Vehicle Driving Assistance Device

Abstract

To provide a vehicle operation support device capable of reducing a possibility of an own vehicle to excessively approach an object intersection target.SOLUTION: A vehicle operation support device DS includes a control unit (10). The control unit performs at least one control between own vehicle travel restriction control (e.g., brake-holding control to prohibit a start of an own vehicle) and attention calling warning control for issuing warning sound to a driver in a manner to allow the driver to recognize that a warning sound source exists in one of right and left directions where a control object target is approaching the own vehicle, in a case where existence of the object intersection target being the target approaching from a side part of the own vehicle to intersect with a travel prediction route of the own vehicle is determined based on left-front-side radar target information and right-front-side radar target information, and in a case where occurrence of a specific state is determined, in which a visual line of the driver detected by a driver monitor device 60 is not directed to the control object target being the target reaching fastest an intersection position with the travel prediction route of the own vehicle among the object intersection targets.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle driving assistance device that executes control to prevent a host vehicle from coming too close to a target that a driver of the host vehicle should pay attention to when the target is present to the front side of the host vehicle. [Background technology]

[0002] Conventionally, a vehicle periphery monitoring device that uses a front-side radar (e.g., a left front-side radar and a right front-side radar) has been known. One such periphery monitoring device (hereinafter referred to as a "conventional device") uses a front-side radar to detect a target approaching the predicted travel path of the vehicle so as to intersect with the predicted travel path. Hereinafter, a target approaching the predicted travel path of the vehicle so as to intersect with the predicted travel path is also referred to as a "target intersecting target." The position where the predicted travel path of the vehicle and the predicted path of the target intersecting target intersect is also referred to as a "predicted intersection position."

[0003] The conventional device calculates the time it takes for the detected target intersection target to reach the predicted intersection position (hereinafter also referred to as "intersection time"). When the calculated intersection time becomes shorter than a threshold intersection time, the conventional device displays an attention-calling image on a display. This attention-calling image is an image that indicates the direction (either left or right) from which the target intersection target is coming (see Patent Document 1).

[0004] Furthermore, when the intersection time becomes shorter than the threshold intersection time, the conventional device executes brake assist control by sending an instruction to the brake ECU. The brake assist control is a control that applies a braking force to the vehicle that is greater than the "braking force applied to the vehicle based on a normal brake operation" when the driver applies the brakes (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-52987 A (for example, paragraphs

[0075] to

[0080] , FIG. 3) [Patent Document 2] JP 2014-2610 A Summary of the Invention

[0006] However, the driver of the host vehicle does not necessarily see (gaze) the target intersection target, and there remains a possibility that the host vehicle may approach the target intersection target excessively. More specifically, for example, as shown in Fig. 8, there is a case where the host vehicle HV stops temporarily before the intersection IN, and a truck TR approaching from the right decelerates or stops to give way to the host vehicle HV.

[0007] In this case, the conventional device recognizes the truck TR as a target intersecting object and displays a warning image before the truck TR starts to decelerate. Therefore, the driver of the host vehicle HV recognizes that the truck TR is approaching and keeps his / her eyes on the truck TR. Then, when the driver of the host vehicle HV visually confirms that the truck TR has decelerated or stopped, he / she releases the brake pedal of the host vehicle HV while keeping his / her eyes on the truck TR and starts the host vehicle HV. At this time, the conventional device detects the bicycle BY approaching from the left and displays a warning image, but since the driver of the host vehicle HV is already watching the truck TR, he / she does not see the warning image and does not notice the bicycle BY. As a result, there is a risk that the bicycle BY and the host vehicle HV will get too close to each other.

[0008] The present invention has been made to solve the above-mentioned problems, and aims to provide a vehicle driving assistance device that can reduce the possibility of the host vehicle coming too close to a target intersecting object.

[0009] In order to achieve the above object, one aspect of the present invention is to one or more sensors (41, 51) configured to be able to acquire information on a target located on the front left side of the host vehicle and information on a target located on the front right side of the host vehicle; A driver monitoring device (60) configured to be able to detect the line of sight of the driver of the vehicle; When it is determined that there is a target intersecting target that is approaching the vehicle from the side so as to intersect with the predicted travel path of the vehicle based on the target information acquired by the sensor (step 420), Calculate an intersection time (ETC) for each of the target intersection objects, which is a time required for the target intersection object to reach a predicted intersection position where the predicted travel path of the host vehicle and the predicted path of the target intersection object intersect (step 430); Identifying a minimum intersection time from the calculated intersection times (ETC) (step 440); If the identified minimum crossing time is shorter than a predetermined threshold crossing time (ETCth) (step 440: Yes), The driver's line of sight detected by the driver monitoring device is , the target intersection having the specified minimum intersection time When it is determined that a specific state that is not suitable for the target object to be controlled has occurred (step 460: Yes), Using the braking device of the vehicle, The above-mentioned intersection of the control object A host vehicle travel suppression control (steps 530, 550, and 760) for automatically applying a braking force to the host vehicle so that the host vehicle does not reach the difference predicted position. , and Attention-calling warning control (step 540) that uses a warning device of the vehicle to generate a warning sound for the driver in a manner that the driver recognizes that a warning sound source is present in either the left or right direction in which the control target object is approaching the vehicle; A control unit (10) for controlling at least one of the above. Equipped with.

[0010] According to this aspect, when a specific state occurs in which a target intersection target, which is a target approaching from the side of the vehicle so as to intersect with the predicted travel path of the vehicle, and the detected driver of the vehicle's line of sight is not directed toward a "control target, which is the target among the target intersection targets that will reach a position intersecting with the predicted travel path of the vehicle earliest," at least one of vehicle travel suppression control and attention warning control is executed.

[0011] Therefore, when the host vehicle travel suppression control is executed, even if the driver tries to move the host vehicle without noticing the control target, the host vehicle will not reach the predicted intersection position with the control target, and therefore, it is possible to reduce the possibility that the host vehicle will come too close to the control target.

[0012] On the other hand, when the attention-calling warning control is executed, the possibility that the driver moves the host vehicle toward the predicted intersection position without noticing the control target can be reduced, and therefore the possibility that the host vehicle comes too close to the control target can be reduced.

[0013] In one aspect of the present invention, The control unit includes: When the specific state occurs and the host vehicle is stopped (step 520 in FIG. 5: Yes), The host vehicle progress suppression control is configured to execute brake hold control using the host vehicle's braking device to forcibly apply a stopping braking force to the host vehicle so that the host vehicle remains stopped (step 530).

[0014] According to this embodiment, even if the driver of the vehicle tries to start the vehicle without noticing the control target (for example, by releasing the brake pedal or depressing the accelerator pedal), the vehicle is maintained in a stopped state. Therefore, it is possible to reliably reduce the possibility that the vehicle will come too close to the control target.

[0015] In one aspect of the present invention, The control unit includes: When the specific state occurs and the host vehicle is not stopped (step 520 in FIG. 5 or FIG. 7: No), The host vehicle progress suppression control is configured to execute an automatic collision avoidance braking control, which uses the host vehicle's braking device to forcibly apply a braking force for collision avoidance to the host vehicle so that the host vehicle stops just before the predicted intersection position with the control target (steps 550 and 760).

[0016] According to this aspect, it is possible to prevent the driver of the host vehicle from advancing to a predicted intersection position with the control target without noticing the control target, and therefore it is possible to reliably reduce the possibility that the host vehicle will come too close to the control target.

[0017] In one aspect of the present invention, The control unit includes: When the specific state occurs and the host vehicle is stopped (step 520 in FIG. 7: Yes), Even if the accelerator pedal of the host vehicle is operated, the system is configured to execute starting driving force suppression control that controls the drive device of the host vehicle so that a driving force equal to or less than the creep force that is applied to the host vehicle when the accelerator pedal of the host vehicle is released is applied to the host vehicle (step 730).

[0018] According to this aspect, even if the driver of the host vehicle operates the accelerator pedal when there is a high possibility that the driver does not notice the control target, the host vehicle starts with an extremely small acceleration. Therefore, it is possible to increase the possibility that the driver of the host vehicle notices the control target and stops the host vehicle, and it is possible to reliably reduce the possibility that the host vehicle will come too close to the control target.

[0019] In one aspect of the present invention, The control unit includes: An intersection time, which is the time it takes for the control object to reach the predicted intersection position, is calculated, and when the intersection time is shorter than a threshold intersection time (step 440: Yes), at least one of the host vehicle travel suppression control and the attention warning control is started (step 470).

[0020] According to this aspect, it is possible to prevent the host vehicle travel suppression control and / or the attention-call warning control from being executed in an unnecessary situation.

[0021] In the above description, in order to facilitate understanding of the invention, the reference numerals used in the description of the embodiments described below are enclosed in parentheses with respect to the constituent elements of the invention corresponding to the embodiments described below. However, the constituent elements of the invention are not limited to the embodiments defined by the reference numerals. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic configuration diagram of a vehicle driving assistance device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of a vehicle and its surroundings, showing the detection ranges of each radar. [Diagram 3] FIG. 3 is a diagram showing a specific scene for explaining the operation of the vehicle driving support device shown in FIG. [Figure 4] FIG. 4 is a flowchart showing a routine executed by the CPU of the driving assistance ECU shown in FIG. [Diagram 5] FIG. 5 is a flowchart showing a routine executed by the CPU of the driving assistance ECU shown in FIG. [Figure 6] FIG. 6 is a diagram for explaining the operation of the vehicle driving support device shown in FIG. [Figure 7] FIG. 7 is a flowchart showing a routine executed by a CPU of a modified example of the driving assistance ECU shown in FIG. [Figure 8] FIG. 8 is a diagram showing a specific scene for explaining the operation of a conventional vehicle driving support device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] (composition) A vehicle driving assistance device (assistance device) DS according to the embodiment of the present invention shown in FIG. 1 is mounted on a vehicle (hereinafter referred to as "host vehicle" in order to distinguish it from other vehicles) HV shown in FIG.

[0024] As shown in FIG. 1, the assistance device DS includes a driving assistance ECU 10, a front camera device 20, a front radar device 30, a left front side radar device 40, a right front side radar device 50, a driver monitor device 60, a powertrain ECU 70, a powertrain actuator 71, a brake ECU 80, a brake actuator 81, an alarm ECU 90, a left speaker 91L, a right speaker 91R, a display ECU 100, a display device 101, a vehicle speed sensor 111, an accelerator pedal operation amount sensor 112, a brake pedal operation amount sensor 113, and a steering angle sensor 114.

[0025] In this specification, "ECU" refers to an electronic control unit having a microcomputer as its main component, and is also called a controller. The microcomputer includes a CPU (processor), ROM, RAM, non-volatile memory, and an interface I / F. The CPU is adapted to realize various functions by executing instructions (programs, routines) stored in the ROM. Some or all of the multiple ECUs may be integrated into one ECU. Furthermore, the multiple ECUs are connected to each other via a CAN (Controller Area Network) so that they can exchange information with each other.

[0026] As shown in FIG. 2, each of the multiple ECUs described above calculates "the position of the target, the relative speed of the target, etc." with respect to the host vehicle HV using an orthogonal coordinate system (X-axis and Y-axis) described below. Origin: Center position of the front end of the vehicle HV in the width direction X-axis: The axis that passes through the origin and extends in the fore-and-aft direction of the host vehicle HV. The front of the host vehicle HV is the positive direction. Y-axis: The axis that passes through the origin and extends in the left-right direction of the host vehicle HV. The right side of the host vehicle HV is the positive direction.

[0027] The driving assistance ECU 10 is a central ECU of the assistance device DS, and executes driving assistance control (such as host vehicle advance suppression control and attention-call warning control) as described below.

[0028] The forward camera device 20 includes a forward camera 21 and an image ECU 22 .

[0029] The front camera 21 is disposed at the top and center of the front windshield of the host vehicle HV, as shown in Fig. 2. The front camera 21 is a stereo camera that captures an image of a scene (including the road surface and targets) in front of the host vehicle HV at predetermined time intervals to obtain a pair of left and right image data. The imaging range (angle of view) of the front camera 21 is within an angle θfc with the X-axis as the central axis. That is, the front camera 21 captures an image of a scene included in the range of an angle (θfc / 2) in the rightward and leftward directions in front of the vehicle.

[0030] The image ECU 22 analyzes the image data transmitted from the forward camera 21 at predetermined intervals to generate image target information. The image target information includes the target position, the relative speed and type of the target (stationary object, pedestrian, bicycle, motorcycle, other vehicle, etc.), lane position information, etc.

[0031] The front radar device 30 is a device that acquires information about a target that exists in front of the host vehicle HV, and includes a front radar 31 and a front radar ECU 32.

[0032] 2, the front radar 31 is disposed at the position of the origin described above, and transmits millimeter wave band radio waves within a detection range of an angle θfr having the X-axis as a central axis (radar axis). That is, the front radar 31 transmits radio waves within an angle range of (θfr / 2) to the right and left of the vehicle.

[0033] When a target exists within the transmission range (detection range) of the radio waves of the front radar 31, the target reflects the radio waves transmitted from the front radar 31. As a result, a reflected wave is formed. The front radar 31 receives this reflected wave. The front radar 31 transmits information about the transmitted radio waves and information about the received reflected wave to the front radar ECU 32 every time a predetermined time elapses.

[0034] The front radar ECU 32 acquires target information about targets present within the detection range of the front radar 31 based on information transmitted from the front radar 31. This target information is called "front radar target information" and includes the distance between the target and the origin, the azimuth of the target, and the relative speed of the target.

[0035] The left front-side radar device 40 is a device that acquires information about targets present on the forward left side of the vehicle HV (i.e., diagonally forward and to the left of the vehicle HV), and includes a left front-side radar 41 and a left front-side radar ECU 42.

[0036] As shown in FIG. 2, the left front side radar 41 is disposed at the left corner of the front end of the vehicle HV, and transmits millimeter wave band radio waves to a detection range having a central axis (radar axis) in the diagonally forward left direction of the vehicle HV. That is, the left front side radar 41 transmits radio waves to a range of angle θs from angle (-θ2) to angle (-θ1). If a target exists within the transmission range (detection range) of the radio waves of the left front side radar 41, the target reflects the radio waves transmitted from the left front side radar 41. As a result, a reflected wave is formed. Like the forward radar 31, the left front side radar 41 transmits information about the transmitted radio waves and information about the received reflected waves to the left front side radar ECU 42 every time a predetermined time elapses.

[0037] The left front-side radar ECU 42 acquires target information about targets existing within the detection range of the left front-side radar 41 based on information transmitted from the left front-side radar 41. This target information is called "left front-side radar target information" and includes the distance between the target and the origin, the azimuth of the target, and the relative speed of the target, etc.

[0038] The right front-side radar device 50 is a device that acquires information about targets present on the front right side of the host vehicle HV (i.e., diagonally forward and to the right of the host vehicle HV), and includes a right front-side radar 51 and a right front-side radar ECU 52.

[0039] As shown in FIG. 2, the right front-side radar 51 is disposed at the right corner of the front end of the vehicle HV, and transmits millimeter-wave radio waves to a detection range having a central axis (radar axis) in a diagonally forward right direction of the vehicle HV. That is, the right front-side radar 51 transmits radio waves to a range of angle θs from angle (+θ2) to angle (+θ1). If a target exists within the transmission range (detection range) of the radio waves of the right front-side radar 51, the target reflects the radio waves transmitted from the right front-side radar 51. As a result, a reflected wave is formed. Like the forward radar 31, the right front-side radar 51 transmits information about the transmitted radio waves and information about the received reflected waves to the right front-side radar ECU 52 every time a predetermined time elapses.

[0040] The right front-side radar ECU 52 acquires target information about targets existing within the detection range of the right front-side radar 51 based on information transmitted from the right front-side radar 51. This target information is called "right front-side radar target information" and includes the distance between the target and the origin, the azimuth of the target, the relative speed of the target, etc.

[0041] The driver monitor device 60 is a driver monitoring device that acquires information indicating the state of the driver of the host vehicle HV (including the driver's line of sight), and includes a driver monitor camera 61 and a driver monitor ECU 62. The driver monitor device 60 itself is well known and is disclosed, for example, in Japanese Patent Application Publication No. 2019-87143, Japanese Patent Application Publication No. 2019-87029, Japanese Patent Application Publication No. 2016-38866, and Japanese Patent Application Publication No. 2013-152700.

[0042] The driver monitor camera 61 is disposed in an appropriate position (for example, above the steering column) in front of the driver's seat of the host vehicle HV, and captures an image of the face of the driver of the host vehicle HV at predetermined intervals to generate facial image data.

[0043] The driver monitor ECU 62 detects the facial direction, line of sight, etc. of the driver of the host vehicle HV based on the facial image data transmitted from the driver monitor camera 61 .

[0044] More specifically, the driver monitor ECU 62 prestores face shape data of the driver facing forward. The driver monitor ECU 62 generates a face image of the driver from face image data transmitted from the driver monitor camera 61. The driver monitor ECU 62 rotates the generated face image, and detects the direction of the driver's face based on the rotation angle of the face image when the matching rate between the rotated face image and the stored face shape data is maximized.

[0045] The driver monitor ECU 62 identifies a face area from the generated face image of the driver and detects face parts by extracting feature points of the face parts such as the eyes, nose, and mouth. Furthermore, the driver monitor ECU 62 detects the position of the Purkinje image (corneal reflection image) and the position of the pupil center, and obtains the positional relationship between the Purkinje image and the pupil center. Then, the driver monitor ECU 62 detects the driver's line of sight (line of sight direction) based on the positional relationship between the Purkinje image and the pupil center and the detected face direction of the driver.

[0046] The powertrain ECU 70 is connected to a powertrain actuator 71. The powertrain actuator 71 is an actuator for changing the operating state of a drive device of the host vehicle HV (the drive power source of the host vehicle, in this case, an internal combustion engine). In this example, the internal combustion engine is a gasoline fuel injection, spark ignition, multi-cylinder engine, and is equipped with a throttle valve for adjusting the amount of intake air. The powertrain actuator 71 includes at least a throttle valve actuator for changing the opening degree of the throttle valve.

[0047] The powertrain ECU 70 can change the torque generated by the drive device by driving the powertrain actuator 71. The torque generated by the drive device is transmitted to drive wheels (not shown) via a gear mechanism (not shown). Therefore, the powertrain ECU 70 can control the drive force of the host vehicle HV by controlling the drive device via the powertrain actuator 71.

[0048] The drive device of the host vehicle HV may be an electric motor. In other words, the host vehicle HV may be an electric vehicle, in which case the power train actuator 71 is an inverter capable of changing the torque of the electric motor. The drive device of the host vehicle HV may be both an internal combustion engine and an electric motor. In other words, the host vehicle HV may be a hybrid vehicle, in which case the power train actuator 71 includes an inverter capable of changing the torque of the electric motor and a throttle valve actuator of the internal combustion engine.

[0049] The brake ECU 80 is connected to a brake actuator 81. The brake actuator 81 is an actuator for controlling friction brake devices (braking devices) arranged on each wheel of the host vehicle HV to change the braking force (friction braking force) applied to the vehicle. Therefore, the brake ECU 80 can control the braking force applied to the host vehicle HV by controlling the braking devices via the brake actuator 81.

[0050] The alarm ECU 90 is connected to a left speaker 91L and a right speaker 91R, and can generate alarm sounds from each of these speakers. The left speaker 91L and the right speaker 91R only need to be sound generating devices (alarm sound generating devices), and may be replaced with a left buzzer and a right buzzer that generate alarm sounds, respectively.

[0051] The left speaker 91L is disposed at a position on the front left side inside the vehicle SV. Therefore, when an alarm sound is generated only from the left speaker 91L among the left speaker 91L and the right speaker 91R, the driver of the vehicle SV can recognize that the alarm sound is generated from the left side (front left) of the vehicle. That is, in this case, the driver recognizes that the alarm sound source is present on the left side (front left) of the vehicle.

[0052] The right speaker 91R is disposed at a position on the front right side inside the vehicle SV. Therefore, when an alarm sound is generated only from the right speaker 91R among the left speaker 91L and the right speaker 91R, the driver of the vehicle SV can recognize that the alarm sound is generated from the right side (right front) of the vehicle. That is, in this case, the driver recognizes that the alarm sound source is located to the right side (right front) of the vehicle.

[0053] The display ECU 100 is connected to a display device 101 which is a display device. The display ECU 100 can display on the display device 101 an attention-calling image indicating the direction (either the left or right direction) from which a target intersection target (i.e., a target approaching the predicted travel path of the vehicle so as to intersect with the predicted travel path of the vehicle) is coming. For example, the display device 101 can selectively display either the image LM or the image RM as an attention-calling image based on an instruction from the display ECU 100. The image LM is an image accompanied by a pattern (e.g., an arrow pointing to the right) indicating that the target intersection target is approaching from the front left side of the vehicle HV. The image RM is an image accompanied by a pattern (e.g., an arrow pointing to the left) indicating that the target intersection target is approaching from the front right side of the vehicle HV. The display device 101 may be a so-called meter display. In addition, the attention-calling image may be determined in advance and displayed by turning on or blinking a lamp located behind the image.

[0054] The driving assistance ECU 10 is further connected to sensors described below, and receives output values ​​(detection values) of these sensors. A vehicle speed sensor 111 that detects the speed of the host vehicle HV (i.e., the vehicle speed SPD). An accelerator pedal operation amount sensor 112 that detects the operation amount AP of an accelerator pedal (not shown) of the host vehicle HV. A brake pedal operation amount sensor 113 detects an operation amount BP of a brake pedal (not shown) of the host vehicle HV. A steering angle sensor 114 that detects the steering angle (steering angle) Sa of the host vehicle HV.

[0055] The driving assistance ECU 10 is also connected to other driving condition sensors that indicate the driving condition of the vehicle. The driving condition sensors include, for example, wheel rotation speed sensors for each wheel and a brake switch that generates an ON signal when the brake pedal is operated. Furthermore, each sensor may be connected to an ECU other than the driving assistance ECU 10. In this case, the driving assistance ECU 10 inputs the "output value of that sensor" from the ECU to which the sensor is connected via the CAN.

[0056] (Overview of operation) The support device DS operates, for example, in the scene shown in FIG. 3 as follows. This is a scene in which the following situation occurs: The host vehicle HV is stopped just before the intersection IN in order to enter the intersection IN. A truck TR approaching the host vehicle HV from the front and right so as to cross the host vehicle's predicted path Ehv slows down or stops to give way to the host vehicle HV. A bicycle BY is approaching from the front and left of the vehicle HV so as to intersect with the predicted path Ehv of the vehicle.

[0057] In this case, the driver Dr of the host vehicle HV is watching the truck TR, which has approached the host vehicle's predicted travel path Ehv before the bicycle BY. When the driver Dr visually confirms that the truck TR has decelerated or stopped, he releases the brake pedal of the host vehicle HV and starts the host vehicle HV toward the intersection IN. At this time, the driver Dr of the host vehicle HV is not visually checking (gazing at) the bicycle BY and is unaware of the host vehicle BY. As a result, there is a risk that the bicycle BY and the host vehicle HV will come too close to each other.

[0058] Therefore, the support device DS uses the driver monitor device 60 to detect the line of sight Sd of the driver Dr of the host vehicle HV. When the support device DS detects that the line of sight Sd of the driver Dr is not directed toward the bicycle BY, the support device DS does not allow the host vehicle HV to start by forcibly applying a braking force to the host vehicle HV (prohibiting the host vehicle HV from starting). That is, the support device DS executes brake hold control. At the same time, the support device DS uses the left speaker 91L to generate an alarm sound from the left front of the driver Dr, thereby urging the driver Dr to pay attention to the bicycle BY. That is, the support device DS executes attention-calling alarm control. As a result, the possibility of the bicycle BY and the host vehicle HV coming too close to each other can be reduced.

[0059] (Specific operation) The CPU of the driving assistance ECU 10 (hereinafter simply referred to as the "CPU") executes the routines shown in the flowcharts of FIG. 4 and FIG. 5 every time a predetermined time elapses.

[0060] <Setting the start suppression flag> Therefore, when an appropriate time arrives, the CPU starts the process from step 400 in Fig. 4 and proceeds to step 410. In step 410, the CPU determines whether or not at least one of the left front side radar 41 and the right front side radar 51 has detected a moving target (a target having a speed) based on the left front side radar target information and the right front side radar target information. In other words, the CPU determines whether or not there is a moving target (either or both of a moving target located on the front left side of the host vehicle HV and a moving target located on the front right side) that may not be recognized by either the front camera 21 or the front radar 31. Hereinafter, a moving target detected by at least one of the left front side radar 41 and the right front side radar 51 may be referred to as a "front lateral moving target".

[0061] If at least one of the left front-side radar 41 and the right front-side radar 51 detects a moving target (i.e., a forward lateral moving target), the CPU determines "Yes" in step 410 and proceeds to step 420. In step 420, the CPU obtains a position where the "predicted vehicle travel path" and the "predicted target path of the forward lateral moving target" intersect (hereinafter referred to as "predicted intersection position Cp").

[0062] In the example shown in FIG. 3, these paths and cross prediction positions Cp are as follows: - Estimated vehicle path: Ehv - Estimated target path of bicycle BY, a forward moving target: Eby - Predicted intersection position Cp between the predicted vehicle path Ehv and the predicted bicycle BY target path Eby: Cpby - Estimated target path of truck TR, which is a forward moving target: Etr · Predicted intersection position Cp: Cptr between the predicted vehicle path Ehv and the predicted target path Etr of the truck TR

[0063] The operation of the CPU in step 420 will now be described in more detail.

[0064] First, the CPU obtains the host vehicle predicted travel path Ehv. The host vehicle predicted travel path Ehv is a future path of the host vehicle HV that the host vehicle HV (the center position in the vehicle width direction of the leading end of the host vehicle HV) is likely to pass through in a predetermined estimation period, assuming that the host vehicle HV maintains the "steering angle Sa and vehicle speed SPD" at the current time. The estimation period is a period from the "current time" to the "time when a predetermined certain time (e.g., several seconds) has elapsed from the current time." The length (distance) of the host vehicle predicted travel path Ehv is set to a length equal to or greater than a predetermined certain minimum length (e.g., several meters). Therefore, when the host vehicle HV is stopped, the length of the host vehicle predicted travel path Ehv is set to the "minimum length."

[0065] Next, the CPU calculates a predicted target path of the forward lateral moving target. The predicted target path of the forward lateral moving target is a future path of the forward lateral moving target that the forward lateral moving target will pass during the estimation period. More specifically, the CPU calculates the moving direction of the forward lateral moving target based on the latest position of the forward lateral moving target, the "position of the forward lateral moving target and the position of the host vehicle HV" a first predetermined time ago (Δt seconds), and the "position of the forward lateral moving target and the position of the host vehicle HV" a second predetermined time ago (2·Δt seconds), etc.

[0066] The CPU determines the predicted target path (paths Eby and Etr in FIG. 3) of the forward lateral moving target under the assumption that the forward lateral moving target moves while maintaining the above-mentioned "determined moving direction" and "current speed of the forward lateral moving target" during the estimation period. Then, the CPU determines the position of the point where the host vehicle's predicted travel path Ehv and the predicted target path of the forward lateral moving target intersect, as the predicted intersection position Cp (predicted intersection position Cpby and predicted intersection position Cptr in FIG. 3). Finally, the CPU judges whether the forward lateral moving target is approaching the "predicted intersection position between the host vehicle's predicted travel path Ehv and the forward lateral moving target."

[0067] When there is a lateral moving target ahead approaching the "predicted intersection position between the predicted vehicle travel path Ehv and the lateral moving target ahead," the CPU determines "Yes" in step 420 and proceeds to step 430. In step 430, the CPU calculates an estimated time to crossing (ETC) for each lateral moving target ahead approaching the predicted intersection position.

[0068] In the example shown in Figure 3, the bicycle BY and the truck TR are both traveling straight ahead. Therefore, their respective intersection times ETC are calculated as follows: ·Bicycle BY intersection time ETC (= ETCby) = Dby / Vby Here, Dby is the distance from the current position of the bicycle BY to the predicted intersection position Cpby, and Vby is the ground speed in the direction of the predicted intersection position Cpby of the bicycle BY. The ground speed of a moving target is calculated from the traveling direction of the host vehicle, the vehicle speed SPD of the host vehicle HV, the moving direction of the moving target, and the relative speed of the moving target with respect to the host vehicle HV, etc. ·Track TR crossing time ETC (=ETCtr) = Dtr / Vtr Here, Dtr is the distance from the current position of the truck TR to the predicted cross position Cptr, and Vtr is the ground speed of the truck TR in the direction of the predicted cross position Cptr.

[0069] Next, the CPU proceeds to step 440, identifies the minimum intersecting time among the intersecting times ETC of the forward lateral moving targets approaching the predicted intersecting position, and determines whether the identified minimum intersecting time ETC is shorter than a predetermined threshold intersecting time ETCth.

[0070] For example, in the example shown in FIG. 3, the CPU identifies the minimum (shorter) intersection time from the "intersection time ETCby of bicycle BY" and the "intersection time ETCtr of truck TR." In this example, the distance Dtr and the distance Dby are approximately equal to each other, and the truck TR is approximately stopped while the bicycle BY has a speed, so the minimum intersection time is the intersection time ETCby of the bicycle BY. Therefore, in step 440, the CPU determines whether the intersection time ETCby is shorter than the threshold intersection time ETCth. Note that if there is only one forward lateral moving object approaching the predicted intersection position, the intersection time of that forward lateral moving object is selected as the "minimum intersection time."

[0071] If the minimum crossing time ETC is shorter than the predetermined threshold crossing time ETCth, the CPU determines “Yes” in step 440 and proceeds to step 450 .

[0072] When the CPU determines in step 450 that the forward lateral moving object having the minimum crossing time ETC is approaching from the front left side of the host vehicle HV, it transmits an instruction to the display ECU 100 to cause the display device 101 to display "an image LM with a rightward arrow (see FIG. 1)." On the other hand, when the CPU determines in step 450 that the forward lateral moving object having the minimum crossing time ETC is approaching from the front right side of the host vehicle HV, it transmits an instruction to the display ECU 100 to cause the display device 101 to display "an image RM with a leftward arrow (see FIG. 1)."

[0073] Next, the CPU proceeds to step 460 and determines whether the line of sight Sd of the driver Dr of the vehicle HV detected by the driver monitor device 60 is not directed toward the "front lateral moving target having the shortest crossing time ETC". The front lateral moving target having the shortest crossing time ETC may be referred to as the "control priority target" hereinafter. Therefore, it can be said that the CPU determines whether a state in which the driver Dr is not gazing (visually recognizing) the control priority target occurs in step 440. Note that the CPU determines that the line of sight Sd is not directed toward the control priority target when the position of the control priority target is not included within a sector of a predetermined angle (e.g., an acute angle of about 10 degrees to 20 degrees) having the line of sight Sd of the driver Dr as the central axis and the position of the driver Dr's eyes as the origin.

[0074] If the line of sight Sd of the driver Dr is not directed toward the control priority target (i.e., if the driver Dr is not gazing (visually recognizing) the control priority target), the CPU determines "Yes" in step 460 and proceeds to step 470, where it sets the value of the start suppression flag Xr to "1." After that, the CPU proceeds to step 495, where it temporarily ends this routine. The value of the start suppression flag Xr is set to "0" in an initialization routine executed by the CPU when the ignition key switch of the host vehicle HV is changed from off to on.

[0075] Furthermore, if the CPU determines "No" in any of steps 410, 420, 440, and 460, the CPU proceeds from the step where the determination was "No" to step 480. The CPU sets (clears) the value of the start suppression flag Xr to "0" in step 480. After that, the CPU proceeds to step 495 and temporarily ends this routine.

[0076] <Start suppression control and warning control> 5, the CPU starts the process at step 500 and proceeds to step 510 to determine whether the value of the start suppression flag Xr is "1." If the value of the start suppression flag Xr is not "1" (i.e., if it is "0"), the CPU determines "No" at step 510 and proceeds directly to step 595 to temporarily end this routine.

[0077] On the other hand, if the value of the start suppression flag Xr is "1", the CPU determines "Yes" in step 510 and proceeds to step 520. In step 520, the CPU determines whether the host vehicle HV is stopped (i.e., the vehicle speed SPD = 0).

[0078] If the host vehicle HV is stopped, the CPU determines "Yes" in step 520 and proceeds to step 530. The CPU executes brake hold control as vehicle travel suppression control (start suppression control) in step 530. More specifically, the CPU controls the brake actuator 81 via the brake ECU 80 so that a large braking force is forcibly (automatically) applied to the host vehicle HV so that the host vehicle HV does not move (start) even if the host vehicle HV is stopped on a slope. This brake hold control is a host vehicle travel suppression control that automatically applies a braking force to the host vehicle HV so that the host vehicle HV does not reach a predicted intersection position, which is a position where the predicted travel path of the host vehicle HV and the predicted path of the control target object intersect. Furthermore, the CPU controls the power train actuator 71 via the power train ECU 70 so that the driving force of the host vehicle HV does not increase even if the driver Dr of the host vehicle HV operates the accelerator pedal. That is, the CPU forcibly maintains the host vehicle HV in a stopped state in step 530.

[0079] When the value of the start suppression flag Xr is "0", the powertrain ECU 70 controls the powertrain actuator 71 so that a driving force equal to a target driving force determined based on the accelerator pedal operation amount AP and the vehicle speed SPD is applied to the host vehicle HV. Therefore, when the value of the start suppression flag Xr is "0", the powertrain ECU 70 applies a predetermined driving force, a creep force (driving force for creeping), to the host vehicle HV when the accelerator pedal is released and the accelerator pedal operation amount AP is "0".

[0080] Next, the CPU proceeds to step 540 and executes attention-call warning control (eye-guiding warning processing). More specifically, the CPU identifies whether the control priority object is approaching the vehicle HV (more precisely, the predicted intersection position between the vehicle HV and the control priority object) from the left or right side with respect to the X-axis of the vehicle HV. Then, as shown in FIG. 6, when the CPU determines that the control priority object (e.g., bicycle BY) is approaching the predicted intersection position from the left side with respect to the X-axis of the vehicle HV, it transmits an instruction to the warning ECU 90 to generate a predetermined warning sound (e.g., a "beep beep" warning sound) from only the left speaker 91L of the left speaker 91L and the right speaker 91R.

[0081] In this case, the warning ECU 90 may emit a warning sound from both the left speaker 91L and the right speaker 91R within a range where the driver Dr of the host vehicle HV can recognize that "the warning sound is coming from his / her left side (the warning sound source is present on the left side of the driver Dr)". In other words, the warning ECU 90 may adjust the direction of the warning sound source (the source generating the warning sound) by utilizing a stereo effect.

[0082] In contrast, if it is determined that the control priority target is approaching the predicted intersection position from the right side with respect to the X-axis of the vehicle HV, the CPU sends an instruction to the alarm ECU 90 to generate a predetermined alarm sound (e.g., a "beep beep" alarm sound) from only the right speaker 91R out of the left speaker 91L and the right speaker 91R.

[0083] Even in this case, the warning ECU 90 may emit a warning sound from both the left speaker 91L and the right speaker 91R within a range where the driver Dr of the host vehicle HV can recognize that "the warning sound is coming from the right side of the driver Dr (the warning sound source is present to the right of the driver Dr)". In other words, the warning ECU 90 may adjust the direction of the warning sound source by utilizing the stereo effect.

[0084] 5, if the host vehicle HV is not stopped, the CPU determines "No" in step 520 and proceeds to step 550. In step 550, the CPU executes automatic collision avoidance braking control.

[0085] More specifically, the CPU calculates the deceleration required for the host vehicle HV to stop at the stop target position as the target deceleration. In this example, the stop target position is a position that is closer to the current position of the host vehicle HV by a predetermined margin distance from the predicted intersection position with the control priority target. Then, the CPU controls the brake actuator 81 via the brake ECU 80 so that the actual deceleration of the host vehicle HV coincides with the target deceleration. This braking control is the collision avoidance automatic braking control. The collision avoidance automatic braking control is also one of the "host vehicle travel suppression controls that automatically apply a braking force to the host vehicle HV so that the host vehicle HV does not reach the predicted intersection position". Thereafter, the CPU executes the process of step 540 described above, proceeds to step 595, and temporarily ends this routine.

[0086] The margin distance may be any value equal to or greater than 0, but is preferably a constant positive distance (for example, 50 cm to 1 m). Furthermore, the stop target position may be an entrance position (a connecting position between the road on which the vehicle HV is traveling and a road that intersects with the road) on the predicted travel route Ehv of the vehicle at the intersection IN into which the vehicle HV is about to enter, or a position that is a predetermined margin distance away from the entrance position to the current position of the vehicle HV.

[0087] As described above, when the driving support device DS determines that a specific state has occurred in which the driver's line of sight is not directed toward the control target, which is "the target that reaches the position intersecting the predicted travel path of the vehicle earliest among the target intersecting targets" (step 460: Yes), if the vehicle is stopped, it executes brake hold control as the host vehicle travel suppression control (step 530), and if the vehicle is not stopped, it executes collision avoidance automatic braking control as the host vehicle travel suppression control (step 550). Furthermore, even if the accelerator pedal of the host vehicle is operated during the execution of the brake hold control, the driving support device DS also executes starting driving force suppression control to control the drive device of the host vehicle so that a driving force equal to or less than "the creep force applied to the host vehicle when the accelerator pedal of the host vehicle is released" is applied to the host vehicle.

[0088] Therefore, the driving support device DS can reduce the possibility that the host vehicle and the control target object become excessively close to each other.

[0089] Furthermore, when the specific state occurs, the driving assistance device DS executes attention-attention warning control in which an alarm sound is generated for the driver in a manner that the driver can recognize if an alarm sound source is present in either the left or right direction of the controlled object approaching the vehicle (step 540).

[0090] Therefore, the driving support device DS can reduce the possibility that the vehicle and the control target object will come too close to each other even by using the warning sound.

[0091] <Modification> The modified example of the driving assistance device DS differs from the driving assistance device DS only in that the CPU of the driving assistance ECU 10 executes "a routine shown in the flowchart of FIG. 7" instead of the flowchart shown in FIG.

[0092] More specifically, when an appropriate time arrives, the CPU of the driving assistance ECU 10 of the modified example starts processing from step 700 in Fig. 7. In the routine shown in the flowchart of Fig. 7, steps that perform the same processing as the steps of the routine shown in the flowchart of Fig. 5 are given the reference numerals shown in Fig. 5. Descriptions of the processing of the steps given the reference numerals shown in Fig. 5 will be omitted as appropriate.

[0093] Assume now that the value of the start suppression flag Xr is set to "1" and the host vehicle HV is stopped. In this case, the CPU judges "Yes" in each of "steps 510 and 520" in FIG. 7 and proceeds to step 730.

[0094] In step 730, the CPU executes driving force suppression control as start suppression control. More specifically, the CPU controls the powertrain actuator 71 via the powertrain ECU 70 so that the driving force of the host vehicle HV does not increase even if the driver Dr of the host vehicle HV operates the accelerator pedal. In other words, the driving force applied to the host vehicle HV is adjusted to be equal to or less than the creep force when the accelerator pedal is not operated. This control is the driving force suppression control. After that, the CPU proceeds to step 540 in FIG. 7, executes the attention warning control described above, and proceeds to step 795 to temporarily end this routine.

[0095] On the other hand, if the host vehicle HV is not stopped when the CPU proceeds to "step 520 in FIG. 7", the CPU determines "No" in step 520 and proceeds to step 750.

[0096] In step 750, the CPU calculates a cross collision time to collision (estimated collision time to collision) CTTC according to the following formula. Cross collision margin time CTTC=(Dhv-Mα) / SPD Dhv is the distance from the current position of the host vehicle HV to the "predicted intersection position between the host vehicle HV and the control priority target." Mα is a predetermined margin distance ("0" or a positive value). SPD is the vehicle speed of the host vehicle HV.

[0097] Furthermore, the CPU determines whether the cross collision margin time CTTC is shorter than a predetermined threshold margin time CTTCth in step 750. If the cross collision margin time CTTC is equal to or greater than the threshold margin time CTTCth, the CPU determines "No" in step 750 and proceeds to step 730 described above.

[0098] On the other hand, if the cross collision margin time CTTC is shorter than the predetermined threshold margin time CTTCth, the CPU determines "Yes" in step 750 and proceeds to step 760. In step 760, the CPU executes collision avoidance automatic braking control similar to the control executed in the above-mentioned step 550. Thereafter, the CPU proceeds to step 540 in Fig. 7, executes the above-mentioned attention calling warning control, and proceeds to step 795 to temporarily end this routine.

[0099] As described above, in the modified driving assistance device DS, when it is determined that a specific state has occurred in which the line of sight of the driver of the vehicle is not directed toward the control target, which is "the target among the target intersecting targets that will reach a position intersecting the predicted travel path of the vehicle earliest" (step 460: Yes), if the vehicle is stopped, even if the accelerator pedal of the vehicle is operated, starting driving force suppression control is executed to control the drive device of the vehicle so that a driving force equal to or less than "the creep force applied to the vehicle when the accelerator pedal of the vehicle is released" is applied to the vehicle (step 730).

[0100] As a result, even if the driver releases the brake pedal and depresses the accelerator pedal, the host vehicle starts moving slowly, so that the driver of the host vehicle can be more likely to notice the control target and stop the host vehicle. Therefore, this modified example can reduce the possibility that the host vehicle and the control target get too close to each other.

[0101] The present invention is not limited to the above-described embodiment and modifications, and various modifications can be adopted within the scope of the present invention.

[0102] For example, the driving assistance device DS may be configured to execute at least one of the host vehicle advance suppression control and the attention-call warning control when it is determined that the specific state is occurring.

[0103] In addition, the left front side radar 41 and the right front side radar 51 may be replaced with a left side camera capable of capturing a scene on the left front side and a right side camera capable of capturing a scene on the right front side, respectively. Furthermore, the left front side radar 41 and the right front side radar 51 may be a single sensor (e.g., LiDAR) that detects targets existing in the entire area in front of (including the sides of) the host vehicle HV. [Explanation of symbols]

[0104] 10...driving assistance ECU, 20...forward camera device, 30...forward radar device, 40...left front side radar device, 41...left front side radar, 42...left front side radar ECU, 50...right front side radar device, 51...right front side radar, 52...right front side radar ECU, 60...driver monitor device, 61...driver monitor camera, 62...driver monitor ECU, 70...powertrain ECU, 71...powertrain actuator, 80...brake ECU, 81...brake actuator, 90...alarm ECU, 91L...left speaker, 91R...right speaker, 100...display ECU, 101...display device.

Claims

1. One or more sensors configured to be able to acquire information on a target located on the front left side of the host vehicle and information on a target located on the front right side of the host vehicle; A driver monitoring device configured to detect the line of sight of the driver of the vehicle; When it is determined that there is a target intersecting target that is approaching the vehicle from the side so as to intersect with the predicted travel path of the vehicle based on the target information acquired by the sensor, Calculating an intersection time (ETC) for each of the target intersection targets, which is a time required for the target intersection target to reach a predicted intersection position, which is a position where a predicted travel path of the host vehicle and a predicted path of the target intersection target intersect; Identifying a minimum intersection time from among the calculated intersection times (ETC); When the specified minimum crossing time is shorter than a predetermined threshold crossing time (ETCth), when it is determined that a specific state occurs in which the line of sight of the driver detected by the driver monitoring device is not directed toward a control target object that is the target crossing target having the specified minimum crossing time, A host vehicle travel suppression control that automatically applies a braking force to the host vehicle using a braking device of the host vehicle so that the host vehicle does not reach the predicted intersection position of the control target object; and an attention-calling warning control that generates a warning sound for the driver using a warning device of the vehicle in such a manner that the driver recognizes that a warning sound source is present in either the left or right direction in which the control target object is approaching the vehicle; A control unit for controlling at least one of the above. Equipped with Vehicle driving assistance device.

2. The vehicle driving support device according to claim 1, The control unit includes: When the specific state occurs and the host vehicle is in a stopped state, The host vehicle advance suppression control is configured to execute a brake hold control that forcibly applies a braking force for stopping the host vehicle to the host vehicle so that the host vehicle continues to be stopped, using a braking device of the host vehicle. Vehicle driving assistance device.

3. The vehicle driving support device according to claim 2, The control unit includes: When the specific state occurs and the host vehicle is not stopped, The host vehicle travel suppression control is configured to execute a collision avoidance automatic braking control that forcibly applies a braking force for collision avoidance to the host vehicle using a braking device of the host vehicle so that the host vehicle stops before a predicted intersection position with the control target. Vehicle driving assistance device.

4. The vehicle driving support device according to claim 1, The control unit includes: When the specific state occurs and the host vehicle is in a stopped state, The vehicle is configured to execute a starting driving force suppression control for controlling a drive device of the vehicle so that a driving force equal to or less than a creep force applied to the vehicle when the accelerator pedal of the vehicle is released is applied to the vehicle even when the accelerator pedal of the vehicle is operated. Vehicle driving assistance device.

5. The vehicle driving support device according to claim 1, The control unit includes: An intersection time, which is a time required for the control object to reach the intersection predicted position, is calculated, and when the intersection time is shorter than a threshold intersection time, at least one of the host vehicle travel suppression control and the attention warning control is started. Vehicle driving assistance device.

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