Driving assistance device, driving assistance method, and program

Abstract

To provide a drive assisting device capable of reducing a possibility such that, when there is a vehicle approaching from the back side, an own vehicle collides with the approaching vehicle from the back side.SOLUTION: A drive assisting device executes, when there is a possibility such that an own vehicle deviates from a running region through which the own vehicle is running or when the own vehicle deviates from the running region, a deviation control that is at least either one of a deviation alert for causing a driver to know the deviation from the running region or a vehicle control to control the own vehicle so as to prevent the own vehicle from deviating from the running region. The operation assisting device does not execute the deviation control when an over-ride condition such that a steering index value relating to a steering operation performed by the driver while the deviation control is being executed is greater than or equal to a threshold is enacted, and makes the enactment of the over-ride condition difficult in comparison with a case in which there is no approaching vehicle from the back side when there is the approaching vehicle from the back side approaching to the own vehicle from the back side of the own vehicle in the running region.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a driving assistance device that executes at least one of a departure warning to notify the driver of departure from a driving area and vehicle control of the driving state of the vehicle as departure control to prevent the vehicle from departing from the driving area, a driving assistance method in which a computer mounted on the vehicle executes departure control, and a program that causes a computer mounted on the vehicle to execute departure control. [Background technology]

[0002] Conventionally, there are known driving assistance devices that execute departure control when there is a possibility that the vehicle will deviate from the driving area or when the vehicle has deviated from the driving area. For example, the driving assistance device described in Patent Document 1 (hereinafter referred to as the "conventional device") suspends the departure control when an override condition is met, that is, when the driver has intervened in steering. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-81115 Summary of the Invention

[0004] When a vehicle approaching from behind is present in the driving area in which the host vehicle is traveling, the vehicle may change lanes to overtake the host vehicle. If the driver of the host vehicle changes lanes without noticing the vehicle approaching from behind, the host vehicle may depart from the driving area, so departure control is executed. If the driver continues to steer the vehicle to change lanes after the departure control is executed, conventional systems are likely to determine that a steering intervention has occurred and suspend departure control. If departure control is suspended under such circumstances, there is a risk of a collision between the host vehicle and the vehicle approaching from behind.

[0005] The present invention has been made to address the above-mentioned problems, and an object of the present invention is to provide a driving assistance device that can reduce the possibility of a collision between a host vehicle and a vehicle approaching from behind when the host vehicle is present.

[0006] When there is a possibility that the host vehicle (SV) will depart from the driving area (TA) in which the host vehicle is traveling, or when the host vehicle has departed from the driving area (step 310 "Yes"), the driving assistance device of the present invention (hereinafter referred to as "the device of the present invention") executes, as departure control (step 340), at least one of a departure warning to notify the driver of the departure from the driving area and vehicle control to control the driving state of the host vehicle to prevent the host vehicle from deviating from the driving area. The driving assistance device If an override condition is met that the steering index value related to the steering operation performed by the driver is equal to or greater than a threshold value while the departure control is being executed (step 335 "Yes"), the departure control is interrupted or terminated (step 350), When a rear approaching vehicle (RV) approaching the host vehicle from behind is present in the travel area (step 405 "Yes"), the override condition is made less likely to be satisfied (step 415) compared to when the rear approaching vehicle is not present (step 405 "No"). It is structured as follows.

[0007] According to the device of the present invention, when a vehicle approaching from behind is present, the override condition is less likely to be met than when no vehicle approaching from behind is present. A vehicle approaching from behind is likely to change lanes to overtake the host vehicle. According to the device of the present invention, it is possible to reduce the possibility that departure control will be interrupted if the host vehicle changes lanes without the driver of the host vehicle noticing that the vehicle approaching from behind has (or is) making a lane change. This reduces the possibility of a collision between the host vehicle and the vehicle approaching from behind. [Brief explanation of the drawings]

[0008] [Figure 1]1 is a schematic system configuration diagram of a driving assistance device according to an embodiment of the present invention; [Figure 2] 3A and 3B are explanatory diagrams illustrating an example of operation of the driving assistance device according to the embodiment of the present invention. [Figure 3] 2 is a flowchart of a departure control routine executed by a CPU of the ECU shown in FIG. 1. [Figure 4] 2 is a flowchart of a threshold angle setting subroutine executed by a CPU of the ECU shown in FIG. 1. [Figure 5] 6 is a flowchart of a departure control routine executed by a CPU of an ECU of a driving assistance device according to a first modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] As shown in FIG. 1, a driving assistance device 10 according to this embodiment (hereinafter referred to as "the device 10") is applied to a host vehicle SV, and includes the components shown in FIG.

[0010] In this specification, "ECU 20" refers to an electronic control device that includes a microcomputer as its main component. The ECU 20 is also referred to as a control unit, a controller, and a computer. The microcomputer includes a CPU (processor), a ROM, a RAM, an interface, and the like. The functions realized by the ECU 20 may be realized by multiple ECUs.

[0011] The front camera 22 acquires front image data by capturing an image of the scenery ahead of the host vehicle SV. The rear camera 24 acquires rear image data by capturing an image of the scenery behind the host vehicle SV. The ECU 20 acquires the front image data and rear image data from the front camera 22 and the rear camera 24, respectively.

[0012] The vehicle speed sensor 28 detects the host vehicle speed Vs, which indicates the speed of the host vehicle SV. The yaw rate sensor 30 detects the yaw rate Yr of the host vehicle SV. The steering angle sensor 30 detects the steering angle θ of the steering wheel SW (see FIG. 2). When the steering wheel SW is steered to the right from the neutral position of the steering wheel SW, the steering angle θ becomes a negative value, and when the steering wheel SW is steered to the left from the neutral position, the steering angle θ becomes a positive value. The steering torque sensor 32 detects the steering torque Tr of the steering wheel SW. The acceleration sensor 34 detects the acceleration Gx in the longitudinal direction of the host vehicle SV and the acceleration Gy in the transverse direction of the host vehicle SV. The ECU 20 acquires the detection values ​​of these sensors.

[0013] The vehicle-to-vehicle communication interface (I / F) 38 is an interface for performing vehicle-to-vehicle communication between the vehicle SV and other vehicles.

[0014] The steering motor 40 is incorporated into a steering mechanism 42. The steering mechanism 42 is a mechanism for steering the steered wheels in response to the operation of the steering wheel SW. In response to a command from the ECU 20, the steering motor 40 causes the steering mechanism 42 to generate an assist torque for assisting the operation of the steering wheel SW, and causes the steering mechanism 42 to generate an automatic steering torque for changing the steering angle of the steered wheels.

[0015] The display device 44 displays a departure warning screen, which will be described later. The speaker 46 issues a departure warning sound, which will be described later.

[0016] <Deviation Control> The departure control will be described below with reference to FIG. The ECU 20 recognizes the boundaries BL (right boundary RBL and left boundary LBL) of the traveling area TA in which the host vehicle SV is traveling based on the front image data. Examples of the boundaries BL include white lines on the road, guardrails, curbs, and walls. The ECU 20 sets reference lines RL (right reference line RRL and left reference line LRL) at positions that are a predetermined reference distance Dref away from the boundaries BL inward of the traveling area TA in a direction perpendicular to the boundaries BL.

[0017] When either of the following conditions E1 and E2 is satisfied, the ECU 20 determines that the execution condition is satisfied and executes departure control. Condition E1: The predicted course PR of the host vehicle SV intersects with the reference line RL when the course distance Dpr along the predicted course PR is less than a predetermined threshold distance Dth (if this condition E1 is met, ECU 20 determines that there is a possibility that the host vehicle SV will deviate from the driving area TA). Condition E2: Part or all of the body of the host vehicle SV deviates from the reference line RL. As an example, the ECU 20 acquires the predicted course PR based on the host vehicle speed Vs and the yaw rate Yr.

[0018] In this embodiment, the ECU 20 executes the departure control by controlling the traveling state (the steering angle of the steering wheels) of the host vehicle SV so that the host vehicle SV does not depart from the traveling area TA. Specifically, the ECU 20 acquires the departure prevention steering angle θdev for preventing the host vehicle SV from departing from (or having deviated from) the reference line RL (i.e., for returning the host vehicle SV to the inside of the reference line RL). The ECU 20 controls the steering motor 40 so that the steering angle θ coincides with the departure prevention steering angle θdev.

[0019] When an override condition is met, ECU 20 suspends departure control. As an example, the override condition is met when the magnitude (|θ|) of steering angle θ is equal to or greater than a threshold angle θth.

[0020] (Overview of operation) When there is a rear approaching vehicle RV traveling behind the host vehicle SV in the same traveling area TA as the host vehicle SV and approaching the host vehicle SV, the ECU 20 makes it more difficult for the override condition to be satisfied than when there is no rear approaching vehicle RV.

[0021] As an example, when there is no rear approaching vehicle RV, ECU20 sets the threshold angle θth to the first threshold angle θ1th, and when there is a rear approaching vehicle RV, ECU20 sets the threshold angle θth to a "second threshold angle θ2th greater than the first threshold angle θ1th."

[0022] The vehicle RV approaching from behind is likely to change lanes to overtake the host vehicle SV (see the arrow in Figure 2). If the host vehicle SV changes lanes in this case, the execution condition will eventually be met and departure control will be executed. If the driver continues to perform a steering operation to change lanes even after departure control is executed, the magnitude of the steering angle θ will likely become larger than the threshold angle θth, and the override condition will likely be met.

[0023] According to this embodiment, when a vehicle RV is approaching from behind, the override condition is less likely to be satisfied than when no vehicle RV is approaching from behind, so even if the driver continues to perform a steering operation to change lanes after departure control is executed, the override condition is less likely to be satisfied. As a result, departure control is more likely to continue to be executed, and the possibility of a collision between the host vehicle SV and the vehicle RV approaching from behind can be reduced.

[0024] (Example of operation) At time t1 shown in Figure 2, the driver of the host vehicle SV starts steering the steering wheel SW to the right, and the host vehicle SV starts changing lanes to the right lane of the driving area TA. At time t1, the execution condition is not yet met, so departure control is not executed.

[0025] At time t2, the execution condition is met and the ECU 20 starts departure control. There is a vehicle RV approaching from behind. Therefore, the ECU 20 sets the threshold angle θth to the second threshold angle θth2, making it more difficult for the override condition to be met.

[0026] (Specific operation) <Deviation Control> The CPU of the ECU 20 executes the routine shown in the flowchart of FIG. 3 every time a predetermined time period elapses.

[0027] When an appropriate time arrives, the CPU starts processing from step 300 in FIG. 3, and in step 305, determines whether the value of the execution flag Xexe is "0." The value of the execution flag Xexe is set to "1" when the execution condition is met, and is set to "0" when the termination condition is met. The value of the execution flag Xexe is set to "0" in an initial routine. The initial routine is executed by the CPU when the ignition key switch (not shown) of the host vehicle SV is changed from the off position to the on position.

[0028] If the value of the execution flag Xexe is "0", the CPU determines "Yes" in step 305, and the process proceeds to step 310. In step 310, the CPU determines whether the execution condition is met by determining whether either the above condition E1 or the above condition E2 is met.

[0029] If the execution condition is not met, the CPU determines "No" in step 310, and the process proceeds to step 395. In step 395, the CPU temporarily ends this routine. On the other hand, if the execution condition is met, the CPU determines "Yes" in step 310, and the process proceeds to step 315. In step 315, the CPU sets the value of the execution flag Xexe to "1." Thereafter, the process proceeds to step 395, and the CPU temporarily ends this routine.

[0030] If the value of the execution flag Xexe is "1" when the process proceeds to step 305, the CPU determines "No" in step 305, and the process proceeds to step 320. In step 320, the CPU determines whether or not the termination condition is met. As an example, the CPU determines that the termination condition is met when a predetermined termination time Tend has elapsed since the execution condition was met.

[0031] If the termination condition is not met, the CPU determines "No" in step 320, and the process proceeds to step 325. In step 325, the CPU determines whether the value of the override flag Xovr is "0".

[0032] The value of the override flag Xovr is set to "1" when the override condition is met, and is set to "0" when a predetermined time has passed since the override condition was met or when the termination condition is met. The value of the override flag Xovr is also set to "0" in the initial routine.

[0033] If the value of the override flag Xovr is “0”, the CPU determines “Yes” in step 325 and executes steps 330 and 335 . The process proceeds to step 330. Step 330: The CPU executes a threshold angle setting subroutine (see FIG. 4) for setting the threshold angle θth. The details of the threshold angle setting subroutine will be described later. Step 335: The CPU determines whether the magnitude (|θ|) of the steering angle θ is equal to or greater than the threshold angle θth (that is, determines whether the override condition is met).

[0034] If the magnitude (|θ|) of the steering angle θ is less than the threshold angle θth (that is, if the override condition is not met), the CPU determines “No” in step 335 and the process proceeds to step 340 .

[0035] In step 340, the CPU sets the target steering angle θtgt to the departure prevention steering angle θdev, and controls the steering motor 40 so that the steering angle θ coincides with the target steering angle θtgt. Then, the process proceeds to step 395, and the CPU temporarily ends this routine.

[0036] When the processing proceeds to step 335, if the magnitude (|θ|) of the steering angle θ is equal to or greater than the threshold angle θth (i.e., if the override condition is met), the CPU determines "Yes" in step 335 and executes steps 345 and 350.

[0037] Step 345: The CPU sets the target steering angle θtgt to "the manual steering angle θman corresponding to the steering angle θ" and controls the steering motor 40 so that the steering angle θ coincides with the target steering angle θtgt. As a result, the steering angle of the steered wheels of the vehicle is controlled in accordance with the manual steering angle θman determined by the driver's steering operation, rather than the departure prevention steering angle θdev. Therefore, if the override condition is met, departure control is interrupted. Thereafter, the process proceeds to step 395, and the CPU temporarily ends this routine.

[0038] If the value of the override flag Xovr is "1" when the process proceeds to step 325, the CPU determines "No" in step 325, and the process proceeds to step 355. In step 355, the CPU determines whether a predetermined time has elapsed since the override condition was met. As an example, this predetermined time is set to a value shorter than the end time Tend.

[0039] If the predetermined time has not elapsed since the condition was met, the CPU determines "No" in step 355, and the process proceeds to step 350. On the other hand, if the predetermined time has elapsed since the condition was met, the CPU determines "Yes" in step 355, and the process proceeds to step 360. In step 360, the CPU sets the value of the override flag Xovr to "0." Then, the process proceeds to step 340.

[0040] If the termination condition is met when the process proceeds to step 320, the CPU determines "Yes" in step 320, and the process proceeds to step 365. In step 365, the CPU sets the value of the execution flag Xexe to "0" and sets the value of the override flag Xovr to "0". Thereafter, the process proceeds to step 395, and the CPU temporarily ends this routine.

[0041] <Threshold angle setting> When the process proceeds to step 330 in Fig. 3, the CPU starts the process from step 400 in Fig. 4, and the process proceeds to step 405. In step 405, the CPU determines whether or not a rear approaching vehicle RV is present based on the rear image data.

[0042] If there is no rear-approaching vehicle RV, the CPU determines "No" in step 405, and the process proceeds to step 410. In step 410, the CPU sets the threshold angle θth to the first threshold angle θth1. Thereafter, the process proceeds to step 495, and the CPU temporarily ends this routine.

[0043] If a rear-approaching vehicle RV is present, the CPU determines "Yes" in step 405, and the process proceeds to step 415. In step 415, the CPU sets the threshold angle θth to "a second threshold angle θth2 that is greater than the first threshold angle θth1." Thereafter, the process proceeds to step 495, and the CPU temporarily ends this routine.

[0044] As described above, according to this embodiment, when a rear approaching vehicle RV is present, the override condition (more specifically, the override condition on both sides) is less likely to be satisfied than when a rear approaching vehicle RV is not present, thereby reducing the possibility of a collision between the host vehicle SV and the rear approaching vehicle RV.

[0045] (First Modification) In this modified example, the ECU 20 acquires the magnitude of the steering angle θ having a negative value as the right steering angle θR, and acquires the magnitude of the steering angle θ having a positive value as the left steering angle θL. The ECU 20 determines that the override condition is met when the right steering angle θR is equal to or greater than the right threshold angle θRth (when the right override condition is met), or when the left steering angle θL is equal to or greater than the left threshold angle θLth (when the left override condition is met).

[0046] When there is no rear approaching vehicle RV, the ECU 20 sets the right threshold angle θRth and the left threshold angle θLth to a first right threshold angle θRth1 and a first left threshold angle θLth1, respectively.

[0047] When a rear-approaching vehicle RV is present and the rear-approaching vehicle RV intends to change lanes to the right, the ECU 20 sets the right threshold angle θRth to a "second right threshold angle θRth2 larger than the first right threshold angle θRth1," and sets the left threshold angle θLth to a first left threshold angle θLth1. Note that when the rear-approaching vehicle RV intends to change lanes to the left, the ECU 20 sets the left threshold angle θLth to a "second left threshold angle θLth2 larger than the first left threshold angle θLth1," and sets the right threshold angle θRth to the first right threshold angle θRth1. In other words, when the rear-approaching vehicle RV intends to change lanes, the ECU 20 makes it more difficult for the override condition for the lane change destination of the rear-approaching vehicle RV to be satisfied than when there is no rear-approaching vehicle RV.

[0048] The ECU 20 makes it difficult for the override condition to be satisfied only on the side where the host vehicle SV is more likely to collide with the rear-approaching vehicle RV. This reduces the possibility of the host vehicle SV colliding with the rear-approaching vehicle RV. Furthermore, when the driver performs a steering operation toward the side where the host vehicle SV is less likely to collide with the rear-approaching vehicle RV, the override condition is satisfied as usual, reducing the possibility of the driver feeling uncomfortable.

[0049] When the vehicle RV approaching from behind does not intend to change lanes and an overtaking lane exists adjacent to the driving area TA, the ECU 20 sets the threshold angle θth on the overtaking lane side of the right threshold angle θRth and the left threshold angle θLth to a larger value than when no vehicle RV approaching from behind exists. In countries where driving is on the left side, an overtaking lane exists on the right side of the driving area TA, so the ECU 20 sets the right threshold angle θRth to a second right threshold angle θRth2. In countries where driving is on the right side, an overtaking lane exists on the left side of the driving area TA, so the ECU 20 sets the left threshold angle θLth to a second left threshold angle θLth2. The following explanation assumes a country where driving is on the left side.

[0050] The vehicle RV approaching from behind may suddenly change lanes without indicating an intention to change lanes. In such a case, the vehicle RV approaching from behind is likely to change lanes to the overtaking lane. If the vehicle RV approaching from behind does not intend to change lanes, the ECU 20 makes it difficult for only the override condition for the overtaking lane to be satisfied, thereby reducing the possibility of the driver feeling uncomfortable and reducing the possibility of the host vehicle SV colliding with the vehicle RV approaching from behind.

[0051] The CPU of the ECU 20 of this modified example executes a threshold angle setting subroutine shown in FIG. 5 instead of the threshold angle setting subroutine shown in FIG.

[0052] When the process proceeds to step 330 in Fig. 3, the CPU starts the process from step 500 in Fig. 5. In step 505, the CPU determines whether or not there is a vehicle RV approaching from behind.

[0053] If there is no rear-approaching vehicle RV, the CPU determines "No" in step 505, and the process proceeds to step 510. In step 510, the CPU sets the right threshold angle θRth to a first right threshold angle θRth1, and sets the left threshold angle θLth to a first left threshold angle θLth1. After executing step 510, the process proceeds to step 595, and the CPU temporarily ends this routine. Thereafter, the process proceeds to step 335 in FIG. 3, where the CPU determines whether either a right override condition, that the right steering angle θR is equal to or greater than the right threshold angle θRth, or a left override condition, that the left steering angle θL is equal to or greater than the left threshold angle θLth, is satisfied.

[0054] If either the right override condition or the left override condition is met, the CPU determines "Yes" in step 335. If neither the right override condition nor the left override condition is met, the CPU determines "No" in step 335.

[0055] If a rear-approaching vehicle RV is present when the process proceeds to step 505, the CPU determines "Yes" in step 505, and the process proceeds to step 515. In step 515, the CPU determines whether the rear-approaching vehicle RV intends to change lanes. As one example, the CPU determines that the rear-approaching vehicle RV intends to change lanes if it determines, based on the rear image data, that the rear-approaching vehicle RV's turn signal is on. As another example, the CPU determines that the rear-approaching vehicle RV intends to change lanes if the lateral speed of the rear-approaching vehicle RV acquired based on multiple rear image data is equal to or greater than a threshold speed. Note that lateral acceleration may be used instead of the lateral speed. As yet another example, the CPU determines that the rear-approaching vehicle RV intends to change lanes if the vehicle-to-vehicle communication I / F 38 receives a "lane change signal indicating that a lane change is about to be made" from the rear-approaching vehicle RV.

[0056] If the rear approaching vehicle RV intends to change lanes, the CPU determines "Yes" in step 515, and the process proceeds to step 520. In step 520, the CPU determines whether the rear approaching vehicle RV intends to change lanes to the right.

[0057] If the lane change direction is to the right, the CPU determines "Yes" in step 520, and the process proceeds to step 525. In step 525, the CPU sets the right threshold angle θRth to the second right threshold angle θRth2, and sets the left threshold angle θLth to the first left threshold angle θLth1. Thereafter, the process proceeds to step 595, where the CPU temporarily ends this routine and executes step 335 in FIG. 3.

[0058] If the lane change direction is to the left, the CPU determines "No" in step 520, and the process proceeds to step 530. In step 530, the CPU sets the right threshold angle θRth to the first right threshold angle θRth1, and sets the left threshold angle θLth to the second left threshold angle θLth2. Thereafter, the process proceeds to step 595, where the CPU temporarily ends this routine and executes step 335 in FIG. 3.

[0059] If there is no rear approaching vehicle RV when the process proceeds to step 515, the CPU determines "No" in step 515, and the process proceeds to step 535. In step 535, the CPU determines whether or not there is an overtaking lane on the right side of the driving area TA based on the previous image data. The overtaking lane is a lane adjacent to the driving area TA, and is a lane in which travel in the same direction as the host vehicle SV is permitted.

[0060] If an overtaking lane exists, the CPU determines "Yes" in step 535, and the process proceeds to step 525. If an overtaking lane does not exist, the CPU determines "No" in step 535, and the process proceeds to step 510.

[0061] As described above, according to this modified example, only the override condition on the side where the rear-approaching vehicle RV is more likely to change lanes is made less likely to be met, thereby reducing the possibility of the driver feeling uncomfortable and reducing the possibility of the host vehicle SV colliding with the rear-approaching vehicle RV.

[0062] It is also possible to make it easier for the override condition to be satisfied for the vehicle RV approaching from behind to not change lanes (or the side opposite the passing lane). When the vehicle RV approaching from behind overtakes the host vehicle SV, the driver of the host vehicle SV may intentionally perform a steering operation "on the side opposite to the side on which the vehicle RV approaching from behind will overtake the host vehicle SV" in order to avoid the vehicle RV approaching from behind attempting to overtake the host vehicle SV. If departure control is executed during such a steering operation, the departure control is immediately stopped, thereby reducing the possibility that the departure control will cause the driver discomfort.

[0063] Furthermore, if the CPU determines "No" in step 505, it may determine whether or not there is an overtaking lane adjacent to the traveling area TA, and proceed to step 515 only if there is an overtaking lane.

[0064] (Second Modification) The ECU 20 may execute departure warning as departure control instead of vehicle control, or may execute both vehicle control and departure warning as departure control. In other words, the ECU 20 executes at least one of vehicle control and departure warning as departure control.

[0065] In the departure warning, the ECU 20 displays a departure warning screen on the display device 44 to notify the driver that the host vehicle SV may depart (or has departed) from the traveling area TA. The ECU 20 may also cause the speaker 46 to emit a departure warning sound to notify the driver that the host vehicle SV may depart (or has departed) from the traveling area TA.

[0066] (Third Modification) Although the ECU 20 makes it difficult for the override condition to be satisfied by increasing the threshold angle θth (right threshold angle θRth and left threshold angle θLth), this is not limiting. For example, the ECU 20 may make the steering angle θ compared with the threshold angle θth smaller than the actual steering angle θ to make it difficult for the override condition to be satisfied. Specifically, the ECU 20 uses a value obtained by multiplying the actual steering angle θ by a weighting coefficient α (0≦α<1) as the steering angle θ to be compared with the threshold angle θth.

[0067] (Fourth Modification) The ECU 20 determines that the override condition is met when the steering angle θ is equal to or greater than the threshold angle θth, but is not limited to this. Instead of the steering angle θ, at least one of the steering torque Tr, steering angular velocity, steering angle of the steered wheels, steering angular velocity, lateral velocity of the host vehicle SV, and lateral acceleration Gy of the host vehicle SV may be used. These values ​​are related to the steering operation performed by the driver and are also referred to as steering index values.

[0068] (Fifth Modification) The ECU 20 determines that the termination condition is satisfied when a predetermined termination time Tend has elapsed since the execution condition was satisfied, but is not limited to this. For example, the ECU 20 may determine that the termination condition is satisfied when the host vehicle SV is positioned inside an "end reference line set inside the reference line RL." As another example, the ECU 20 may determine that the termination condition is satisfied when the predicted path PR no longer intersects with the reference line RL or the end reference line.

[0069] (Sixth Modification) When the override condition is met, ECU 20 may set the value of the execution flag Xexe to "0" and terminate departure control.

[0070] (Seventh Modification) The ECU 20 may set the reference line RL outside the boundary BL. The device 10 may include a sensor (such as Lidar, millimeter wave radar, or sonar) capable of detecting an object on the host vehicle SV, instead of the rear camera 24.

[0071] The device 10 is applicable to vehicles such as internal combustion engine vehicles, hybrid vehicles, plug-in hybrid vehicles, fuel cell vehicles, and electric vehicles. The device 10 is also applicable to autonomous vehicles. The present invention can also be understood as a non-transitory storage medium on which a program for realizing the functions of the device 10 is stored and which is readable by a computer. [Explanation of symbols]

[0072] 10...driving assistance device, 20...ECU, 22...front camera, 24...rear camera, 40...steering motor, 44...display device, 46...speaker

Claims

1. A driving assistance device that executes, as departure control, at least one of a departure warning for notifying a driver of departure from a driving area in which the host vehicle is traveling or a vehicle control for controlling a driving state of the host vehicle to prevent the host vehicle from departing from the driving area when the host vehicle is likely to depart from the driving area in which the host vehicle is traveling or when the host vehicle departs from the driving area, The driving assistance device When an override condition is established that a steering index value related to a steering operation performed by the driver is equal to or greater than a threshold value while the departure control is being executed, the departure control is suspended or terminated; When a vehicle approaching from behind the host vehicle is present in the travel area, the override condition is made less likely to be satisfied than when the vehicle approaching from behind is not present. A driving assistance device configured as follows.

2. The driving assistance device according to claim 1, the override conditions include a right override condition and a left override condition; The driving assistance device When a right steering index value related to a right steering operation performed by the driver is equal to or greater than the threshold value, it is determined that the right override condition is established; If a left steering index value related to a left steering operation performed by the driver is equal to or greater than the threshold value, it is determined that the left override condition is satisfied; When the rear approaching vehicle is present and has an intention to change lanes, the override condition of the right override condition and the left override condition, which is on the lane to which the rear approaching vehicle is to change lanes, is made less likely to be satisfied than when the rear approaching vehicle is not present. A driving assistance device configured as follows.

3. The driving assistance device according to claim 2, When the approaching vehicle from behind is present and the approaching vehicle from behind does not intend to change lanes, if the host vehicle is traveling in a traveling area adjacent to an overtaking lane, the override condition on the overtaking lane side of the right override condition and the left override condition is configured to be less likely to be satisfied than when the approaching vehicle from behind is not present. Driving assistance device.

4. In a driving assistance method, when there is a possibility that the host vehicle will depart from a driving area in which the host vehicle is traveling or when the host vehicle departs from the driving area, a computer mounted on the host vehicle executes, as departure control, at least one of a departure warning to notify a driver of the departure from the driving area and vehicle control to control a driving state of the host vehicle to prevent the host vehicle from deviating from the driving area, The driving assistance method includes: When an override condition is established that a steering index value related to a steering operation performed by the driver is equal to or greater than a threshold value while the departure control is being executed, the computer suspends or terminates the departure control; a step in which, when a rear approaching vehicle approaching the host vehicle from behind is present in the traveling area, the computer makes it more difficult for the override condition to be satisfied than when the rear approaching vehicle is not present; A driving assistance method including:

5. A program that causes a computer mounted on the host vehicle to execute, as departure control, at least one of a departure warning for notifying a driver of departure from the driving area in which the host vehicle is traveling or a vehicle control for controlling a driving state of the host vehicle to prevent the host vehicle from departing from the driving area, when the host vehicle is likely to depart from the driving area in which the host vehicle is traveling or when the host vehicle departs from the driving area, The program When an override condition is established that a steering index value related to a steering operation performed by the driver is equal to or greater than a threshold value while the departure control is being executed, causing the computer to suspend or terminate the departure control; a step of making it more difficult for the computer to satisfy the override condition when a rear approaching vehicle approaching the host vehicle from behind is present in the traveling area compared to when the rear approaching vehicle is not present; Programs including.

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