. In this determination, vehicle collision avoidance assist device 10 determines that the condition for implementing forced steering control (forced steering implementation condition Cs_steer) is met, and determines that the forced steering start timing Ts_steer has arrived.

[0117] When it is determined that the forced steering start timing Ts_steer has come, the vehicle collision avoidance assistance device 10 sets the avoidance path R to be acquired at the time point or the avoidance path R that has already been acquired at the time point as a target avoidance path Rtgt, and starts the forced steering control in such a manner that the host vehicle 100 travels along the target avoidance path Rtgt.

[0118] The vehicle collision avoidance assistance device 10 acquires the current position of the host vehicle 100 on the basis of the longitudinal acceleration Gx, the lateral acceleration Gy, the yaw rate YR, and the left-right dividing line LM, and so on in the implementation of the forced steering control, and controls the steering force applied to the host vehicle 100 in such a manner that the host vehicle 100 travels along the target avoidance path Rtgt on the basis of the acquired current position of the host vehicle 100.

[0119] Thus, first, the host vehicle 100 starts turning as shown in (A) of FIG. 10, and then turns in the opposite direction, and the traveling direction thereof becomes parallel to the home lane LN, so that the host vehicle 100 passes by the front object 200 as shown in (B) of FIG. 10. Thus, the collision of the host vehicle 100 with the front object 200 is avoided. Then, when the host vehicle 100 passes by the front object 200 as shown in (C) of FIG. 10, the vehicle collision avoidance assistance device 10 ends the forced steering control. Figure 6 Figure 6 Thus, first, the host vehicle 100 starts turning as shown in (A) of FIG. 10, and then turns in the opposite direction, and the traveling direction thereof becomes parallel to the home lane LN, so that the host vehicle 100 passes by the front object 200 as shown in (B) of FIG. 10. Thus, the collision of the host vehicle 100 with the front object 200 is avoided. Then, when the host vehicle 100 passes by the front object 200 as shown in (C) of FIG. 10, the vehicle collision avoidance assistance device 10 ends the forced steering control. Figure 6

[0120] It is to be noted that the vehicle collision avoidance assistance device 10 does not implement the forced steering control at the time point when the forced steering start timing Ts_steer comes in the case where the avoidance path R cannot be acquired for the reason that there is no space for the host vehicle 100 to pass by the front object 200, and so on.

[0121] Further, the vehicle collision avoidance assistance device 10 can be configured to implement the forced steering control and to cause the host vehicle 100 to decelerate by causing the driving force applied to the host vehicle 100 to drop or by limiting the driving force applied to the host vehicle 100 to a certain value or less.

[0122] Further, the vehicle collision avoidance assistance device 10 can be configured to implement the forced steering control and to cause the host vehicle 100 to decelerate by applying a braking force to the host vehicle 100, so that the host vehicle 100 stops. In this case, the vehicle collision avoidance assistance device 10 is configured to end the forced steering control when the host vehicle 100 stops.

[0123] ​​Further, the vehicle collision avoidance assist device 10 can also be configured to suspend the forced steering control in a case where the driver input torque TQs_driver becomes a prescribed torque TQth or more in the implementation of the forced steering control (in other words, in a case where the amount of operation of the steering wheel 35 by the driver of the host vehicle 100 becomes a prescribed amount or more in the implementation of the forced steering control).

[0124] <Setting of Forced Steering Start Timing>

[0125] Further, in order to more reliably avoid a collision of the host vehicle 100 with the front object 200 by the forced steering control, it is preferable that the start timing of the forced steering control be early. However, if the start timing of the forced steering control is too early, the driver of the host vehicle 100 can feel discomfort in a case where the forced steering control is started during a period in which the driver of the host vehicle 100 considers that the host vehicle 100 has not approached the front object 200 to a degree that collision avoidance steering wheel operation (rotation operation of the steering wheel 35 for avoiding a collision of the host vehicle 100 with the front object 200) must be started. Nevertheless, if the start timing of the forced steering control is too late, a collision of the host vehicle 100 with the front object 200 can not be avoided even if the forced steering control is implemented.

[0126] Further, in a case where the driver of the host vehicle 100 is closing his eyes due to drowsiness, syncope, or the like, even if the host vehicle 100 is about to collide with the front object 200, the driver can not be aware of this and thus can not perform collision avoidance steering wheel operation (collision avoidance steering operation) with a high probability. In such a case, even if the forced steering control is started at an early timing, the driver can not feel discomfort.

[0127] Further, in a situation where the driver is not holding the steering wheel 35 or is holding the steering wheel 35 with only one hand, or the like, even if the driver performs steering wheel operation, the steering wheel operation can not be performed to a degree that can avoid a collision of the host vehicle 100 with the front object 200. In such a situation, it is preferable that the forced steering control be started at an early timing.

[0128] Therefore, the vehicle collision avoidance assist device 10 sets the forced steering start timing Ts_steer in accordance with the condition of the driver as explained below. In the present example, the vehicle collision avoidance assist device 10 sets the forced steering start timing Ts_steer corresponding to the condition of the driver by setting a collision determination time TTCth corresponding to the condition of the driver.

[0129] The vehicle collision avoidance assistance device 10 determines a self collision avoidance possibility. The self collision avoidance possibility is a possibility that a collision of the host vehicle 100 with the front object 200 can be avoided by a steering wheel operation (driving operation on the host vehicle 100) by the driver of the host vehicle 100 himself / herself.

[0130] The vehicle collision avoidance assistance device 10 sets the forced steering start timing Ts_steer to a timing earlier than that in the case where the self collision avoidance possibility is determined to exist, in the case where the self collision avoidance possibility is determined not to exist. The forced steering start timing Ts_steer becomes an earlier timing by extending the collision determination time TTCth. Therefore, in the present example, the vehicle collision avoidance assistance device 10 sets the collision determination time TTCth to a time longer than that in the case where the self collision avoidance possibility is determined to exist, in the case where the self collision avoidance possibility is determined not to exist.

[0131] The self collision avoidance possibility is determined on the basis of the driver's wakefulness state and the driver's steering wheel holding state.

[0132] In the present example, the driver's wakefulness state is whether or not the eyes of the driver of the host vehicle 100 are open (i.e., whether or not the driver is awake). The vehicle collision avoidance assistance device 10 determines the driver's wakefulness state on the basis of information provided from the driver monitoring camera 71.

[0133] The vehicle collision avoidance assistance device 10 can also be configured to make the determination of the self collision avoidance possibility on the basis of the driver's wakefulness state when the forced steering start determination condition Cd_steer is satisfied, but in the present example, the determination is made at a prescribed period regardless of whether or not the forced steering start determination condition Cd_steer is satisfied.

[0134] The vehicle collision avoidance assistance device 10 determines that the self collision avoidance possibility exists in the case where the driver is determined to be awake, and determines that the self collision avoidance possibility does not exist in the case where the driver is determined not to be awake.

[0135] On the other hand, the driver's steering wheel holding state is whether or not the driver holds the steering wheel 35 with both hands and whether or not the portion of the steering wheel 35 held by the driver is a prescribed portion 35P. The vehicle collision avoidance assistance device 10 determines the driver's steering wheel holding state (in particular, the portion of the steering wheel 35 held by the driver) on the basis of information provided from the touch sensor 41.

[0136] In the present example, as shown in FIG. 6, the vehicle collision avoidance assistance device 10 determines the driver's steering wheel holding state on the basis of the information provided from the touch sensor 41. Figure 7As shown, the prescribed portion 35P is a portion 35PR of a range of the prescribed angle θp centered on a position 60 degrees to the right from the uppermost center 35C of the steering wheel 35 when the steering wheel 35 is in the neutral position and a portion 35PL of a range of the prescribed angle θp centered on a position 60 degrees to the left from the uppermost center 35C of the steering wheel 35.

[0137] The vehicle collision avoidance assistance device 10 can also be configured to make the self-collision avoidance possibility determination based on the driver's steering wheel holding state when the forced steering start determination condition Cd_steer is satisfied, but in the present example, the determination is made at the prescribed period regardless of whether the forced steering start determination condition Cd_steer is satisfied or not.

[0138] The vehicle collision avoidance assistance device 10 determines that there is a self-collision avoidance possibility when the driver holds the prescribed portion 35P of the steering wheel 35 with both hands and determines that there is no self-collision avoidance possibility when the driver does not hold the prescribed portion 35P of the steering wheel 35 with both hands.

[0139] Then, the vehicle collision avoidance assistance device 10 sets the collision determination time TTCth to the first time TTC l when it is determined based on the driver's alertness state that there is a self-collision avoidance possibility and it is determined based on the driver's steering wheel holding state that there is a self-collision avoidance possibility. In the present example, the first time TTC l is set to a standard time. Therefore, when the collision determination time TTCth is set to the first time TTC l, the forced steering start timing Ts_steer becomes a standard timing.

[0140] On the other hand, the vehicle collision avoidance assistance device 10 sets the collision determination time TTCth to the second time TTC_2 when it is determined based on the driver's alertness state that there is a self-collision avoidance possibility but it is determined based on the driver's steering wheel holding state that there is no self-collision avoidance possibility. The second time TTC_2 is set to a time longer than the first time TTC l. Therefore, when the collision determination time TTCth is set to the second time TTC_2, the forced steering start timing Ts_steer becomes an earlier timing than when the collision determination time TTCth is set to the first time TTC l.

[0141] Further, the vehicle collision avoidance assistance device 10 sets the collision determination time TTCth to the third time TTC_3 regardless of the self-collision avoidance possibility based on the steering wheel holding state of the driver in a case where it is determined based on the wakefulness state of the driver that there is no self-collision avoidance possibility. The third time TTC_3 is set to a time longer than the second time TTC_2. Therefore, in a case where the collision determination time TTCth is set to the third time TTC_3, the forced steering start timing Ts_steer becomes a timing earlier than in a case where the collision determination time TTCth is set to the second time TTC_2.

[0142] The above is a summary of the operation of the vehicle collision avoidance assistance device 10. Thus, the forced steering control is started at a timing corresponding to the possibility that the driver of the host vehicle 100 can avoid a collision between the host vehicle 100 and the preceding object 200 by the driver's own steering wheel operation. Therefore, the forced steering control can be started at an appropriate timing without causing the driver to feel uncomfortable.

[0143] <First Modification>

[0144] Note that the vehicle collision avoidance assistance device 10 can also be configured to set the forced steering start timing Ts_steer to a timing earlier than in a case where it is determined based on either the wakefulness state of the driver or the steering wheel holding state that there is no self-collision avoidance possibility.

[0145] The vehicle collision avoidance assistance device 10 of the first modification of the embodiment of the present application thus configured sets the collision determination time TTCth to the first time TTC_1 in a case where it is determined based on both the wakefulness state of the driver and the steering wheel holding state of the driver that there is a self-collision avoidance possibility.

[0146] In the first modification, the first time TTC_1 can be a time different from the first time TTC_1 of the foregoing embodiment, but in this example, is the same as the first time TTC_1 of the embodiment.

[0147] On the other hand, the vehicle collision avoidance assistance device 10 of the first modification sets the collision determination time TTCth to the second time TTC_2 in a case where it is determined based on the wakefulness state of the driver that there is no self-collision avoidance possibility or it is determined based on the steering wheel holding state that there is no self-collision avoidance possibility.

[0148] In the first modification, the second time TTC_2 is simply a time longer than the first time TTC_l. Thus, for example, the second time TTC_2 of the first modification can be the same time as the second time TTC_2 of the above-described embodiment, or can be a different time from the second time TTC_2 of the above-described embodiment. Note that in the first modification, the second time TTC_2 is the same time as the third time TTC_3 of the above-described embodiment.

[0149] <Second Modification>

[0150] Further, the vehicle collision avoidance assistance device 10 can be configured to set the forced steering start timing Ts_steer in accordance with whether the driver of the host vehicle 100 is holding the steering wheel 35, whether the driver is holding the steering wheel 35 with both hands in the case where the driver is holding the steering wheel 35, and whether the driver is holding a prescribed portion 35P of the steering wheel 35 in the case where the driver is holding the steering wheel 35.

[0151] The vehicle collision avoidance assistance device 10 of the second modification of the embodiment of the present application thus configured sets the collision determination time TTCth to the first time TTC_l in the case where it is determined that there is a possibility of self collision avoidance based on the state of wakefulness of the driver and it is determined that the driver is holding the prescribed portion 35P of the steering wheel 35 with both hands (i.e., there is a possibility of self collision avoidance based on the steering wheel holding state of the driver).

[0152] The first time TTC_l of the second modification can be a different time from the first time TTC_l of the above-described embodiment, but in this example is the same time as the first time TTC_l of the embodiment.

[0153] On the other hand, the vehicle collision avoidance assistance device 10 of the second modification sets the collision determination time TTCth to the second time TTC_2 in the case where it is determined that there is a possibility of self collision avoidance based on the state of wakefulness of the driver, in the case where the driver is holding the steering wheel 35 with both hands but the portion of the steering wheel 35 being held by the driver is not the prescribed portion 35P of the steering wheel 35.

[0154] In the second modification, the second time TTC_2 is simply a time longer than the first time TTC_l. Thus, for example, the second time TTC_2 of the second modification can be the same time as the second time TTC_2 of the above-described embodiment, or can be a different time from the second time TTC_2 of the above-described embodiment.

[0155] Further, the vehicle collision avoidance assistance device 10 sets the collision determination time TTCth to the third time TTC_3 when the driver is holding the steering wheel 35 with only one hand and the portion of the steering wheel 35 held by the driver is the prescribed portion 35P of the steering wheel 35, in a case where it is determined based on the state of wakefulness of the driver that there is a possibility of self collision avoidance.

[0156] In the second modification example, the third time TTC_3 is merely a time that is longer than the second time TTC_2. Therefore, for example, the third time TTC_3 of the second modification example can be the same time as the third time TTC_3 of the above-described embodiment, or can be a different time from the third time TTC_3 of the above-described embodiment.

[0157] Further, the vehicle collision avoidance assistance device 10 sets the collision determination time TTCth to the fourth time TTC_4 when the driver is not holding the steering wheel 35, in a case where it is determined based on the state of wakefulness of the driver that there is a possibility of self collision avoidance.

[0158] In the second modification example, the fourth time TTC_4 is merely a time that is longer than the third time TTC_3.

[0159] Further, the vehicle collision avoidance assistance device 10 sets the collision determination time TTCth to the fourth time TTC_4 when the driver is not holding the steering wheel 35, in a case where it is determined based on the state of wakefulness of the driver that there is a possibility of self collision avoidance.

[0160] In the second modification example, the fifth time TTC_5 is merely a time that is longer than the fourth time TTC_4. In the second modification example, the fifth time TTC_5 is the same time as the third time TTC_3 of the above-described embodiment.

[0161] Further, the vehicle collision avoidance assistance device 10 can also be configured to execute forced braking control in addition to the forced steering control, or to execute forced braking control instead of the forced steering control. The forced braking control is control for avoiding collision of the host vehicle 100 with the front object 200 by forcibly applying a braking force to the host vehicle 100 to stop the host vehicle 100 right in front of the front object 200.

[0162] In this case, when it is determined that the driver is not holding the steering wheel 35, the vehicle collision avoidance assistance device 10 executes the forced braking control. Figure 8As shown in (A), when the vehicle 100 approaches an object 200 without the driver performing any collision avoidance steering wheel operations, and the predicted arrival time TTC shortens to the collision determination time TTCth, the vehicle collision avoidance assist device 10 also determines that if the vehicle 100 continues to move as before, it will collide with the object 200. Under this determination, the vehicle collision avoidance assist device 10 determines that the condition for implementing forced braking control (forced braking implementation condition Cs_brake) has been met, and determines that the forced braking start time Ts_brake has arrived.

[0163] When it is determined that the forced braking start time Ts_brake has arrived, the vehicle collision avoidance assist device 10 sets the deceleration of the vehicle 100 required to stop the vehicle 100 in front of the object 200 as the target deceleration Gtgt, and starts forced braking control to control the braking force applied to the vehicle 100 in a manner that the vehicle 100 decelerates at the target deceleration Gtgt.

[0164] Therefore, this vehicle 100 Figure 8 Start braking as shown in (B), and then, as... Figure 8 The vehicle 100 stops in front of the object 200 as shown in (C). Thus, a collision between the vehicle 100 and the object 200 is avoided. Then, when the vehicle 100 stops in front of the object 200, the vehicle collision avoidance assist device 10 terminates the forced braking control.

[0165] The vehicle collision avoidance assist device 10 can also be configured to adjust the start timing of the forced braking control by setting the collision determination time TTCth according to the self-collision avoidance probability as described above when the forced braking control is configured to be implemented in this way.

[0166] That is, the vehicle collision avoidance assist device 10 can also be configured to implement forced steering control and / or forced braking control as a collision avoidance control for avoiding a collision between the vehicle 100 and the object 200 in front, and is configured to determine the possibility of self-collision avoidance, and if it is determined that there is no possibility of self-collision avoidance, set the start time of the collision avoidance control to a time earlier than the start time of the collision avoidance control if it is determined that there is a possibility of self-collision avoidance.

[0167] <The specific operation of vehicle collision avoidance assist devices>

[0168] Next, the specific operation of the vehicle collision avoidance assist device 10 will be explained. The CPU of the ECU 90 of the vehicle collision avoidance assist device 10 according to the specified calculation cycle... Figure 9The example shown. Therefore, when the specified timing is reached, the CPU starts from... Figure 9 The process begins at step 900 and proceeds to step 905 to determine whether the driver is conscious. That is, the CPU determines the possibility of self-collision avoidance based on the driver's conscious state.

[0169] If the CPU determines "yes" in step 905, the process proceeds to step 910 to determine whether the driver of the vehicle 100 is in a specified state (i.e., holding the steering wheel 35 with both hands on a specified portion 35P). That is, the CPU determines whether there is a possibility of self-collision avoidance based on the steering wheel grip state.

[0170] If the CPU determines "yes" in step 910, it proceeds to step 915 to set the first time TTC_1 as the collision determination time TTCth. Then, the CPU proceeds to step 995 to temporarily terminate this routine.

[0171] On the other hand, if the CPU determines "no" in step 910, it causes the process to proceed to step 920 to set the second time TTC_2 as the collision determination time TTCth. Then, the CPU causes the process to proceed to step 995 to temporarily terminate this routine.

[0172] Furthermore, if the CPU determines "no" in step 905, it proceeds to step 925 to set the third time TTC_3 as the collision determination time TTCth. Then, the CPU proceeds to step 995 to temporarily terminate this routine.

[0173] Furthermore, the CPU of the ECU90 of the vehicle collision avoidance assist device 10 in the first modification executes according to the prescribed operation cycle. Figure 10 The example shown. Therefore, when the specified timing is reached, the CPU starts from... Figure 10 The process begins at step 1000 and proceeds to step 1005 to determine whether the driver is conscious. That is, the CPU determines whether there is a possibility of self-collision avoidance based on the driver's conscious state.

[0174] If the CPU determines "yes" in step 1005, the process proceeds to step 1010 to determine whether the driver's steering wheel grip is in a specified state (i.e., gripping a specified portion 35P of the steering wheel 35 with both hands). That is, the CPU determines whether there is a possibility of self-collision avoidance based on the steering wheel grip state.

[0175] When the CPU determines "Yes" in step 1010, it makes the process proceed to step 1015 to set the first time TTC l as the collision determination time TTCth. Then, the CPU makes the process proceed to step 1095 to temporarily end the routine.

[0176] On the other hand, when the CPU determines "No" in step 1010, it makes the process proceed to step 1020 to set the second time TTC_2 as the collision determination time TTCth. Then, the CPU makes the process proceed to step 1095 to temporarily end the routine.

[0177] Further, when the CPU determines "No" in step 1005, it also makes the process proceed to step 1020 to set the second time TTC_2 as the collision determination time TTCth. Then, the CPU makes the process proceed to step 1095 to temporarily end the routine.

[0178] Further, the CPU of the ECU 90 of the vehicle collision avoidance assistance device 10 of the second modification example executes the routine shown in FIG. 11 at a prescribed operation cycle. Therefore, when it becomes a prescribed timing, the CPU starts the process from step 1100 of FIG. 11, makes the process proceed to step 1105 to determine whether or not the driver is sober. That is, the CPU determines whether or not there is a self-collision avoidance possibility based on the sober state of the driver. Figure 11 Figure 11 When the CPU determines "Yes" in step 1105, it makes the process proceed to step 1110 to determine whether or not the holding level Lv is the first level Lv l. The first level Lv l is a level when the driver of the host vehicle 100 holds the prescribed portion 35P of the steering wheel 35 with both hands.

[0179] When the CPU determines "Yes" in step 1110, it makes the process proceed to step 1115 to set the first time TTC l as the collision determination time TTCth. Then, the CPU makes the process proceed to step 1195 to temporarily end the routine.

[0180] On the other hand, when the CPU determines "No" in step 1110, it makes the process proceed to step 1120 to determine whether or not the holding level Lv is the second level Lv 2. The second level Lv 2 is a level when the driver holds the steering wheel 35 with both hands but the portion of the steering wheel 35 held by the driver is not the prescribed portion 35P of the steering wheel 35.

[0181] When the CPU determines "Yes" in step 1120, it makes the process proceed to step 1125 to set the second time TTC_2 as the collision determination time TTCth. Then, the CPU makes the process proceed to step 1195 to temporarily end the routine.

[0182] On the other hand, when the CPU determines "No" in step 1110, it makes the process proceed to step 1120 to determine whether or not the holding level Lv is the second level Lv 2. The second level Lv 2 is a level when the driver holds the steering wheel 35 with both hands but the portion of the steering wheel 35 held by the driver is not the prescribed portion 35P of the steering wheel 35. ​

[0183] On the other hand, in the case where the CPU determines "NO" in step 1120, the processing is caused to proceed to step 1130 to determine whether the holding level Lv is a third level Lv_3. The third level Lv_3 is a level when the portion of the steering wheel 35 held by the driver is a prescribed portion 35P of the steering wheel 35 although the driver holds the steering wheel 35 with only one hand.

[0184] In the case where the CPU determines "YES" in step 1130, the processing is caused to proceed to step 1135 to set a third time TTC_3 as the collision determination time TTCth. Subsequently, the CPU causes the processing to proceed to step 1195 to temporarily end the present routine.

[0185] On the other hand, in the case where the CPU determines "NO" in step 1130, the processing is caused to proceed to step 1140 to set a fourth time TTC_4 as the collision determination time TTCth. Subsequently, the CPU causes the processing to proceed to step 1195 to temporarily end the present routine.

[0186] Further, in the case where the CPU determines "NO" in step 1105, the processing is caused to proceed to step 1145 to set a fifth time TTC_5 as the collision determination time TTCth. Subsequently, the CPU causes the processing to proceed to step 1195 to temporarily end the present routine.

[0187] Further, the CPU executes the routine shown in FIG. 12 in a prescribed operation cycle. Therefore, when it becomes a prescribed timing, the CPU starts the processing from step 1200 of FIG. 12, and causes the processing to proceed to step 1205 to determine whether the avoidance path acquisition condition Croute and the forced steering start determination condition Cd_steer are satisfied. More specifically, the CPU determines whether the object distance D200 is equal to or less than the collision possibility determination distance Dth. Figure 12 Figure 12 In the case where the CPU determines "YES" in step 1205, the processing is caused to proceed to step 1210 to acquire the avoidance path R. Subsequently, the CPU causes the processing to proceed to step 1215 to acquire the predicted time to collision TTC. Subsequently, the CPU causes the processing to proceed to step 1220 to determine whether the forced steering implementation condition Cs_steer is satisfied. More specifically, the CPU determines whether the predicted time to collision TTC is equal to or less than the collision determination time TTCth.

[0188] In the case where the CPU determines "YES" in step 1220, the processing is caused to proceed to step 1225 to determine whether the avoidance path R is acquired.

[0189] In the case where the CPU determines "YES" in step 1220, the processing is caused to proceed to step 1225 to determine whether the avoidance path R is acquired.

[0190] ​When the CPU determines YES in step 1225, the CPU sets the acquired avoidance path R as the target avoidance path Rtgt. Next, the CPU advances the process to step 1235 to execute the forced steering control. Next, the CPU advances the process to step 1295 to temporarily end the routine.

[0191] On the other hand, when the CPU determines NO in step 1225, the CPU advances the process directly to step 1295 to temporarily end the routine. In this case, the forced steering control is not executed.

[0192] Further, when the CPU determines NO in step 1205 or step 1220, the CPU also advances the process directly to step 1295 to temporarily end the routine. In this case, the forced steering control is also not executed.

[0193] Note that, in a case where the vehicle collision avoidance assist device 10 is configured to execute forced braking control instead of the forced steering control, the CPU executes the routine illustrated in FIG. 13 in place of the routine illustrated in FIG. 12. Thus, when it becomes the prescribed timing, the CPU starts the process from step 1300 of FIG. 13, and advances the process to step 1305 to determine whether a forced braking start timing determination condition is satisfied. More specifically, the CPU determines whether the object distance D200 is equal to or less than the collision possibility determination distance Dth. Figure 13 Figure 13

[0194] When the CPU determines YES in step 1305, the CPU advances the process to step 1310 to acquire the predicted time to collision TTC. Next, the CPU advances the process to step 1315 to determine whether a forced braking execution condition Cs_brake is satisfied. More specifically, the CPU determines whether the predicted time to collision TTC is equal to or less than the collision determination time TTCth.

[0195] When the CPU determines YES in step 1315, the CPU advances the process to step 1320 to acquire the target deceleration Gtgt. Next, the CPU advances the process to step 1325 to execute the forced braking control. Next, the CPU advances the process to step 1395 to temporarily end the routine.

[0196] On the other hand, when the CPU determines NO in step 1315, the CPU advances the process directly to step 1395 to temporarily end the routine. In this case, the forced braking control is not executed.

[0197] Further, when the CPU determines NO in step 1305, the CPU also advances the process directly to step 1395 to temporarily end the routine.

[0198] The above is the detailed operation of the vehicle collision avoidance assist device 10.​​

[0199] Note that the present application is not limited to the above-described embodiments and modifications, and various modifications can be made within the scope of the present application.

Claims

1. A vehicle collision avoidance assistance device configured to implement collision avoidance control for avoiding a collision of a host vehicle with an object ahead of the host vehicle, wherein the vehicle collision avoidance assistance device is configured to: detect a holding state of a steering wheel of the host vehicle by a driver of the host vehicle and a state of alertness of the driver of the host vehicle; perform a first self-collision avoidance possibility determination in which a self-collision avoidance possibility is determined based on the holding state; and perform a second self-collision avoidance possibility determination in which a self-collision avoidance possibility is determined based on the state of alertness, the self-collision avoidance possibility being a possibility that a collision of the host vehicle with the object ahead of the host vehicle can be avoided by a driving operation of the host vehicle performed by the driver of the host vehicle himself / herself, the vehicle collision avoidance assistance device being configured to: set a start timing of the collision avoidance control to a first start timing that is earlier than a start timing of the collision avoidance control in a case where the self-collision avoidance possibility is determined based on the second self-collision avoidance possibility determination but the self-collision avoidance possibility is not determined based on the first self-collision avoidance possibility determination; and set the start timing of the collision avoidance control to a second start timing that is earlier than the first start timing in a case where the self-collision avoidance possibility is not determined based on the second self-collision avoidance possibility determination.

2. The vehicle collision avoidance assistance device according to claim 1, wherein the vehicle collision avoidance assistance device is configured to implement forced steering control for avoiding a collision of the host vehicle with the object ahead of the host vehicle by forcibly steering the host vehicle as the collision avoidance control.

3. The vehicle collision avoidance assistance device according to claim 1, wherein the vehicle collision avoidance assistance device is configured to detect a holding or non-holding of the steering wheel by the driver of the host vehicle as the holding state.

4. The vehicle collision avoidance assistance device according to claim 1, wherein the vehicle collision avoidance assistance device is configured to detect a portion of the steering wheel held by the driver of the host vehicle as the holding state.

5. The vehicle collision avoidance assistance device according to claim 1, wherein the vehicle collision avoidance assistance device is configured to: determine that the self-collision avoidance possibility is not present in a case where the self-collision avoidance possibility is not determined based on the second self-collision avoidance possibility determination even if the self-collision avoidance possibility is determined based on the first self-collision avoidance possibility determination.

6. The vehicle collision avoidance assistance device according to claim 5, wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The vehicle collision avoidance assistance device is configured to determine that the self-collision avoidance is not possible in a case where it is determined that the self-collision avoidance is possible according to the second self-collision avoidance possibility determination and it is determined that the self-collision avoidance is not possible according to the first self-collision avoidance possibility determination.

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