Vehicle control device, vehicle control method, and vehicle control program

Abstract

To provide a vehicle control device that has a risk reduction function of reducing a risk of contact between an own vehicle and an object and that can sufficiently reduce the risk of contact in a specific scene where a risk of contact could not be reduced much by a conventional device.SOLUTION: A vehicle control device comprises: an on-vehicle sensor that acquires information on an object OB present around an own vehicle; and a processor that can execute risk reducing processing which controls the own vehicle so that a risk of contact between the own vehicle and the object is reduced on the basis of the information. The processor starts the risk reducing processing in a scene where there is a dead angle region BA in which the on-vehicle sensor cannot detect the object OB due to the presence of a vehicle ahead V1 which is located in a region being diagonally in front of the own vehicle and within the field of view of the on-vehicle sensor and which is traveling in the same direction as the own vehicle, if the vehicle ahead V1 is decelerating and a cause that makes the vehicle ahead V1 decelerate cannot be detected.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a vehicle control device, a vehicle control method, and a vehicle control program for reducing the contact risk between a host vehicle and an object.

Background Art

[0002] A vehicle control device having a function of reducing the contact risk between a host vehicle and an object has been proposed (see, for example, Patent Document 1 below). This vehicle control device (hereinafter referred to as the "conventional device") includes in-vehicle sensors such as a camera and a radar. The vehicle control device acquires the distance between the host vehicle and the object, the relative velocity vector, etc., and based on this information, predicts (calculates) the time from the current time until the time when it is predicted that the host vehicle and the object will come into contact. When the predicted time is less than or equal to a threshold value, the conventional device executes a deceleration process for controlling the braking device of the host vehicle so that the host vehicle decelerates (automatic deceleration function).

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

[0004] Incidentally, for example, a scene is assumed in which another vehicle (hereinafter referred to as "preceding vehicle") traveling in the same direction as the host vehicle in a travel lane adjacent to the travel lane in which the host vehicle is traveling is located within the field of view (detectable area) of the in-vehicle sensor of the host vehicle (hereinafter referred to as "specific scene"). In this specific scene, the in-vehicle sensor cannot detect an object located in an area farther from the host vehicle than the preceding vehicle (hereinafter referred to as "blind spot area") as viewed from the host vehicle. If an object moves from the blind spot area to the front area of the host vehicle, the in-vehicle sensor can detect the object, but at that time, there is a risk that the prediction time until the host vehicle contacts the object is considerably shorter than the threshold value. Therefore, even if the conventional device starts deceleration processing from that point, there is a risk that the contact risk between the host vehicle and the object is not significantly reduced.

[0005] One object of the present invention is to provide a vehicle control device having a risk reduction function for reducing the contact risk between the host vehicle and an object, which can sufficiently reduce the contact risk in a specific scene in which the conventional device could not significantly reduce the contact risk.

[0006] In order to solve the above problems, the vehicle control device (1) of the present invention includes: an in-vehicle sensor (20) for acquiring information about an object existing around the host vehicle; a processor (10) capable of executing a risk reduction process for controlling the host vehicle so that the contact risk between the host vehicle and the object is reduced based on the information; and is provided with. The processor In a specific scene (S) in which there is a preceding vehicle (V1) located in a region diagonally in front of the host vehicle and within the field of view (FOV) of the in-vehicle sensor, and there is a blind spot area (BA) where the in-vehicle sensor cannot detect an object because there is a preceding vehicle traveling in the same direction as the host vehicle, when a first specific condition (X1) for determining that the preceding vehicle is decelerating rapidly is satisfied and a second specific condition (Y1 / Y2 / Y3) for determining that a factor for decelerating the preceding vehicle cannot be detected is satisfied, the risk reduction process is started. is configured as follows.

[0007] In order to solve the above problems, the vehicle control method of the present invention includes an information acquisition step of acquiring information on an object existing around the host vehicle using an in-vehicle sensor, a risk reduction step of executing a risk reduction process for controlling the host vehicle so that the contact risk between the host vehicle and the object is reduced based on the information, and includes. The risk reduction step includes a start step of starting the risk reduction process in a specific situation where there is a blind spot area where the in-vehicle sensor cannot detect an object because a preceding vehicle traveling diagonally in front of the host vehicle is located within the field of view of the in-vehicle sensor, the preceding vehicle is decelerating, and a factor for decelerating the preceding vehicle cannot be detected. is configured as follows.

[0008] In order to solve the above problems, the vehicle control program of the present invention causes a computer provided in the host vehicle to execute an information acquisition step of acquiring information on an object existing around the host vehicle using an in-vehicle sensor, and a risk reduction step of executing a risk reduction process for controlling the host vehicle so that the contact risk between the host vehicle and the object is reduced based on the information. and execute. The risk reduction step includes a start step of starting the risk reduction process when a first specific condition for determining that a preceding vehicle located in an area diagonally in front of the host vehicle and within the field of view of the in-vehicle sensor and traveling in the same direction as the host vehicle is rapidly decelerating is satisfied, and a second specific condition for determining that a factor for decelerating the preceding vehicle cannot be detected is satisfied in a specific scene where there is a blind spot area where the in-vehicle sensor cannot detect an object. is configured as follows.

[0009] In the above specific scene, if the leading vehicle is decelerating rapidly and the cause cannot be detected, there is a high possibility that an object (e.g., a pedestrian or a bicycle as a moving body) as the cause exists in the blind spot area. And there is a high possibility that this object will move into the front area of the host vehicle. Therefore, in the present invention, when the leading vehicle is decelerating rapidly in the specific scene and the cause cannot be detected (when the first specific condition is satisfied and the second specific condition is satisfied), the processor starts the risk reduction process. That is, even when the processor has not directly detected an object highly likely to come into contact with the host vehicle, if it can be determined based on the behavior of the leading vehicle and the surrounding situation that there is a high possibility that an object will move from the blind spot area into the front area of the host vehicle later, the risk reduction process is started. That is, in a specific scene, when specific conditions are satisfied, the processor can start the risk reduction process earlier (before detecting the object) than in the past. Therefore, according to the present invention, in a specific scene where the contact risk could not be significantly reduced by a conventional device, the contact risk can be sufficiently reduced.

[0010] In a vehicle control device according to an aspect of the present invention, The risk reduction process is a process executed when the first specific condition and the second specific condition are satisfied in the specific scene, A first process (PP1) of controlling a notification device so as to enhance the responsiveness of a driver to an object when the object has moved from the blind spot area to a front area of the host vehicle where the in-vehicle sensor can detect the object, A second process (PP2) of controlling a braking device so as to enhance the responsiveness of the vehicle body of the host vehicle to an operation of braking the host vehicle, which is assumed to be manually or automatically executed triggered by the object having moved from the blind spot area to the front area, and A third process (PP3) of controlling a steering device so as to enhance the responsiveness of the vehicle body of the host vehicle to an operation of changing the steering angle of the host vehicle, which is assumed to be manually or automatically executed triggered by the object having moved from the blind spot area to the front area, includes at least one of the processes.

[0011] When the first specific condition and the second specific condition are satisfied in a specific scene, by executing the first process, the driver's responsiveness to an object that has advanced from a blind spot area to the front area of the host vehicle is enhanced. That is, the time required for the driver to recognize an object that has advanced from the blind spot area to the front area of the host vehicle is shortened compared to the case where the first process is not executed. And the start timing of a manual driving operation (an action to avoid contact between the host vehicle and the object) is advanced.

[0012] Also, it is assumed that when an object advances from a blind spot area to the front area of the host vehicle, the driver performs a driving operation to manually avoid the object. Also, there may be a case where the processor is configured to automatically execute the driving operation. By executing a second process as a preparation process prior to the braking operation as the driving operation, the responsiveness of the host vehicle to the braking operation is enhanced. That is, the time from the braking operation until the host vehicle starts to decelerate is shortened compared to the case where the second process is not executed.

[0013] Also, by executing a third process as a preparation process prior to the steering angle change operation as the driving operation, the responsiveness of the host vehicle to the steering angle change operation is enhanced. That is, the time from the steering angle change operation until the steering angle of the host vehicle starts to change is shortened compared to the case where the third process is not executed.

[0014] In a vehicle control device according to another aspect of the present invention, the first process includes a process of presenting information indicating that an object is likely to advance from the blind spot area to the front area to the driver of the host vehicle.

[0015] According to this, the driver can recognize that an object is likely to advance from the blind spot area to the front area of the host vehicle. Therefore, the concentration of the driver on the driving operation (attention to the blind spot area and its peripheral area) is enhanced.

[0016] In a vehicle control device according to another aspect of the present invention, the braking device (40) includes a brake mechanism (41) for applying a braking force to the wheels of the host vehicle, and a brake actuator (42) for driving the brake mechanism. The second process includes a process of driving the brake actuator so that the braking force is not applied to the wheels before an operation of braking the host vehicle that is assumed to be manually or automatically executed thereafter.

[0017] Here, in the situation where the second process is executed, the driver cannot visually recognize an object that obstructs the progress of the host vehicle. In this situation, if the host vehicle is automatically braked, the driver may feel discomfort with the automatic braking. The processor of the vehicle control device according to this aspect drives the brake actuator to such an extent that the host vehicle does not decelerate in the second process. That is, the brake actuator is controlled so that the brake mechanism can be immediately driven, or the brake mechanism can immediately generate a braking force (a state where the play of the brake mechanism is "0" or minimal). Therefore, according to the vehicle control device according to this aspect, the discomfort of the driver as described above can be suppressed.

[0018] In a vehicle control device according to another aspect of the present invention, the steering device (50) includes a steering mechanism (51) for changing the steering angle of the host vehicle and a steering actuator (52) for driving the steering mechanism. The third process includes a process of driving the steering actuator so that the steering angle is not changed before an operation of changing the steering angle of the host vehicle that is assumed to be manually or automatically executed thereafter.

[0019] Here, in the situation where the third process is executed, the driver cannot visually recognize an object that obstructs the progress of the host vehicle. In this situation, if the host vehicle is automatically steered, the driver may feel uncomfortable with the automatic steering. The processor of the vehicle control system according to this aspect drives the steering actuator to such an extent that the host vehicle is not steered in the third process. That is, the steering actuator is controlled so that the steering mechanism can be immediately driven, or the steering mechanism can immediately drive the steered wheels (a state where the play of the steering mechanism is "0" or minimal). Therefore, according to the vehicle control device according to this aspect, the discomfort of the driver as described above can be suppressed.

[0020] In a vehicle control device according to another aspect of the present invention, the processor determines that the second specific condition is satisfied when at least one of the following situations applies: a situation where there is no moving object in a predetermined area in front of the preceding vehicle, a situation where there is no sign restricting the progress of the preceding vehicle in the predetermined area, and a situation where the turn signal of the preceding vehicle is not operating. According to this, the processor can acquire information about an object located in front of the preceding vehicle or information about the behavior of the preceding vehicle from in-vehicle sensors, and can relatively easily determine whether the second specific condition is satisfied based on that information.

[0021]

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4

Figure 5

MODE FOR CARRYING OUT THE INVENTION

[0023] (Schematic) As shown in FIG. 1, a vehicle control device 1 according to an embodiment of the present invention is applied to a vehicle V (hereinafter referred to as the "host vehicle") having an automatic driving function. The vehicle control device 1 has a risk reduction function that executes a risk reduction process for controlling the host vehicle (notification device 30, braking device 40, and steering device 50) so that the contact risk between the host vehicle and an object located around it is reduced in a state where the automatic driving function is disabled.

[0024] (Specific Configuration) As shown in FIG. 1, the vehicle control device 1 includes an ECU 10, an in - vehicle sensor 20, a notification device 30, a braking device 40, and a steering device 50.

[0025] The ECU 10 includes a microcomputer including a CPU 10a, a ROM 10b (rewritable non - volatile memory), a RAM 10c, a timer 10d, etc. The CPU realizes various functions by executing a program (instruction) stored in the ROM. The ECU 10 is connected to other ECUs via a CAN (Controller Area Network).

[0026] The in - vehicle sensor 20 includes an object detection sensor DS for detecting an object OB located in front of the host vehicle. The object detection sensor DS includes a camera 21 and a millimeter - wave radar 22.

[0027] Camera 21 is equipped with an imaging device and an image analysis device. The imaging device incorporates, for example, a CCD. The imaging device is installed at the front of the host vehicle and is directed forward of the host vehicle. The imaging device captures the forward area of the host vehicle at a predetermined frame rate to acquire image data. The image analysis device acquires the image data from the imaging device, analyzes the image data, and recognizes (identifies) the targets present within the angle of view. The image analysis device recognizes, for example, lane marks (the dividing lines of the driving lane). Also, the image analysis device recognizes, for example, a preceding vehicle V1 located within a section of the driving lane L2 adjacent to the driving lane L1 on which the host vehicle is traveling and in a section ahead of the host vehicle (the diagonally forward area of the host vehicle). Further, the image analysis device recognizes, for example, signs (traffic lights, stop signs, etc.). The image analysis device provides the recognition result (the identification result of the target) to the ECU10.

[0028] The millimeter-wave radar 22 is equipped with a transmitting / receiving unit and a signal processing unit. The transmitting / receiving unit radiates radio waves in the millimeter-wave band (hereinafter referred to as "millimeter waves") to the surrounding area of the host vehicle (the front of the host vehicle), and receives the millimeter waves (reflected waves) reflected by a three-dimensional object located within the area (for example, a three-dimensional object located within the driving lane L2). The signal processing unit acquires various information regarding each reflection point of the millimeter waves based on physical quantities such as the time from when the transmitting / receiving unit radiates the millimeter waves until the reflected waves are received, the attenuation level of the reflected waves, and the difference between the frequency of the radiated millimeter waves and the frequency of the received reflected waves. For example, the signal processing unit calculates the position of each reflection point (the relative position (direction and distance) with respect to the transmitting / receiving unit). Also, the signal processing unit calculates the speed (relative speed vr (vector)) of each reflection point with respect to the host vehicle. Then, the calculation result (data indicating the distribution of the reflection points (data including the position and speed related to each reflection point)) is provided to the ECU10.

[0029] Here, the angle of view (image capture range) of the camera 21 and the field of view (area where millimeter waves are emitted) of the millimeter wave radar 22 overlap. In the following description, the overlapping area between the two is referred to as the field of view FOV of the object detection sensor DS. As shown in FIG. 2, the field of view FOV has a sector shape in a planar view. The ECU 10 can acquire information about an object OB present within the field of view FOV (type of object (pedestrian, vehicle, etc.), position of the object relative to the host vehicle, speed (vector) of the object relative to the host vehicle, etc.) based on fusion information that combines information acquired from the camera 21 and information acquired from the millimeter wave radar 22.

[0030] The on-vehicle sensor 20 further includes a vehicle speed sensor 23. The vehicle speed sensor 23 includes a rotation speed measurement circuit and a vehicle speed calculation device. The rotation speed measurement circuit includes a pulse generation circuit that outputs a pulse (electrical signal) every time a wheel of the vehicle rotates by a predetermined angle, and a counter circuit that counts the number of the pulses. The vehicle speed calculation device acquires an output value (number of pulses) of the counter circuit at a predetermined cycle (each time a unit time elapses), and resets the count value to "0". In this way, the vehicle speed calculation device acquires the number of rotations N of the wheel per unit time. The vehicle speed calculation device acquires the vehicle speed vs (the speed (absolute value) in the front-rear (vertical) direction) of the vehicle by multiplying the number of rotations N by a coefficient k. The vehicle speed calculation device then provides the acquired vehicle speed vs to the ECU 10. The ECU 10 can obtain the speed vs1 (speed relative to the road surface) of the preceding vehicle V1 based on the relative speed (vector) between the preceding vehicle V1 and the vehicle itself obtained from the millimeter wave radar 22 and the speed vs obtained from the vehicle speed sensor 23.

[0031] The notification device 30 includes an image display device and an audio device. The image display device is disposed, for example, on an instrument panel (near the speed display device). The image display device displays an image based on an image display command obtained from the ECU 10. The audio device reproduces audio based on an audio reproduction command obtained from the ECU 10.

[0032] The braking device 40 applies a braking force to the wheels. The braking device 40 includes a brake mechanism (brake caliper) 41, a brake actuator 42, a brake ECU 43, etc. The brake mechanism 41 includes brake pads that are pressed against a brake disk assembled to the wheels. The brake actuator 42 is a hydraulic actuator composed of a cylinder, a piston, a reservoir, an oil pump, various valve devices, a hydraulic sensor, etc. not shown in the figure. The brake pads are connected to the tip of the piston.

[0033] When the driver depresses a brake pedal (not shown) of the host vehicle (when a manual braking operation is executed), the ECU 10 transmits a braking command (target value of the braking force) corresponding to the mode (depression depth) of the operation to the brake ECU 43. Also, when a predetermined condition is satisfied while the brake pedal is not depressed, the ECU 10 transmits a predetermined braking command (target value of the braking force) to the brake ECU 43. That is, when a predetermined condition is satisfied, a braking operation is automatically executed.

[0034] The brake ECU 43 determines (calculates) the target value of the hydraulic pressure in the cylinder of the brake actuator 42 based on the command (target value of the braking force) acquired from the ECU 10. The brake ECU 43 controls the oil pump so that the output value of the hydraulic sensor matches the target value. In this way, the brake pads are driven by the brake actuator 42. Thereby, the braking force (frictional force between the brake pads and the brake disk) is made to match the target value.

[0035] Here, when the brake actuator 42 is not operating (when the target value of the braking force is "0"), there may be a gap (play) formed between the brake pad and the brake disk. From this state, when the ECU 10 sends a command to generate a braking force for the wheel to the brake ECU 43, the distance between the brake pad and the brake disk is narrowed, and it takes a little time until the brake pad contacts the brake disk. Therefore, in order to shorten the time from when the ECU 10 sends a braking command to the brake ECU until the distance between the brake pad and the brake disk is narrowed by the movement of the piston of the brake actuator 42 and the brake pad contacts the brake disk (until the braking force starts to be generated) (to enhance the responsiveness of the vehicle body to the braking operation), the ECU 10 can send a command (a backlash elimination command) for controlling the brake actuator 42 so that the brake pad is in a state of lightly contacting the brake disk (a state where the braking force is "0" or very small) in a situation where the target value of the braking force is "0". Hereinafter, this process is referred to as the "backlash elimination process of the braking mechanism".

[0036] The steering device 50 changes the steering angle of the steered wheels. The steering device 50 includes a steering mechanism 51, a steering actuator 52, a steering ECU 53, and the like. The steering mechanism 51 includes a link mechanism composed of a rack bar, a pinion, a steering rod, etc. that are connected (linked) to the steered wheels. The steering actuator 52 includes an electric motor (not shown) and a steering sensor. The output shaft of the electric motor is engaged with the steering mechanism 51 (for example, the steering rod) via a reduction gear. The steering sensor detects the rotation angle or torque of the output shaft of the electric motor.

[0037] When the driver rotates the steering wheel (not shown) of the host vehicle (when an operation to manually change the steering angle is performed), the ECU 10 transmits a steering command (target value of the steering angle) corresponding to the mode of the operation (rotation angle of the steering wheel) to the steering ECU 53. Further, when a predetermined condition is satisfied in a state where the steering wheel is not being rotated, the ECU 10 transmits a predetermined steering command (target value of the steering angle) to the steering ECU 53. That is, when the predetermined condition is satisfied, an operation to automatically change the steering angle (automatic steering) is performed.

[0038] Based on the steering command (target value of the steering angle) acquired from the ECU 10, the steering ECU 53 determines (calculates) the target value of the rotation angle (or torque) of the electric motor of the steering actuator 52. The steering ECU 53 controls the electric motor of the steering actuator 52 so that the output value of the steering sensor matches the target value. In this way, the steering mechanism 51 is driven by the steering actuator 52 (for example, the steering rod is rotationally driven). Thereby, the steering force of the driver (rotation operation torque of the steering wheel) is reduced. Also, in automatic steering, the steering angle of the steered wheels is made to match the target value.

[0039] Here, when the steering actuator 52 is not operating (when the target value of the steering angle is "0" (neutral position)), there may be a gap (play) formed at the engagement part between the components constituting the steering mechanism 51 (for example, the rack bar and the pinion). From this state, when the ECU 10 sends a steering command to change the steering angle to the steering ECU, it takes a little time until the gap at the engagement part between the components constituting the steering mechanism 51 is narrowed and the components come into contact with each other. Therefore, in order to shorten the time from when the ECU 10 sends a steering command to the steering ECU until the gap at the engagement part between the components of the steering mechanism 51 is narrowed by the electric motor of the steering actuator 52 and these components come into contact with each other (until the steering angle starts to change) (to enhance the responsiveness of the vehicle body to steering), the ECU 10 can send a command (a backlash elimination command) for controlling the steering actuator 52 so that the components of the steering mechanism 51 are in a state of lightly contacting each other (a state where the change in the steering angle is "0" or very small) in a situation where the target value of the steering angle is "0". That is, the ECU 10 rotates the output shaft of the electric motor of the steering actuator 52 by a minute angle. Note that the ECUI 10 determines the rotation direction of the electric motor according to the success or failure of various conditions. Hereinafter, this process is referred to as the "backlash elimination process of the steering mechanism".

[0040] (Risk reduction function) When the ignition switch is in the ON state, the ECU 10 acquires various information from the in-vehicle sensor 20 at a predetermined cycle, and based on the information, acquires the time to collision TTC until the host vehicle contacts an object OB (moving body) located in front of the host vehicle (inside the field of view FOV). Specifically, the ECU 10 determines whether an object OB exists in front of the host vehicle based on the information acquired from the camera 21 and the millimeter-wave radar 22. When the ECU 10 determines that an object OB exists in front of the host vehicle, based on the information acquired from the camera 21 and the millimeter-wave radar 22, the ECU 10 acquires the distance D between the host vehicle and the object OB and the relative speed vr (the speed at which the object OB is approaching the host vehicle). Then, the ECU 10 acquires the value obtained by dividing the distance D by the relative speed vr as the time to collision TTC (= D / vr). When the time to collision TTC is equal to or less than the threshold value TTCth, the ECU 10 executes the following warning process P1, automatic braking process P2, and automatic steering process P3 as risk reduction processes to reduce the risk of contact between the host vehicle and the object OB.

[0041] (Warning process P1) The ECU 10 transmits a predetermined warning command to the notification device 30 in order to prompt the driver to start an avoidance action to avoid contact between the host vehicle and the object OB. The image display device of the notification device 30 displays, as an image corresponding to the warning command, for example, the "icon representing the brake pedal" and the "icon representing the steering wheel" shown in FIG. 3A. Note that the ECU 10 may calculate the direction of rotating the steering wheel according to the positional relationship between the host vehicle and the object OB, and cause the image display device to display an image (icon indicating the direction in which the steering wheel should be rotated) according to the calculation result. Further, the acoustic device of the notification device 30 reproduces, as a voice corresponding to the warning command, for example, a voice saying "Please start the avoidance action".

[0042] (Automatic braking process P2) ECU 10 determines the target value F of the braking force based on the time TTC. Here, a map M1 that defines the relationship between the time TTC and the target value F of the braking force is stored in the ROM 10b. ECU 10 determines the target value F by referring to the map M1. Note that the map M1 is designed such that the target value Fa of the braking force corresponding to the time TTCa is greater than the target value Fb corresponding to the time TTCb that is greater than the time TTCa. ECU 10 transmits the determined target value F as a braking command to the brake ECU 43.

[0043] (Automatic steering process P3) ECU 10 determines the target value θ (including the steering direction) of the steering angle based on the time TTC and the direction γ of the object OB as seen from the host vehicle. Here, a map M2 that defines the relationship between the time TTC and the direction γ and the target value θ of the steering angle is stored in the ROM 10b. ECU 10 determines the target value θ by referring to the map M2. Note that the map M2 is designed such that the absolute value of the target value θa corresponding to the time TTCa is greater than the absolute value of the target value θb corresponding to the time TTCb that is greater than the time TTCa. ECU 10 transmits the determined target value θ as a steering command to the steering ECU 53.

[0044] While the ECU 10 is executing the above warning process P1, automatic braking process P2, and automatic steering process P3, if the driver manually starts a driving operation (avoidance action), the warning process P1, automatic braking process P2, and automatic steering process P3 are interrupted (override process).

[0045] Here, as shown in FIG. 4, a scene (hereinafter referred to as "specific scene S") is assumed in which a preceding vehicle V1 traveling in the same direction as the host vehicle in a travel lane L2 adjacent to the travel lane L1 in which the host vehicle is traveling is located within the field of view FOV of the object detection sensor DS of the host vehicle. In this specific scene S, the camera 21 and the millimeter-wave radar 22 cannot detect an object OB located in a region farther from the preceding vehicle V1 than the host vehicle (hereinafter referred to as "blind spot region BA") when viewed from the host vehicle. Therefore, as shown in FIGS. 4(A) and 4(B), if there are no objects other than the preceding vehicle V1 in the region excluding the blind spot region BA in the field of view FOV, the ECU10 does not execute the above-described warning process P1, automatic braking process P2, and automatic steering process P3. In this example, the preceding vehicle V1 is located diagonally in front of the host vehicle and is traveling in the same direction as the host vehicle. Therefore, the time to collision TTC exceeds the threshold TTCth. Thus, the ECU10 does not execute the warning process P1, automatic braking process P2, and automatic steering process P3 for reducing the contact risk between the preceding vehicle V1 and the host vehicle.

[0046] By the way, in the specific scene S, when the preceding vehicle V1 is decelerating and its deceleration α (backward acceleration) is relatively large (sudden deceleration state), and there is no target that causes the preceding vehicle V1 to decelerate in front of the preceding vehicle V1, or when the preceding vehicle V1 is not trying to change lanes, there is a high possibility that an object OB (for example, a pedestrian, a bicycle, etc.) that causes the preceding vehicle V1 to decelerate exists in the blind spot region BA. As this scene, for example, as shown in FIGS. 4(A) and 4(B), a scene in which an object OB (pedestrian) jumps out into the front region of the preceding vehicle V1 is assumed. And as shown in FIG. 4(C), there is a possibility that this object OB will jump out into the front region of the host vehicle.

[0047] Therefore, when the preceding vehicle V1 is decelerating rapidly in a specific scene S and the ECU 10 cannot detect the cause of the rapid deceleration of the preceding vehicle V1, in order to reduce the risk of contact between the host vehicle and the object OB, as risk reduction processing, the following warning processing PP1, braking preparation processing PP2, and steering preparation processing PP3 are executed.

[0048] Here, in the present embodiment, when the following condition X1 is satisfied, it is considered that the preceding vehicle V1 is decelerating rapidly. [Condition X1]... The deceleration α exceeds the threshold value αth.

[0049] Further, in the present embodiment, when at least one of the following conditions Y1, Y2, and Y3 regarding the situation (presence or absence of a predetermined target) in the front area FA of the preceding vehicle V1 and the turn signal of the preceding vehicle V1 is satisfied, it is considered that the cause of the rapid deceleration of the preceding vehicle V1 cannot be detected. [Condition Y1]... There is no preceding vehicle V2 (a vehicle different from the preceding vehicle V1) in the front area FA. [Condition Y2]... There is no sign (such as a traffic signal with a yellow or red light color, a stop sign once) that restricts the progress of the preceding vehicle V1 in the front area FA. [Condition Y3]... The turn signal of the preceding vehicle V1 is not operating.

[0050] The ECU 10 sequentially acquires the speed vs1 of the preceding vehicle V1 based on the information obtained from the object detection sensor DS, and acquires the deceleration α based on the change in the speed vs1. The ECU 10

[0051] Further, the ECU 10 acquires information about a target located in the front area FA (the section immediately in front of the preceding vehicle V1 in the driving lane L2) from the object detection sensor DS. Further, the ECU 10 acquires the operating state of the direction indicator of the preceding vehicle V1 based on the information acquired from the object detection sensor DS. Note that the ECU 10 may acquire information about a sign located in the front area FA based on the map information of a navigation system (not shown).

[0052] When the condition X1 is satisfied and at least one of the conditions Y1, Y2, and Y3 is satisfied, the ECU 10 executes the following alert processing PP1, braking preparation processing PP2, and steering preparation processing PP3.

[0053] (Alert Processing PP1) The ECU 10 transmits a predetermined alert command to the notification device 30 in order to alert the driver to the sudden appearance of the object OB from the blind spot area BA into the front area of the host vehicle. The image display device of the notification device 30 displays, as an image corresponding to the alert command, for example, the image (icon) showing the scene where the object (pedestrian) has suddenly appeared as shown in FIG. 3B. Note that the ECU 10 may cause the image display device to display an image corresponding to the direction of the blind spot area BA as seen from the host vehicle. Specifically, when the blind spot area BA is located diagonally in front of the host vehicle on the right as seen from the host vehicle, the ECU 10 causes the image display device to display an image (FIG. 3B) showing the scene where the object (pedestrian) moves from right to left. On the other hand, when the blind spot area BA is located diagonally in front of the host vehicle on the left as seen from the host vehicle, the ECU 10 causes the image display device to display an image (the image obtained by inverting the image shown in FIG. 3B horizontally to the right direction) showing the scene where the object (pedestrian) moves from left to right. Further, the acoustic device of the notification device 30 reproduces, as a voice corresponding to the alert command, for example, the voice "Please pay attention to the sudden appearance of an object".

[0054] (Braking Preparation Processing PP2) When an object OB jumps out from the blind spot area BA into the front area of the host vehicle, the ECU10 executes the backlash elimination process of the braking mechanism described above so that the responsiveness of the vehicle body of the host vehicle to a braking operation (a stepping operation of the brake pedal or an automatic braking process) that is assumed to be manually or automatically executed is enhanced.

[0055] (Steering preparation process PP3) When an object OB jumps out from the blind spot area BA into the front area of the host vehicle, the ECU10 executes the backlash elimination process of the steering mechanism described above so that the responsiveness of the vehicle body of the host vehicle to an operation of changing the steering angle (a rotation operation of the steering wheel or an automatic steering process) that is assumed to be manually or automatically executed is enhanced.

[0056] Next, with reference to FIG. 5, a program PR1 executed by the CPU10a (hereinafter simply referred to as "CPU") of the ECU10 will be described to realize a function of controlling the notification device 30, the braking device 40, and the steering device 50 in a predetermined manner in preparation for a situation where an object OB jumps out from the blind spot area BA.

[0057] When the ignition switch is in the ON state, the CPU starts executing the program PR1 at a predetermined cycle. The CPU starts executing the program PR1 from step 100 and proceeds to step 101.

[0058] At step 101, the CPU determines whether there is a preceding vehicle V1 diagonally in front of the host vehicle. If the CPU determines that there is a preceding vehicle V1 diagonally in front of the host vehicle (103: Yes), the CPU proceeds to step 102. On the other hand, if the CPU does not determine that there is a preceding vehicle V1 diagonally in front of the host vehicle (101: No), the CPU proceeds to step 107, and at this step 107, the execution of the program PR1 is terminated.

[0059] At step 102, the CPU calculates the deceleration α (the absolute value of the backward acceleration) of the preceding vehicle V1, and determines whether the deceleration α exceeds the threshold value αth (whether condition X1 is satisfied). If the CPU determines that the deceleration α exceeds the threshold value αth (102: Yes), the process proceeds to step 103. On the other hand, if the CPU does not determine that the deceleration α exceeds the threshold value αth (103: No), the process proceeds to step 107, and at this step 107, the execution of program PR1 is terminated.

[0060] At step 103, the CPU determines whether it is impossible to detect the cause of the sudden deceleration of the preceding vehicle V1 (whether at least one of condition Y1, condition Y2, and condition Y3 is satisfied). If the CPU determines that it is impossible to detect the cause (103: Yes), the process proceeds to step 104. On the other hand, if the CPU does not determine that it is impossible to detect the cause (104: No), the process proceeds to step 107, and at this step 107, the execution of program PR1 is terminated.

[0061] At step 104, the CPU executes the attention - calling process PP1. Then, the CPU proceeds to step 105.

[0062] At step 105, the CPU executes the braking - preparation process PP2. Then, the CPU proceeds to step 106.

[0063] The CPU executes the steering preparation process PP3 in step 106. Next, the CPU proceeds to step 107 and ends the execution of program PR1 in this step 107. In the case where it is preferable not to steer the host vehicle because there is a preceding vehicle V1a diagonally in front of the right side of the host vehicle and a preceding vehicle V1b diagonally in front of the left side of the host vehicle (or when the steering direction cannot be predicted), the CPU skips this step 106. In addition to executing program PR1, the CPU executes a program similar to the conventional device. That is, when the time to collision TTC between the object OB detected by the object detection sensor DS and the host vehicle is equal to or less than the threshold value, the CPU executes the warning process P1, the automatic braking process P2, and the automatic steering process P3.

[0064] (Effect) When the preceding vehicle V1 is decelerating rapidly in the specific scene S and the cause cannot be detected, there is a high possibility that an object OB (for example, a pedestrian or a bicycle as a moving body) as the cause exists in the blind spot area BA. And there is a high possibility that this object OB will proceed into the front area of the host vehicle. Therefore, in the present embodiment, when the preceding vehicle V1 is decelerating rapidly in the specific scene S and the cause cannot be detected, the ECU10 executes a warning process, a braking preparation process, and a steering preparation process as risk reduction processes. That is, even when the ECU10 does not directly detect an object OB highly likely to come into contact with the host vehicle, based on the behavior of the preceding vehicle V1 and the surrounding situation, if it can be determined that there is a high possibility that the object OB will proceed from the blind spot area BA into the front area of the host vehicle later, the risk reduction process is started. That is, in the specific scene S, when a specific condition is satisfied, the ECU10 can start the risk reduction process earlier (before detecting the object) than in the past. According to the vehicle control device 1 configured as described above, in the specific scene S where the conventional device could not reduce the contact risk so much, the contact risk can be sufficiently reduced.

[0065] The present invention is not limited to the above-described embodiments, and as described below, various modifications can be adopted within the scope of the present invention.

[0066] <Modification Example 1> In the above embodiment, when any one of the conditions Y1 to Y3 is satisfied, it is regarded that the factor causing the preceding vehicle V1 to decelerate rapidly cannot be detected. Instead, when condition Y1 is satisfied, condition Y2 is satisfied, and further condition Y3 is satisfied, it may be regarded that the factor causing the preceding vehicle V1 to decelerate rapidly cannot be detected.

[0067] <Modification Example 2> In the above embodiment, when the ECU 10 detects the object OB, it executes the warning process, the automatic braking process, and the automatic steering process. Instead, when the ECU 10 detects the object OB, it may be capable of executing only any one of the warning process, the automatic braking process, and the automatic steering process.

Explanation of Reference Numerals

[0068] 1... Vehicle control device, 10... ECU, 20... In-vehicle sensor, 30... Notification device, 40... Braking device, 50... Steering device

Claims

1. An in-vehicle sensor for acquiring information about an object existing around the host vehicle, a processor capable of executing a risk reduction process for controlling the host vehicle so that the contact risk between the host vehicle and the object is reduced based on the information, A vehicle control device comprising: The processor is In a specific scene where there is a dead angle area where the in-vehicle sensor cannot detect an object because there is a preceding vehicle located in a region diagonally in front of the host vehicle and within the field of view of the in-vehicle sensor and traveling in the same direction as the host vehicle, when a first specific condition for determining that the preceding vehicle is decelerating rapidly is satisfied and a second specific condition for determining that a factor for decelerating the preceding vehicle cannot be detected is satisfied, start the risk reduction process. A vehicle control device configured as described above.

2. In the vehicle control device according to Claim 1, The risk reduction process is a process executed when the first specific condition and the second specific condition are satisfied in the specific scene, A first process of controlling a notification device so as to enhance the driver's responsiveness to an object when the object travels from the dead angle area to a front area of the host vehicle where the in-vehicle sensor can detect the object, A second process of controlling a braking device so as to enhance the responsiveness of the vehicle body of the host vehicle to an operation of braking the host vehicle that is assumed to be manually or automatically executed triggered by the object traveling from the dead angle area to the front area, and A third process of controlling a steering device so as to enhance the responsiveness of the vehicle body of the host vehicle to an operation of changing the steering angle of the host vehicle that is assumed to be manually or automatically executed triggered by the object traveling from the dead angle area to the front area, A vehicle control device including at least one of the processes.

3. In the vehicle control device according to Claim 2, The first process includes a process of presenting information indicating that there is a high possibility that an object will travel from the dead angle area to the front area to the driver of the host vehicle. A vehicle control device.

4. In the vehicle control device according to Claim 2, The braking device includes a brake mechanism for applying a braking force to the wheels of the host vehicle and a brake actuator for driving the brake mechanism, The vehicle control device, wherein the second process includes a process of driving the brake actuator to such an extent that braking force is not applied to the wheels before an operation of braking the host vehicle, which is assumed to be manually or automatically executed thereafter.

5. In the vehicle control device according to claim 2, the steering device includes a steering mechanism for changing the steering angle of the host vehicle and a steering actuator for driving the steering mechanism, and the third process includes a process of driving the steering actuator to such an extent that the steering angle is not changed before an operation of changing the steering angle of the host vehicle, which is assumed to be manually or automatically executed thereafter.

6. In the vehicle control device according to any one of claims 1 to 5, the processor is configured to determine that the second specific condition is satisfied when at least any one of the following situations occurs: a situation where no moving object exists in a predetermined area in front of the preceding vehicle; a situation where no sign for restricting the progress of the preceding vehicle exists in the predetermined area; and a situation where the turn signal of the preceding vehicle is not operating.

7. An information acquisition step of acquiring information on an object existing around the host vehicle using an in-vehicle sensor, and a risk reduction step of executing a risk reduction process for controlling the host vehicle so that the contact risk between the host vehicle and the object is reduced based on the information. The vehicle control method includes an information acquisition step of acquiring information on an object existing around the host vehicle using an in-vehicle sensor, and a risk reduction step of executing a risk reduction process for controlling the host vehicle so that the contact risk between the host vehicle and the object is reduced based on the information.

8. A vehicle control program for causing a computer provided in the host vehicle to execute an information acquisition step of acquiring information on an object existing around the host vehicle using an in-vehicle sensor, and a risk reduction step of executing a risk reduction process for controlling the host vehicle so that the contact risk between the host vehicle and the object is reduced based on the information. The risk reduction step includes a start step of starting the risk reduction process in a specific situation where there is a blind spot area where the in-vehicle sensor cannot detect an object because a preceding vehicle traveling diagonally in front of the host vehicle is located within the field of view of the in-vehicle sensor, the preceding vehicle is decelerating, and a factor for decelerating the preceding vehicle cannot be detected.

9. A vehicle control program for causing a computer provided in the host vehicle to execute an information acquisition step of acquiring information on an object existing around the host vehicle using an in-vehicle sensor, and a risk reduction step of executing a risk reduction process for controlling the host vehicle so that the contact risk between the host vehicle and the object is reduced based on the information. The risk reduction step includes a start step of starting the risk reduction process in a specific situation where there is a blind spot area where the in-vehicle sensor cannot detect an object because a preceding vehicle traveling diagonally in front of the host vehicle is located within the field of view of the in-vehicle sensor, the preceding vehicle is decelerating, and a factor for decelerating the preceding vehicle cannot be detected.

10. A vehicle control program for causing a computer provided in the host vehicle to execute an information acquisition step of acquiring information on an object existing around the host vehicle using an in-vehicle sensor, and a risk reduction step of executing a risk reduction process for controlling the host vehicle so that the contact risk between the host vehicle and the object is reduced based on the information.

11. A vehicle control program for causing a computer provided in the host vehicle to execute an information acquisition step of acquiring information on an object existing around the host vehicle using an in-vehicle sensor, and a risk reduction step of executing a risk reduction process for controlling the host vehicle so that the contact risk between the host vehicle and the object is reduced based on the information. The risk reduction step includes a start step of starting the risk reduction process in a specific situation where there is a blind spot area where the in-vehicle sensor cannot detect an object because a preceding vehicle traveling diagonally in front of the host vehicle is located within the field of view of the in-vehicle sensor, the preceding vehicle is decelerating, and a factor for decelerating the preceding vehicle cannot be detected.

12. A vehicle control program for causing a computer provided in the host vehicle to execute an information acquisition step of acquiring information on an object existing around the host vehicle using an in-vehicle sensor, and a risk reduction step of executing a risk reduction process for controlling the host vehicle so that the contact risk between the host vehicle and the object is reduced based on the information. In a specific scene where there is a leading vehicle located in the diagonally forward area of the host vehicle and within the field of view of the in-vehicle sensor, and there is a blind spot area where the in-vehicle sensor cannot detect an object due to the presence of a leading vehicle traveling in the same direction as the host vehicle, when a first specific condition for determining that the leading vehicle is decelerating rapidly is satisfied, and a second specific condition for determining that a factor causing the leading vehicle to decelerate cannot be detected is satisfied, it includes a start step of starting the risk reduction process. A vehicle control program configured as described above.

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