Driving assistance device and driving assistance method for vehicle

Abstract

The invention relates to a driving assistance apparatus and a driving assistance method for a vehicle. The driving assistance ECU determines whether or not there is another vehicle on the collision route based on the other vehicle information. The ECU determines whether or not a predetermined execution condition for executing the collision avoidance assistance operation is satisfied when it is determined that there is another vehicle on the collision route, and starts execution of the collision avoidance assistance operation when it is determined that the execution condition is satisfied. The ECU determines whether the other vehicle on the collision route is approaching from the driver seat side of the own vehicle or approaching from the front passenger seat side of the own vehicle, and determines whether the driver of the own vehicle visually recognizes that the other vehicle on the collision route is highly safe. And changing the execution condition.

Description

Technical Field

[0001] The present invention relates to a driving assistance device and a driving assistance method for a vehicle, which can reduce the possibility of a collision between the own vehicle and another vehicle due to a collision course phenomenon. Background Art

[0002] In the past, there is a known device that detects other vehicles and performs collision avoidance assistance at a predetermined timing (timing) when the driver of the own vehicle recognizes "other vehicles with a high possibility of collision with the own vehicle (other vehicles on the collision path)" at a late time due to the collision path phenomenon (for example, see Japanese Patent Application Laid-Open Nos. 2012-58827 and 2018-206210). The collision avoidance assistance action is, for example, an automatic braking action. Summary of the invention

[0003] However, conventional devices have a problem in that collision avoidance assistance may be performed even when the driver recognizes another vehicle on the collision course, and the driver may feel that the collision avoidance assistance is unnecessary or may not trust the collision avoidance assistance.

[0004] The present invention is made to solve the above-mentioned problems. That is, one of the objects of the present invention is to provide a vehicle driving assistance device that can perform a collision avoidance assistance action for avoiding a collision between a vehicle and another vehicle on a collision course at a more appropriate timing.

[0005] A technical solution of a driving assistance device for a vehicle of the present invention (hereinafter also referred to as "the device of the present invention") includes a controller, which obtains other vehicle information, which is information about the position of other vehicles located in an area obliquely in front of the own vehicle relative to the own vehicle. When the controller determines based on the other vehicle information that there are other vehicles traveling in a manner that produces a collision course phenomenon relative to the own vehicle, that is, other vehicles on the collision course, the controller determines whether an execution condition for executing a collision avoidance assistance action is met, and starts executing the collision avoidance assistance action when it is determined that the execution condition is met. The collision avoidance assistance action is an action for avoiding a collision between the own vehicle and other vehicles on the collision course.

[0006] The controller is configured to change the execution condition based on at least one of an approach direction determination result and a visual recognition determination result, wherein the approach direction determination result is a determination result as to whether the other vehicles on the collision route are approaching from the direction of the driver's seat side of the own vehicle or from the direction of the passenger seat side of the own vehicle, and the visual recognition determination result is a determination result as to whether the possibility (possibility, probability) that the driver of the own vehicle visually recognizes the other vehicles on the collision route is high.

[0007] The driver's field of view of the diagonal front of the own vehicle changes greatly depending on whether the vehicle structure (such as the A-pillar) significantly enters the field of view. That is, the driver's field of view of the diagonal front is greatly different depending on whether the other vehicles on the collision route are approaching from the driver's seat side or from the passenger seat side. Therefore, whether the driver can visually identify other vehicles on the collision route also depends on the direction in which the other vehicles on the collision route are approaching. Therefore, if the execution condition is changed according to the approaching direction determination result, the collision avoidance driving action can be started at a more appropriate time.

[0008] Furthermore, if the execution condition is changed according to the visual recognition determination result as to whether the driver visually recognizes the other vehicle on the collision course, the collision avoidance driving action can be started at a more appropriate timing.

[0009] In the above description, in order to help understand the present invention, the names and / or figure marks used in the embodiments are added in brackets for the components of the invention corresponding to the embodiments described later. However, the components of the present invention are not limited to the embodiments specified by the names and / or figure marks. The present invention also relates to a vehicle driving assistance method and a program thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Hereinafter, features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described with reference to the accompanying drawings, in which like reference numerals represent like elements, and wherein:

[0011] Figure 1 is a schematic diagram of the structure of a driving assistance device for a vehicle according to an embodiment of the present invention;

[0012] Figure 2 It is a diagram used to illustrate the collision path phenomenon;

[0013] Figure 3 yes Figure 1 The routine executed by the CPU of the driving assistance ECU shown;

[0014] Figure 4 yes Figure 1The routine executed by the CPU of the driving assistance ECU shown;

[0015] Figure 5 yes Figure 1 The routine executed by the CPU of the driving assistance ECU shown;

[0016] Fig. 6A is a diagram showing an example of the driver's sight line direction; and

[0017] Figure 6B This is a diagram showing another example of the driver's line of sight direction. DETAILED DESCRIPTION

[0018] A driving assistance device DS for a vehicle according to an embodiment of the present invention (hereinafter referred to as "device DS") includes: Figure 1 The components shown are applied (mounted) on the vehicle itself. The vehicle itself may be any of a vehicle using an internal combustion engine as a power source, a vehicle using an electric motor as a power source, and a hybrid electric vehicle.

[0019] In this specification, "ECU" is an electronic control device (control unit) including a microcomputer including a CPU (processor), ROM, RAM, and an interface (I / F), etc. ECU is also called a controller or a computer. Figure 1 The plurality of ECUs shown are connected via CAN (Controller Area Network) so as to be able to exchange information with each other. Some or all of the plurality of ECUs may be integrated into one ECU.

[0020] As described in detail later, the driving assistance ECU 10 executes the "collision avoidance control / collision damage reduction control" as driving assistance control when there are "other vehicles on the collision course". "Other vehicles on the collision course" are "other vehicles that are difficult for the driver of the own vehicle to recognize as other vehicles with a high possibility of collision with the own vehicle" due to the collision course phenomenon. Figure 2 As shown, the collision path phenomenon is a phenomenon in which the driver of the own vehicle HV mistakenly recognizes that the other vehicle OV is stationary. The reason for the collision path phenomenon is that the own vehicle HV and the other vehicle OV are both moving in a straight line at a uniform speed toward the point P where they intersect each other, and the "angle θ formed by the straight line L1 parallel to the front and rear axes of the own vehicle HV and the straight line L2 passing through the driver of the own vehicle HV and the other vehicle OV" is maintained at a roughly constant angle. When the collision path phenomenon occurs, the driver of the own vehicle HV either does not perform collision avoidance driving operations or performs collision avoidance driving operations late.

[0021] Re-reference Figure 1The front camera device 20 includes a front camera 21 and an image ECU 22. The front camera 21 has Figure 2 The image ECU 22 captures the scene in the front direction and obliquely in front direction of the own vehicle and obtains image data every predetermined time. The image ECU 22 generates camera information by analyzing the image data from the front camera 21, and sends the camera information to the driving assistance ECU 10. The camera information includes the image data itself and the information such as the "position relative to the own vehicle, relative longitudinal speed, relative lateral speed and category" of the captured target object. Therefore, the camera information includes other vehicle information about other vehicles located in the obliquely front area of ​​the own vehicle to determine the position relative to the own vehicle.

[0022] The radar device 30 is a well-known device that uses radio waves in the millimeter wave band to obtain information about targets existing in the front direction and oblique front direction of the own vehicle, and includes a radar 31 and a radar ECU 32. The radar 31 sends a signal to the vehicle at a predetermined time. Figure 2 The radar 31 sends millimeter waves within the detection range represented by the straight line R1 and the straight line R2, and receives the millimeter waves reflected by the target object. The radar 31 sends information about the sent and received millimeter waves to the radar ECU 32. The radar ECU 32 obtains radar information based on the information from the radar 31 and sends the radar information to the driving assistance ECU 10. The radar information includes the distance to the target object, the direction of the target object, and the relative speed of the target object. Therefore, the radar information includes other vehicle information about other vehicles located in the area diagonally in front of the own vehicle to determine the position relative to the own vehicle.

[0023] The driver monitoring device (driver monitor) 40 obtains the driver's line of sight information indicating the state of the driver of the vehicle (including the driver's facial orientation relative to the own vehicle and the driver's line of sight direction relative to the front of the face, etc.), and based on the driver's line of sight information, obtains "the driver's line of sight direction in the left-right direction in front of the front and rear axles of the own vehicle (hereinafter referred to as 'the line of sight direction to the front and rear axles')" and "the driver's line of sight direction in the up-down direction (hereinafter referred to as 'the up-down line of sight direction')". The driver monitoring device 40 includes a driver monitoring camera 41 and a driver monitoring ECU 42. The driver monitoring device 40 itself is well known, as disclosed in, for example, Japanese Patent Laid-Open Nos. 2019-87143, 2019-87029, 2016-38866, and 2013-152700.

[0024] The driver monitoring camera 41 is disposed at an appropriate position in front of the driver's seat of the vehicle (for example, above the steering column) and captures the driver's face at predetermined intervals to generate facial image data and transmit the facial image data to the driver monitoring ECU 42 .

[0025] The driver monitoring ECU 42 generates a facial image based on the facial image data from the driver monitoring camera 41, and rotates the generated facial image. The driver monitoring ECU 42 obtains the driver's facial orientation based on the rotation angle of the facial image when the consistency rate between the rotated facial image and the pre-stored "facial shape data when the driver faces forward" is the maximum.

[0026] Furthermore, the driver monitoring ECU 42 determines the facial area from the generated facial image of the driver, and detects the facial organs by extracting the feature points of the facial organs such as the eyes, nose and mouth. In addition, the driver monitoring ECU 42 detects the position of the Purkinje image (corneal reflection image) and the position of the pupil center, and obtains the driver's line of sight relative to the front of the face based on the positional relationship between the Purkinje image and the pupil center. After that, the driver monitoring ECU 42 obtains the driver's line of sight direction to the front and rear axis and the up and down line of sight direction based on the driver's facial orientation direction and the driver's line of sight relative to the front of the face, and sends the obtained information to the driving assistance ECU 10.

[0027] The brake ECU 50 controls the brake device of the vehicle (not shown) by driving the brake actuator 51 based on the operation amount BP of the brake pedal detected by the brake pedal operation amount sensor 73 described later. That is, the brake ECU 50 adjusts the braking force applied to the own vehicle so that the larger the operation amount BP of the brake pedal, the larger the deceleration (the magnitude of the negative acceleration) of the own vehicle. Furthermore, the brake ECU 50 adjusts the braking force according to the instruction (instruction signal) from the driving assistance ECU 10, and applies automatic braking to the own vehicle.

[0028] The alarm ECU 60 displays a warning on the warning display device 61 and sounds an alarm on the alarm sound generator 62 according to an instruction (instruction signal) from the driving support ECU 10. The alarm ECU 60, the warning display device 61 and the alarm sound generator 62 are also called attention reminder devices or notification devices.

[0029] The driving support ECU 10 inputs detection values ​​(output values) of the following “sensors and switches”.

[0030] An accelerator pedal operation amount sensor 71 that detects the operation amount AP of the accelerator pedal of the own vehicle.

[0031] An accelerator switch 72 that outputs an ON signal when the accelerator pedal of the vehicle is depressed, and outputs an OFF signal when the accelerator pedal is released.

[0032] A brake pedal operation amount sensor 73 that detects an operation amount BP of a brake pedal of the own vehicle.

[0033] A brake switch 74 that outputs an on signal when the brake pedal of the vehicle is in a depressed state, and outputs an off signal when the brake pedal is in a released state.

[0034] A vehicle speed sensor 75 that detects the speed of the own vehicle (ie, own vehicle speed Vh).

[0035] An acceleration sensor 76 that detects the acceleration Gh of the host vehicle in the front-rear direction.

[0036] A steering angle sensor 77 that detects a steering angle St of the own vehicle. The steering angle St is "0" when a steering wheel of the own vehicle (not shown) is in a neutral position.

[0037] Summary of work

[0038] The device DS determines whether there is another vehicle on the collision course based on at least the other vehicle information. When it is determined that there is another vehicle on the collision course, the device DS changes the execution conditions of the collision avoidance assistance action for the other vehicle on the collision course based on the determination result (approaching direction determination result) of whether the other vehicle is approaching the own vehicle from "the passenger seat side of the other vehicle that is relatively easy for the driver of the own vehicle to visually recognize" or "the driver seat side of the other vehicle that is relatively difficult for the driver of the own vehicle to visually recognize".

[0039] Furthermore, the device DS determines whether the probability (likelihood) of the driver visually recognizing other vehicles on the collision path is high based on the driver's line of sight to the front and rear axles and whether there are vehicle structures (such as A-pillars) in the driver's line of sight to the front and rear axles, and changes the execution conditions of the collision avoidance assistance action for the other vehicles based on the probability of the visual recognition (visual recognition judgment result). In addition, the device DS determines whether the driver is performing a collision avoidance driving operation (such as a deceleration operation) to avoid collision with other vehicles on the collision path, and changes the execution conditions of the collision avoidance assistance action for the other vehicles based on the presence or absence of the collision avoidance driving operation (driving operation judgment result). In this way, the device DS changes the execution conditions of the collision avoidance assistance action based on the approach direction judgment result, the visual recognition judgment result, and the driving operation judgment result, thereby changing the start timing of the collision avoidance assistance action for other vehicles on the collision path.

[0040] Specific work

[0041] The CPU of the driving support ECU 10 (hereinafter referred to as “CPU”) executes the following operation every time a predetermined time (computation cycle) dt elapses. Figure 3 A routine represented by a flowchart in .

[0042] When the appropriate time comes, the CPU Figure 3 Step 300 (hereinafter, "step" is referred to as "S") starts processing and enters S305, and determines whether a target object is detected based on the camera information and radar information. If no target object is detected, the CPU directly enters S395 from S305 and temporarily ends this routine.

[0043] When the target object is detected, the CPU enters S310 from S305 to determine whether a collision path phenomenon has occurred (whether there are other vehicles on the collision path), and sets the value of the collision path flag XC based on the result. The value of the flag XC is set to "0" in the initialization routine executed by the CPU when the ignition key switch of the own vehicle (not shown) is changed from the off position to the on position. When the collision path flag XC has a value of "1", it indicates that a collision path phenomenon has occurred (there are other vehicles on the collision path).

[0044] More specifically, when the CPU enters S310, Figure 4 The S400 starts Figure 4 The process of the collision path phenomenon determination subroutine shown in FIG. 1 is followed by the step S410 to determine whether the detected target object is another vehicle and whether the other vehicle (hereinafter referred to as the "target vehicle") is located in the front front range of the own vehicle. The front front range is a strip area having the width of the own vehicle set in the direction in which the own vehicle is estimated to travel.

[0045] When the target vehicle is located in the frontal range of the own vehicle, no collision path phenomenon occurs. In this case, the CPU enters S420 from S410, sets the value of the collision path flag XC to "0", and then enters S495. Figure 3 S315.

[0046] In contrast, when the target vehicle is not located in the front front range of the own vehicle, the CPU proceeds from S410 to S430 to determine whether the own vehicle is substantially performing uniform linear motion based on the own vehicle speed Vh, the acceleration Gh of the own vehicle, and the steering angle St. That is, when the own vehicle speed Vh is greater than "0", the magnitude of the acceleration Gh is less than a small predetermined threshold value Ghth, and the magnitude of the steering angle St is less than a small predetermined threshold value Stth, the CPU determines that the own vehicle is substantially performing uniform linear motion.

[0047] When the own vehicle is substantially moving in a straight line at a uniform speed, the CPU proceeds from S430 to S440, and obtains the position of the target vehicle relative to the own vehicle at the current moment based on the own vehicle speed Vh, the steering angle St, the camera information, the radar information, etc. Furthermore, the CPU determines whether the target vehicle is substantially moving in a straight line at a uniform speed based on the historical records of the positions of the target vehicles relative to the own vehicle obtained in the past, the movement history records of the own vehicle, and the position of the target vehicle relative to the own vehicle at the current moment (i.e., the time change of the absolute position of the target vehicle).

[0048] When the target vehicle is actually performing uniform linear motion, the CPU enters S450 from S440 to determine whether the target vehicle is located in the front oblique direction range of the own vehicle. The front oblique direction range includes the angle from the front and rear axles of the own vehicle to the right "becoming the angle range from the first angle 'θ1-α1' to the second angle 'θ1+α1'" and the angle from the front and rear axles of the own vehicle to the left "becoming the angle range from the third angle 'θ2-α2' to the fourth angle 'θ2+α2'". In addition, θ1 and θ2 may also be equal to each other, for example, 45°. α1 and α2 may also be equal to each other, for example, 10°.

[0049] When the target vehicle is located within the oblique direction range in front of the own vehicle, the CPU proceeds from S450 to S460, and determines whether the background image of the target vehicle changes over time based on the camera information. More specifically, the CPU generates a frame obtained by enlarging and reducing the target vehicle to a certain size based on the camera information, and determines whether the image other than the target vehicle (i.e., the background image) in the frame changes over time.

[0050] For example, Figure 2 As shown, when the other vehicle OV is traveling on the collision route, when time t is t0, the background image of the other vehicle OV includes the building B1, and when time t is t1, the background image of the other vehicle OV includes the building B2. In this case, the CPU determines that the background image changes with the passage of time.

[0051] When the judgment is "yes" in each step from S430 to S450, and the background image changes with the passage of time, it can be inferred that a collision path phenomenon has occurred. In other words, it can be determined that the target vehicle is another vehicle on the collision path. Therefore, in this case, the CPU enters S470 from S460 and sets the value of the collision path flag XC to "1". Then the CPU enters S495 and then enters Figure 3 S315.

[0052] If the CPU makes a "No" determination in any of steps S430 to S460, the CPU proceeds to S420 from the step where the determination is "No" and enters Figure 3 S315.

[0053] CPU entry Figure 3 At S315, it is determined whether the value of the collision course flag XC is "1". When the value of the collision course flag XC is "0", the CPU directly enters S395 from S315. In addition, in this case, the normal collision avoidance control (control for avoiding collision with a target object located in the traveling direction of the own vehicle) is performed.

[0054] In contrast, when the value of the collision course flag XC is "1", the CPU proceeds from S315 to S320, and determines whether another vehicle on the collision course is approaching the own vehicle (to be precise, the point where the traveling direction of the own vehicle intersects the traveling direction of another vehicle on the collision course) from the driver's seat side (the right side if it is a right-hand drive car) based on the camera information and radar information. In addition, the determination result of whether another vehicle on the collision course is approaching the own vehicle from the driver's seat side or from the passenger seat side is also referred to as the approach direction determination result.

[0055] For example, when the vehicle is a right-hand drive car, the distance between the driver's seat and the right A-pillar as a vehicle structure that blocks the driver's field of view is shorter than the distance between the driver's seat and the left A-pillar as a vehicle structure that blocks the driver's field of view. As a result, the driver's field of view on the right side of the oblique front is blocked in a relatively wide range relative to the field of view on the left side of the oblique front. Therefore, when other vehicles on the collision route approach from the driver's seat side, the driver is more likely to be unable to visually recognize (not notice) other vehicles on the collision route than when other vehicles on the collision route approach from the co-pilot seat side. This is also the same when the vehicle is a left-hand drive car.

[0056] Therefore, when another vehicle on the collision path is approaching from the driver's seat, the CPU enters S325 from S320 and sets the collision time threshold TTCth described later to "the value obtained by adding the positive predetermined value A to the standard threshold Tn". As a result, the timing of executing the collision avoidance auxiliary action described later is relatively early. After that, the CPU enters S335.

[0057] On the other hand, when another vehicle on the collision course is approaching from the passenger seat side, the CPU proceeds from S320 to S330 to set the collision time threshold value TTCth to the "standard threshold value Tn". Thereafter, the CPU proceeds to S335.

[0058] When the CPU enters S335, it determines whether the driver visually recognizes other vehicles on the collision route (whether the probability of visual recognition is high), and sets the value of the visual recognition flag XW based on the result (visual recognition determination result). The value of the visual recognition flag XW is set to "0" in the above-mentioned initialization routine. When the visual recognition flag XW has a value of "1", it indicates that the driver visually recognizes other vehicles on the collision route (the probability of visual recognition is high). Therefore, the visual recognition flag XW indicates the determination result (visual recognition determination result) of whether the driver of the own vehicle visually recognizes other vehicles on the collision route with high probability.

[0059] More specifically, when the CPU enters S335, Figure 5 The S500 starts Figure 5 The process of the visibility determination subroutine shown then proceeds to S505 to determine whether the current time is immediately after the "time point at which the value of the collision course flag XC changes from '0' to '1' (hereinafter also referred to as 'collision course phenomenon start time point')".

[0060] In the case where the current moment is immediately after the collision path phenomenon starts, the CPU enters S510 from S505 and sets (resets) the value of the timer Timer to "0". The timer Timer is a timer that measures the cumulative time estimated as the state of the driver visually recognizing other vehicles on the collision path. Then, the CPU enters S515, sets the value of the visual recognition flag XW to "0", and then enters S520. In contrast, in the case where the current moment is not immediately after the collision path phenomenon starts, the CPU directly enters S520 from S505.

[0061] In S520, the CPU obtains the position (actually the orientation) of other vehicles on the collision route relative to the own vehicle based on the camera information and the radar information.

[0062] Next, the CPU obtains the front-rear axis viewing direction and the up-down viewing direction from the driver monitoring device 40 in S525 .

[0063] Next, the CPU proceeds to S530 to determine whether other vehicles on the collision course are located within the sight line of the driver of the own vehicle (ie, whether the driver can visually see other vehicles on the collision course).

[0064] More specifically, when both the following conditions 1 and 2 are satisfied, the CPU determines that the other vehicle on the collision course is located within the sight direction of the driver of the own vehicle.

[0065] (Condition 1) The up and down sight line direction of the driver Dr of the own vehicle is within the first angle range AR1 when the driver Dr observes the outside of the own vehicle (see Fig. 6A ). The first angle range is a range that is above an angle D1 directed downward from the horizontal direction HL and below an angle D2 directed upward from the horizontal direction HL.

[0066] (Condition 2) When the "angle (left-right direction angle) relative to the front FD of the front and rear axles of the own vehicle HV" of the driver Dr of the own vehicle's line of sight in the front and rear axles is angle θ3, the other vehicle on the collision path is located in the second angle range AR2 (referenced to the angle "θ3-β1" to the angle "θ3+β1" from the front FD of the front and rear axles of the own vehicle to the left or right) Figure 6B ) is within the range of β1. β1 is, for example, 15°.

[0067] When the other vehicle on the collision path is within the sight line of the driver of the own vehicle, the CPU proceeds from S530 to S535 to determine whether there is no "vehicle structure (blocking object) of the own vehicle" that blocks the driver's field of vision within the sight line of the driver of the own vehicle (the second angle range AR2 described above). A representative example of such a vehicle structure of the own vehicle is the A-pillar (see Figure 6B A-pillar BS shown).

[0068] Even if other vehicles on the collision course are within the sight line range (second angle range AR2) of the driver of the own vehicle, if the vehicle structure of the own vehicle is within the sight line range, the driver of the own vehicle will not be able to see other vehicles on the collision course.

[0069] In other words, when it is determined as "yes" in S530, and there is no "vehicle structure of the own vehicle" that blocks the driver's field of vision within the line of sight direction range (second angle range AR2) of the driver of the own vehicle, it can be inferred that the driver is observing other vehicles on the collision route. Therefore, in this case, the CPU enters S540 from S535 to increase the value of the timer Timer by a predetermined time (operation cycle) dt. As can be seen from the above, when the driver of the own vehicle is always looking at directions other than other vehicles on the collision route, the value of the timer Timer will not increase. In contrast, when the driver is always looking at other vehicles on the collision route, or looking at them intermittently, the value of the timer Timer will gradually increase. Therefore, when the value of the timer Timer is above the visual recognition determination time threshold Tth, it can be inferred that the driver of the own vehicle is visually recognizing (identifying by vision) other vehicles on the collision route.

[0070] Then, when the CPU enters S545 from S540, it determines whether the value of the timer Timer is greater than the visual recognition determination time threshold Tth. If the value of the timer Timer is greater than the visual recognition determination time threshold Tth, the CPU enters S550 from S545 and sets the value of the visual recognition flag XW to "1". After that, the CPU enters S595 and then enters Figure 3 S340.

[0071] In addition, if the CPU determines "No" in any of steps S530, S535 and S545, the CPU directly proceeds to S595 from the step in which the determination is "No", and then proceeds to S596. Figure 3 In this way, when the driver of the own vehicle visually recognizes (identifies by vision) another vehicle on the collision course with high probability, the value of the visual recognition flag XW is set to "1", and otherwise, the value of the visual recognition flag XW is set to "0".

[0072] When the CPU enters S340, it determines whether the value of the visual recognition flag XW is "1". When the value of the visual recognition flag XW is "1", the CPU enters S345 from S340 to reduce the collision time threshold TTCth by a positive predetermined value B. As a result, the timing of the collision avoidance auxiliary action being executed is relatively delayed. After that, the CPU enters S350. In contrast, when the value of the visual recognition flag XW is not "1", the CPU directly enters S350 from S340.

[0073] The CPU determines in S350 whether the driver of the own vehicle is performing a collision avoidance driving operation. The determination result in S350 is also referred to as a driving operation determination result. More specifically, the CPU determines that the driver of the own vehicle is performing a collision avoidance driving operation when the signal from the brake switch 74 becomes an on signal. In addition, the CPU may also determine that the driver of the own vehicle is performing a collision avoidance driving operation in any of the following situations (when the driver of the own vehicle is performing a deceleration operation for decelerating the own vehicle).

[0074] When the signal from the accelerator switch 72 becomes an OFF signal.

[0075] The operation amount AP of the accelerator pedal decreases with the passage of time.

[0076] The case where the operation amount BP of the brake pedal increases with the passage of time.

[0077] When the driver of the own vehicle is performing a collision avoidance driving operation, the CPU proceeds from S350 to S355, and reduces the collision time threshold TTCth by a positive predetermined value C. As a result, the timing at which the collision avoidance auxiliary action is performed is relatively delayed. Thereafter, the CPU proceeds to S360. In contrast, when the driver of the own vehicle is not performing a collision avoidance driving operation, the CPU proceeds directly from S350 to S360.

[0078] In S360, the CPU determines whether a predetermined execution condition for executing a collision avoidance assist action for avoiding a collision with another vehicle on the collision path is satisfied. More specifically, in S360, the CPU determines whether a collision margin time (TTC: Time To Collision) is below a collision time threshold value TTCth. The collision margin time TTC is obtained by dividing the distance DP between the point P where the own vehicle and the other vehicle on the collision path intersect each other and the own vehicle by the vehicle speed Vh of the own vehicle (refer to Figure 2 ).

[0079] When the collision margin time TTC is less than the collision time threshold value TTCth, the execution condition is satisfied. In this case, the CPU enters S365 from S360 and executes the collision avoidance assistance action (collision avoidance control / collision damage reduction control). More specifically, the CPU operates the brake actuator 51 by sending an instruction signal to the brake ECU 50, applies a braking force to the own vehicle to decelerate the own vehicle (execute automatic braking) so that the own vehicle stops in front of the point P where it intersects with other vehicles on the collision route. Furthermore, the CPU sends an instruction signal to the alarm ECU 60, causing the warning display device 61 to display a warning and the alarm sound generating device 62 to emit an alarm sound.

[0080] On the other hand, when the collision margin time TTC is larger than the collision time threshold value TTCth, the CPU directly proceeds from S360 to S395 to temporarily terminate this routine.

[0081] As described above, according to the embodiment of the present invention, the execution condition (TTCth) of the collision avoidance assistance operation is changed based on the approach direction determination result, the recognition determination result, and the driving operation determination result, so that the collision avoidance assistance operation can be started at an appropriate timing.

[0082] In addition, the present invention is not limited to the above-mentioned embodiments and variations, and various variations can be adopted within the scope of the present invention. For example, the above-mentioned device DS can also change the execution conditions of the collision avoidance auxiliary action based on at least one or any two of the approach direction determination result, the visual recognition determination result, and the driving operation determination result. Figure 3 The processing group from S320 to S330, Figure 3 The processing groups S335 to S345 and Figure 3 Any one or any two of the processing groups of S350 and S355 are omitted. In this case, the default value of the collision time threshold value TTCth is set to the standard threshold value Tn.

[0083] Furthermore, the collision avoidance assistance action may not include automatic braking, but only "warning and alarm sound", or only warning. In addition, it is also possible to execute only "warning and alarm sound" when the collision margin time TTC is less than the first collision time threshold TTCth1, and execute "automatic braking" when the collision margin time TTC is less than "the second collision time threshold TTCth2 smaller than the first collision time threshold TTCth1". In this case, the first collision time threshold TTCth1 and the second collision time threshold TTCth2 can be changed based on at least one or any two of the approach direction determination result, the visual recognition determination result and the driving operation determination result as described above.

[0084] In addition, for example, the present invention can be applied to a vehicle in a state where the driving mode is changed from automatic driving to driving by a driver in an automatic driving vehicle.

Claims

1. A driving assistance device for a vehicle, comprising a controller, The controller obtains other vehicle information, the other vehicle information being information about the position of other vehicles located in an area obliquely in front of the own vehicle relative to the own vehicle, and when it is determined based on the other vehicle information that there are other vehicles traveling in a manner that produces a collision course phenomenon relative to the own vehicle, that is, other vehicles on the collision course, the controller determines whether an execution condition for executing a collision avoidance assistance action is met, and starts executing the collision avoidance assistance action when it is determined that the execution condition is met, the collision avoidance assistance action being an action for avoiding a collision between the own vehicle and other vehicles on the collision course, The controller is configured to change the execution condition based on at least one of an approach direction determination result and a visual recognition determination result, wherein the approach direction determination result is a determination result as to whether the other vehicles on the collision route are approaching from the direction of the driver's seat side of the own vehicle or from the direction of the passenger seat side of the own vehicle, and the visual recognition determination result is a determination result as to whether the probability of the driver of the own vehicle visually recognizing the other vehicles on the collision route is high.

2. The driving assistance device for a vehicle according to claim 1, The controller is configured to change the execution condition also based on a driving operation determination result, which is a determination result as to whether the driver is performing a collision avoidance driving operation for avoiding the collision.

3. The driving assistance device for a vehicle according to claim 1 or 2, The controller is configured to change the execution condition based on the visual recognition determination result. Furthermore, the controller is configured to obtain the visual recognition determination result by the following processing: Obtaining the sight direction of the driver; measuring a cumulative time in which another vehicle on the collision route is within a sight line direction range and a vehicle structure of the own vehicle is not within the sight line direction range, the sight line direction range being a range determined based on the sight line direction; When the accumulated time is greater than a predetermined threshold, it is determined that the probability that the driver of the own vehicle visually recognizes the other vehicle on the collision route is high, and when the accumulated time is less than a predetermined threshold, it is determined that the probability that the driver of the own vehicle visually recognizes the other vehicle on the collision route is low.

4. The driving assistance device for a vehicle according to claim 1, The controller is configured to change the execution condition based on the approach direction determination result and the visibility determination result. Furthermore, the controller is configured as follows: The execution condition is changed so that when another vehicle on the collision path is approaching from the direction of the driver's seat side, the timing of starting to execute the collision avoidance assistance action is advanced compared with when another vehicle on the collision path is approaching from the direction of the passenger seat side; The execution condition is changed so that when the driver visually recognizes that there is a low probability of another vehicle on the collision course, the timing of starting to execute the collision avoidance assistance action is advanced compared to when the driver visually recognizes that there is a high probability of another vehicle on the collision course.

5. A driving assistance method for a vehicle, comprising: A step of obtaining other vehicle information, wherein the other vehicle information is information about the position of other vehicles located in an area obliquely in front of the own vehicle relative to the own vehicle; A step of determining whether an execution condition for executing a collision avoidance assist action is satisfied when it is determined based on the other vehicle information that there is another vehicle traveling in a manner that generates a collision course phenomenon with respect to the own vehicle, that is, another vehicle on the collision course, the collision avoidance assist action being an action for avoiding a collision between the own vehicle and the other vehicle on the collision course; and the step of starting to execute the collision avoidance assistance action when it is determined that the execution condition is satisfied, The driving assistance method includes a step of changing the execution condition based on at least one of an approach direction determination result and a visual recognition determination result, wherein the approach direction determination result is a determination result as to whether the other vehicle on the collision route is approaching from the direction of the driver's seat side of the own vehicle or from the direction of the passenger seat side of the own vehicle, and the visual recognition determination result is a determination result as to whether the probability of the driver of the own vehicle visually recognizing the other vehicle on the collision route is high.

Images