Vehicle collision avoidance assistance device

Abstract

The vehicle collision avoidance assist device is configured as follows: when the driver's vehicle has the possibility of colliding with an object in front of the driver's vehicle, forced braking or forced steering is performed; at least one of information related to the condition of the driver's vehicle and information related to the situation around the driver's vehicle is obtained; based on the obtained information, it is determined whether a request condition for requesting the execution of forced steering and whether a prohibition condition for prohibiting the execution of forced steering is satisfied are satisfied; when the request condition is not satisfied, forced braking is performed regardless of whether the prohibition condition is satisfied; when the prohibition condition is not satisfied and the request condition is satisfied, forced steering is performed; and when the prohibition condition is satisfied, forced braking is performed even if the request condition is satisfied.

Description

Technical Field

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

[0002] A vehicle collision avoidance assist device configured to perform collision avoidance braking and collision avoidance steering to avoid a collision between a driver's vehicle and an object in front of the driver's vehicle is known. Collision avoidance braking is a collision avoidance process for avoiding a collision between the driver's vehicle and an object by forcibly applying a braking force to the driver's vehicle even if the driver of the driver's vehicle does not operate a brake pedal. Collision avoidance steering is a collision avoidance process for avoiding a collision between the driver's vehicle and an object by forcibly steering the driver's vehicle even if a steering wheel is not operated in the driver's vehicle.

[0003] As such a vehicle collision avoidance assist device, a vehicle collision avoidance assist device is known that is configured to start collision avoidance braking when a determination is made that the driver's vehicle is likely to collide with an object in front of the driver's vehicle, and to start collision avoidance steering when a determination is made that a collision between the driver's vehicle and the object in front of the driver's vehicle is still unavoidable (see, for example, Japanese Unexamined Patent Application Publication No. 2017-43262 (JP 2017-43262 A). Summary of the invention

[0004] Regardless of the situation around the driver's vehicle, when a determination is made that the driver's vehicle may collide with an object in front of the driver's vehicle, the vehicle collision avoidance assist device starts collision avoidance braking instead of collision avoidance steering. However, depending on the situation around the driver's vehicle, a collision between the driver's vehicle and the object may be more appropriately avoided by starting collision avoidance steering instead of collision avoidance braking.

[0005] The present invention provides a vehicle collision avoidance assist device capable of performing appropriate collision avoidance processing depending on the situation around the driver's vehicle.

[0006] A first aspect of the present invention relates to a vehicle collision avoidance assist device, which includes a processor. The processor is configured to perform forced braking or forced steering when the driver's vehicle has the possibility of colliding with an object in front of the driver's vehicle. Forced braking is braking for circumventing a collision between the driver's vehicle and the object by applying a braking force to the driver's vehicle to stop the driver's vehicle before the driver's vehicle collides with the object. Forced steering is steering for circumventing a collision between the driver's vehicle and the object by steering the driver's vehicle to pass on one side of the object. The processor is configured to obtain at least one of information related to the condition of the driver's vehicle and information related to the situation around the driver's vehicle, and based on the information obtained, determine whether a request condition for requesting the execution of forced steering and whether a prohibition condition for prohibiting the execution of forced steering are met. The processor is configured to perform forced braking regardless of whether the prohibition condition is met when the request condition is not met; perform forced steering when the prohibition condition is not met and the request condition is met; and perform forced braking even if the request condition is met when the prohibition condition is met.

[0007] According to the first aspect, a determination is made as to whether the request condition is satisfied and whether the prohibition condition is satisfied, taking into account the condition of the driver's vehicle or the situation around the driver's vehicle. When the request condition is not satisfied, forced braking is performed regardless of whether the prohibition condition is satisfied. When the prohibition condition is not satisfied and the request condition is satisfied, forced steering is performed. When the prohibition condition is satisfied, forced braking is performed even if the request condition is satisfied. Therefore, in a scenario where the execution of forced steering is preferred so that the request condition is satisfied, forced steering is performed unless it is a situation where the non-execution of forced steering is preferred so that the prohibition condition is satisfied. Thus, appropriate collision avoidance processing can be performed depending on the situation around the driver's vehicle.

[0008] In the first aspect, the processor can be configured to: obtain a degradation state of a braking device configured to apply a braking force to a driver's vehicle as information related to the condition of the driver's vehicle; when the processor determines that the braking device is degraded based on the degradation state of the braking device, determine that the request condition is met; and when the processor determines that the braking device is not degraded based on the degradation state of the braking device, determine that the request condition is not met.

[0009] The deterioration state of the brake device is an effective indicator for determining whether it is preferable to perform forced steering rather than forced braking. According to the above configuration, the processor determines whether the request condition is satisfied in consideration of the deterioration state of the brake device. Thus, a more appropriate collision avoidance process can be performed depending on the situation around the driver's vehicle.

[0010] In the first aspect, the processor can be configured to: obtain a degradation state of a brake pad of a braking device configured to apply a braking force to a driver's vehicle as information related to the condition of the driver's vehicle; when the processor determines that the brake pad is degraded based on the degradation state of the brake pad, determine that the request condition is met; and when the processor determines that the brake pad is not degraded based on the degradation state of the brake pad, determine that the request condition is not met.

[0011] The deterioration state of the brake pad is an effective indicator for determining whether it is preferable to perform forced steering rather than forced braking. According to the above configuration, the processor considers the deterioration state of the brake pad to determine whether the request condition is met. Thus, a more appropriate collision avoidance process can be performed depending on the situation around the driver's vehicle.

[0012] In the first aspect, the processor can be configured to: obtain a deterioration state of brake oil used to operate a braking device configured to apply braking force to a driver's vehicle as information related to the condition of the driver's vehicle; when the processor determines that the brake oil is deteriorated based on the deterioration state of the brake oil, determine that the request condition is met; and when the processor determines that the brake oil is not deteriorated based on the deterioration state of the brake oil, determine that the request condition is not met.

[0013] The deterioration state of the brake oil is an effective indicator for determining whether it is preferred to perform forced steering rather than forced braking. According to the above configuration, the processor considers the deterioration state of the brake oil to determine whether the request condition is met. Thus, a more appropriate collision avoidance process can be performed depending on the situation around the driver's vehicle.

[0014] In the first aspect, the processor can be configured to: control the operation of a braking device configured to apply braking force to a driver vehicle so that the braking device applies braking force to the driver vehicle based on the operation amount of a brake pedal of the driver vehicle; when the brake pedal is operated by a driver of the driver vehicle, obtain the deceleration of the driver vehicle as information related to the condition of the driver vehicle; when the deceleration is lower than or equal to a reference deceleration set based on the operation amount of the brake pedal operated by the driver, determine that the request condition is met; and when the deceleration is higher than the reference deceleration, determine that the request condition is not met.

[0015] The relationship between the operation amount of the brake pedal operated by the driver and the deceleration of the driver's vehicle at this time is an effective indicator for determining whether it is preferred to perform forced steering rather than forced braking. According to the above configuration, the processor considers the relationship between the operation amount of the brake pedal operated by the driver and the deceleration of the driver's vehicle at this time to determine whether the request condition is satisfied. Thus, a more appropriate collision avoidance process can be performed depending on the situation around the driver's vehicle.

[0016] In the first aspect, the processor may be configured to obtain the speed of the driver's vehicle and the gradient of the road on which the driver's vehicle is traveling. The processor may be configured not to obtain the deceleration of the driver's vehicle when the speed is lower than a reference speed or the gradient is greater than a reference gradient.

[0017] When the speed of the driver's vehicle is low or the gradient of the road surface on which the driver's vehicle is traveling is large, there is a possibility that the deceleration of the driver's vehicle cannot be accurately acquired. According to the above configuration, when the speed of the driver's vehicle is lower than the reference speed or the gradient of the road surface on which the driver's vehicle is traveling is greater than the reference gradient, the deceleration of the driver's vehicle is not acquired. Therefore, it is possible to acquire only the accurate deceleration of the driver's vehicle.

[0018] In the first aspect, the processor can be configured to: obtain the weight of the driver's vehicle as information related to the condition of the driver's vehicle; when the processor determines that the weight is greater than or equal to a predetermined weight, determine that the request condition is met; and when the processor determines that the weight is less than the predetermined weight, determine that the request condition is not met.

[0019] Since the weight of the driver's vehicle affects the deceleration of the driver's vehicle when the driver's vehicle is braked, the weight of the driver's vehicle is an effective indicator for determining whether it is preferred to perform forced steering rather than forced braking. According to the above configuration, a determination is made as to whether the request condition is satisfied in consideration of the weight of the driver's vehicle. Thus, a more appropriate collision avoidance process can be performed depending on the situation around the driver's vehicle.

[0020] In the first aspect, the processor can be configured to: obtain the number of occupants of the driver's vehicle as information related to the condition of the driver's vehicle; when the number of occupants is greater than or equal to a predetermined number, determine that the request condition is met; and when the number of occupants is less than the predetermined number, determine that the request condition is not met.

[0021] As described above, since the weight of the driver's vehicle affects the deceleration of the driver's vehicle when the driver's vehicle is braked, the weight of the driver's vehicle is an effective indicator for determining whether it is preferable to perform forced steering rather than forced braking. The weight of the driver's vehicle varies depending on the number of occupants of the driver's vehicle. According to the above configuration, a determination is made as to whether the request condition is satisfied in consideration of the number of occupants of the driver's vehicle. Thus, a more appropriate collision avoidance process can be performed depending on the situation around the driver's vehicle.

[0022] In a first aspect, the processor may be configured to obtain a pressure in a master cylinder of a brake device as information related to a condition of a driver's vehicle. The brake device may be configured to apply a braking force to the driver's vehicle. The processor may be configured to determine that a request condition is satisfied when the pressure in the master cylinder is lower than or equal to a predetermined pressure, and to determine that a request condition is not satisfied when the pressure in the master cylinder is higher than the predetermined pressure.

[0023] The pressure in the master cylinder is an effective indicator for determining whether forced steering is preferably performed rather than forced braking. According to the above configuration, a determination is made as to whether the request condition is satisfied in consideration of the pressure in the master cylinder. Thus, a more appropriate collision avoidance process can be performed depending on the situation around the driver's vehicle.

[0024] In the first aspect, the processor can be configured to: determine whether a subsequent moving object moving behind the driver's vehicle in the same direction as the driving direction of the driver's vehicle has a possibility of collision with the driver's vehicle under the assumption that forced braking has been performed; obtain a determination result on whether the subsequent moving object has a possibility of collision as information related to the situation around the driver's vehicle; when the processor determines that the subsequent moving object has a possibility of collision with the driver's vehicle, determine that the request condition is met; and when the processor determines that the subsequent moving object does not have a possibility of collision with the driver's vehicle, determine that the request condition is not met.

[0025] Whether the subsequent moving object collides with the driver's vehicle when forced braking is performed is an effective indicator for determining whether it is preferable to perform forced steering rather than forced braking. According to the above configuration, a determination is made whether the request condition is satisfied by considering whether the subsequent moving object collides with the driver's vehicle when forced braking is performed. Thus, a more appropriate collision avoidance process can be performed depending on the situation around the driver's vehicle.

[0026] In the first aspect, the processor can be configured to: obtain the position of the subsequent moving object; determine that the subsequent moving object has the possibility of collision when the processor determines that the subsequent moving object is within a predetermined distance from the driver's vehicle based on the position of the subsequent moving object; and determine that the subsequent moving object does not have the possibility of collision when the processor determines that the subsequent moving object is not within the predetermined distance from the driver's vehicle based on the position of the subsequent moving object.

[0027] The position of the subsequent moving object is an effective indicator for accurately determining whether the subsequent moving object collides with the driver's vehicle when forced braking is performed. According to the above configuration, a determination is made as to whether the subsequent moving object collides with the driver's vehicle when forced braking is performed by using the position of the subsequent moving object. Thus, a more appropriate collision avoidance process can be performed depending on the situation around the driver's vehicle.

[0028] In the first aspect, the processor can be configured to: obtain a predicted driving area of ​​the driver's vehicle; obtain the position of a subsequent moving object and the predicted moving area of ​​the subsequent moving object; when the processor determines that the predicted moving area overlaps with the predicted driving area and determines that the subsequent moving object exists within a predetermined distance from the driver's vehicle based on the position of the subsequent moving object, determine that the subsequent moving object has a possibility of collision; when the processor determines that the predicted moving area overlaps with the predicted driving area and determines that the subsequent moving object does not exist within a predetermined distance from the driver's vehicle based on the position of the subsequent moving object, determine that the subsequent moving object does not have a possibility of collision; and when the processor determines that the predicted moving area does not overlap with the predicted driving area, regardless of whether the subsequent moving object exists within the predetermined distance from the driver's vehicle, determine that the subsequent moving object does not have a possibility of collision.

[0029] Not only the position of the subsequent moving object, but also the information on whether the predicted moving area and the predicted running area overlap with each other is an effective index for accurately determining whether the subsequent moving object collides with the driver's vehicle when forced braking is performed. According to the above configuration, by using not only the position of the subsequent moving object, but also the information on whether the predicted moving area and the predicted running area overlap with each other, the processor determines whether the subsequent moving object collides with the driver's vehicle when forced braking is performed. Thus, more appropriate collision avoidance processing can be performed depending on the situation around the driver's vehicle.

[0030] In the first aspect, the processor can be configured to: obtain the gradient of the road on which the driver's vehicle is traveling as information related to the situation around the driver's vehicle; determine that the request condition is met when the gradient is less than zero and the absolute value of the gradient is greater than or equal to a first gradient; and determine that the request condition is not met when the gradient is greater than or equal to zero, or when the absolute value of the gradient is less than the first gradient and the gradient is less than zero.

[0031] The gradient of the road on which the driver's vehicle is traveling is an effective indicator for determining whether it is preferable to perform forced steering rather than forced braking. According to the above configuration, the processor considers the gradient of the road on which the driver's vehicle is traveling to determine whether the request condition is satisfied. Thus, a more appropriate collision avoidance process can be performed depending on the situation around the driver's vehicle.

[0032] In a first aspect, the processor may be configured to obtain the gradient of the road surface on which the driver's vehicle is traveling and the friction coefficient of the road surface as information related to the situation around the driver's vehicle, and determine that the request condition is satisfied when the friction coefficient is less than or equal to a predetermined friction coefficient, the gradient is less than zero, and the absolute value of the gradient is greater than or equal to a first gradient. The processor may be configured to determine that the request condition is not satisfied when the friction coefficient is less than or equal to the predetermined friction coefficient and the gradient is greater than or equal to zero, or when the absolute value of the gradient is less than the first gradient and the gradient is less than zero. The processor may be configured to determine that the request condition is satisfied when the friction coefficient is greater than the predetermined friction coefficient, the gradient is less than zero, the absolute value of the gradient is greater than or equal to the first gradient, and the absolute value of the gradient is less than or equal to a second gradient greater than the first gradient. The processor may be configured to determine that the request condition is not satisfied when the friction coefficient is greater than the predetermined friction coefficient and the gradient is greater than or equal to zero, or when the gradient is less than zero and the absolute value of the gradient is less than the first gradient or greater than the second gradient.

[0033] The friction coefficient of the road surface on which the driver's vehicle is traveling is an effective indicator for determining whether it is preferable not to perform forced steering. According to the above configuration, the processor determines whether the request condition is satisfied considering the gradient and friction coefficient of the road surface on which the driver's vehicle is traveling. Thus, more appropriate collision avoidance processing can be performed depending on the situation around the driver's vehicle.

[0034] The processor can be configured to: obtain the inclination of the road on which the driver's vehicle is traveling as information related to the situation around the driver's vehicle; when the inclination is greater than or equal to a predetermined inclination, determine that the prohibition condition is met; and when the inclination is less than the predetermined inclination, determine that the prohibition condition is not met.

[0035] The inclination of the road on which the driver's vehicle is traveling is an effective indicator for determining whether it is preferable not to perform forced steering. According to the above configuration, the processor considers the inclination of the road on which the driver's vehicle is traveling to determine whether the prohibition condition is satisfied. Thus, more appropriate collision avoidance processing can be performed depending on the situation around the driver's vehicle.

[0036] The processor can be configured to: obtain information about whether vehicle stability control for adjusting the driving force or braking force applied to the driver's vehicle to stabilize the driving behavior of the driver's vehicle is performed as information related to the condition of the driver's vehicle; when the vehicle stability control is performed, determine that the prohibition condition is met; and when the vehicle stability control is not performed, determine that the prohibition condition is not met.

[0037] Whether the vehicle stability control is performed is an effective indicator for determining whether it is preferable not to perform forced steering. According to the above configuration, the processor considers whether the vehicle stability control is performed to determine whether the prohibition condition is satisfied. Thus, a more appropriate collision avoidance process can be performed depending on the situation around the driver's vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like numerals represent like elements, and in which:

[0039] Figure 1 is a diagram showing a vehicle collision avoidance assist device and a vehicle (driver's vehicle) including the vehicle collision avoidance assist device according to an embodiment of the present invention;

[0040] Figure 2 is a graph showing, for example, the distance between the driver's vehicle and an object (vehicle) in front of the driver's vehicle and the distance between the driver's vehicle and an object (vehicle) behind the driver's vehicle;

[0041] Figure 3A is a diagram showing a scenario in which a driver's vehicle is decelerated by forced braking;

[0042] Figure 3B is a diagram showing a scenario in which a driver's vehicle is stopped by forced braking;

[0043] Figure 4A is a diagram showing a scene in which forced steering is started;

[0044] Figure 4B is a diagram showing a scenario in which a driver's vehicle turns by forced steering;

[0045] Figure 4C is a diagram showing a scene in which a driver's vehicle passes by one side of an object by forced steering;

[0046] Figure 5A is a diagram showing a predicted travel area of ​​a driver's vehicle;

[0047] Figure 5B is a diagram showing a scene in which an object (vehicle) exists in a predicted travel area of ​​a driver's vehicle;

[0048] Fig. 6A is a diagram showing a scene in which a driver's vehicle approaches an object (vehicle) existing in a predicted travel area of ​​the driver's vehicle;

[0049] Figure 6B is a diagram showing a target avoidance path in forced steering;

[0050] Fig. 7Ais a diagram showing a scene in which no object such as a vehicle exists behind a driver's vehicle;

[0051] Figure 7B is a diagram showing a scene in which an object (vehicle) exists behind a driver's vehicle;

[0052] Fig. 8A is a diagram showing a scene in which a predicted movement area of ​​a subsequent moving object and a predicted travel area of ​​a driver's vehicle do not overlap with each other;

[0053] Figure 8B is a diagram showing a scene in which a predicted movement area of ​​a subsequent moving object and a predicted travel area of ​​a driver's vehicle overlap with each other;

[0054] Fig. 9A is a diagram showing a scenario in which the driver's vehicle begins to turn along a target avoidance path by forced steering;

[0055] Fig. 9B is a diagram showing a scene in which the driver's vehicle passes by one side of a front object (vehicle) by forced steering;

[0056] Fig. 9C is a diagram showing a scenario in which the driver's vehicle has passed a front object (vehicle) and forced steering is terminated;

[0057] Fig.10 is a flowchart showing a routine to be executed by the vehicle collision avoidance assistance device according to an embodiment of the present invention;

[0058] Fig.11 is a flowchart showing a routine to be executed by the vehicle collision avoidance assistance device according to an embodiment of the present invention;

[0059] Fig.12 is a flowchart showing a routine to be executed by the vehicle collision avoidance assistance device according to an embodiment of the present invention;

[0060] Fig.13 is a flowchart showing a routine to be executed by the vehicle collision avoidance assistance device according to an embodiment of the present invention;

[0061] Fig.14 is a flowchart showing a routine to be executed by the vehicle collision avoidance assist device according to an embodiment of the present invention;

[0062] Fig.15 is a flowchart showing a routine to be executed by the vehicle collision avoidance assist device according to an embodiment of the present invention;

[0063] Fig.16 is a flowchart showing a routine to be executed by the vehicle collision avoidance assistance device according to an embodiment of the present invention;

[0064] Fig.17 is a flowchart showing a routine to be executed by the vehicle collision avoidance assist device according to the embodiment of the present invention; and

[0065] Fig.18 is a flowchart showing a routine to be executed by the vehicle collision avoidance assist device according to the embodiment of the present invention. DETAILED DESCRIPTION

[0066] The vehicle collision avoidance assistance device according to an embodiment of the present invention will be described below with reference to the accompanying drawings. Figure 1 As shown in FIG. 1 , the vehicle collision avoidance assistance device 10 according to an embodiment of the present invention is mounted on a driver's vehicle 100 .

[0067] ECU

[0068] The vehicle collision avoidance assist device 10 includes an ECU 90. The term "ECU" is an abbreviation of an "electronic control unit". The ECU 90 includes a microcomputer as a main component. The microcomputer includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a non-volatile memory, and an interface. The CPU executes instructions, programs, or routines stored in the ROM to implement various functions.

[0069] Drives and other devices

[0070] Driver vehicle 100 includes a drive device 21 , a brake device 22 , and a steering device 23 .

[0071] Drive device

[0072] The drive device 21 outputs a drive torque TQ_D (driving force) to be applied to the driver's vehicle 100 to cause the driver's vehicle 100 to travel, and the drive device 21 is represented by an internal combustion engine or a motor. The drive device 21 is electrically connected to the ECU 90. The ECU 90 can control the drive torque TQ_D to be output from the drive device 21 by controlling the operation of the drive device 21.

[0073] Braking device

[0074] The brake device 22 outputs a braking torque TQ_B (braking force) to be applied to the driver's vehicle 100 to brake the driver's vehicle 100, and the brake device 22 is represented by a brake. The brake device 22 is electrically connected to the ECU 90. The ECU 90 can control the braking torque TQ_B to be output from the brake device 22 by controlling the operation of the brake device 22.

[0075] Steering

[0076] The steering device 23 outputs a steering torque TQs (steering force) to be applied to the driver's vehicle 100 to steer the driver's vehicle 100, and the steering device 23 is represented by a power steering device. The steering device 23 is electrically connected to the ECU 90. The ECU 90 can control the steering torque TQs to be output from the steering device 23 by controlling the operation of the steering device 23.

[0077] Sensors and other devices

[0078] The driver vehicle 100 also includes 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 brake device state detection device 40, a vehicle movement amount detection device 50, a peripheral information detection device 60, and a seat sensor 71.

[0079] Accelerator pedal operation amount sensor

[0080] The accelerator pedal operation amount sensor 32 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 about 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 the accelerator pedal operation amount AP based on the information.

[0081] The ECU 90 obtains the requested drive torque TQ_D_req (requested drive force) by calculation based on the accelerator pedal operation amount AP and the vehicle speed V100 of the driver's vehicle 100. The requested drive torque TQ_D_req is the drive torque TQ_D to be output from the drive device 21 according to the request. The ECU 90 controls the operation of the drive device 21 to output the requested drive torque TQ_D_req.

[0082] Brake pedal operation sensor

[0083] The brake pedal operation amount sensor 34 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 about 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 the brake pedal operation amount BP based on the information.

[0084] The ECU 90 obtains the requested braking torque TQ_B_req (requested braking force) by calculation based on the brake pedal operation amount BP. The requested braking torque TQ_B_req is the braking torque TQ_B to be output from the braking device 22 according to the request. The ECU 90 controls the operation of the braking device 22 to output the requested braking torque TQ_B_req.

[0085] Steering angle sensor

[0086] The steering angle sensor 37 detects the rotation angle of the steering shaft 36 relative to the neutral position. The steering angle sensor 37 is electrically connected to the ECU 90. The steering angle sensor 37 sends information about 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 the steering angle θsteer based on the information.

[0087] Steering torque sensor

[0088] The steering torque sensor 38 detects the torque inputted by the driver to the steering shaft 36 via the steering wheel 35. The steering torque sensor 38 is electrically connected to the ECU 90. The steering torque sensor 38 transmits information about the detected torque to the ECU 90. The ECU 90 acquires the torque (driver input torque TQs_driver) inputted by the driver to the steering shaft 36 via the steering wheel 35 based on the information.

[0089] Braking device status detection device

[0090] The brake device state detection device 40 detects the state of the brake device 22 , and in this example includes a master cylinder pressure sensor 41 .

[0091] Master cylinder pressure sensor

[0092] The master cylinder pressure sensor 41 detects the pressure in the master cylinder of the brake device 22. The master cylinder pressure sensor 41 is electrically connected to the ECU 90. The master cylinder pressure sensor 41 sends information about the detected pressure in the master cylinder to the ECU 90. The ECU 90 acquires the pressure in the master cylinder (master cylinder pressure Pm) based on the information.

[0093] Vehicle motion detection device

[0094] The vehicle movement amount detection device 50 detects the movement amount of the driver's vehicle 100 , and in this example includes a vehicle speed detection device 51 , a longitudinal acceleration sensor 52 , a lateral acceleration sensor 53 , and a yaw rate sensor 54 .

[0095] Vehicle speed detection device

[0096] The vehicle speed detecting device 51 detects the vehicle speed of the driver's vehicle 100, and the vehicle speed detecting device 51 is represented by a wheel speed sensor. The vehicle speed detecting device 51 is electrically connected to the ECU 90. The vehicle speed detecting device 51 sends information about the detected vehicle speed of the driver's vehicle 100 to the ECU 90. The ECU 90 acquires the vehicle speed V100 of the driver's vehicle 100 based on the information.

[0097] ECU 90 obtains the requested steering torque TQs_req by calculation based on the acquired steering angle θsteer, the acquired driver input torque TQs_driver and the acquired vehicle speed V100. The requested steering torque TQs_req is the steering torque TQs to be output from the steering device 23 according to the request. ECU 90 controls the operation of the steering device 23 to output the requested steering torque TQs_req from the steering device 23. When the forced steering described later is performed, ECU 90 appropriately determines the steering torque TQs required to cause the driver vehicle 100 to travel along the target avoidance path Rtgt as the requested steering torque TQs_req, regardless of the steering angle θsteer, etc. Then, ECU 90 controls the operation of the steering device 23 to output the requested steering torque TQs_req.

[0098] Longitudinal acceleration sensor

[0099] The longitudinal acceleration sensor 52 detects the acceleration of the driver's vehicle 100 in the front-rear direction. The longitudinal acceleration sensor 52 is electrically connected to the ECU 90. The longitudinal acceleration sensor 52 sends information about the detected acceleration to the ECU 90. The ECU 90 acquires the acceleration of the driver's vehicle 100 in the front-rear direction as the longitudinal acceleration Gx based on the information.

[0100] Lateral acceleration sensor

[0101] The lateral acceleration sensor 53 detects the acceleration in the lateral direction (width direction) of the driver's vehicle 100. The lateral acceleration sensor 53 is electrically connected to the ECU 90. The lateral acceleration sensor 53 sends information about the detected acceleration to the ECU 90. The ECU 90 acquires the acceleration in the lateral direction of the driver's vehicle 100 as the lateral acceleration Gy based on the information.

[0102] Yaw rate sensor

[0103] The yaw rate sensor 54 detects the yaw rate YR of the driver vehicle 100. The yaw rate sensor 54 is electrically connected to the ECU 90. The yaw rate sensor 54 sends information about the detected yaw rate YR to the ECU 90. The ECU 90 acquires the yaw rate YR of the driver vehicle 100 based on the information.

[0104] Peripheral information detection device

[0105] The surrounding information detection device 60 detects information around the driver's vehicle 100, and in this example, the surrounding information detection device 60 includes a radio wave sensor 61 and an image sensor 62. Examples of the radio wave sensor 61 include a radar sensor (such as a millimeter wave radar). Examples of the image sensor 62 include a camera. The surrounding information detection device 60 may include an acoustic wave sensor such as an ultrasonic sensor (clearance sonar) or an optical sensor such as a laser radar (Light Detection And Ranging, LiDAR).

[0106] Radio wave sensor

[0107] The radio wave sensor 61 is electrically connected to the ECU 90. The radio wave sensor 61 transmits radio waves and receives radio waves (reflected waves) reflected by an object. The radio wave sensor 61 sends information (detection results) related to the transmitted radio waves and the received radio waves (reflected waves) to the ECU 90. In other words, the radio wave sensor 61 detects objects present around the driver's vehicle 100 and sends information (detection results) related to the detected objects to the ECU 90. The ECU 90 can obtain information (object information I_O) related to objects present around the driver's vehicle 100 based on the information (radio wave information I_RO).

[0108] In this example, the object is a vehicle, a motorcycle, a bicycle, or a person, etc.

[0109] Image Sensor

[0110] The image sensor 62 is electrically connected to the ECU 90. The image sensor 62 captures an image around the driver's vehicle 100 and transmits information about the captured image to the ECU 90. The ECU 90 can acquire information about the periphery of the driver's vehicle 100 (periphery detection information Idct) based on the information (image information I_C).

[0111] When Figure 2When there is an object (front object 200F) in front of the driver's vehicle 100, the ECU 90 detects the front object 200F based on the surrounding detection information Idct. The front object 200F is a vehicle, a motorcycle, a bicycle, or a person. Figure 2 In the example shown in , the front object 200F is a vehicle.

[0112] When ECU 90 detects front object 200F, ECU 90 can acquire, for example, "the distance between front object 200F and driver's vehicle 100 (object distance D200)" and "the speed of driver's vehicle 100 relative to front object 200F (relative speed ΔV200)" based on surrounding detection information Idct.

[0113] When Figure 2 When there is an object (subsequent moving object 300) moving behind the driver's vehicle 100 to follow the driver's vehicle 100 in the same direction as the driving direction of the driver's vehicle 100, the ECU 90 detects the subsequent moving object 300 based on the surrounding detection information Idct. The subsequent moving object 300 is a vehicle, a motorcycle, a bicycle, or a person, etc. Figure 2 In the example shown in , the subsequent moving object 300 is a vehicle.

[0114] When ECU 90 detects the subsequent moving object 300, ECU 90 can obtain, for example, "the distance between the subsequent moving object 300 and the driver's vehicle 100 (object distance D300)" and "the speed of the subsequent moving object 300 relative to the driver's vehicle 100 (relative speed ΔV300)" based on the peripheral detection information Idct.

[0115] The ECU 90 identifies “the right lane marking line LM_R and the left lane marking line LM_L that define the driving lane (driver vehicle lane LN) of the driver vehicle 100” based on the peripheral detection information Idct. The ECU 90 can determine the range of the driver vehicle lane LN based on the identified left and right lane marking lines LM (i.e., the right lane marking line LM_R and the left lane marking line LM_L).

[0116] Seat sensor

[0117] The seating sensor 71 detects an occupant sitting on a seat of the driver's vehicle 100, and is mounted on the driver's vehicle 100 in association with each seat. The seating sensor 71 is electrically connected to the ECU 90. When the seating sensor 71 detects an occupant sitting on a seat, the seating sensor 71 sends a signal indicating that the occupant is sitting on the seat to the ECU 90. The ECU 90 acquires the number of occupants of the driver's vehicle 100 based on the signal.

[0118] Overview of the operation of the vehicle collision avoidance assist system

[0119] Next, an outline of the operation of the vehicle collision avoidance assist device 10 will be described. The vehicle collision avoidance assist device 10 is configured to perform forced braking or forced steering when the driver vehicle 100 is likely to collide with an object in front of the driver vehicle 100 (front object).

[0120] Forced braking

[0121] When Figure 3A As shown in FIG. 2 , there is an object 200F in front (in FIG. Figure 3A and Figure 3B In the example shown in FIG. 1 , when the vehicle in front of the driver's vehicle 100 is stopped, the braking force is applied to the driver's vehicle 100 to Figure 3B As shown in FIG. 1 , the driver vehicle 100 is stopped before the driver vehicle 100 collides with the front object 200F to perform compulsory braking to avoid the collision between the driver vehicle 100 and the front object 200F. When the driver vehicle 100 stops behind the front object 200F, the compulsory braking is terminated.

[0122] Forced Turn

[0123] When Figure 4A As shown in FIG. 1 , there is a front object 200F in front of the driver's vehicle 100 (in FIG. Figure 4A , 4B In the example shown in FIG. 4C , when the vehicle is stopped in front of the driver's vehicle 100, Figure 4B As shown in FIG. 1 , the driver turns the vehicle 100 to Figure 4C As shown in FIG. 1 , the driver vehicle 100 passes by the front object 200F to perform forced steering to avoid a collision between the driver vehicle 100 and the front object 200F. When the driver vehicle 100 passes by the front object 200F, the forced steering is terminated.

[0124] Request conditions / prohibition conditions

[0125] The vehicle collision avoidance assistance device 10 obtains information related to the condition of the driver's vehicle 100 (driver vehicle information I_100) and information related to the situation around the driver's vehicle 100 (driver vehicle surrounding information I_S), and based on the driver vehicle information I_100 and the driver vehicle surrounding information I_S, determines whether the condition for requesting the execution of forced steering (request condition Creq) and whether the condition for prohibiting the execution of forced steering (prohibition condition Cfbd) are met.

[0126] The vehicle collision avoidance assistance device 10 can obtain the driver vehicle information I_100 or the driver vehicle surrounding information I_S, and determine whether the request condition Creq is satisfied and whether the prohibition condition Cfbd is satisfied based on the obtained driver vehicle information I_100 or the obtained driver vehicle surrounding information I_S.

[0127] Deterioration of the brake system

[0128] The vehicle collision avoidance assist device 10 acquires the degradation state of the brake device 22 as the driver vehicle information I_100 while the driver vehicle 100 is traveling, and determines whether the request condition Creq is satisfied based on the degradation state of the brake device 22 .

[0129] By grasping the braking performance of the brake device 22, it is possible to grasp the degradation state of the brake device 22. By grasping the relationship between the brake pedal operation amount BP and the braking force thereby applied from the brake device 22 to the driver's vehicle 100, it is possible to grasp the braking performance of the brake device 22. The braking force applied from the brake device 22 to the driver's vehicle 100 appears as a deceleration of the driver's vehicle 100 (i.e., a negative longitudinal acceleration Gx; hereinafter referred to as "deceleration GD").

[0130] In order to accurately obtain the degradation state of the braking device 22, the vehicle collision avoidance assistance device 10 first determines whether the vehicle speed V100 of the driver's vehicle 100 is higher than or equal to the predetermined vehicle speed (reference speed or lower limit vehicle speed Vlimit) and whether the absolute value of the road surface gradient GR is less than or equal to the predetermined gradient (reference gradient or upper limit gradient GRlimit) (that is, whether the braking performance judgment conditions are met).

[0131] When the braking performance determination condition is satisfied, the vehicle collision avoidance assist device 10 determines whether the brake pedal operation amount BP is greater than or equal to a predetermined brake pedal operation amount BPth.

[0132] When the vehicle collision avoidance assistance device 10 determines that the brake pedal operation amount BP is greater than or equal to the predetermined brake pedal operation amount BPth, the vehicle collision avoidance assistance device 10 obtains the deceleration GD of the driver vehicle 100 at this time as the driver vehicle information I_100, and determines whether the absolute value of the deceleration GD is less than or equal to the predetermined deceleration (reference deceleration GDbase) set based on the brake pedal operation amount BP. The reference deceleration GDbase is set to the deceleration expected to be generated in the driver vehicle 100 based on the brake pedal operation amount BP when the brake device 22 has sufficient braking performance.

[0133] When the vehicle collision avoidance assist device 10 determines that the absolute value of the deceleration GD of the driver's vehicle 100 is less than or equal to the reference deceleration GDbase, the vehicle collision avoidance assist device 10 may determine that the request condition Creq (first request condition Creq_1) caused by the braking performance is satisfied. However, in this example, the vehicle collision avoidance assist device 10 increases the index value (braking performance index value) indicating the possibility of satisfying the first request condition Creq_1 by a predetermined value. When the vehicle collision avoidance assist device 10 determines that the absolute value of the deceleration GD of the driver's vehicle 100 is greater than the reference deceleration GDbase, the vehicle collision avoidance assist device 10 may determine that the first request condition Creq_1 is not satisfied. However, in this example, the vehicle collision avoidance assist device 10 decreases the braking performance index value by a predetermined value.

[0134] The vehicle collision avoidance assistance device 10 uses the braking performance counter Cbrake as the braking performance index value. When the vehicle collision avoidance assistance device 10 determines that the absolute value of the deceleration GD of the driver's vehicle 100 is less than or equal to the reference deceleration GDbase, the vehicle collision avoidance assistance device 10 increments the braking performance counter Cbrake. When the vehicle collision avoidance assistance device 10 determines that the absolute value of the deceleration GD of the driver's vehicle 100 is greater than the reference deceleration GDbase, the vehicle collision avoidance assistance device 10 decrements the braking performance counter Cbrake.

[0135] The vehicle collision avoidance assist device 10 determines that the first request condition Creq_1 is not satisfied when the braking performance counter Cbrake is less than the predetermined value Cbrake_th, and determines that the first request condition Creq_1 is satisfied when the braking performance counter Cbrake reaches the predetermined value Cbrake_th.

[0136] When the brake pads used in the brake device 22 deteriorate, the braking performance of the brake device 22 decreases, and as a result, the deceleration GD of the driver vehicle 100 decreases. Therefore, the determination as to whether the first request condition Creq_1 is satisfied based on the deceleration GD of the driver vehicle 100 corresponds to the determination as to whether the first request condition Creq_1 is satisfied based on the degradation state of the brake pads acquired as the driver vehicle information I_100.

[0137] Moreover, when the brake oil used in the brake device 22 deteriorates, the braking performance of the brake device 22 decreases, and as a result, the deceleration GD of the driver vehicle 100 decreases. Therefore, the determination as to whether the first request condition Creq_1 is satisfied based on the deceleration GD of the driver vehicle 100 corresponds to the determination as to whether the first request condition Creq_1 is satisfied based on the deterioration state of the brake oil acquired as the driver vehicle information I_100.

[0138] When the weight of the driver's vehicle 100 including the occupants increases, the deceleration GD of the driver's vehicle 100 decreases even if the braking performance of the braking device 22 does not decrease. Therefore, the determination as to whether the first request condition Creq_1 is satisfied based on the deceleration GD of the driver's vehicle 100 corresponds to the determination as to whether the first request condition Creq_1 is satisfied based on whether the weight of the driver's vehicle 100 including the occupants acquired as the driver's vehicle information I_100 is greater than or equal to a predetermined weight.

[0139] When the weight of the driver's vehicle 100 including the occupants increases as described above, the deceleration GD of the driver's vehicle 100 decreases even if the braking performance of the braking device 22 does not decrease. That is, when the number of occupants in the driver's vehicle 100 increases, the deceleration GD of the driver's vehicle 100 decreases even if the braking performance of the braking device 22 does not decrease. Therefore, the vehicle collision avoidance assistance device 10 can acquire the number of occupants of the driver's vehicle 100 as the driver's vehicle information I_100, determine that the request condition Creq is satisfied when the acquired number of occupants is greater than or equal to a predetermined number, and determine that the request condition Creq is not satisfied when the acquired number of occupants is less than the predetermined number.

[0140] Master cylinder pressure

[0141] When an abnormality occurs in the master cylinder, the master cylinder pressure Pm decreases, resulting in a decrease in the braking performance of the brake device 22. Therefore, the vehicle collision avoidance assist device 10 acquires the master cylinder pressure Pm as the driver vehicle information I_100 and determines whether the master cylinder pressure Pm is lower than or equal to a predetermined pressure Pm_th.

[0142] When the vehicle collision avoidance assist device 10 determines that the master cylinder pressure Pm is lower than or equal to the predetermined pressure Pm_th, the vehicle collision avoidance assist device 10 determines that the request condition Creq (the second request condition Creq_2) caused by the braking performance is satisfied. When the vehicle collision avoidance assist device 10 determines that the master cylinder pressure Pm is higher than the predetermined pressure Pm_th, the vehicle collision avoidance assist device 10 determines that the second request condition Creq_2 is not satisfied.

[0143] Road conditions

[0144] The vehicle collision avoidance assist device 10 acquires information about the road surface on which the driver vehicle 100 is traveling (road surface information Iroad) as the driver vehicle surrounding information I_S while the driver vehicle 100 is traveling, and determines whether the prohibition condition Cfbd is satisfied based on the road surface information Iroad.

[0145] Even when the driver's vehicle 100 is driving on a downhill slope with a large gradient and performing forced braking, there is a possibility that the driver's vehicle 100 does not decelerate as expected. In this case, it is preferred to avoid a collision between the driver's vehicle 100 and an object by forced steering rather than forced braking.

[0146] When forced steering is performed while the driver's vehicle 100 is traveling on a road surface having a large inclination, the traveling behavior of the driver's vehicle 100 may become unstable.

[0147] In order to accurately obtain the road surface gradient GR and the road surface inclination CT, the vehicle collision avoidance assistance device 10 first determines whether the absolute value of the acceleration of the driver's vehicle 100 (i.e., the longitudinal acceleration Gx including negative values) is less than or equal to the predetermined acceleration (upper limit acceleration Glimit) (i.e., whether the road surface determination condition is met).

[0148] When the vehicle collision avoidance assist device 10 determines that the road surface determination condition is satisfied, the vehicle collision avoidance assist device 10 acquires the road surface gradient GR and the road surface inclination CT as the driver vehicle surrounding information I_S. The road surface gradient GR and the road surface inclination CT may be acquired by a predetermined method based on the surrounding detection information Idct.

[0149] The vehicle collision avoidance assist device 10 determines whether the road surface gradient GR is less than zero and its absolute value is greater than or equal to a predetermined gradient (first gradient GR_1), and whether the absolute value of the road surface inclination CT is greater than or equal to a predetermined value (predetermined inclination CTth).

[0150] When the vehicle collision avoidance assistance device 10 determines that the road surface gradient GR is less than zero and its absolute value is greater than or equal to the first gradient GR_1, the vehicle collision avoidance assistance device 10 determines that the request condition Creq (third request condition Creq_3) caused by the road surface gradient is satisfied. When the vehicle collision avoidance assistance device 10 determines that the road surface gradient GR is greater than or equal to zero or that the road surface gradient GR is less than zero but its absolute value is less than the first gradient GR_1, the vehicle collision avoidance assistance device 10 determines that the third request condition Creq_3 is not satisfied.

[0151] When the absolute value of the road surface inclination CT is greater than or equal to the predetermined inclination CTth, the vehicle collision avoidance assistance device 10 determines that the prohibition condition Cfbd (first prohibition condition Cfbd_1) caused by the road surface inclination is satisfied. When the absolute value of the road surface inclination CT is less than the predetermined inclination CTth, the vehicle collision avoidance assistance device 10 determines that the first prohibition condition Cfbd_1 is not satisfied.

[0152] When forced steering is performed while the driver vehicle 100 is traveling on a road surface with a small friction coefficient, the driving behavior of the driver vehicle 100 may become unstable. In this case, it is preferred to avoid a collision between the driver vehicle 100 and an object by forced braking rather than forced steering.

[0153] Therefore, the vehicle collision avoidance assistance device 10 can obtain the road friction coefficient μ as the driver's vehicle surrounding information I_S in addition to the road gradient GR, and determine whether the third request condition Creq_3 is satisfied based on the road gradient GR and the road friction coefficient μ, rather than determining whether the third request condition Creq_3 is satisfied based only on the road gradient GR. The road friction coefficient μ can be obtained by a predetermined method based on the surrounding detection information Idct.

[0154] When the road surface friction coefficient μ is less than or equal to the predetermined friction coefficient μ_th, and a determination is made that the road surface gradient GR is less than zero and its absolute value is greater than or equal to the first gradient GR_1, the vehicle collision avoidance assistance device 10 determines that the request condition Creq (third request condition Creq_3) caused by the road surface gradient is satisfied. When the road surface friction coefficient μ is less than or equal to the predetermined friction coefficient μ_th, and a determination is made that the road surface gradient GR is greater than or equal to zero or that the road surface gradient GR is less than zero but its absolute value is less than the first gradient GR_1, the vehicle collision avoidance assistance device 10 determines that the third request condition Creq_3 is not satisfied.

[0155] When the road surface friction coefficient μ is greater than the predetermined friction coefficient μ_th, the road surface gradient GR is less than zero and its absolute value is greater than or equal to the first gradient GR_1 and less than or equal to the predetermined gradient (second gradient GR_2) greater than the first gradient GR_1, the vehicle collision avoidance assistance device 10 determines that the third request condition Creq_3 is satisfied. When the road surface friction coefficient μ is greater than the predetermined friction coefficient μ_th, and the road surface gradient GR is greater than or equal to zero or although the road surface gradient GR is less than zero, its absolute value is less than the first gradient GR_1 or greater than the second gradient GR_2, the vehicle collision avoidance assistance device 10 determines that the third request condition Creq_3 is not satisfied.

[0156] Whether to perform vehicle stability control

[0157] When the driving behavior of the driver vehicle 100 is unstable while the driver vehicle 100 is driving, the vehicle collision avoidance assistance device 10 performs the so-called vehicle stability control for stabilizing the driving behavior of the driver vehicle 100 by adjusting the driving force or braking force to be applied to each wheel of the driver vehicle 100 to stabilize the driving behavior of the driver vehicle 100.

[0158] When the vehicle stability control is performed, the vehicle collision avoidance assist device 10 determines that the prohibition condition Cfbd (the second prohibition condition Cfbd_2) caused by the vehicle stability control is satisfied. When the vehicle stability control is not performed, the vehicle collision avoidance assist device 10 determines that the second prohibition condition Cfbd_2 is not satisfied. In this way, the vehicle collision avoidance assist device 10 acquires information on whether the vehicle stability control is performed as the driver vehicle information I_100, and determines whether the prohibition condition Cfbd is satisfied based on whether the vehicle stability control is performed.

[0159] Collision avoidance execution conditions

[0160] While the driver's vehicle 100 is traveling, the vehicle collision avoidance assist device 10 performs processing for detecting an object such as a vehicle ahead of the traveling direction of the driver's vehicle 100 based on the surrounding detection information Idct. When the vehicle collision avoidance assist device 10 does not detect an object ahead of the traveling direction of the driver's vehicle 100, the vehicle collision avoidance assist device 10 performs normal traveling control.

[0161] In this normal travel control, when the requested driving torque TQ_D_req (requested driving force) is greater than zero, the operation of the driving device 21 is controlled to output the requested driving torque TQ_D_req from the driving device 21. When the requested braking torque TQ_B_req (requested braking force) is greater than zero, the operation of the braking device 22 is controlled to output the requested braking torque TQ_B_req from the braking device 22. When the requested steering torque TQs_req (requested steering force) is greater than zero, the operation of the steering device 23 is controlled to output the requested steering torque TQs_req from the steering device 23.

[0162] When the vehicle collision avoidance assist device 10 detects an object ahead of the driving direction of the driver's vehicle 100 , the vehicle collision avoidance assist device 10 determines whether the object exists in the predicted driving area A100 based on the surrounding detection information Idct.

[0163] like Figure 5A As shown in , the predicted traveling area A100 is an area having a width equal to that of the driver vehicle 100, and its center corresponds to the predicted traveling route R100 of the driver vehicle 100. The predicted traveling route R100 is a traveling route predicted to be traveled in the future by the driver vehicle 100 when the driver vehicle 100 travels while maintaining the steering angle θsteer at that time. Figure 5A The predicted travel route R100 shown in FIG. 1 is a straight line, but may be a curve depending on circumstances.

[0164] When the detected object does not exist in the predicted traveling area A100, the vehicle collision avoidance assist device 10 continues the normal traveling control.

[0165] When Figure 5B The object 200 shown in Figure 5B In the example shown in , when an object 200 is present in the predicted driving area A100, the vehicle collision avoidance assistance device 10 identifies the object 200 as a front object 200F, and obtains the "distance between the front object 200F and the driver's vehicle 100 (object distance D200)" and the "speed of the driver's vehicle 100 relative to the front object 200F (relative speed ΔV200)" based on the peripheral detection information Idct.

[0166] The vehicle collision avoidance assist device 10 acquires the predicted arrival time period TTC through calculation based on the acquired object distance D200 and the acquired relative speed ΔV200.

[0167] The predicted arrival time period TTC is a time period that is predicted to be required for the driver's vehicle 100 to reach the front object 200F. The vehicle collision avoidance assist device 10 obtains the predicted arrival time period TTC by dividing the object distance D200 by the relative speed ΔV200 (TTC=D200 / ΔV200). The vehicle collision avoidance assist device 10 obtains the object distance D200, the relative speed ΔV200, and the predicted arrival time period TTC in a predetermined calculation cycle while determining that the front object 200F exists in the predicted travel area A100.

[0168] When the relative speed ΔV200 is constant, the predicted arrival time period TTC decreases as the driver's vehicle 100 approaches the front object 200F.

[0169] The vehicle collision avoidance assist device 10 continues the normal running control while the predicted arrival time period TTC is longer than the predetermined predicted arrival time period TTCth.

[0170] When Fig. 6A When the driver vehicle 100 shown in FIG. 1 then approaches the front object 200F and the predicted arrival time period TTC decreases to a predetermined time period (predetermined predicted arrival time period TTCth), the vehicle collision avoidance assist device 10 determines that the collision avoidance execution condition Cstart is satisfied.

[0171] That is, the vehicle collision avoidance assistance device 10 obtains the predicted arrival time period TTC as an index value indicating the possibility of the driver's vehicle 100 colliding with the front object 200F, and when the index value is greater than or equal to the predetermined index value, it is determined that the collision avoidance execution condition Cstart is satisfied. In this case, the index value indicating the possibility of the driver's vehicle 100 colliding with the front object 200F increases as the predicted arrival time period TTC decreases.

[0172] Obtaining the target avoidance path

[0173] When the vehicle collision avoidance assistance device 10 determines that the collision avoidance execution condition Cstart is satisfied, Figure 6B As shown in FIG. 1 , the target avoidance path Rtgt is set by the vehicle collision avoidance assist device 10. The target avoidance path Rtgt is a travel path of the driver vehicle 100 in which the driver vehicle 100 can pass by the side of the front object 200F while traveling in the driver vehicle lane LN.

[0174] exist Figure 6B In the example shown in , the target avoidance path Rtgt is a path extending on the right side of the front object 200F. When there is a space on the left side of the front object 200F where the driver's vehicle 100 can pass by on the side of the front object 200F while traveling in the driver's vehicle lane LN, the path extending on the left side of the front object 200F can be acquired as the target avoidance path Rtgt.

[0175] When the vehicle collision avoidance assist device 10 cannot set the target avoidance path Rtgt because there is no space for the driver's vehicle 100 to pass through on the side of the front object 200F, the vehicle collision avoidance assist device 10 determines that the prohibition condition Cfbd (third prohibition condition Cfbd_3) caused by the collision avoidance path is satisfied. When the target avoidance path Rtgt can be set, the vehicle collision avoidance assist device 10 determines that the third prohibition condition Cfbd_3 is not satisfied. In this way, the vehicle collision avoidance assist device 10 obtains the determination result on whether the target avoidance path Rtgt can be set as the driver vehicle information I_100, and determines whether the third prohibition condition Cfbd_3 is satisfied based on the determination result.

[0176] Target deceleration setting

[0177] When the vehicle collision avoidance assist device 10 determines that the collision avoidance execution condition Cstart is satisfied, the vehicle collision avoidance assist device 10 obtains by calculation the deceleration (target deceleration GDtgt) of the driver's vehicle 100 required to stop the driver's vehicle 100 by forced braking before colliding with the front object 200F.

[0178] Acquisition of subsequent moving object information

[0179] When the vehicle collision avoidance assistance device 10 determines that the collision avoidance execution condition Cstart is satisfied, the vehicle collision avoidance assistance device 10 determines whether there is a subsequent moving object 300 based on the surrounding detection information Idct.

[0180] like Fig. 7AAs shown in FIG. 1 , when no object exists behind the driver vehicle 100, the vehicle collision avoidance assist device 10 determines that there is no subsequent moving object 300. When there is no subsequent moving object 300, even if forced braking is performed, no subsequent moving object 300 collides with the driver vehicle 100, and there is no need to avoid the collision between the driver vehicle 100 and the front object 200F by forced steering. Therefore, the vehicle collision avoidance assist device 10 determines that the request condition Creq (the fourth request condition Creq_4) caused by the subsequent moving object is not satisfied.

[0181] When Figure 7B It is shown that there is an object behind the driver's vehicle 100 (at Figure 7B When the vehicle 300 is detected in the example shown in FIG, the vehicle collision avoidance assistance device 10 determines that there is a subsequent moving object 300 and acquires a predicted movement area A300 of the subsequent moving object 300 based on the surrounding detection information Idct.

[0182] like Figure 7B As shown in FIG. 1 , the predicted movement area A300 is an area having a width equal to that of the subsequent moving object 300, and its center corresponds to a predicted movement route R300 of the subsequent moving object 300. The predicted movement route R300 is a travel route that the subsequent moving object 300 is predicted to travel in the future. Figure 7B The predicted movement route R300 shown in FIG. 1 is a straight line, but may be a curve depending on circumstances.

[0183] The vehicle collision avoidance assistance device 10 determines whether the predicted movement area A300 and the predicted travel area A100 overlap with each other.

[0184] When the predicted movement area A300 and the predicted driving area A100 have Fig. 8A . The vehicle collision avoidance assistance device 10 determines that the predicted movement area A300 and the predicted travel area A100 do not overlap with each other. When the predicted movement area A300 and the predicted travel area A100 do not overlap with each other, even if forced braking is performed, the subsequent moving object 300 does not collide with the driver's vehicle 100, and there is no need to avoid the collision between the driver's vehicle 100 and the front object 200F by forced steering. Therefore, the vehicle collision avoidance assistance device 10 determines that the fourth request condition Creq_4 is not satisfied.

[0185] When the predicted movement area A300 and the predicted driving area A100 have Figure 8B When the relationship shown in , the vehicle collision avoidance assistance device 10 determines that the predicted movement area A300 and the predicted travel area A100 overlap with each other, and determines whether the subsequent moving object 300 may collide with the driver vehicle 100 under the assumption that forced braking is performed based on the surrounding detection information Idct.

[0186] More specifically, the vehicle collision avoidance assistance device 10 obtains by calculation the distance (required stopping distance Dreq_stop) that the subsequent moving object 300 moves before the subsequent moving object 300 stops, under the assumption that the subsequent moving object 300 starts to decelerate at the maximum deceleration GDmax in response to the start of deceleration of the driver's vehicle 100 when the predetermined period Tth has passed since the driver's vehicle 100 started to decelerate at the target deceleration GDtgt by starting forced braking. The predetermined period Tth is a period that may be generally required for the subsequent moving object 300 to start decelerating in response to the start of deceleration of the driver's vehicle 100. The maximum deceleration GDmax is the maximum value of the deceleration that can be achieved by the subsequent moving object 300.

[0187] The vehicle collision avoidance assist device 10 obtains the period required for the subsequent moving object 300 to move the required stopping distance Dreq_stop (required stopping period Treq_stop) by calculation, and obtains the distance to be traveled by the driver vehicle 100 within the required stopping period Treq_stop during forced braking (driver vehicle traveling distance Dtravel) by calculation.

[0188] When the required stopping distance Dreq_stop is longer than the driver vehicle travel distance Dtravel, the vehicle collision avoidance assist device 10 may determine that the subsequent moving object 300 may collide with the driver vehicle 100 when forced braking is performed. In this example, the vehicle collision avoidance assist device 10 determines that the subsequent moving object 300 may collide with the driver vehicle 100 when forced braking is performed not only when the required stopping distance Dreq_stop is longer than the driver vehicle travel distance Dtravel but also when the required stopping distance Dreq_stop is equal to or shorter than the driver vehicle travel distance Dtravel and the difference ΔD between the two distances is less than or equal to the predetermined distance ΔDth.

[0189] When the vehicle collision avoidance assist device 10 determines that the subsequent moving object 300 may collide with the driver vehicle 100 in the case where forced braking is performed, it is preferred to avoid the collision between the driver vehicle 100 and the front object 200F by forced steering. Therefore, the vehicle collision avoidance assist device 10 determines that the fourth request condition Creq_4 is satisfied. When the vehicle collision avoidance assist device 10 determines that the subsequent moving object 300 will not collide with the driver vehicle 100 even in the case of forced braking, the vehicle collision avoidance assist device 10 determines that the fourth request condition Creq_4 is not satisfied.

[0190] Based on the determination as to whether the fourth request condition Creq_4 is satisfied, the vehicle collision avoidance assistance device 10 determines that the fourth request condition Creq_4 is satisfied when it is determined that the predicted moving area A300 overlaps with the predicted driving area A100 and based on the position of the subsequent moving object 300 (the relative position P300 of the subsequent moving object 300 relative to the driver's vehicle 100), it is determined that the subsequent moving object 300 exists within a predetermined distance Dth from the driver's vehicle 100.

[0191] Based on the judgment on whether the fourth request condition Creq_4 is satisfied, the vehicle collision avoidance assistance device 10 determines that the fourth request condition Creq_4 is not satisfied when it is determined that the predicted moving area A300 and the predicted driving area A100 overlap with each other and when it is determined based on the position of the subsequent moving object 300 that the subsequent moving object 300 does not exist within a predetermined distance Dth from the driver's vehicle 100.

[0192] Based on the judgment on whether the fourth request condition Creq_4 is met, when the vehicle collision avoidance assistance device 10 makes a judgment that the predicted moving area A300 and the predicted driving area A100 do not overlap with each other, regardless of whether the subsequent moving object 300 exists within the range of a predetermined distance Dth from the driver's vehicle 100, it is determined that the fourth request condition Creq_4 is not met.

[0193] As described above, the vehicle collision avoidance assist device 10 in this example determines whether the fourth request condition Creq_4 is satisfied based on whether there is a collision possibility of the subsequent moving object 300 colliding with the driver's vehicle 100 under the assumption that compulsory braking is performed.

[0194] Execution of forced braking

[0195] When none of the first to fourth request conditions Creq_1 to Creq_4 is satisfied, the vehicle collision avoidance assist device 10 performs forced braking regardless of whether the first to third prohibition conditions Cfbd_1 to Cfbd_3 are satisfied.

[0196] When any one of the first to third prohibition conditions Cfbd_1 to Cfbd_3 is satisfied, the vehicle collision avoidance assist device 10 performs forced braking even if any one of the first to fourth request conditions Creq_1 to Creq_4 is satisfied.

[0197] When compulsory braking is started, the vehicle collision avoidance assist device 10 controls the braking force to be applied to the driver vehicle 100 to decelerate the driver vehicle 100 at the target deceleration GDtgt. When the driver vehicle 100 stops, the vehicle collision avoidance assist device 10 terminates the compulsory braking.

[0198] Execution of forced steering

[0199] When any one of the first to fourth request conditions Creq_1 to Creq_4 is satisfied and none of the first to third prohibition conditions Cfbd_1 to Cfbd_3 is satisfied, the vehicle collision avoidance assist device 10 performs forced steering.

[0200] When the forced steering is started, the vehicle collision avoidance assist device 10 starts a process of controlling the steering torque TQs to be output from the steering device 23 so as to cause the driver vehicle 100 to travel along the target avoidance path Rtgt.

[0201] The vehicle collision avoidance assist device 10 obtains the current position of the driver's vehicle 100 based on the longitudinal acceleration Gx, lateral acceleration Gy, yaw angular velocity YR, left and right lane marking lines LM, etc. during forced steering, and controls the steering torque TQ to be output from the steering device 23 based on the obtained current position of the driver's vehicle 100 so that the driver's vehicle 100 travels along the target avoidance path Rtgt.

[0202] Results, such as Fig. 9A The driver vehicle 100 starts turning, and as shown in Fig. 9B As shown in FIG. 1 , the vehicle 100 passes by the front object 200F on one side. Therefore, the collision between the driver vehicle 100 and the front object 200F is avoided.

[0203] When Fig. 9C When the driver vehicle 100 shown in FIG. 1 has passed by one side of the front object 200F, the vehicle collision avoidance assist device 10 terminates the forced steering.

[0204] In addition to forced steering, the vehicle collision avoidance assist device 10 can decelerate the driver vehicle 100 by reducing the driving force applied to the driver vehicle 100, limiting the driving force to a certain value or less, or applying a braking force to the driver vehicle 100. In this case, when the driver vehicle 100 stops, the vehicle collision avoidance assist device 10 terminates the forced steering.

[0205] For example, when there is a possibility that the driver vehicle 100 will collide with another object, such as a person that has appeared from behind the front object 200F, during forced turning, the vehicle collision avoidance assistance device 10 can perform forced braking by applying braking force to the driver vehicle 100 and forcibly stopping the driver vehicle 100 to avoid a collision between the driver vehicle 100 and the other object.

[0206] When the driver input torque TQs_driver is greater than or equal to a predetermined relatively large torque TQth during forced steering, the vehicle collision avoidance assist device 10 may stop forced steering.

[0207] The above is an operation summary of the vehicle collision avoidance assist device 10. According to the above description, in a scenario where the execution of forced steering is preferred so that the request condition Creq is satisfied, forced steering is performed unless it is a case where the non-execution of forced steering is preferred so that the prohibition condition Cfbd is satisfied. Therefore, appropriate collision avoidance processing is performed depending on the situation around the driver's vehicle 100.

[0208] Specific operation of vehicle collision avoidance assistance device

[0209] Next, the specific operation of the vehicle collision avoidance assist device 10 will be described. The CPU of the ECU 90 of the vehicle collision avoidance assist device 10 executes the following calculation cycle at a predetermined time. Fig.10 At a predetermined time, the CPU starts Fig.10 The process starts at step 1000 in the process and proceeds to step 1005 to determine whether the vehicle speed V100 of the driver's vehicle 100 is higher than or equal to the lower limit vehicle speed Vlimit and whether the road surface gradient GR is lower than or equal to the upper limit gradient GRlimit.

[0210] When the CPU determines “YES” in step 1005 , the CPU advances the process to step 1010 to determine whether the brake pedal operation amount BP is greater than or equal to a predetermined brake pedal operation amount BPth.

[0211] When the CPU determines “YES” in step 1010 , the CPU advances the process to step 1015 to determine whether the deceleration GD of the driver's vehicle 100 is lower than or equal to the reference deceleration GDbase.

[0212] When the CPU makes a “Yes” determination in step 1015 , the CPU advances the process to step 1020 to increment the braking performance counter Cbrake. Next, the CPU advances the process to step 1030 .

[0213] When the CPU makes a “No” determination in step 1015 , the CPU proceeds with the process to step 1025 to decrement the brake performance counter Cbrake. Next, the CPU proceeds with the process to step 1030 .

[0214] When the CPU advances the process to step 1030 , the CPU determines whether the brake performance counter Cbrake is greater than or equal to a predetermined value Cbrake_th.

[0215] When the CPU determines "yes" in step 1030, the CPU sets the value of the first request condition flag Xreq_1 to "1". The first request condition flag Xreq_1 indicates whether the first request condition Creq_1 is satisfied. When the value is "1", the first request condition flag Xreq_1 indicates that the first request condition Creq_1 is satisfied. When the value is "0", the first request condition flag Xreq_1 indicates that the first request condition Creq_1 is not satisfied.

[0216] Next, the CPU advances the processing to step 1095 to temporarily terminate this routine.

[0217] When the CPU determines “NO” in step 1030 , the CPU advances the process to step 1040 to set the value of the first request condition flag Xreq_1 to “0.” Next, the CPU advances the process to step 1095 to temporarily terminate the routine.

[0218] When the CPU determines “NO” in step 1005 or step 1010 , the CPU directly advances the processing to step 1095 to temporarily terminate the routine.

[0219] The CPU executes in predetermined computation cycles Fig.11 At a predetermined time, the CPU starts Fig.11 The process starts at step 1100 in the flowchart and proceeds to step 1105 to determine whether the master cylinder pressure Pm is lower than or equal to a predetermined pressure Pm_th.

[0220] When the CPU determines "yes" in step 1105, the CPU advances the processing to step 1110 to set the value of the second request condition flag Xreq_2 to "1". The second request condition flag Xreq_2 indicates whether the second request condition Creq_2 is satisfied. When the value is "1", the second request condition flag Xreq_2 indicates that the second request condition Creq_2 is satisfied. When the value is "0", the second request condition flag Xreq_2 indicates that the second request condition Creq_2 is not satisfied.

[0221] Next, the CPU advances the processing to step 1195 to temporarily terminate the routine.

[0222] When the CPU determines “NO” in step 1105 , the CPU advances the process to step 1115 to set the value of the second request condition flag Xreq_2 to “0.” Next, the CPU advances the process to step 1195 to temporarily terminate the routine.

[0223] The CPU executes in predetermined computation cycles Fig.12 At a predetermined time, the CPU starts Fig.12 The process starts at step 1200 in the process, and proceeds to step 1205 to determine whether the absolute value of the acceleration (longitudinal acceleration Gx) of the driver's vehicle 100 is less than or equal to the upper limit acceleration Glimit.

[0224] When the CPU determines "yes" in step 1205, the CPU advances the process to step 1210 to obtain the road surface gradient GR. Next, the CPU advances the process to step 1215 to obtain the road surface inclination CT. Next, the CPU advances the process to step 1220 to determine whether the road surface gradient GR is less than zero and its absolute value is greater than or equal to the first gradient GR_1.

[0225] When the CPU determines "yes" in step 1220, the CPU advances the process to step 1225 to set the value of the third request condition flag Xreq_3 to "1". The third request condition flag Xreq_3 indicates whether the third request condition Creq_3 is satisfied. When the value is "1", the third request condition flag Xreq_3 indicates that the third request condition Creq_3 is satisfied. When the value is "0", the third request condition flag Xreq_3 indicates that the third request condition Creq_3 is not satisfied.

[0226] Next, the CPU advances the process to step 1235 .

[0227] When the CPU makes a “No” determination in step 1220 , the CPU advances the process to step 1230 to set the value of the third request condition flag Xreq_3 to “0.” Next, the CPU advances the process to step 1235 .

[0228] When the CPU advances the process to step 1235 , the CPU determines whether the road surface inclination CT is greater than or equal to a predetermined inclination CTth.

[0229] When the CPU determines "yes" in step 1235, the CPU advances the processing to step 1240 to set the value of the first prohibition condition flag Xfbd_1 to "1". The first prohibition condition flag Xfbd_1 indicates whether the first prohibition condition Cfbd_1 is satisfied. When the value is "1", the first prohibition condition flag Xfbd_1 indicates that the first prohibition condition Cfbd_1 is satisfied. When the value is "0", the first prohibition condition flag Xfbd_1 indicates that the first prohibition condition Cfbd_1 is not satisfied.

[0230] Next, the CPU advances the processing to step 1295 to temporarily terminate the routine.

[0231] When the CPU determines “NO” in step 1235 , the CPU advances the process to step 1245 to set the value of the first prohibition condition flag Xfbd_1 to “0.” Next, the CPU advances the process to step 1295 to temporarily terminate the routine.

[0232] When the CPU determines “NO” in step 1205 , the CPU directly advances the processing to step 1295 to temporarily terminate this routine.

[0233] The CPU can execute in predetermined computation cycles Fig.13 Instead of the routine shown in Fig.12 At a predetermined time, the CPU starts Fig.13 The process starts at step 1300 in the process and proceeds to step 1305 to determine whether the absolute value of the acceleration Gx of the driver's vehicle 100 is less than or equal to the upper limit acceleration Glimit.

[0234] When the CPU determines "yes" in step 1305, the CPU advances the processing to step 1310 to obtain the road surface gradient GR. Then, the CPU advances the processing to step 1315 to obtain the road surface inclination CT. Then, the CPU advances the processing to step 1320 to obtain the road surface friction coefficient μ. Then, the CPU advances the processing to step 1325 to determine whether the road surface friction coefficient μ is greater than or equal to the predetermined friction coefficient μ_th.

[0235] When the CPU determines “YES” in step 1325 , the CPU advances the process to step 1330 to determine whether the road surface gradient GR is less than zero and its absolute value is greater than or equal to the first gradient GR_1 .

[0236] When the CPU determines “YES” in step 1330 , the CPU advances the process to step 1335 to set the value of the third request condition flag Xreq_3 to “1.” Next, the CPU advances the process to step 1350 .

[0237] When the CPU makes a “No” determination in step 1330 , the CPU advances the process to step 1340 to set the value of the third request condition flag Xreq_3 to “0.” Next, the CPU advances the process to step 1350 .

[0238] When the CPU determines "No" in step 1325, the CPU advances the processing to step 1345 to execute Fig.14 When the CPU advances the processing to step 1345, the CPU Fig.14 The process starts at step 1400 in the flowchart and proceeds to step 1405 to determine whether the road surface gradient GR is less than zero and its absolute value is greater than or equal to the first gradient GR_1 and less than or equal to the second gradient GR_2.

[0239] When the CPU determines "yes" in step 1405, the CPU advances the process to step 1410 to set the value of the third request condition flag Xreq_3 to "1". Next, the CPU advances the process to step 1495. Fig.13 Step 1350 in .

[0240] When the CPU determines "No" in step 1405, the CPU advances the process to step 1415 to set the value of the third request condition flag Xreq_3 to "0". Next, the CPU advances the process to step 1495. Fig.13 Step 1350 in .

[0241] When the CPU advances the process to step 1350 , the CPU determines whether the road surface inclination CT is greater than or equal to a predetermined inclination CTth.

[0242] When the CPU determines “YES” in step 1350 , the CPU advances the process to step 1355 to set the value of the first prohibition condition flag Xfbd_1 to “1.” Next, the CPU advances the process to step 1395 to temporarily terminate the routine.

[0243] When the CPU determines “NO” in step 1350 , the CPU advances the process to step 1360 to set the value of the first prohibition condition flag Xfbd_1 to “0.” Next, the CPU advances the process to step 1395 to temporarily terminate the routine.

[0244] When the CPU determines “NO” in step 1305 , the CPU directly advances the processing to step 1395 to temporarily terminate this routine.

[0245] The CPU executes in predetermined computation cycles Fig.15 At a predetermined time, the CPU starts Fig.15The process starts at step 1500 in the process and proceeds to step 1505 to determine whether the conditions for performing vehicle stability control are met.

[0246] When the CPU determines "yes" in step 1505, the CPU advances the processing to step 1510 to start the vehicle stability control. Next, the CPU advances the processing to step 1515 to set the value of the second prohibition condition flag Xfbd_2 to "1". The second prohibition condition flag Xfbd_2 indicates whether the second prohibition condition Cfbd_2 is satisfied. When the value is "1", the second prohibition condition flag Xfbd_2 indicates that the second prohibition condition Cfbd_2 is satisfied. When the value is "0", the second prohibition condition flag Xfbd_2 indicates that the second prohibition condition Cfbd_2 is not satisfied.

[0247] Next, the CPU advances the processing to step 1595 to temporarily terminate the routine.

[0248] When the CPU determines “NO” in step 1505 , the CPU advances the process to step 1520 to determine whether a condition for terminating the vehicle stability control is satisfied.

[0249] When the CPU determines “Yes” in step 1520, the CPU advances the process to step 1525 to terminate the vehicle stability control. Next, the CPU advances the process to step 1530 to set the value of the second prohibition condition flag Xfbd_2 to “0”. Next, the CPU advances the process to step 1595 to temporarily terminate the routine.

[0250] When the CPU determines “NO” in step 1520 , the CPU directly advances the processing to step 1595 to temporarily terminate this routine.

[0251] The CPU executes in predetermined computation cycles Fig.16 At a predetermined time, the CPU starts Fig.16 The process starts at step 1600 in the flowchart and proceeds to step 1605 to determine whether the front object 200F is detected.

[0252] When the CPU determines "Yes" in step 1605, the CPU advances the process to step 1610 to acquire the predicted arrival time period TTC. Next, the CPU advances the process to step 1615 to determine whether the predicted arrival time period TTC is shorter than or equal to a predetermined predicted arrival time period TTCth.

[0253] When the CPU determines "yes" in step 1615, the CPU advances the processing to step 1620 to execute Fig.17 When the CPU advances the process to step 1620, the CPU Fig.17 The CPU starts the process at step 1700 in the embodiment and advances the process to step 1705 to set the target avoidance path Rtgt. Next, the CPU advances the process to step 1710 to determine whether the target avoidance path Rtgt can be set.

[0254] When the CPU determines "yes" in step 1710, the CPU advances the processing to step 1715 to set the value of the third prohibition condition flag Xfbd_3 to "0". The third prohibition condition flag Xfbd_3 indicates whether the third prohibition condition Cfbd_3 is satisfied. When the value is "1", the third prohibition condition flag Xfbd_3 indicates that the third prohibition condition Cfbd_3 is satisfied. When the value is "0", the third prohibition condition flag Xfbd_3 indicates that the third prohibition condition Cfbd_3 is not satisfied.

[0255] Next, the CPU advances the process to step 1795. Fig.16 Step 1625 in .

[0256] When the CPU determines "No" in step 1710, the CPU advances the process to step 1720 to set the value of the third prohibition condition flag Xfbd_3 to "1". Next, the CPU advances the process to step 1795. Fig.16 Step 1625 in .

[0257] When the CPU advances processing to Fig.16 At step 1625 in the above process, the CPU acquires the target deceleration GDtgt. Next, the CPU advances the process to step 1630 to determine whether the subsequent moving object 300 is detected.

[0258] When the CPU determines "yes" in step 1630, the CPU advances the process to step 1635 to execute Fig.18 When the CPU advances the processing to step 1635, the CPU Fig.18 The CPU starts the process at step 1800 in step 1805 to acquire the predicted travel area A100. Next, the CPU advances the process to step 1810 to acquire the predicted movement area A300. Next, the CPU advances the process to step 1815 to determine whether the predicted movement area A300 and the predicted travel area A100 overlap with each other.

[0259] When the CPU determines "yes" in step 1815, the CPU advances the processing to step 1820 to obtain the required stopping distance Dreq_stop and the driver's vehicle travel distance Dtravel. Next, the CPU advances the processing to step 1825 to determine whether the required stopping distance Dreq_stop is longer than or equal to the distance obtained by subtracting the predetermined distance ΔDth from the driver's vehicle travel distance Dtravel.

[0260] When the CPU determines "yes" in step 1825, the CPU advances the processing to step 1830 to set the value of the fourth request condition flag Xreq_4 to "1". The fourth request condition flag Xreq_4 indicates whether the fourth request condition Creq_4 is satisfied. When the value is "1", the fourth request condition flag Xreq_4 indicates that the fourth request condition Creq_4 is satisfied. When the value is "0", the fourth request condition flag Xreq_4 indicates that the fourth request condition Creq_4 is not satisfied.

[0261] Next, the CPU advances the process to step 1895. Fig.16 Step 1640 in .

[0262] When the CPU determines "No" in step 1825, the CPU advances the process to step 1835 to set the value of the fourth request condition flag Xreq_4 to "0". Next, the CPU advances the process to step 1895. Fig.16 Step 1640 in .

[0263] When the CPU determines "No" in step 1815, the CPU advances the process to step 1835 to set the value of the fourth request condition flag Xreq_4 to "0". Next, the CPU advances the process to step 1895. Fig.16 Step 1640 in .

[0264] When the CPU advances processing to Fig.16 At step 1640 in the above process, the CPU determines whether the values ​​of all the first request condition flag Xreq_1 to the fourth request condition flag Xreq_4 are "0".

[0265] When the CPU determines "YES" in step 1640, the CPU advances the process to step 1645 to perform forced braking. Next, the CPU advances the process to step 1695 to temporarily terminate the routine.

[0266] When the CPU determines “NO” in step 1640 , the CPU advances the process to step 1650 to determine whether the values ​​of all of the first to third prohibition condition flags Xfbd_1 to Xfbd_3 are “0”.

[0267] When the CPU determines "YES" in step 1650, the CPU advances the process to step 1655 to perform forced steering. Next, the CPU advances the process to step 1695 to temporarily terminate the routine.

[0268] When the CPU determines "NO" in step 1650, the CPU advances the process to step 1645 to perform forced braking. Next, the CPU advances the process to step 1695 to temporarily terminate this routine.

[0269] When the CPU determines “NO” in step 1605 or step 1615 , the CPU directly advances the processing to step 1695 to temporarily terminate the routine.

[0270] The above is the specific operation of the vehicle collision avoidance assistance device 10 .

[0271] The present invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of the present invention.

Claims

1. A vehicle collision avoidance assist device, characterized in that: The invention comprises a processor, wherein the processor is configured to: When the driver vehicle has a possibility of colliding with an object in front of the driver vehicle, performing forced braking or forced steering, wherein the forced braking is braking for avoiding a collision between the driver vehicle and the object by applying a braking force to the driver vehicle to stop the driver vehicle before the driver vehicle collides with the object, and the forced steering is steering for avoiding a collision between the driver vehicle and the object by steering the driver vehicle to pass on one side of the object; acquiring at least one of information related to a condition of the driver's vehicle and information related to a situation around the driver's vehicle; determining whether an absolute value of the acceleration of the driver's vehicle is less than or equal to a predetermined acceleration; When the absolute value of the acceleration of the driver's vehicle is less than or equal to the predetermined acceleration, acquiring the inclination of the road on which the driver's vehicle is traveling as information related to the situation around the driver's vehicle; determining, based on the acquired information, whether a request condition for requesting execution of the forced steering is satisfied and whether a prohibition condition for prohibiting execution of the forced steering is satisfied; When the inclination is greater than or equal to a predetermined inclination, determining that the prohibition condition is satisfied; When the inclination is less than the predetermined inclination, determining that the prohibition condition is not satisfied; When the request condition is not satisfied, the forced braking is performed regardless of whether the prohibition condition is satisfied; When the prohibition condition is not satisfied and the request condition is satisfied, performing the forced steering; as well as When the prohibition condition is satisfied, the forced braking is performed even if the request condition is satisfied.

2. The vehicle collision avoidance assistance device according to claim 1, characterized in that: The processor is configured as follows: acquiring, as information related to a condition of the driver vehicle, a degradation state of a braking device configured to apply the braking force to the driver vehicle; When the processor determines that the brake device is degraded based on the degradation state of the brake device, determining that the request condition is satisfied; as well as When the processor determines that the brake device is not degraded based on the degradation state of the brake device, it is determined that the request condition is not satisfied.

3. The vehicle collision avoidance assistance device according to claim 1, characterized in that: The processor is configured as follows: acquiring a degradation state of a brake pad of a brake device configured to apply the braking force to the driver vehicle as information related to a condition of the driver vehicle; When the processor determines that the brake pad is degraded based on the degraded state of the brake pad, determining that the request condition is satisfied; as well as When the processor determines that the brake pad is not degraded based on the degradation state of the brake pad, it is determined that the request condition is not satisfied.

4. The vehicle collision avoidance assistance device according to claim 1, characterized in that: The processor is configured as follows: acquiring, as information related to a condition of the driver's vehicle, a deterioration state of brake oil used to operate a brake device configured to apply the braking force to the driver's vehicle; When the processor determines that the brake oil is deteriorated based on the deterioration state of the brake oil, determining that the request condition is satisfied; as well as When the processor determines that the brake oil is not degraded based on the deterioration state of the brake oil, it is determined that the request condition is not satisfied.

5. The vehicle collision avoidance assistance device according to claim 1, characterized in that: The processor is configured as follows: controlling operation of a brake device configured to apply the braking force to the driver vehicle so that the brake device applies the braking force to the driver vehicle based on an operation amount of a brake pedal of the driver vehicle; when the brake pedal is operated by a driver of the driver vehicle, acquiring a deceleration of the driver vehicle as information related to a condition of the driver vehicle; determining that the request condition is satisfied when the deceleration is lower than or equal to a reference deceleration set based on the operation amount of the brake pedal operated by the driver; as well as When the deceleration is higher than the reference deceleration, it is determined that the request condition is not satisfied.

6. The vehicle collision avoidance assistance device according to claim 5, characterized in that: The processor is configured to obtain a vehicle speed of the driver's vehicle and a gradient of a road surface on which the driver's vehicle is traveling; and The processor is configured not to obtain the deceleration of the driver's vehicle when the vehicle speed is lower than a reference vehicle speed or the gradient is greater than a reference gradient.

7. The vehicle collision avoidance assistance device according to claim 1, characterized in that: The processor is configured as follows: obtaining a weight of the driver's vehicle as information related to a condition of the driver's vehicle; When the processor determines that the weight is greater than or equal to a predetermined weight, determining that the request condition is satisfied; as well as When the processor determines that the weight is less than the predetermined weight, it determines that the request condition is not satisfied.

8. The vehicle collision avoidance assistance device according to claim 1, characterized in that: The processor is configured as follows: acquiring the number of passengers of the driver's vehicle as information related to the condition of the driver's vehicle; When the number of passengers is greater than or equal to a predetermined number, determining that the request condition is satisfied; as well as When the number of occupants is smaller than the predetermined number, it is determined that the request condition is not satisfied.

9. The vehicle collision avoidance assistance device according to claim 1, characterized in that: The processor is configured as follows: acquiring a pressure in a master cylinder of a brake device as information related to a condition of the driver's vehicle, the brake device being configured to apply the braking force to the driver's vehicle; when the pressure in the master cylinder is lower than or equal to a predetermined pressure, determining that the request condition is satisfied; as well as When the pressure in the master cylinder is higher than the predetermined pressure, it is determined that the request condition is not satisfied.

10. The vehicle collision avoidance assistance device according to claim 1, characterized in that: The processor is configured as follows: Under the assumption that the forced braking is performed, determining whether a subsequent moving object moving behind the driver's vehicle in the same direction as the driving direction of the driver's vehicle has a collision possibility with the driver's vehicle; acquiring a determination result as to whether the subsequent moving object has the collision possibility as information related to the situation around the driver's vehicle; When the processor determines that the subsequent moving object has a possibility of colliding with the driver's vehicle, determining that the request condition is satisfied; as well as When the processor determines that the subsequent moving object does not have a possibility of colliding with the driver's vehicle, it is determined that the request condition is not satisfied.

11. The vehicle collision avoidance assistance device according to claim 10, characterized in that: The processor is configured as follows: Obtaining the position of the subsequent moving object; When the processor determines that the subsequent moving object exists within a predetermined distance from the driver's vehicle based on the position of the subsequent moving object, determining that the subsequent moving object has the collision possibility; as well as When the processor determines that the subsequent moving object does not exist within a predetermined distance from the driver's vehicle based on the position of the subsequent moving object, it is determined that the subsequent moving object does not have the collision possibility.

12. The vehicle collision avoidance assistance device according to claim 10, characterized in that: The processor is configured as follows: Acquiring a predicted driving area of ​​the driver's vehicle; Acquiring the position of the subsequent moving object and the predicted moving area of ​​the subsequent moving object; determining that the subsequent moving object has the collision possibility when the processor determines that the predicted movement area and the predicted travel area overlap each other and determines that the subsequent moving object exists within a predetermined distance from the driver's vehicle based on the position of the subsequent moving object; When the processor determines that the predicted movement area and the predicted travel area overlap each other and determines based on the position of the subsequent moving object that the subsequent moving object does not exist within the range of the predetermined distance from the driver's vehicle, determining that the subsequent moving object does not have the collision possibility; as well as When the processor determines that the predicted movement area and the predicted travel area do not overlap with each other, the subsequent moving object is determined not to have the collision possibility regardless of whether the subsequent moving object exists within the range of the predetermined distance from the driver's vehicle.

13. The vehicle collision avoidance assistance device according to claim 1, characterized in that: The processor is configured as follows: acquiring a gradient of a road surface on which the driver's vehicle is traveling as information related to conditions surrounding the driver's vehicle; When the gradient is less than zero and the absolute value of the gradient is greater than or equal to the first gradient, determining that the request condition is satisfied; as well as When the gradient is greater than or equal to zero, or when the absolute value of the gradient is less than the first gradient and the gradient is less than zero, it is determined that the request condition is not satisfied.

14. The vehicle collision avoidance assistance device according to claim 1, characterized in that: The processor is configured as follows: acquiring a gradient of a road surface on which the driver's vehicle is traveling and a friction coefficient of the road surface as information related to conditions around the driver's vehicle; When the friction coefficient is less than or equal to a predetermined friction coefficient, the gradient is less than zero, and the absolute value of the gradient is greater than or equal to a first gradient, determining that the request condition is satisfied; When the friction coefficient is less than or equal to the predetermined friction coefficient and the gradient is greater than or equal to zero, or when the absolute value of the gradient is less than the first gradient and the gradient is less than zero, determining that the request condition is not satisfied; When the friction coefficient is greater than the predetermined friction coefficient, the gradient is less than zero, the absolute value of the gradient is greater than or equal to the first gradient, and the absolute value of the gradient is less than or equal to a second gradient greater than the first gradient, determining that the request condition is satisfied; as well as When the friction coefficient is greater than the predetermined friction coefficient and the gradient is greater than or equal to zero, or when the gradient is less than zero and the absolute value of the gradient is less than the first gradient or greater than the second gradient, it is determined that the request condition is not satisfied.

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