Vehicle control device

Abstract

To set a control termination condition for deceleration control so as to appropriately handle a case where the possibility of a collision increased again after the end of deceleration control.SOLUTION: A vehicle control device (1A, 1B, 1C) includes: a braking device (40) for braking an own vehicle (100); and a control device (10) configured to start deceleration control for controlling the braking device (40) so as to decelerate the own vehicle (100) when it is determined that possibility of a collision between the own vehicle (100) and a target ahead (OB), which is a target existing in the traveling direction of the own vehicle (100), is high, and to end the deceleration control when a predetermined control termination condition holds during the execution of deceleration control. The control termination condition includes an allowance level condition which holds when an allowance level representing a magnitude of allowance for avoiding a collision between the own vehicle (100) and the preceding target (OB) after deceleration control is ended is equal to or higher than a predetermined threshold allowance level.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a vehicle control device capable of performing deceleration control.

Background Art

[0002] Patent Document 1 discloses a vehicle control device capable of performing deceleration control. When the vehicle control device disclosed in Patent Document 1 determines that there is a high possibility of collision between the host vehicle and an object (hereinafter referred to as a preceding object) existing in the traveling direction of the host vehicle, it starts deceleration control to decelerate the host vehicle by operating a braking device. This deceleration control ends when a predetermined control end condition is satisfied. Patent Document 1 exemplifies, as a predetermined control end condition, a condition that the speed of the host vehicle is lower than the speed of the preceding object.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The vehicle control device according to Patent Document 1 starts deceleration control when it determines that there is a high possibility of collision between the host vehicle and a preceding object, and ends the deceleration control when the speed of the host vehicle becomes lower than the speed of the preceding object during the execution of the deceleration control. In this case, there is a possibility that the possibility of collision between the host vehicle and the preceding object may increase again after the deceleration control ends due to the behavior of the preceding object. According to the vehicle control device according to Patent Document 1, since the countermeasure in the case where the possibility of collision increases again after the end of the deceleration control is not considered, there is room for improvement in the setting of the control end condition of the deceleration control.

[0005] An object of the present disclosure is to provide a vehicle control device capable of solving the above-described problems.

[0006] The vehicle control device (1A, 1B, 1C) according to the present disclosure includes a braking device (40) that brakes the host vehicle (100), and a control device (10) configured to start deceleration control for controlling the braking device (40) so that the host vehicle (100) decelerates when it is determined that there is a high possibility of collision between the host vehicle (100) and a preceding target (OB) that is a target existing in the traveling direction of the host vehicle (100), and to end the deceleration control when a predetermined control end condition is satisfied during the execution of the deceleration control. The control end condition includes a margin condition that is satisfied when a margin representing the magnitude of the margin for avoiding a collision between the host vehicle (100) and the preceding target (OB) after ending the deceleration control is equal to or greater than a predetermined threshold margin.

[0007] According to the vehicle control device of the present disclosure, the deceleration control is ended when there is a margin for avoiding a collision between the host vehicle and the preceding target after ending the deceleration control. Therefore, even if the possibility of collision between the host vehicle and the preceding target increases again after the end of the deceleration control, it is possible to avoid a collision between the host vehicle and the preceding target with a margin.

[0008] Further, the vehicle control device according to the present disclosure includes a braking device (40) that brakes the host vehicle (100), and a control device (10) configured to start deceleration control for controlling the braking device (40) so that the host vehicle (100) decelerates when it is determined that there is a high possibility of collision between the host vehicle (100) and a preceding target (OB) that is a target existing in the traveling direction of the host vehicle (100), and to end the deceleration control when a predetermined control end condition is satisfied during the execution of the deceleration control. The control device (10) determines that the control end condition is satisfied when a relative speed condition that is satisfied when the relationship between the speed of the host vehicle (100) and the speed of the preceding target (OB) is in a relationship that enables avoidance of a collision between the host vehicle (100) and the preceding target (OB) is satisfied during the execution of the deceleration control, and when a margin condition that is satisfied when a margin representing the magnitude of the margin for avoiding a collision between the host vehicle (100) and the preceding target (OB) after ending the deceleration control is equal to or greater than a predetermined threshold margin is satisfied.

[0009] According to the vehicle control device related to the present disclosure, during the execution of deceleration control, the relationship between the speed of the host vehicle and the speed of the preceding object is such that it is possible to avoid a collision between the host vehicle and the preceding object, and the deceleration control is terminated when there is a margin to avoid a collision between the host vehicle and the preceding object even after the deceleration control is terminated. Therefore, even if the possibility of a collision between the host vehicle and the preceding object increases again after the deceleration control is terminated, it is possible to avoid a collision between the host vehicle and the preceding object with a margin.

[0010] In one aspect of the vehicle control device related to the present disclosure, the control device (10) determines that the margin condition is satisfied when the acceleration condition that holds when the acceleration (α0) of the preceding object (OB) is greater than or equal to a predetermined threshold acceleration (αth) is satisfied during the execution of deceleration control. That is, the acceleration condition is the margin condition, and the acceleration (α0) of the preceding object (OB) is the margin. Therefore, according to this aspect, the control termination condition of the deceleration control includes the acceleration condition that holds when the acceleration (α0) of the preceding object (OB) is greater than or equal to a predetermined threshold acceleration (αth). In this case, the acceleration (α0) of the preceding object (OB) may be the acceleration (longitudinal acceleration) acting in the traveling direction (front-rear direction) of the preceding object (OB).

[0011] When the acceleration (longitudinal acceleration) of the preceding object is greater than or equal to a predetermined threshold acceleration during the execution of deceleration control, the preceding object moves away from the host vehicle that is executing deceleration control. Therefore, when the acceleration condition is satisfied and the deceleration control is terminated during the execution of deceleration control, even if the possibility of a collision between the host vehicle and the preceding object increases again due to the subsequent behavior of the preceding object, it is possible to avoid a collision between the host vehicle and the preceding object with a margin.

[0012] Also, when the acceleration condition is not satisfied, for example, when the leading object is decelerating, the control end condition is not satisfied, so the deceleration control continues. Therefore, it is possible to effectively prevent the possibility of the host vehicle colliding with the leading object again after the deceleration control ends due to the deceleration control ending when the leading object is decelerating. Furthermore, by ending the deceleration control during the deceleration of the leading object, it is possible to effectively prevent the possibility of collision between the host vehicle and the leading object increasing again after the deceleration control ends and the deceleration control being restarted, that is, the end and start of the deceleration control being repeated.

[0013] The threshold acceleration may be set so that the margin condition is satisfied when the leading object has an acceleration of 0 or positive. In other words, the margin condition may be a condition that is satisfied when the leading object is not decelerating. This is because if the leading object is not decelerating during the deceleration control, it is considered that the leading object will not approach the host vehicle that is decelerating due to the deceleration control.

[0014] In another aspect of the vehicle control device according to the present disclosure, during the execution of the deceleration control, when the relative distance condition that is satisfied when the relative distance (Lr) between the host vehicle (100) and the leading object (OB) is equal to or greater than a predetermined threshold distance (Lth) is satisfied, it is determined that the margin condition is satisfied. That is, the relative distance condition is the margin condition, and the relative distance (Lr) is the margin. Therefore, according to this aspect, the control end condition of the deceleration control includes the relative distance condition that is satisfied when the relative distance (Lr) between the host vehicle (100) and the leading object (OB) is equal to or greater than a predetermined threshold distance (Lth).

[0015] When the relative distance between the host vehicle and the preceding object target is equal to or greater than a predetermined threshold distance during the execution of the deceleration control, even if the deceleration control is terminated, a distance margin for avoiding a collision between the host vehicle and the preceding object target is ensured. Therefore, when the relative distance condition is satisfied during the execution of the deceleration control and the deceleration control is terminated, even if the possibility of a collision between the host vehicle and the preceding object target increases again due to the behavior of the preceding object target thereafter, there is a distance margin until the host vehicle collides with the preceding object target, so the collision between the host vehicle and the preceding object target can be avoided with a margin.

[0016] In another aspect of the vehicle control device according to the present disclosure, during the execution of the deceleration control, when a predicted time condition that is satisfied when a predicted time (TTCv) required for the host vehicle (100) to reach the preceding object target (OB) is equal to or greater than a threshold time (TTCvth) when the deceleration of the host vehicle (100) is set to 0 is satisfied, it is determined that the margin condition is satisfied. That is, the predicted time condition is the margin condition, and the predicted time is the margin. Therefore, according to this aspect, the control termination condition of the deceleration control includes a predicted time condition that is satisfied when a predicted time (TTCv) required for the host vehicle (100) to reach the preceding object target (OB) is equal to or greater than a threshold time (TTCvth) when the deceleration of the host vehicle (100) is set to 0.

[0017] When the predicted time is equal to or greater than the threshold time during the execution of the deceleration control, even if the deceleration control is terminated, a time margin for avoiding a collision between the host vehicle and the preceding object target is ensured. Therefore, when the predicted time condition is satisfied during the execution of the deceleration control and the deceleration control is terminated, even if the possibility of a collision between the host vehicle and the preceding object target increases again due to the behavior of the preceding object target thereafter, there is a time margin until the host vehicle collides with the preceding object target, so the collision between the host vehicle and the preceding object target can be avoided with a margin.

[0018] In another aspect of the vehicle control device according to the present disclosure, during the execution of the deceleration control, when the speed (V1) of the host vehicle (100) falls below the speed (V0) of the preceding object (OB) by a predetermined speed, it is determined that the relative speed condition is satisfied. According to this, based on the speed of the host vehicle and the speed of the preceding object, it is possible to appropriately determine that it is possible to avoid a collision between the host vehicle and the preceding object.

[0019] In another aspect of the vehicle control device according to the present disclosure, when the relative speed condition is satisfied and the target speed condition that is satisfied when the speed (V0) of the preceding object (OB) is equal to or higher than a predetermined lower limit speed (Vd) is satisfied, and when the margin condition is satisfied, it is determined that the control end condition is satisfied. According to this, the target speed condition that is satisfied when the speed of the preceding object is equal to or higher than the lower limit speed is included in the control end condition of the deceleration control. Therefore, even if the relative speed condition and the margin condition are satisfied, the deceleration control is not terminated unless the preceding object is moving at a speed equal to or higher than the lower limit speed. In other words, when the relative speed condition and the margin condition are satisfied and the preceding object is moving at a relatively high speed equal to or higher than the lower limit speed, the deceleration control is not continued. Therefore, when the preceding object and the host vehicle are moving at a relatively high speed, the deceleration control is continued to avoid the host vehicle from colliding with an object (for example, a following vehicle) that is moving in the same direction as the traveling direction of the host vehicle behind the host vehicle.

[0020] Further, the vehicle control method according to the present disclosure includes a start step (S106) of starting deceleration control for controlling the braking device (40) of the host vehicle (100) so that the host vehicle (100) decelerates when it is determined that there is a high possibility of collision between the host vehicle (100) and a preceding object (OB) that is an object existing in the traveling direction of the host vehicle (100), and an end step (S110) of ending the deceleration control when a predetermined control end condition is satisfied during the execution of the deceleration control. The control end condition includes a margin condition that is satisfied when a margin representing the magnitude of the margin for avoiding a collision between the host vehicle (100) and the preceding object (OB) after ending the deceleration control is equal to or greater than a predetermined threshold margin.

[0021] In addition, the vehicle control method according to the present disclosure includes a start step (S106) of starting deceleration control for controlling a braking device (40) of the host vehicle (100) so that the host vehicle (100) decelerates when it is determined that there is a high possibility of collision between the host vehicle (100) and a preceding target (OB) that is a target existing in the traveling direction of the host vehicle (100), and an end step (S110) of ending the deceleration control when a predetermined control end condition is satisfied during the execution of the deceleration control. The control end condition is satisfied when, during the execution of the deceleration control, a relative speed condition that is satisfied when the relationship between the speed (V1) of the host vehicle (100) and the speed (V0) of the preceding target (OB) is a relationship in which it is possible to avoid a collision between the host vehicle (100) and the preceding target (OB) is satisfied, and a margin condition that is satisfied when a margin representing the magnitude of the margin for avoiding a collision between the host vehicle (100) and the preceding target (OB) after ending the deceleration control is equal to or greater than a predetermined threshold margin is satisfied.

[0022] According to these vehicle control methods, deceleration control is ended when there is a margin for avoiding a collision between the host vehicle and the preceding target after ending the deceleration control. Therefore, even if the possibility of collision between the host vehicle and the preceding target increases again after the end of the deceleration control, it is possible to avoid a collision between the host vehicle and the preceding target with a margin.

[0023] In addition, the program according to the present disclosure causes a computer provided in the host vehicle (100) to execute a start step (S106) of starting deceleration control for controlling a braking device (40) of the host vehicle (100) so that the host vehicle (100) decelerates when it is determined that there is a high possibility of collision between the host vehicle (100) and a preceding target (OB) that is a target existing in the traveling direction of the host vehicle (100), and an end step (S110) of ending the deceleration control when a predetermined control end condition is satisfied during the execution of the deceleration control. The control end condition includes a margin condition that is satisfied when a margin representing the magnitude of the margin for avoiding a collision between the host vehicle (100) and the preceding target (OB) after ending the deceleration control is equal to or greater than a predetermined threshold margin.

[0024] In addition, when it is determined that the possibility of collision between the host vehicle (100) and a preceding target (OB) which is an object existing in the traveling direction of the host vehicle (100) is high, the program according to the present disclosure causes a computer provided in the host vehicle (100) to start deceleration control for controlling a braking device (40) of the host vehicle (100) so that the host vehicle (100) decelerates, and an end step (S110) for ending the deceleration control when a predetermined control end condition is satisfied during the execution of the deceleration control. The control end condition is satisfied when a relative speed condition which is satisfied when the relationship between the speed (V1) of the host vehicle (100) and the speed (V0) of the preceding target (OB) is a relationship in which collision between the host vehicle (100) and the preceding target (OB) can be avoided is satisfied during the execution of the deceleration control, and a margin condition which is satisfied when a margin representing the magnitude of a margin for avoiding collision between the host vehicle (100) and the preceding target (OB) after ending the deceleration control is equal to or greater than a predetermined threshold margin is satisfied.

[0025] By causing the computer provided in the host vehicle to execute these programs, the deceleration control is ended when there is a margin for avoiding collision between the host vehicle and the preceding target after ending the deceleration control. For this reason, even if the possibility of collision between the host vehicle and the preceding target increases again after ending the deceleration control, it is possible to avoid collision between the host vehicle and the preceding target with a margin.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

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MODE FOR CARRYING OUT THE INVENTION

[0027] (First Embodiment) The vehicle control device according to the present disclosure is mounted on a vehicle. Hereinafter, the vehicle equipped with the vehicle control device according to the present disclosure is referred to as the host vehicle 100. Therefore, as shown in FIG. 1, the vehicle control device 1A according to the first embodiment of the present disclosure is mounted on the host vehicle 100.

[0028] The vehicle control device 1A includes a vehicle control ECU 10, an in-vehicle sensor 20, a drive device 30, a braking device 40, and a steering device 50.

[0029] The vehicle control ECU 10 is a control device having a microcomputer as a main part. The vehicle control ECU 10 includes a CPU 11, a ROM 12, a RAM 13, a non-volatile memory 14, an interface 15, etc. The CPU 11 is a processor for realizing various functions by executing instructions (programs, routines) stored in the ROM 12. Note that ECU is an abbreviation for Electronic Control Unit.

[0030] The drive device 30 generates a driving force and applies the driving force to the drive wheels of the host vehicle 100. The drive device 30 includes a drive ECU 31, a drive actuator 32, a drive source 33, a transmission 34, and a driving force transmission mechanism (not shown) that transmits the driving force to the drive wheels. The drive ECU 31 is electrically connected to the drive actuator 32 so as to be able to control the operation of the drive actuator 32. The drive actuator 32 is configured to be able to adjust the driving force of the drive source 33 by operating.

[0031] The drive ECU 31 controls the driving force generated by the drive source 33 by controlling the operation of the drive actuator 32. The driving force generated by the drive source 33 is transmitted to the drive wheels of the host vehicle 100 via the transmission 34 and the driving force transmission mechanism. Therefore, the drive ECU 31 can control the driving force of the host vehicle 100 by controlling the drive actuator 32. Further, the drive actuator 32 also operates when the accelerator pedal 35 provided in the host vehicle 100 is operated. Therefore, the host vehicle 100 can generate a driving force corresponding to the operation amount of the accelerator pedal 35.

[0032] Note that when the drive source 33 is an internal combustion engine, the drive ECU 31 controls the driving force generated by the internal combustion engine. Also, when the host vehicle 100 is a hybrid vehicle (HEV), the drive ECU 31 controls the driving force generated by either one or both of the internal combustion engine and the electric motor as the drive source 33. When the host vehicle 100 is a battery electric vehicle (BEV), the drive ECU 31 controls the driving force generated by the electric motor as the drive source 33.

[0033] The braking device 40 applies a braking force to the wheels of the host vehicle 100. The braking device 40 includes a braking ECU 41, a braking actuator 42, and a braking mechanism 43. The braking ECU 41 is electrically connected to the braking actuator 42 so as to be able to control the operation of the braking actuator 42. The braking actuator 42 includes a known hydraulic circuit and includes a reservoir, an oil pump, various valve devices, etc. not shown in the figure. The braking mechanism 43 includes a brake disk, a caliper, a piston, and brake pads, and generates a frictional braking force when the brake pads are pressed against the brake disk by the hydraulic pressure (i.e., the braking pressure) supplied from the braking actuator 42. The host vehicle 100 is braked by the frictional braking force generated by the braking mechanism 43.

[0034] The braking actuator 42 adjusts the hydraulic pressure (braking pressure) supplied to the braking mechanism 43 in accordance with an instruction from the braking ECU 41. The frictional braking force generated on the wheels changes according to the braking pressure. Therefore, the braking ECU 41 can control the braking force of the host vehicle 100 by controlling the braking actuator 42. Further, the braking actuator 42 also operates when the brake pedal 44 provided on the host vehicle 100 is operated. Therefore, the host vehicle 100 can generate a braking force corresponding to the operation amount of the brake pedal 44.

[0035] The steering device 50 is a device for steering the host vehicle 100. The steering device 50 includes a steering ECU 51, a steering actuator 52, and a steering mechanism 53. The steering ECU 51 is electrically connected to the steering actuator 52 so as to be able to control the operation of the steering actuator 52. The steering mechanism 53 includes a steering wheel 53a, a steering shaft 53b, a steering gear box (not shown), a tie rod (not shown), and the like. The steering mechanism 53 is configured to be able to steer the steered wheels by a rotational operation of the steering wheel 53a. The steering actuator 52 is, for example, an electric motor, and is connected to the steering mechanism 53 so as to be able to apply power for steering the steered wheels to the steering mechanism 53. This steering actuator 52 can also be configured to generate a steering assist force for assisting the operation of the steering wheel 53a by the driver. The steering ECU 51 controls the operation of the steering mechanism 53 by controlling the operation of the steering actuator 52. Therefore, the steering ECU 51 can control the steering angle of the steered wheels of the host vehicle 100 by controlling the steering actuator 52.

[0036] The in-vehicle sensor 20 includes an accelerator pedal operation amount sensor 21, a brake pedal operation amount sensor 22, a steering angle sensor 23, a steering torque sensor 24, a vehicle momentum detection sensor 25, and a surrounding information detection sensor 26.

[0037] The accelerator pedal operation amount sensor 21 detects the operation amount of the accelerator pedal 35. The accelerator pedal operation amount sensor 21 is electrically connected to the vehicle control ECU 10. The accelerator pedal operation amount sensor 21 transmits information representing the detected operation amount of the accelerator pedal 35 to the vehicle control ECU 10. The vehicle control ECU 10 acquires the operation amount of the accelerator pedal 35 as the accelerator pedal operation amount based on the information received from the accelerator pedal operation amount sensor 21.

[0038] The brake pedal operation amount sensor 22 detects the operation amount of the brake pedal 44. The brake pedal operation amount sensor 22 is electrically connected to the vehicle control ECU 10. The brake pedal operation amount sensor 22 transmits information representing the detected operation amount of the brake pedal 44 to the vehicle control ECU 10. The vehicle control ECU 10 acquires the operation amount of the brake pedal 44 as the brake pedal operation amount based on the information received from the brake pedal operation amount sensor 22.

[0039] The steering angle sensor 23 detects the rotation angle of the steering shaft 53b with respect to the neutral position. The steering angle sensor 23 is electrically connected to the vehicle control ECU 10. The steering angle sensor 23 transmits information representing the detected rotation angle of the steering shaft 53b to the vehicle control ECU 10. The vehicle control ECU 10 acquires the rotation angle of the steering shaft 53b as the steering angle θ1 based on the information received from the steering angle sensor 23.

[0040] The steering torque sensor 24 detects the torque input by the driver to the steering shaft 53b via the steering wheel 53a. The steering torque sensor 24 is electrically connected to the vehicle control ECU 10. The steering torque sensor 24 transmits information representing the detected torque to the vehicle control ECU 10. The vehicle control ECU 10 acquires the torque input by the driver to the steering shaft 53b via the steering wheel 53a as the steering torque based on the information received from the steering torque sensor 24.

[0041] The vehicle momentum detection sensor 25 detects the momentum of the host vehicle 100. The vehicle momentum detection sensor 25 includes a vehicle speed sensor 251, an acceleration sensor 252, and a yaw rate sensor 253.

[0042] The vehicle speed sensor 251 detects the traveling speed of the host vehicle 100, that is, the host vehicle speed V1 which is the speed in the traveling direction of the host vehicle 100. The vehicle speed sensor 251 is, for example, a wheel speed sensor that detects the rotational speed of the wheels of the host vehicle 100. The vehicle speed sensor 251 is electrically connected to the vehicle control ECU 10. The vehicle speed sensor 251 transmits information representing the detected host vehicle speed V1 to the vehicle control ECU 10. The vehicle control ECU 10 acquires the host vehicle speed V1 based on the information received from the vehicle speed sensor 251.

[0043] The acceleration sensor 252 detects the acceleration (longitudinal acceleration) acting in the traveling direction (front-rear direction) of the host vehicle 100. The acceleration sensor 252 is electrically connected to the vehicle control ECU 10. The acceleration sensor 252 transmits information representing the detected acceleration to the vehicle control ECU 10. The vehicle control ECU 10 acquires the acceleration α1 acting in the traveling direction (front-rear direction) of the host vehicle 100 based on the information received from the acceleration sensor 252. The acceleration sensor 252 detects the acceleration when the host vehicle 100 accelerates forward as a positive acceleration, and detects the acceleration when the host vehicle 100 accelerates rearward, that is, the deceleration, as a negative acceleration. In this specification, "acceleration" is longitudinal acceleration unless otherwise specified.

[0044] The yaw rate sensor 253 detects the yaw rate of the host vehicle 100. The yaw rate sensor 253 is electrically connected to the vehicle control ECU 10. The yaw rate sensor 253 transmits information representing the detected yaw rate to the vehicle control ECU 10. The vehicle control ECU 10 acquires the yaw rate Y1 of the host vehicle 100 based on the information received from the yaw rate sensor 253.

[0045] The surrounding information detection sensor 26 detects information regarding the environment around the host vehicle 100. In the present embodiment, the surrounding information detection sensor 26 includes a radio wave sensor and an image sensor. The radio wave sensor is, in the present embodiment, a radar sensor 261 that detects surrounding information using radar as the radio wave. The image sensor is, in the present embodiment, a camera sensor 262. The surrounding information detection sensor 26 may include a sound wave sensor such as an ultrasonic sensor (clearance sonar) or an optical sensor such as LiDAR, or may include a ToF sensor (Time of Flight sensor).

[0046] The radar sensor 261 is electrically connected to the vehicle control ECU 10. The radar sensor 261 transmits a radar (for example, millimeter wave radar) and receives the radar (reflected wave) reflected by an object. The radar sensor 261 transmits object detection information obtained from the transmitted radar and the received radar to the vehicle control ECU 10. The radar sensor 261 detects, for example, an object existing around the host vehicle 100 based on the relationship between the transmitted radar and the received radar, and transmits information regarding the detected object to the vehicle control ECU 10 as detection information. The vehicle control ECU 10 acquires information regarding an object existing around the host vehicle 100 based on the detection information received from the radar sensor 261.

[0047] The radar sensor 261 includes a front radar sensor. FIG. 2 is a diagram showing the mounting positions of the front radar sensor and the front camera sensor described later on the host vehicle 100. As shown in FIG. 2, the front radar sensor 261a is mounted substantially at the center of the front end portion (e.g., the front bumper) of the host vehicle 100, emits radar waves into the front area of the host vehicle 100, and receives reflected waves from the front area of the host vehicle 100. The front radar sensor 261a detects a target existing in the front area of the host vehicle 100 based on the relationship between the transmitted wave and the received wave, and transmits information about the detected target to the vehicle control ECU 10. The vehicle control ECU 10 acquires information about a target existing in front (in the traveling direction) of the host vehicle 100 based on the information received from the front radar sensor 261a. For example, the vehicle control ECU 10 acquires the type of a preceding target that is a target existing in front (in the traveling direction) of the host vehicle 100, the relative distance Lr between the host vehicle 100 and the preceding target, the relative speed Vr, etc. based on the information received from the front radar sensor 261a.

[0048] The camera sensor 262 is electrically connected to the vehicle control ECU 10. The camera sensor 262 includes a camera device and an image analysis device. The camera device is, for example, a digital camera incorporating an image sensor composed of a CCD (Charge Coupled Device) or a CIS (CMOS Image Sensor). The camera device captures the peripheral area of the host vehicle 100 at a predetermined frame rate to respectively acquire image data. The camera device transmits each piece of image data to the image analysis device. The image analysis device analyzes the acquired image data, acquires information about a target and a display existing around the host vehicle 100 from the image, and transmits the information to the vehicle control ECU 10. The vehicle control ECU 10 acquires information about a target and a display existing around the host vehicle 100 based on the information received from the image analysis device.

[0049] The camera sensor 262 includes a front camera sensor. As shown in FIG. 2, the front camera sensor 262a is attached to approximately the center of the upper part of the front window of the host vehicle 100, captures the front area of the host vehicle 100, and acquires image data. The front camera sensor 262a analyzes the acquired image data, obtains information regarding targets and displays existing in front (the traveling direction) of the host vehicle 100 from the image, and transmits the information to the vehicle control ECU 10. The vehicle control ECU 10 obtains information regarding targets and displays existing in front (the traveling direction) of the host vehicle 100 based on the information received from the front camera sensor 262a. For example, the vehicle control ECU 10 obtains the lane in which the host vehicle 100 is traveling, the type of the preceding target, etc. based on the information received from the front camera sensor 262a.

[0050] Note that the vehicle control ECU 10 may also integrate the information received from the front radar sensor 261a and the information received from the front camera sensor 262a to obtain information regarding the preceding target.

[0051] The radar sensor 261 may include a rear radar sensor that transmits radar to the rear of the host vehicle 100, a side radar sensor that transmits radar to the side of the host vehicle 100, etc. The camera sensor 262 may include a rear camera sensor that captures the rear area of the host vehicle, a side camera sensor that captures the side area of the host vehicle 100, etc.

[0052] As shown in FIG. 1, the vehicle control ECU 10 is connected to other ECUs including the drive ECU 31, the brake ECU 41, and the steering ECU 51 via a CAN (Controller Area Network) so as to be able to transmit and receive information mutually. Therefore, each ECU can obtain the information acquired by other ECUs through the CAN.

[0053] In addition, the vehicle control device 1A is configured to be able to execute automatic driving control so that the host vehicle 100 executes automatic driving. For example, the vehicle control ECU 10 transmits control signals to the drive ECU 31, the brake ECU 41, and the steering ECU 51 via the CAN respectively based on the information obtained from the in-vehicle sensor 20. The drive ECU 31 controls the drive actuator 32 based on the control signal received from the vehicle control ECU 10. The brake ECU 41 controls the brake actuator 42 based on the control signal received from the vehicle control ECU 10. The steering ECU 51 controls the steering actuator 52 based on the control signal received from the vehicle control ECU 10. Thereby, automatic driving is realized.

[0054] (Outline of the operation of automatic brake control) When the host vehicle 100 is executing automatic driving or when the driver is manually driving the host vehicle 100, the vehicle control ECU 10 starts automatic brake control when it determines that there is a high possibility of collision between the host vehicle 100 and a preceding target OB which is a target existing in the traveling direction of the host vehicle 100. This automatic brake control is a deceleration control that controls the braking device 40 so that the host vehicle 100 decelerates. In addition, the vehicle control ECU 10 is configured to end the automatic brake control when a predetermined control end condition is satisfied during the execution of the automatic brake control. The outline of the operation of this automatic brake control will be described.

[0055] During the running of the host vehicle 100, the vehicle control ECU 10 calculates the predicted running area of the host vehicle 100. FIG. 3 is a diagram showing the predicted running area of the host vehicle 100. As shown in FIG. 3, the predicted running area A100 is an area having a width equal to the vehicle width of the host vehicle 100 with the predicted running path R100 of the host vehicle 100 as the center. The predicted running path R100 is a running path predicted that the center portion in the vehicle width direction of the host vehicle 100 will run when the host vehicle 100 runs while maintaining the current steering angle θ1 or yaw rate Y1. Therefore, although the predicted running path R100 shown in FIG. 3 is linear, it may be curved depending on the situation.

[0056] The vehicle control ECU 10 calculates a predicted travel route R100, which is the route along which the center part of the host vehicle 100 travels in the vehicle width direction, based on the host vehicle speed V1, the acceleration α1, and the steering angle θ1 (or the yaw rate Y1). Further, the vehicle control ECU 10 calculates a predicted travel area A100 based on the calculated predicted travel route R100 and the value of the vehicle width of the host vehicle 100.

[0057] Based on the information acquired from the front radar sensor 261a and the front camera sensor 262a, the vehicle control ECU 10 determines whether there is an object within the predicted travel area A100, that is, in the traveling direction of the host vehicle 100. When the vehicle control ECU 10 determines that there is an object within the predicted travel area A100, it sets that object as a preceding object OB existing in the traveling direction of the host vehicle 100.

[0058] When the preceding object OB exists, the vehicle control ECU 10 acquires a relative distance Lr between the host vehicle 100 and the preceding object OB, and a relative speed Vr, which is the difference between the speed V0 of the preceding object OB and the host vehicle speed V1, based on the information acquired from the front radar sensor 261a and the front camera sensor 262a. The relative distance Lr and the relative speed Vr can be acquired, for example, based on the relationship between the radar (transmitted wave) transmitted by the front radar sensor 261a and the received radar (reflected wave). At this time, the vehicle control ECU 10 may also specify the type of the preceding object OB. The preceding object OB may be a vehicle, a two-wheeled vehicle, or a bicycle.

[0059] Furthermore, the vehicle control ECU 10 calculates a predicted time to collision TTC with respect to the preceding object OB. The predicted time to collision TTC is the time predicted to be required until the host vehicle 100 reaches the preceding object OB. The predicted time to collision TTC can be calculated by dividing the relative distance Lr by the absolute value of the relative speed Vr.

[0060] The predicted time to collision TTC becomes shorter as the host vehicle 100 approaches the preceding object OB when the relative speed Vr is constant. Therefore, the predicted time to collision TTC is an index value (collision possibility index value) representing the possibility of the host vehicle 100 colliding with the preceding object OB. The shorter the predicted time to collision TTC, the higher the possibility of collision between the host vehicle 100 and the preceding object OB.

[0061] The vehicle control ECU 10 determines whether the predicted time to collision TTC is less than or equal to the collision determination time TTCth. When the vehicle control ECU 10 determines that the predicted time to collision TTC is less than or equal to the collision determination time TTCth, it determines that the possibility of collision between the host vehicle 100 and the preceding object OB is high. When the vehicle control ECU 10 determines that the possibility of collision between the host vehicle 100 and the preceding object OB is high, it starts automatic braking control.

[0062] When the vehicle control ECU 10 starts automatic braking control, it outputs a command signal to the brake ECU 41 so that the host vehicle 100 is forcibly braked. As a result, the brake actuator 42 operates and the host vehicle 100 is forcibly braked. In this case, the host vehicle 100 may be braked with a constant braking force, or the host vehicle 100 may be braked with a braking force that changes according to the relative distance Lr or the relative speed Vr.

[0063] During the execution of the automatic braking control, the vehicle control ECU 10 determines whether a predetermined control termination condition is satisfied. The vehicle control ECU 10 is configured to terminate the automatic braking control when it determines that the control termination condition is satisfied. Here, the conventional vehicle control device determines whether a relative speed condition is satisfied during the execution of the automatic braking control, and when the relative speed condition is satisfied, it determines that the control termination condition is satisfied. The relative speed condition is a condition that is satisfied when the relationship between the speed V0 of the current preceding object OB and the vehicle speed V1 is such that it is possible to avoid a collision between the host vehicle 100 and the preceding object OB. For example, when the vehicle speed V1 is lower than the speed V0 of the preceding object OB by a predetermined speed, that is, when the relative speed Vr (=V0 - V1) is positive, the preceding object OB is moving away from the host vehicle 100, so it is possible to avoid a collision between the host vehicle 100 and the preceding object OB. Therefore, in such a case, the relative speed condition is satisfied. When the preceding object OB is a stationary object, the relative speed Vr is negative or 0, so the relative speed condition is not satisfied.

[0064] However, if the automatic braking control is terminated when the relative speed condition is satisfied, it is assumed that the effect of executing the automatic braking control cannot be fully exerted. This will be explained. FIG. 4 is a graph showing an example of the speed change of the host vehicle 100 and the speed change of the preceding object OB when the conventional vehicle control device executes the automatic braking control. The vertical axis in FIG. 4 is the speed, and the horizontal axis is the time. Also, the solid line in FIG. 4 is a graph representing the speed change of the host vehicle 100, and the dashed line in FIG. 4 is a graph representing the speed change of the preceding object OB. As shown in FIG. 4, between times t0 and t1, the host vehicle 100 is performing constant-speed driving at speed Va. On the other hand, the preceding object OB was performing constant-speed driving at speed Va before time t0, but has been decelerating at a predetermined deceleration D0 since time t0. Therefore, the speed of the preceding object OB decreases from time t0.

[0065] Therefore, between time t0 and t1, the host vehicle 100 approaches the leading object OB, the relative speed Vr increases in the negative direction, and the relative distance Lr decreases. Thus, the predicted time to collision TTC (= Lr / |Vr|) continues to decrease between time t0 and t1. Then, at time t1, the determination condition that the predicted time to collision TTC is less than or equal to the collision determination time TTCth is satisfied. For this reason, the automatic braking control is started at time t1.

[0066] Between time t1 and t3, the automatic braking control is executed. During the execution of the automatic braking control, the leading object OB continues to decelerate at a predetermined deceleration D0. Also, the host vehicle 100 decelerates at a deceleration D1 greater than the deceleration D0 by the automatic braking control. For this reason, between time t1 and t2, the absolute value of the relative speed Vr decreases, and at time t2, the relative speed Vr becomes 0 and the speed of the host vehicle 100 matches the speed of the leading object OB. After that, between time t2 and t3, the relative speed Vr increases in the positive direction. Then, at time t3, the speed of the host vehicle 100 falls below the speed of the leading object OB by a predetermined speed. Thereby, the relative speed condition is satisfied, and the execution of the automatic braking control ends.

[0067] Between time t3 and t5, the automatic braking control is not executed. For this reason, the host vehicle 100 travels at a constant speed. On the other hand, the leading object OB still continues to decelerate at the deceleration D0. Therefore, between time t3 and t4, the absolute value of the relative speed Vr decreases, and at time t4, the relative speed Vr becomes 0 and the speed of the host vehicle 100 matches the speed of the leading object OB. After that, between time t4 and t5, the relative speed increases in the negative direction and the relative distance Lr decreases. Thus, the predicted time to collision TTC (= Lr / |Vr|) continues to decrease between time t4 and t5. Then, at time t5, the determination condition that the predicted time to collision TTC is less than or equal to the collision determination time TTCth is satisfied again. Therefore, the automatic braking control is started again at time t5.

[0068] Thus, when the behavior of the preceding object OB decelerates even after the automatic braking control ends, if the automatic braking control is ended only because the relative speed condition is satisfied, there is a high possibility that the host vehicle 100 will approach and collide with the preceding object OB again later. Or, the predicted time to collision TTC will become less than or equal to the collision determination time TTCth again later, and the automatic braking control will be started again. That is, the end and start of the automatic braking control are repeated. Repeating the end and start of the automatic braking control means that the control end condition of the automatic braking control is not appropriate.

[0069] In addition, since the relative speed condition is satisfied when the relationship between the speed of the host vehicle 100 and the speed of the preceding object OB is a predetermined relationship, there is a possibility that it will be satisfied even when the relative distance Lr between the host vehicle 100 and the preceding object OB is extremely short when it is satisfied. In this case, the predicted time to collision TTC is short when the automatic braking control ends. Therefore, when the situation is such that the preceding object OB decelerates even after the automatic braking control ends, it is conceivable that the driver of the host vehicle 100 does not have enough room to fully execute a driving operation to avoid a collision between the host vehicle 100 and the preceding object OB.

[0070] On the other hand, in the present embodiment, a margin condition is included in the control end condition of the automatic braking control. Specifically, during the execution of the automatic braking control, when the relative speed condition is satisfied and the margin condition is satisfied, the control end condition is satisfied and the execution of the automatic braking control is ended. In other words, during the execution of the automatic braking control, even if the relative speed condition is satisfied, if the margin condition is not satisfied, the automatic braking control continues.

[0071] The margin condition is a condition that is satisfied when the margin representing the magnitude of the margin for avoiding a collision between the host vehicle 100 and the preceding object OB after the automatic braking control ends is equal to or greater than a predetermined threshold margin. It can also be said that the margin condition is a condition that is satisfied when the host vehicle 100 can avoid the collision with the preceding object OB with a margin even when the possibility of the host vehicle 100 colliding with the preceding object OB increases after the automatic braking control ends.

[0072] The margin condition is not limited to the condition representing the relative relationship between the preceding object OB and the host vehicle 100. The margin condition may be a condition representing the behavior of the preceding object OB. For example, the margin condition can be set to the condition that the preceding object OB is accelerating, specifically, the acceleration condition that the acceleration (longitudinal acceleration) of the preceding object OB is equal to or greater than a predetermined threshold acceleration. When the preceding object OB is accelerating at the time when the automatic braking control ends, even if the relative distance Lr between the host vehicle 100 and the preceding object OB is short at that time, it is expected that the relative distance Lr will become longer thereafter. That is, the preceding object OB moves away from the host vehicle 100. Therefore, even if the automatic braking control ends in this case, the possibility of a collision between the host vehicle 100 and the preceding object OB thereafter is low. Further, when the behavior of the preceding object OB changes after the automatic braking control ends, for example, when the preceding object OB suddenly brakes, it is assumed that the host vehicle 100 approaches the preceding object OB and the possibility of a collision between the host vehicle 100 and the preceding object OB increases again. However, since the preceding object OB was accelerating at the time when the automatic braking control ended, the preceding object OB has once moved away from the host vehicle 100, and even if the preceding object OB suddenly brakes thereafter, there is a time and distance margin until the distance that has moved away is reduced. Therefore, even in the case where the preceding object OB suddenly brakes after the automatic braking control ends, the driver of the host vehicle 100 can perform a driving operation to avoid a collision with the preceding object OB, and thus can avoid the collision with a margin. Therefore, the acceleration of the preceding object OB is a margin representing the magnitude of the margin for avoiding a collision between the host vehicle 100 and the preceding object OB after the automatic braking control ends, and the acceleration condition that the acceleration of the preceding object OB is equal to or greater than the threshold acceleration can be a margin condition.

[0073] Also, when the preceding object OB is not decelerating, even if the execution of the automatic braking control is terminated at that time, the host vehicle 100 will not approach the preceding object OB thereafter. Therefore, even if the automatic braking control is terminated in this case, the possibility of a collision between the host vehicle 100 and the preceding object OB thereafter is low. Also, it is assumed that the behavior of the preceding object OB changes after the automatic braking control is terminated, and for example, if it suddenly brakes, the possibility of a collision between the host vehicle 100 and the preceding object OB increases again. However, since the preceding object OB is not decelerating at the time of termination of the automatic braking control, there is a time margin until the behavior of the preceding object OB changes thereafter. Therefore, even if the preceding object OB suddenly brakes after the automatic braking control is terminated, the driver of the host vehicle 100 can perform a driving operation to avoid a collision with the preceding object OB, and thereby can avoid the collision with a margin. Therefore, the condition that the preceding object OB is not decelerating, that is, the acceleration (longitudinal acceleration) of the preceding object OB is 0 m / s 2 or more can be a margin condition.

[0074] In the present embodiment, the margin condition is an acceleration condition that the acceleration (longitudinal acceleration) of the preceding object OB is equal to or greater than a predetermined threshold acceleration. In this case, after determining that the relative speed condition is satisfied, the vehicle control ECU 10 calculates the acceleration (longitudinal acceleration) α0 of the preceding object OB.

[0075] After calculating the acceleration α0 of the preceding object OB, the vehicle control ECU 10 determines whether the calculated acceleration α0 is equal to or greater than a predetermined threshold acceleration αth set in advance. The threshold acceleration αth is preferably set so that the margin condition is satisfied when the acceleration of the preceding object OB is 0 or positive. The threshold acceleration αth can be set to, for example, 0 m / s 2 or the like. In this case, the vehicle control ECU 10 determines whether the preceding object OB is decelerating. Also, the threshold acceleration αth may be set in consideration of the variation in the acceleration α0 of the preceding object OB or the variation in the estimation accuracy of the acceleration α0. For example, the average value of the acceleration α0 of the preceding object OB is 0 m / s 2However, due to variations in the acceleration α0 or variations in the estimation accuracy of the acceleration α0, the acceleration α0 may become positive or negative. In this case, the threshold acceleration αth can be set to the lower limit value of the acceleration α0 that varies within the range of variations. For example, if the variation in the estimation accuracy of the acceleration α0 is on the order of ±0.5 m / s 2 the threshold acceleration αth can be set to -0.5 m / s 2 In this way, the threshold acceleration αth may be set to a negative value when considering the variations in the acceleration α0 of the preceding object OB or the variations in the estimation accuracy of the acceleration α0.

[0076] When the acceleration α0 of the preceding object OB is less than the threshold acceleration αth, for example, when the preceding object OB is decelerating, the vehicle control ECU10 determines that the margin condition is not satisfied. In this case, since the relative speed condition is satisfied but the margin condition is not satisfied, the vehicle control ECU10 determines that the control termination condition for the automatic brake control is not satisfied and continues the automatic brake control. On the other hand, when the acceleration α0 of the preceding object OB is greater than or equal to the threshold acceleration αth, for example, when the preceding object OB is not decelerating, the vehicle control ECU10 determines that the margin condition is satisfied. In this case, since the relative speed condition is satisfied and the margin condition is also satisfied, the vehicle control ECU10 determines that the control termination condition for the automatic brake control is satisfied and ends the execution of the automatic brake control.

[0077] (Specific operation) FIG. 5 is a flowchart showing an example of an automatic brake control program executed by the CPU 10a (processor) of the vehicle control ECU 10 to execute the automatic brake control. This program is repeatedly executed at a predetermined short time period while the host vehicle 100 is in motion.

[0078] When the automatic braking control program is started, the CPU 10a first determines, at step 101 in FIG. 5 (hereinafter, steps are abbreviated as S), whether an object has been detected within the predicted travel region A100 of the host vehicle 100. If the CPU 10a does not detect an object, or even if an object is detected but the object exists outside the predicted travel region A100 (S101: No), this program is temporarily terminated. On the other hand, when the CPU 10a detects an object within the predicted travel region A100 of the host vehicle 100 (S101: Yes), the process executed by the CPU 10a proceeds to S102.

[0079] In S102, the CPU 10a sets the detected object as the preceding object OB. Next, in S103, the CPU 10a acquires the relative speed Vr and the relative distance Lr. Subsequently, in S104, the CPU 10a calculates the predicted time until the host vehicle 100 reaches the preceding object OB as the predicted time to collision TTC. Next, in S105, the CPU 10a determines whether the calculated predicted time to collision TTC is equal to or less than a preset collision determination time TTCth. If the predicted time to collision TTC is greater than the collision determination time TTCth (S105: No), the CPU 10a temporarily terminates this program. On the other hand, if the predicted time to collision TTC is equal to or less than the collision determination time TTCth (S105: Yes), the CPU 10a determines that the possibility of collision between the host vehicle 100 and the preceding object OB is high. In this case, the process proceeds to S106.

[0080] In S106, the CPU 10a starts the automatic braking control (start step). Next, in S107, the CPU 10a calculates the required deceleration ΔDreq. The required deceleration ΔDreq may be a fixed value or a variable value that changes according to the relative speed Vr or the relative distance Lr. Thereafter, the process proceeds to S108.

[0081] In S108, the CPU 10a outputs a deceleration command signal for controlling the braking actuator 42 to the brake ECU 41 so that the deceleration of the host vehicle 100 matches the required deceleration ΔDreq. As a result, the brake ECU 41 controls the braking actuator 42 so that the deceleration matches the required deceleration ΔDreq. For this reason, the host vehicle 100 decelerates. Thereafter, the process proceeds to S109.

[0082] In S109, the CPU 10a determines whether or not the control end flag F is set to 1. The control end flag F is set to 1 when the control end condition of the automatic brake control is satisfied, and is set to 0 when the control end condition is not satisfied. When the control end flag F is not set to 1, that is, when the control end flag F is set to 0 (S109: No), the CPU 10a determines that the control end condition of the automatic brake control is not satisfied, and the process returns to S107. In this case, the CPU 10a calculates the required deceleration ΔDreq again (S107) and outputs a deceleration command signal (S108). As a result, the automatic brake control is continued. On the other hand, when the control end flag F is set to 1 (S109: Yes), the CPU 10a determines that the control end condition of the automatic brake control is satisfied, and the process proceeds to S110. In S110, the CPU 10a ends the automatic brake control (end step). As a result, the forced deceleration of the host vehicle 100 ends. Thereafter, the CPU 10a temporarily ends this program.

[0083] When the CPU 10a executes the above-described automatic brake control program, when the predicted arrival time TTC until the host vehicle 100 reaches the preceding object OB becomes equal to or less than the collision determination time TTCth, that is, when it is determined that the possibility of collision between the host vehicle 100 and the preceding object OB is high, the automatic brake control is started and the host vehicle 100 decelerates. Also, when the control end flag F is not set to 1 during the execution of the automatic brake control, it is determined that the control end condition is not satisfied and the automatic brake control is continued. When the control end flag F is set to 1 during the execution of the automatic brake control, it is determined that the control end condition is satisfied and the execution of the automatic brake control is ended.

[0084] Figure 6 is a flowchart showing an example of a control end determination program executed by the CPU 10a to set the control end flag F. This control end determination program is executed when the automatic brake control is started in S106 of FIG. 5.

[0085] When the control end determination program is started, the CPU 10a first determines, in S201 of FIG. 6, whether the host vehicle speed V1 is 0 km / h, that is, whether the host vehicle 100 is stopped. If the host vehicle 100 is stopped (S201: Yes), the process proceeds to S206. On the other hand, if the host vehicle 100 is not stopped (S201: No), the process proceeds to S202.

[0086] In S202, the CPU 10a determines whether the host vehicle speed V1 is less than or equal to the speed obtained by subtracting a predetermined reference speed Vs from the speed V0 of the preceding object OB. That is, in S202, the CPU 10a determines whether the host vehicle speed V1 is less than the speed V0 of the preceding object OB by the predetermined reference speed Vs or more. The condition shown in S202, that is, the condition that the host vehicle speed V1 is less than the speed V0 of the preceding object OB by the reference speed Vs or more, is the relative speed condition. Note that the speed V0 can be obtained by adding the relative speed Vr (= V0 - V1) to the host vehicle speed V1. If the host vehicle speed V1 is not less than the speed V0 of the preceding object OB by the reference speed Vs or more (S202: No), the CPU 10a determines that the relative speed condition is not satisfied, and the process proceeds to S207. On the other hand, if the host vehicle speed V1 is less than the speed V0 of the preceding object OB by the reference speed Vs or more (S202: Yes), the CPU 10a determines that the relative speed condition is satisfied, and the process proceeds to S203.

[0087] In S203, the CPU 10a determines whether the speed V0 of the preceding object OB is equal to or higher than a predetermined lower limit speed Vd. The lower limit speed Vd is set in advance. The lower limit speed Vd can be set to any positive speed. The lower limit speed Vd can be set to a speed within a range of, for example, 8 km / H or more and 12 km / H or less. The lower limit speed Vd can be set to, for example, 10 km / H. If the speed V0 of the preceding object OB is less than the lower limit speed Vd (S203: No), the process proceeds to S207. On the other hand, if the speed V0 of the preceding object OB is equal to or higher than the lower limit speed Vd (S203: Yes), the process proceeds to S204.

[0088] In S204, the CPU 10a calculates the acceleration α0 of the preceding object OB. The acceleration α0 is the acceleration acting in the longitudinal direction (travel direction) of the preceding object OB. The acceleration α0 can be calculated, for example, based on the amount of change in time of the speed V0 of the preceding object OB. After calculating the acceleration α0, the process proceeds to S205.

[0089] In S205, the CPU 10a determines whether the acceleration α0 is equal to or higher than a threshold acceleration αth. The threshold acceleration αth is set in advance. The threshold acceleration αth can be set to a value for which the result of S205 is Yes when the acceleration α0 is 0 or positive. The threshold acceleration αth can be set to a positive acceleration. The threshold acceleration αth can be set to 0 m / s 2 It can be set to. When the threshold acceleration αth is set to 0 m / s 2 The determination in S205 will be to determine whether the preceding object OB is not decelerating. Also, the threshold acceleration αth can be set to a negative acceleration within a range considering the variation of the acceleration α0 or the variation of the estimation accuracy of the acceleration α0. For example, if the variation of the estimation accuracy of the acceleration α0 is ±0.5 m / s 2 In this case, the threshold acceleration αth is set to -0.5 m / s 2It can be set to. The condition shown in S205, that is, the condition that the acceleration α0 of the preceding object OB is equal to or greater than the threshold acceleration αth, is the acceleration condition as the margin condition, and the acceleration α0 of the preceding object OB is the margin representing the magnitude of the margin for avoiding a collision between the host vehicle 100 and the preceding object OB. When the acceleration α0 is less than the threshold acceleration αth (S205: No), the CPU 10a determines that the margin condition (acceleration condition) is not satisfied, and the process proceeds to S207. On the other hand, when the acceleration α0 is equal to or greater than the threshold acceleration αth (S205: Yes), the CPU 10a determines that the margin condition (acceleration condition) is satisfied, and the process proceeds to S206.

[0090] In S206, the CPU 10a determines that the control end condition of the automatic brake control is satisfied, and sets the control end flag F to 1. Then, the CPU 10a ends this program. Also, in S207, the CPU 10a determines that the control end condition of the automatic brake control is not satisfied, and sets the control end flag to 0. Then, the CPU 10a ends this program.

[0091] By executing the control end determination program described above by the CPU 10a, when the host vehicle 100 stops, the control end flag F is set to 1. That is, the control end condition is satisfied. When the host vehicle 100 stops during the execution of the automatic brake control, there is no meaning in continuing the automatic brake control any further, so the automatic brake control is ended. Also, in this case, thereafter, the stop holding control is continuously executed so that the host vehicle 100 maintains the stop.

[0092] Also, when the CPU 10a executes the above-described control end determination program, during the execution of the automatic braking control, when all of the following conditions (relative speed condition), (target speed condition), and (acceleration condition) are satisfied: the condition that the own vehicle speed V1 is lower than the reference speed Vs which is the speed V0 of the preceding target OB (relative speed condition), the condition that the speed V0 of the preceding target OB is equal to or higher than the lower limit speed Vd (target speed condition), and the condition that the acceleration α0 of the preceding target OB is equal to or higher than the threshold acceleration αth (acceleration condition), the control end flag F is set to 1, and the control end condition is satisfied. Among the above conditions, the target speed condition is provided to prevent the following vehicle of the own vehicle 100 from contacting the own vehicle 100 by continuing the automatic braking control when the preceding target OB is traveling at a speed equal to or higher than a predetermined speed (for example, at a speed of 10 km / H or higher). Therefore, when not considering the contact of the following vehicle of the own vehicle 100 with the own vehicle 100, or when it is clear that there is no following vehicle of the own vehicle 100, the target speed condition can be omitted.

[0093] As described above, according to the present embodiment, the control end condition of the automatic braking control includes not only the relative speed condition but also the margin condition. In the present embodiment, the margin condition is the acceleration condition of the preceding target OB that the acceleration α0 of the preceding target OB is equal to or higher than a predetermined threshold acceleration αth, for example, α0 is 0 m / s 2 or higher. By including such a margin condition (acceleration condition) in the control end condition, after the end of the automatic braking control, the preceding target OB will not move away from the own vehicle 100 or approach the own vehicle 100. Therefore, even when the possibility of collision between the own vehicle 100 and the preceding target OB increases again due to the sudden braking of the preceding target OB after the end of the automatic braking control, the driver of the own vehicle 100 can execute a driving operation to avoid a collision with the preceding target OB. Thereby, it is possible to avoid a collision between the own vehicle 100 and the preceding target OB with a margin. Therefore, the automatic braking control can be terminated appropriately and safely.

[0094] Also, when the acceleration condition of the preceding object OB is not satisfied, for example, when the preceding object OB is decelerating, the deceleration control continues because the control end condition is not satisfied. Therefore, it is possible to effectively prevent the possibility that the host vehicle 100 collides with the preceding object OB again after the deceleration control ends due to the deceleration control ending when the preceding object OB is decelerating. Further, by ending the deceleration control during the deceleration of the preceding object OB, the relative distance Lr between the host vehicle 100 and the preceding object OB shrinks after the deceleration control ends, thereby effectively preventing the resumption of the deceleration control, that is, the repetition of the end and start of the deceleration control.

[0095] (Second Embodiment) In the first embodiment, an example was described in which the margin condition, which is one of the control end conditions for the automatic brake control, is an acceleration condition that the acceleration α0 of the preceding object OB is equal to or greater than the threshold acceleration αth. In the second embodiment, an example will be described in which the margin condition includes the above acceleration condition and a relative distance condition that the relative distance Lr between the host vehicle 100 and the preceding object OB is equal to or greater than the threshold distance Lth.

[0096] The vehicle control device according to the second embodiment is mounted on the host vehicle 100 in the same manner as the vehicle control device according to the first embodiment. Further, the vehicle control device according to the second embodiment has the configuration shown in FIG. 1. Specifically, the vehicle control device 1B according to the second embodiment includes a vehicle control ECU 10, an in-vehicle sensor 20, a drive device 30, a brake device 40, and a steering device 50. Details of these configurations have been described in the first embodiment, and thus the description thereof will be omitted.

[0097] (Outline of Operation of Automatic Brake Control) When the vehicle control ECU 10 of the vehicle control device 1B according to the second embodiment determines that there is a high possibility of collision between the host vehicle 100 and the preceding object OB existing in the traveling direction of the host vehicle 100, it starts automatic brake control. Further, the vehicle control ECU 10 is configured to end the automatic brake control when a predetermined control end condition is satisfied during the execution of the automatic brake control. The predetermined control end condition includes a margin condition. Therefore, when the margin condition is not satisfied, the control end condition is not satisfied, so the automatic brake control continues. On the other hand, when the margin condition and other necessary conditions (such as the relative speed condition) are satisfied, the control end condition is satisfied, so the automatic brake control ends. The outline of the operation of this automatic brake control is basically the same as the outline of the operation of the automatic brake control executed by the vehicle control ECU 10 of the vehicle control device 1A according to the first embodiment. However, the margin condition used for the control end condition of the automatic brake control is different from that of the first embodiment.

[0098] As described in the first embodiment, the margin condition is a condition that is satisfied when the margin representing the magnitude of the margin for avoiding a collision between the host vehicle 100 and the preceding object OB after the automatic brake control is terminated is equal to or greater than a predetermined threshold margin. Here, when the relative distance Lr between the host vehicle 100 and the preceding object OB is long, even if the automatic brake control is terminated at that time, there is a distance margin until the host vehicle 100 and the preceding object OB collide thereafter. Therefore, when the relative distance Lr is long, it can be said that there is a margin for avoiding a collision between the host vehicle 100 and the preceding object OB even if the automatic brake control is terminated at that time. Also, even in a case where the preceding object OB suddenly brakes after the automatic brake control is terminated, if the relative distance Lr is long, the driver of the host vehicle 100 can perform a driving operation to avoid a collision with the preceding object OB and avoid the collision with a margin. Thus, the relative distance Lr is a margin representing the margin for avoiding a collision between the host vehicle 100 and the preceding object OB after the automatic brake control is terminated, and the relative distance condition that the relative distance Lr is equal to or greater than a predetermined distance can be a margin condition.

[0099] In this embodiment, the margin condition is an acceleration condition and a relative distance condition that the relative distance Lr is equal to or greater than a predetermined threshold distance Lth. In this case, if either the acceleration condition or the relative distance condition is satisfied, the vehicle control ECU 10 determines that the margin condition is satisfied. Specifically, in order to determine whether the margin condition is satisfied, the vehicle control ECU 10 first determines whether the acceleration condition is satisfied. If the acceleration condition is satisfied, the vehicle control ECU 10 determines that the margin condition is satisfied. If the acceleration condition is not satisfied, the vehicle control ECU 10 then determines whether the relative distance condition is satisfied. In this case, the vehicle control ECU 10 determines whether the relative distance Lr is equal to or greater than the threshold distance Lth. If the relative distance Lr is less than the threshold distance Lth, the vehicle control ECU 10 determines that the relative distance condition is not satisfied. On the other hand, if the relative distance Lr is equal to or greater than the threshold distance Lth, the vehicle control ECU 10 determines that the relative distance condition is satisfied. If the relative distance condition is satisfied, the vehicle control ECU 10 determines that the margin condition is satisfied. If neither the acceleration condition nor the relative distance condition is satisfied, the vehicle control ECU 10 determines that the margin condition is not satisfied.

[0100] The threshold distance Lth can be set in advance as a lower limit value (minimum value) of a distance that allows the driver of the host vehicle 100 to avoid a collision with a margin even when the possibility of a collision between the host vehicle 100 and the preceding object OB increases after the automatic brake control ends. The threshold distance Lth may be a fixed value or a variable value that changes according to the host vehicle speed V1 at the time when the automatic brake control ends. Note that the predetermined driving operation for avoiding a collision between the host vehicle 100 and the preceding object OB includes an operation of stopping the host vehicle 100 before colliding with the preceding object OB by the driver operating the brake pedal 44 to brake the host vehicle 100, and an operation of changing the traveling route from a route that collides with the preceding object OB to a route that does not collide by the driver operating the steering wheel 53a.

[0101] (Specific operation) The flowchart showing the automatic braking control program executed by the CPU 10a of the vehicle control ECU 10 to execute automatic braking control in the second embodiment is the same as the flowchart shown in FIG. 5. Therefore, the description of the automatic braking control program according to the present embodiment is omitted.

[0102] Also in the second embodiment, when the CPU 10a executes the automatic braking control program shown in FIG. 5, the vehicle control ECU 10 starts automatic braking control when the predicted arrival time TTC until the host vehicle 100 reaches the preceding object OB becomes less than or equal to the collision determination time TTCth, that is, when the possibility of collision between the host vehicle 100 and the preceding object OB increases. As a result, the host vehicle 100 decelerates. Further, when the control end flag F is not set to 1 during the execution of the automatic braking control, the vehicle control ECU 10 determines that the control end condition is not satisfied and continues the automatic braking control. Also, when the control end flag F is set to 1 during the execution of the automatic braking control, the vehicle control ECU 10 determines that the control end condition is satisfied and ends the execution of the automatic braking control.

[0103] FIG. 7 is a flowchart showing an example of a control end condition determination program executed by the CPU 10a of the vehicle control ECU 10 to set the control end flag F. When the execution of this program is started, the CPU 10a first determines at S301 in FIG. 7 whether the host vehicle speed V1 is 0 km / h, that is, whether the host vehicle 100 is stopped. If the host vehicle 100 is stopped (S301: Yes), the process executed by the CPU 10a proceeds to S308. On the other hand, if the host vehicle 100 is not stopped (S301: No), the process proceeds to S302.

[0104] In S302, the CPU 10a determines whether the own vehicle speed V1 is less than or equal to the speed obtained by subtracting a predetermined reference speed Vs from the speed V0 of the preceding object OB. That is, in S302, the CPU 10a determines whether the own vehicle speed V1 is less than the speed V0 of the preceding object OB by a predetermined reference speed Vs or more. The condition shown in S302 is a relative speed condition. When the own vehicle speed V1 is not less than the speed V0 of the preceding object OB by the reference speed Vs (S302: No), the CPU 10a determines that the relative speed condition is not satisfied, and the process proceeds to S309. On the other hand, when the own vehicle speed V1 is less than the speed V0 of the preceding object OB by the reference speed Vs (S302: Yes), the CPU 10a determines that the relative speed condition is satisfied, and the process proceeds to S303.

[0105] In S303, the CPU 10a determines whether the speed V0 of the preceding object OB is greater than or equal to a predetermined lower limit speed Vd. The lower limit speed Vd is set in advance. The lower limit speed Vd can be set to any positive speed. The lower limit speed Vd can be set to a speed within a range of, for example, 8 km / h or more and 12 km / h or less. The lower limit speed Vd can be set to, for example, 10 km / h. When the speed V0 of the preceding object OB is less than the lower limit speed Vd (S303: No), the process proceeds to S309. On the other hand, when the speed V0 of the preceding object OB is greater than or equal to the lower limit speed Vd (S303: Yes), the process proceeds to S304. The condition shown in S303 is an object speed condition.

[0106] In S304, the CPU 10a calculates the acceleration α0 of the preceding object OB. The acceleration α0 is the acceleration acting in the longitudinal direction (traveling direction) of the preceding object OB. The acceleration α0 can be calculated based on the amount of change in time of the speed V0 of the preceding object OB. After calculating the acceleration α0, the process proceeds to S305.

[0107] In S305, the CPU 10a determines whether the acceleration α0 is greater than or equal to a threshold acceleration αth. The threshold acceleration αth is set in advance. The threshold acceleration αth can be set to any acceleration. The threshold acceleration αth is 0 m / s 2It can be set to. Also, the threshold acceleration can be set to a positive acceleration. The condition shown in S305 is an acceleration condition as a margin condition. When the acceleration α0 is less than the threshold acceleration αth (S305: No), the CPU 10a determines that the acceleration condition is not satisfied, and the process proceeds to S306. On the other hand, when the acceleration α0 is greater than or equal to the threshold acceleration αth (S305: Yes), the CPU 10a determines that the acceleration condition is satisfied, and the process proceeds to S308.

[0108] In S306, the CPU 10a acquires the relative distance Lr, which is the distance between the host vehicle 100 and the preceding object OB, based on the information from the front radar sensor 261a. Next, in S307, the CPU 10a determines whether the relative distance Lr is greater than or equal to the threshold distance Lth. The threshold distance Lth can be set in advance as a distance that can avoid a collision with a margin even when the possibility of a collision between the host vehicle 100 and the preceding object OB increases after the automatic brake control is terminated. The threshold distance Lth can be set, for example, within a range of 8 m or more and 12 m or less. The threshold distance Lth can be set to, for example, 10 m. Further, the threshold distance Lth can be set to change according to the host vehicle speed V1, for example, to be a longer distance as the host vehicle speed V1 is higher. The condition shown in S307 is a relative distance condition as a margin condition. When the relative distance Lr is less than the threshold distance Lth (S307: No), the CPU 10a determines that the relative distance condition is not satisfied, and the process proceeds to S309. On the other hand, when the relative distance Lr is greater than or equal to the threshold distance Lth (S307: Yes), the CPU 10a determines that the relative distance condition is satisfied, and the process proceeds to S308.

[0109] In S308, the CPU 10a determines that the control end condition of the automatic brake control is satisfied, and sets the control end flag F to 1. Then, the CPU 10a terminates this program. Also, in S309, the CPU 10a determines that the control end condition of the automatic brake control is not satisfied, and sets the control end flag F to 0. Then, the CPU 10a terminates this program.

[0110] By executing the above-described control end determination program, when the relative speed condition is satisfied (S302: Yes), the target speed condition is satisfied (S303: Yes), and further, either one of the acceleration condition and the relative distance condition as the margin condition is satisfied (S305: Yes, S307: Yes) during the execution of the automatic braking control, the control end flag F is set to 1. That is, the control end condition is satisfied.

[0111] As described above, according to the present embodiment, the margin condition includes a relative distance condition that the distance (relative distance Lr) between the host vehicle 100 and the preceding target OB is equal to or greater than a predetermined threshold distance Lth, for example, the relative distance Lr is 10 m or more. And even if the acceleration condition is not satisfied, when the relative distance condition is satisfied, the margin condition is satisfied and the automatic braking control is terminated. In this case, a distance margin for avoiding a collision between the host vehicle 100 and the preceding target OB is ensured at the end of the automatic braking control. Therefore, even when the possibility of the host vehicle 100 colliding with the preceding target OB increases again due to the behavior of the preceding target OB after the end of the automatic braking control, since there is a distance margin until the host vehicle 100 collides with the preceding target OB, the driver of the host vehicle 100 can perform a driving operation for avoiding a collision with the preceding target OB during that time, and can avoid a collision between the host vehicle 100 and the preceding target OB with a margin.

[0112] In the above first embodiment, after the automatic braking control is started, the automatic braking control is continued as long as the acceleration condition is not satisfied even if the relative speed condition and the target speed condition are satisfied. Therefore, a scene is assumed in which the automatic braking control is executed even though the host vehicle 100 is significantly separated from the preceding target OB while the acceleration condition is not satisfied. In such a case, the driver of the host vehicle 100 feels that the automatic braking control is unnecessary. In this regard, according to the present embodiment, during the execution of the automatic braking control, even if the acceleration condition is not satisfied, if the relative distance Lr is equal to or greater than the threshold distance Lth (when the relative distance condition is satisfied), the automatic braking control can be terminated. Therefore, it is possible to prevent the driver from feeling that the automatic braking control is unnecessary due to the continuation of the automatic braking control despite the large relative distance Lr.

[0113] (Third Embodiment) In the third embodiment, an example will be described in which the margin condition is a prediction time condition that the virtual predicted time to collision TTCv is equal to or greater than the threshold predicted time TTCvth.

[0114] The vehicle control device according to the third embodiment is mounted on the host vehicle 100 in the same manner as the vehicle control device according to the first embodiment. Further, the vehicle control device according to the third embodiment has the configuration shown in FIG. 1. Specifically, the vehicle control device 1C according to the third embodiment includes a vehicle control ECU 10, an in-vehicle sensor 20, a drive device 30, a braking device 40, and a steering device 50. Details of these configurations have been described in the first embodiment, and the description thereof will be omitted.

[0115] (Outline of Operation of Automatic Braking Control) When the vehicle control ECU 10 of the vehicle control device 1C according to the third embodiment determines that there is a high possibility of collision between the host vehicle 100 and the preceding object OB existing in the traveling direction of the host vehicle 100, it starts automatic braking control. Further, the vehicle control ECU 10 is configured to end the automatic braking control when a predetermined control end condition is satisfied during the execution of the automatic braking control. The predetermined control end condition includes a margin condition. Therefore, when the margin condition is not satisfied, the control end condition is not satisfied, so the automatic braking control continues. On the other hand, when the margin condition and other necessary conditions (such as the relative speed condition) are satisfied, the control end condition is satisfied, so the automatic braking control is ended. The outline of the operation of this automatic braking control is basically the same as the outline of the operation of the automatic braking control executed by the vehicle control ECU 10 of the vehicle control device 1A according to the first embodiment. However, the margin condition used for the control end condition of the automatic braking control is different from that of the first embodiment.

[0116] As described in the first embodiment, the margin condition is a condition that is satisfied when the margin representing the magnitude of the margin for avoiding a collision between the host vehicle 100 and the preceding object OB after ending the automatic braking control is equal to or greater than a predetermined threshold margin. Here, when the virtual predicted arrival time, which is the predicted arrival time calculated assuming that the automatic braking control is ended at the current time during the execution of the automatic braking control, is long, even if the automatic braking control is ended at that time, there is a temporal margin until the host vehicle 100 and the preceding object OB collide thereafter. Therefore, when the virtual predicted arrival time is long, it can be said that there is a margin for avoiding a collision between the host vehicle 100 and the preceding object OB even if the automatic braking control is ended at that time. Also, even if the preceding object OB suddenly brakes after the automatic braking control is ended, if the virtual predicted arrival time is long, the driver of the host vehicle 100 can perform a driving operation to avoid a collision with the preceding object OB and avoid the collision with a margin. Thus, the virtual predicted arrival time is the margin for avoiding a collision between the host vehicle 100 and the preceding object OB after the automatic braking control is ended, and the predicted time condition that the virtual predicted arrival time is equal to or greater than a predetermined threshold predicted time can be the margin condition.

[0117] In this embodiment, the margin condition is a prediction time condition that the virtual predicted time to collision TTCv is equal to or greater than a predetermined threshold predicted time TTCvth. In this case, in order to determine whether or not the margin condition (prediction time condition) is satisfied, the vehicle control ECU 10 calculates the virtual predicted time to collision TTCv during the execution of the automatic braking control. The virtual predicted time to collision TTCv is the predicted time until the host vehicle 100 reaches the preceding object OB when the automatic braking control is terminated at the current time, that is, when the deceleration (acceleration) of the host vehicle 100 is set to 0. As will be described later, the virtual predicted time to collision TTCv can be calculated based on the relative distance Lr, the relative speed Vr, and the acceleration (or deceleration) of the preceding object OB between the host vehicle 100 and the preceding object OB.

[0118] After calculating the virtual predicted time to collision TTCv, the vehicle control ECU 10 determines whether or not the virtual predicted time to collision TTCv is equal to or greater than the threshold predicted time TTCvth. When the virtual predicted time to collision TTCv is equal to or greater than the threshold predicted time TTCvth, the vehicle control ECU 10 determines that the prediction time condition as the margin condition is satisfied. On the other hand, when the virtual predicted time to collision TTCv is less than the threshold predicted time TTCvth, the vehicle control ECU 10 determines that the prediction time condition as the margin condition is not satisfied.

[0119] (Specific operation) The flowchart showing the automatic braking control program executed by the CPU 10a of the vehicle control ECU 10 to execute the automatic braking control in the third embodiment is the same as the flowchart shown in FIG. 5. Therefore, the description of the automatic braking control program according to this embodiment is omitted.

[0120] Also in the third embodiment, when the CPU 10a executes the automatic braking control program shown in FIG. 5, the vehicle control ECU 10 starts the automatic braking control when the predicted arrival time TTC until the host vehicle 100 reaches the preceding object OB becomes equal to or less than the collision determination time TTCth, that is, when the possibility of collision between the host vehicle 100 and the preceding object OB increases. As a result, the host vehicle 100 decelerates. Further, when the control end flag F is not set to 1 during the execution of the automatic braking control, the vehicle control ECU 10 determines that the control end condition is not satisfied and continues the automatic braking control. Also, when the control end flag F is set to 1 during the execution of the automatic braking control, the vehicle control ECU 10 determines that the control end condition is satisfied and ends the execution of the self-braking control.

[0121] FIG. 8 is a flowchart showing an example of a control end condition determination program executed by the CPU 10a of the vehicle control ECU 10 to set the control end flag F. When the execution of this program is started, the CPU 10a first determines at S401 in FIG. 8 whether the host vehicle speed V1 is 0 km / h, that is, whether the host vehicle 100 is stopped. If the host vehicle 100 is stopped (S401: Yes), the process executed by the CPU 10a proceeds to S406. On the other hand, if the host vehicle 100 is not stopped (S401: No), the process proceeds to S402.

[0122] In S402, the CPU 10a determines whether the host vehicle speed V1 is equal to or less than the speed obtained by subtracting a predetermined reference speed Vs from the speed V0 of the preceding object OB. That is, in S402, the CPU 10a determines whether the host vehicle speed V1 is equal to or less than the speed V0 of the preceding object OB by a predetermined reference speed Vs or more. The condition shown in S402 is a relative speed condition. If the host vehicle speed V1 is not less than the speed V0 of the preceding object OB by the reference speed Vs (S402: No), the CPU 10a determines that the relative speed condition is not satisfied, and the process proceeds to S407. On the other hand, if the host vehicle speed V1 is less than the speed V0 of the preceding object OB by the reference speed Vs (S402: Yes), the CPU 10a determines that the relative speed condition is satisfied, and the process proceeds to S403.

[0123] In S403, the CPU 10a determines whether the speed V0 of the preceding object OB is equal to or higher than a predetermined lower limit speed Vd. The lower limit speed Vd is set in advance. The lower limit speed Vd can be set to any positive speed. The lower limit speed Vd can be set to a speed within a range of, for example, 8 km / h or higher and 12 km / h or lower. The lower limit speed Vd can be set to, for example, 10 km / h. If the speed V0 of the preceding object OB is less than the lower limit speed Vd (S403: No), the process proceeds to S407. On the other hand, if the speed V0 of the preceding object OB is equal to or higher than the lower limit speed Vd (S403: Yes), the process proceeds to S404. The condition shown in S403 is the object speed condition.

[0124] In S404, the CPU 10a calculates the virtual predicted time to collision TTCv. The virtual predicted time to collision is calculated, for example, as follows.

[0125] Let the current position of the host vehicle 100 during the execution of the automatic braking control be x e , the current speed be v e , and the current acceleration (longitudinal acceleration) be a e , and let the current position of the preceding object OB be x p , the current speed be v p , and the current acceleration (longitudinal acceleration) be a p . Note that the speed in the traveling direction (forward) of the host vehicle 100 and the preceding object OB is defined as a positive speed, and the acceleration acting in the traveling direction (forward) of the host vehicle 100 and the preceding object OB is defined as a positive acceleration. Also, it is assumed that the position increases as it goes from the host vehicle 100 in the traveling direction of the host vehicle 100.

[0126] The position x et of the host vehicle 100 after the elapse of time t from the current time can be expressed by the following equation (1) using the position x e , speed v e , and acceleration a e of the host vehicle 100 at the current time. The position x pt of the preceding object OB after the elapse of time t from the current time can be expressed by the position x p , speed v p , and acceleration a of the preceding object OB at the current timep It can be expressed by the following formula (2) using

Number

Number

[0127] When the host vehicle 100 and the preceding object target OB collide after the time t has elapsed from the current time, the position x of the host vehicle 100 at the time when the time t has elapsed et and the position x of the preceding object target OB pt coincide, so the following formula (3) holds.

Number

[0128] Substituting formulas (1) and (2) into formula (3), the following formula (4) can be obtained.

Number

[0129] Solving formula (4) for t, from the quadratic formula, the following formula (5) can be obtained.

Number

[0130] When t in formula (5) is the predicted time to collision TTC, the value of TTC is either the value of TTC1 expressed by formula (6) or the value of TTC2 expressed by formula (7).

Number

Number

[0131] Also, when t in Equation (5) is the predicted time to collision TTC, since the value of the predicted time to collision TTC is positive, the right side of Equation (5) must always be positive. In this case, first, in the scenario where the host vehicle 100 collides with the preceding object OB after the execution of the automatic braking control, the acceleration a of the preceding object OB p is negative (a p <0), and the deceleration of the host vehicle (-a e ) is smaller than the deceleration of the preceding object OB (-a p ). Therefore, a p -a e <0. Also, when the preceding object OB and the host vehicle 100 collide, the speed v of the preceding object OB p is smaller than the speed v of the host vehicle 100 e . Therefore, v p -v e <0. Furthermore, until the preceding object OB and the host vehicle 100 collide, the position x of the preceding object OB p is larger than the position x of the host vehicle 100 e . Therefore, x p -x e >0. When these relationships are applied to Equation (5), the denominator (a p -a e ) of the right side of Equation (5) is negative, and the first term (-(v p -v e )) of the numerator of the right side of Equation (5) is positive. Also, of course, the second term of the numerator of the right side of Equation (5) is positive.

[0132] When the above relationships are applied to Equation (6), the numerator of the right side is always positive and the denominator of the right side is negative. Therefore, TTC1 is always negative. Thus, it is verified that TTC2 is always positive.

[0133] FIG. 9 is a graph showing the relationship between the variable y and the time t when the right side of Equation (4) is the variable y. In FIG. 9, the horizontal axis is the time t and the vertical axis is the variable y. As shown in FIG. 9, the graph showing the relationship between the variable y and the time t draws an upwardly convex parabola. This is because the coefficient (a p -a e ) of the third term on the left side of Equation (4) is negative. Also, the intercept of the graph shown in FIG. 9 (xp -x e ) is positive. Therefore, one of the two solutions (TTC1, TTC2) obtained when 0 is substituted into the variable y is always negative and the other is always positive. As described above, since TTC1 is always negative, TTC2 is always positive. Therefore, the predicted time to collision TTC is expressed as in the following equation (8). [Number]

[0134] Since the virtual predicted time to collision TTCv is the predicted time to collision calculated when the acceleration a of the host vehicle 100 e is 0, it can be obtained as in the following equation (9) by substituting a e = 0 into equation (8). [Number]

[0135] In equation (9), v p - v e = Vr, and x p - x e = Lr. Therefore, the virtual predicted time to collision TTCv can be expressed as in equation (10). [Number] In equation (10), Vr is the relative speed and Lr is the relative distance. As shown in equation (10), the virtual predicted time to collision TTCv can be calculated based on the relative speed Vr, the relative distance Lr, and the acceleration a p of the preceding object OB.

[0136] The CPU 10a calculates the virtual predicted time to collision TTCv using, for example, the above equation (10) in S404. After the CPU 10a calculates the virtual predicted time to collision TTCv in S404, the process proceeds to S405.

[0137] In S405, the CPU 10a determines whether the virtual predicted time to collision TTCv is equal to or greater than the threshold predicted time TTCvth. The threshold predicted time TTCvth is set in advance. The threshold predicted time TTCvth can be set in advance as a time that allows for a margin to avoid a collision even when the likelihood of a collision between the host vehicle 100 and the preceding object OB increases after the automatic braking control ends. The threshold time TTCvth can be set, for example, to a time of 4 seconds or more. The threshold time TTCvth can be set, for example, to a time between 4 seconds and 10 seconds. The threshold time TTCvth can be set, for example, to 4 seconds. The condition shown in S405 is the predicted time condition as the margin condition. When the virtual predicted time to collision TTCv is less than the threshold time TTCvth (S405: No), the CPU 10a determines that the predicted time condition as the margin condition is not satisfied, and the process proceeds to S407. On the other hand, when the virtual predicted time to collision TTCv is equal to or greater than the threshold time TTCvth (S405: Yes), the CPU 10a determines that the predicted time condition as the margin condition is satisfied, and the process proceeds to S406.

[0138] In S406, the CPU 10a determines that the control end condition of the automatic braking control is satisfied, and sets the control end flag F to 1. Thereafter, the CPU 10a ends this program. Also, in S407, the CPU 10a determines that the control end condition of the automatic braking control is not satisfied, and sets the control end flag F to 0. Thereafter, the CPU 10a ends this program.

[0139] By executing the above-described control end determination program, when the relative speed condition is satisfied (S402: Yes), the target speed condition is satisfied (S403: Yes), and further, all conditions including the predicted time condition as the margin condition, that is, the condition that the virtual predicted time to collision TTCv is equal to or greater than the threshold predicted time TTCvth (S405), are satisfied during the execution of the automatic braking control, the control end flag F is set to 1. That is, the control end condition is satisfied.

[0140] As described above, according to this embodiment, the margin condition is a prediction time condition that the virtual predicted time to collision TTCv is equal to or greater than the threshold predicted time TTCvth, for example, the virtual predicted time to collision TTCv is 4 seconds or more. By including such a margin condition (prediction time condition) in the control end condition, a temporal margin for avoiding a collision between the host vehicle 100 and the preceding object target OB is ensured at the end of the automatic braking control. Therefore, even if the possibility of the host vehicle 100 colliding with the preceding object target OB increases again due to the behavior of the preceding object target OB after the end of the automatic braking control, there is a temporal margin until the host vehicle 100 collides with the preceding object target OB. Thus, during this period, the driver of the host vehicle 100 can perform a driving operation to avoid a collision with the preceding object target OB, and can avoid a collision between the host vehicle 100 and the preceding object target OB with a margin.

[0141] As described above, the embodiments of the present disclosure have been described. However, the technical idea disclosed in the present disclosure is not limited to the above embodiments. For example, the following modification examples can be shown.

[0142] (Modification Example 1) In the above embodiment, the target speed condition is included in the control end condition. However, the target speed condition may be excluded from the control end condition, and the control end condition may be configured to be satisfied when the relative speed condition is satisfied and the margin condition is satisfied.

[0143] (Modification Example 2) In the above-described second embodiment, an example where the margin condition is satisfied when either the acceleration condition or the relative distance condition is satisfied has been described. However, only the relative distance condition may be set as the margin condition. In this case, the CPU 10a of the vehicle control ECU 10 can execute the control end determination program shown in FIG. 10 instead of the control end determination program shown in FIG. 7. According to the control end determination program shown in FIG. 10, the CPU 10a first determines whether the host vehicle speed V1 is 0 km / h (S501). When the host vehicle speed V1 is not 0 km / h, it determines whether the relative speed condition is satisfied (S502). When the relative speed condition is satisfied, it determines whether the target speed condition is satisfied (S503). When the target speed condition is satisfied, it determines whether the relative distance condition is satisfied (S504). Then, when the relative distance condition is satisfied, the CPU 10a determines that the control end condition is satisfied and sets the control end flag F to 1. When the relative distance condition is not satisfied, the CPU 10a determines that the control end condition is not satisfied and sets the control end flag F to 0.

[0144] (Modification Example 3) The margin condition may be configured to be satisfied when any one of the acceleration condition, the relative distance condition, and the prediction time condition is satisfied. Further, the margin condition may be configured to be satisfied when two of the acceleration condition, the relative distance condition, and the prediction time condition are satisfied, or may be configured to be satisfied when all the conditions are satisfied.

[0145] (Modification Example 4) The relative speed condition and the target speed condition may be excluded from the control end condition, and the control end condition may be configured to be satisfied when only the margin condition is satisfied. For example, when the acceleration condition as the margin condition is satisfied, the control end condition may be configured to be satisfied regardless of whether the relative speed condition is satisfied. Also, when the relative distance condition as the margin condition is satisfied, the control end condition may be configured to be satisfied regardless of whether the relative speed condition is satisfied. Further, when the prediction time condition as the margin condition is satisfied, the control end condition may be configured to be satisfied regardless of whether the relative speed condition is satisfied.

[0146] (Modification Example 5) In the above-described third embodiment, an example in which the margin condition (predicted time condition) is satisfied when the virtual predicted time to collision TTCv, which is an example of the collision possibility index between the host vehicle 100 and the preceding object OB, is equal to or greater than the threshold predicted time TTCvth was shown. However, the validity of the margin condition may be determined based on the comparison result between the collision possibility index calculated by other methods and a predetermined threshold value.

[0147] Thus, the technical idea according to the present disclosure can be modified as long as the gist thereof is not deviated from.

Description of Reference Numerals

[0148] 1A, 1B, 1C... vehicle control devices, 10... vehicle control ECU, 10a... CPU, 20... in-vehicle sensor, 25... vehicle momentum detection sensor, 251... vehicle speed sensor, 252... acceleration sensor, 26... peripheral information detection sensor, 261... radar sensor, 261a... front radar sensor, 262... camera sensor, 262a... front camera sensor, 30... drive device, 31... drive ECU, 41... brake ECU, 40... brake device, 50... steering device, 51... steering ECU, 100... host vehicle, OB... preceding object

Claims

1. A braking device for braking the host vehicle, and a control device configured to start deceleration control for controlling the braking device so that the host vehicle decelerates when it is determined that there is a high possibility of collision between the host vehicle and a preceding target which is a target existing in the traveling direction of the host vehicle, and to end the deceleration control when a predetermined control end condition is satisfied during the execution of the deceleration control, A vehicle control device comprising: wherein the control end condition includes a margin condition that is satisfied when a margin representing a magnitude of a margin for avoiding a collision between the host vehicle and the preceding target after ending the deceleration control is equal to or greater than a predetermined threshold margin, Vehicle control device.

2. The vehicle control device according to claim 1, wherein the control device determines that the margin condition is satisfied when an acceleration condition that is satisfied when an acceleration of the preceding target is equal to or greater than a predetermined threshold acceleration is satisfied during the execution of the deceleration control. Vehicle control device.

3. The vehicle control device according to claim 1, wherein the control device determines that the margin condition is satisfied when a relative distance condition that is satisfied when a relative distance between the host vehicle and the preceding target is equal to or greater than a predetermined threshold distance is satisfied during the execution of the deceleration control. Vehicle control device.

4. The vehicle control device according to claim 1, wherein the control device determines that the margin condition is satisfied when a predicted time condition that is satisfied when a predicted time required for the host vehicle to reach the preceding target when the deceleration of the host vehicle is set to 0 is equal to or greater than a threshold time is satisfied during the execution of the deceleration control. Vehicle control device.

5. A braking device for braking the host vehicle, When it is determined that there is a high possibility of collision between the host vehicle and a preceding target which is a target existing in the traveling direction of the host vehicle, start deceleration control for controlling the braking device so that the host vehicle decelerates, and when a predetermined control end condition is satisfied during the execution of the deceleration control, a control device configured to end the deceleration control, A vehicle control device comprising: The control device is: During the execution of the deceleration control, when a relative speed condition that is satisfied when the relationship between the speed of the host vehicle and the speed of the preceding target is a relationship in which collision between the host vehicle and the preceding target can be avoided is satisfied, and a margin condition that is satisfied when a margin representing the magnitude of the margin for avoiding collision between the host vehicle and the preceding target after ending the deceleration control is equal to or greater than a predetermined threshold margin is satisfied, it is determined that the control end condition is satisfied. Vehicle control device.

6. The vehicle control device according to claim 5, wherein: During the execution of the deceleration control, when an acceleration condition that is satisfied when the acceleration of the preceding target is equal to or greater than a predetermined threshold acceleration is satisfied, the control device determines that the margin condition is satisfied. Vehicle control device.

7. The vehicle control device according to claim 5, wherein: During the execution of the deceleration control, when a relative distance condition that is satisfied when the relative distance between the host vehicle and the preceding target is equal to or greater than a predetermined threshold distance is satisfied, the control device determines that the margin condition is satisfied. Vehicle control device.

8. The vehicle control device according to claim 5, wherein: During the execution of the deceleration control, when a prediction time condition that is satisfied when the prediction time required for the host vehicle to reach the preceding target when the deceleration of the host vehicle is set to 0 is equal to or greater than a threshold time is satisfied, the control device determines that the margin condition is satisfied. Vehicle control device.

9. The vehicle control device according to claim 5, wherein, during execution of the deceleration control, the control device determines that the relative speed condition is satisfied when the speed of the host vehicle falls below the speed of the preceding target by a predetermined speed or more. Vehicle control device.

10. The vehicle control device according to claim 9, wherein the control device determines that the control end condition is satisfied when the relative speed condition is satisfied, a target speed condition that is satisfied when the speed of the preceding target is equal to or higher than a predetermined lower limit speed is satisfied, and the margin condition is satisfied. Vehicle control device.

11. An start step of starting deceleration control for controlling a braking device of the host vehicle so that the host vehicle decelerates when it is determined that there is a high possibility of collision between the host vehicle and a preceding target that is a target existing in the traveling direction of the host vehicle, An end step of ending the deceleration control when a predetermined control end condition is satisfied during execution of the deceleration control, A vehicle control method including: wherein the control end condition includes a margin condition that is satisfied when a margin representing a magnitude of a margin for avoiding a collision between the host vehicle and the preceding target after ending the deceleration control is equal to or greater than a predetermined threshold margin. Vehicle control method.

12. An start step of starting deceleration control for controlling a braking device of the host vehicle so that the host vehicle decelerates when it is determined that there is a high possibility of collision between the host vehicle and a preceding target that is a target existing in the traveling direction of the host vehicle, An end step of ending the deceleration control when a predetermined control end condition is satisfied during execution of the deceleration control, A vehicle control method including: The control end condition is established when, during the execution of the deceleration control, a relative speed condition that is established when the relationship between the speed of the host vehicle and the speed of the preceding target is such that it is possible to avoid a collision between the host vehicle and the preceding target is satisfied, and when a margin condition that is established when a margin representing the magnitude of the margin for avoiding a collision between the host vehicle and the preceding target after the deceleration control is terminated is equal to or greater than a predetermined threshold margin is satisfied. Vehicle control method.

13. A program that causes a computer provided in the host vehicle to execute a start step of starting deceleration control for controlling a braking device of the host vehicle so that the host vehicle decelerates when it is determined that there is a high possibility of a collision between the host vehicle and a preceding target that is a target existing in the traveling direction of the host vehicle, and an end step of ending the deceleration control when a predetermined control end condition is satisfied during the execution of the deceleration control. The control end condition includes a margin condition that is satisfied when a margin representing the magnitude of the margin for avoiding a collision between the host vehicle and the preceding target after the deceleration control is terminated is equal to or greater than a predetermined threshold margin. A program.

14. A program that causes a computer provided in the host vehicle to execute a start step of starting deceleration control for controlling a braking device of the host vehicle so that the host vehicle decelerates when it is determined that there is a high possibility of a collision between the host vehicle and a preceding target that is a target existing in the traveling direction of the host vehicle, and an end step of ending the deceleration control when a predetermined control end condition is satisfied during the execution of the deceleration control. The control end condition includes a margin condition that is satisfied when a margin representing the magnitude of the margin for avoiding a collision between the host vehicle and the preceding target after the deceleration control is terminated is equal to or greater than a predetermined threshold margin. A program. The control end condition is established when, during the execution of the deceleration control, a relative speed condition that is established when the relationship between the speed of the host vehicle and the speed of the preceding object is a relationship that enables avoidance of a collision between the host vehicle and the preceding object is satisfied, and when a margin condition that is established when a margin representing the magnitude of the margin for avoiding a collision between the host vehicle and the preceding object after the deceleration control is terminated is equal to or greater than a predetermined threshold margin is satisfied. Program.

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