Driving assistance device, driving assistance method, and program

Abstract

The invention relates to a driving assistance device, a driving assistance method, and a program. The driving support device is configured to support the driving of the vehicle when the vehicle is likely to depart from a travel area in which the vehicle is traveling or when the vehicle is depart from the travel area. At least one of a departure alarm for notifying the driver of departure from the travel area and vehicle control for controlling the own vehicle in order to prevent the own vehicle from departing from the travel area is executed as departure control. The driving support device does not execute the departure control when an override condition that a steering index value related to a steering operation performed by a driver is equal to or greater than a threshold value is satisfied during execution of the departure control, and does not execute the departure control when a rear approaching vehicle approaching the own vehicle from the rear of the own vehicle is present within the travel area. An override condition is made difficult to satisfy compared to a case where there is no rear approaching vehicle. As a result, it is possible to reduce the possibility of a collision between the own vehicle and a rear approaching vehicle when there is a rear approaching vehicle.

Description

Technical Field

[0001] The present invention relates to a driving assistance device, a driving assistance method and a program, wherein the driving assistance device executes at least one of a departure alarm for notifying a driver of departure (deviation) from a driving area and a vehicle control for controlling the driving state of the own vehicle so as not to depart from the driving area as departure control, the driving assistance method is a method for a computer mounted on the own vehicle to execute the departure control, and the program causes a computer mounted on the own vehicle to execute the departure control. Background Art

[0002] Conventionally, there are known driving assistance devices that perform departure control when the vehicle itself is likely to depart from the driving area or when the vehicle itself has departed from the driving area. For example, the driving assistance device described in Patent Document 1 (hereinafter referred to as "conventional device") interrupts the departure control when an override condition is satisfied, that is, the driver intervenes in steering (steering, turning).

[0003] Prior art literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2003-81115 Summary of the invention

[0005] If there is a rear approaching vehicle that is traveling behind the own vehicle and approaching the own vehicle in the driving area in which the own vehicle is traveling, the rear approaching vehicle may change lanes (lane change) in order to overtake the own vehicle. If the driver of the own vehicle does not notice such a rear approaching vehicle and changes lanes, since there is a possibility of leaving the driving area, the disengagement control is executed. If the driver continues to perform the steering operation for changing lanes after the disengagement control is executed, the existing device determines that there is a high possibility of steering intervention and interrupting the disengagement control. If the disengagement control is interrupted in this situation, the own vehicle and the rear approaching vehicle may collide.

[0006] The present invention is made to address the above-mentioned problems. That is, one object of the present invention is to provide a driving assistance device that can reduce the possibility of a collision between a vehicle and a rear approaching vehicle when there is a rear approaching vehicle.

[0007] The driving assistance device of the present invention (hereinafter referred to as "the present invention device") performs at least one of a departure warning for notifying a driver of departure from a driving area (TA) in which the own vehicle (SV) is likely to depart from the driving area (TA) in which the own vehicle is traveling or the own vehicle has departed from the driving area (step 310: "Yes"), as departure control (step 340). The driving assistance device is configured to interrupt or terminate the departure control (step 350) when an override condition that a steering index value related to a steering operation performed by the driver is greater than a threshold value is satisfied during the execution of the departure control (step 335: "Yes"), and to make the override condition less likely to be satisfied (step 415) when there is a rear approaching vehicle (RV) approaching the own vehicle from behind in the driving area (step 405: "Yes") compared to when there is no rear approaching vehicle (step 405: "No").

[0008] According to the device of the present invention, when there is a vehicle approaching from behind, the overriding condition is less likely to be met than when there is no vehicle approaching from behind. The possibility that the vehicle approaching from behind changes lanes in order to overtake the own vehicle is high. According to the device of the present invention, the possibility of disengagement control being interrupted when the driver of the own vehicle does not notice that the vehicle approaching from behind is about to change lanes (or is in the process of changing lanes) and the own vehicle changes lanes can be reduced. As a result, the possibility of a collision between the own vehicle and the vehicle approaching from behind can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic system configuration diagram of a driving assistance device according to an embodiment of the present invention.

[0010] Figure 2 It is an explanatory diagram of an operation example of the driving assistance device according to the embodiment of the present invention.

[0011] Figure 3 yes Figure 1 Flowchart of a disengagement control routine executed by a CPU (central processing unit) of an ECU (electronic control unit) shown.

[0012] Figure 4 yes Figure 1 Flowchart of a threshold angle setting subroutine executed by the CPU of the ECU shown.

[0013] Figure 5 This 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 the embodiment of the present invention.

[0014] Description of Reference Numerals

[0015] 10 driving assistance device; 20 ECU; 22 front camera; 24 rear camera; 40 steering motor; 44 display device; 46 speaker. DETAILED DESCRIPTION

[0016] like Figure 1 As shown, a driving assistance device 10 according to the present embodiment (hereinafter referred to as “this device 10”) is applied to a vehicle SV and includes Figure 1 The components shown.

[0017] In this specification, "ECU20" is an electronic control device having a microcomputer as a main part. ECU20 is also called a control unit, a controller, and a computer. The microcomputer includes a CPU (processor), ROM, RAM, and an interface (I / F), etc. The functions implemented by ECU20 can also be implemented by multiple ECUs.

[0018] The front camera 22 acquires front image data by photographing the scene in front of the own vehicle SV. The rear camera 24 acquires rear image data by photographing the scene behind the own vehicle SV. The ECU 20 acquires the front image data and the rear image data from the front camera 22 and the rear camera 24, respectively.

[0019] The vehicle speed sensor 28 detects the own vehicle speed Vs indicating the speed of the own vehicle SV. The yaw rate sensor 30 detects the yaw rate Yr of the own vehicle SV. The steering angle sensor 32 detects the steering wheel SW (see Figure 2 ) is a steering angle θ. When the steering wheel SW is steered to the right side of 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 side of the neutral position, the steering angle θ becomes a positive value. The steering torque sensor 34 detects the steering torque Tr of the steering wheel SW. The acceleration sensor 36 detects the acceleration Gx of the front-rear axial direction of the own vehicle SV and the acceleration Gy of the vehicle width direction of the own vehicle SV. The ECU 20 obtains the detection values ​​of these sensors.

[0020] The inter-vehicle communication interface (I / F) 38 is an interface for performing inter-vehicle communication between the own vehicle SV and other vehicles.

[0021] The steering motor 40 is assembled to the steering mechanism 42. The steering mechanism 42 is a mechanism for steering the steering wheel according to the operation of the steering wheel SW. The steering motor 40 generates an assist torque for assisting the operation of the steering wheel SW in accordance with the instruction from the ECU 20, and generates an automatic steering torque for changing the steering angle of the steering wheel.

[0022] The display device 44 displays a separation alarm screen described later. The speaker 46 emits a separation alarm sound described later.

[0023] <Out of Control>

[0024] Below, refer to Figure 2 Indicates being out of control.

[0025] Based on the front image data, the ECU 20 recognizes the boundaries BL (right boundary RBL and left boundary LBL) of the travel area TA where the own vehicle SV travels. Examples of the boundaries BL include white lines on the road, guardrails, curbstones, and walls. The ECU 20 sets reference lines RL (right reference line RRL and left reference line LRL) at positions away from the boundaries BL to the inside of the travel area TA in a direction orthogonal to the boundaries BL by a predetermined reference distance Dref.

[0026] When either one of the following conditions E1 and E2 is satisfied, the ECU 20 determines that the execution condition is satisfied and executes the disengagement control.

[0027] Condition E1: The travel route distance Dpr of the host vehicle SV along the predicted travel route PR is less than a predetermined threshold distance Dth, and the predicted travel route PR intersects the reference line RL (if this condition E1 is satisfied, the ECU 20 determines that the host vehicle SV may leave the driving area TA).

[0028] Condition E2: A part or all of the body of the own vehicle SV is out of the reference line RL.

[0029] As an example, the ECU 20 obtains the predicted course PR based on the vehicle speed Vs and the yaw rate Yr.

[0030] In the present embodiment, the ECU 20 executes vehicle control for controlling the travel state of the own vehicle SV (the steering angle of the steering wheel) so that the own vehicle SV does not deviate from the travel area TA as the departure control.

[0031] Specifically, the ECU 20 acquires a departure prevention steering angle θdev for preventing the vehicle SV from departing from the reference line RL (i.e., returning the vehicle SV to the inner side of the reference line RL). The ECU 20 controls the steering motor 40 so that the steering angle θ matches the departure prevention steering angle θdev.

[0032] The ECU 20 interrupts the disengagement control when the override condition is satisfied. As an example, the override condition is satisfied when the magnitude (|θ|) of the steering angle θ is equal to or greater than a threshold angle θth.

[0033] (Work Summary)

[0034] When there is a rear approaching vehicle RV, ECU20 makes it difficult for the override condition to be satisfied compared to when there is no rear approaching vehicle RV. The rear approaching vehicle RV is a vehicle traveling behind the own vehicle SV in the same traveling area TA as the own vehicle SV and approaching the own vehicle SV.

[0035] As an example, the ECU 20 sets the threshold angle θth to the first threshold angle θ1th when there is no rear vehicle RV approaching, and sets the threshold angle θth to the second threshold angle θ2th larger than the first threshold angle θ1th when there is a rear vehicle RV approaching.

[0036] There is a high possibility that the rear approaching vehicle RV changes lanes in order to overtake the own vehicle SV (see Figure 2 If the vehicle SV changes lanes in this case, the execution condition is satisfied soon and the escape control is executed. If the driver continues to perform the steering operation for changing lanes after the escape control is executed, the magnitude of the steering angle θ becomes larger than the threshold angle θth and the possibility of the override condition being satisfied is high.

[0037] According to the present embodiment, when there is a rear approaching vehicle RV, the override condition is less likely to be established than when there is no rear approaching vehicle RV. Therefore, even if the driver continues to perform the steering operation for lane change after the disengagement control is executed, the override condition is less likely to be established. As a result, the possibility of the disengagement control being continued becomes higher, and the possibility of the own vehicle SV colliding with the rear approaching vehicle RV can be reduced.

[0038] (Working Example)

[0039] exist Figure 2 At time t1 shown, the driver of the own vehicle SV starts steering the steering wheel SW to the right, and the own vehicle SV starts changing lanes to the right lane of the travel area TA. At time t1, since the execution condition is not satisfied, the disengagement control is not executed.

[0040] At time t2, the execution condition is satisfied, and the ECU 20 starts the disengagement control. There is a rear approaching vehicle RV. Therefore, the ECU 20 sets the threshold angle θth to the second threshold angle θth2 to make it difficult for the override condition to be satisfied.

[0041] (Specific work)

[0042] <Out of Control>

[0043] The CPU of the ECU 20 executes the Figure 3 The routine is shown in the flowchart in .

[0044] When the appropriate time comes, the CPU Figure 3 The process starts at step 300 of the control program, and in step 305, it is determined 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 satisfied, and is set to "0" when the end condition is satisfied. In addition, the value of the execution flag Xexe is set to "0" in the initial routine. The initial routine is executed by the CPU when the ignition key switch (not shown) of the own vehicle SV is changed from the OFF position to the ON position.

[0045] When 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 satisfied by determining whether either the condition E1 or the condition E2 is satisfied.

[0046] When the execution condition is not satisfied, the CPU determines "No" in step 310, and the process proceeds to step 395. In step 395, the CPU temporarily terminates the present routine. On the other hand, when the execution condition is satisfied, 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". Then, the process proceeds to step 395, and the CPU temporarily terminates the present routine.

[0047] When the value of the execution flag Xexe is "1" when the process enters step 305, the CPU determines "No" in step 305, and the process enters step 320. In step 320, the CPU determines whether the end condition is satisfied. As an example, when a predetermined end time Tend has passed since the execution condition is satisfied, the CPU determines that the end condition is satisfied.

[0048] When the end condition is not satisfied, the CPU makes a "No" determination 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".

[0049] The value of the override flag Xovr is set to "1" when the override condition is satisfied, and is set to "0" when a predetermined time has passed since the override condition was satisfied or when the end condition is satisfied. The value of the override flag Xovr is also set to "0" in the initial routine.

[0050] When the value of the override flag Xovr is “0”, the CPU makes a “Yes” determination in step 325 , and the CPU executes steps 330 and 335 .

[0051] Step 330: The CPU executes a threshold angle setting subroutine for setting the threshold angle θth (see Figure 4 ). The details of the threshold angle setting subroutine will be described later.

[0052] Step 335: The CPU determines whether the magnitude (|θ|) of the steering angle θ is greater than a threshold angle θth (ie, determines whether the override condition is satisfied).

[0053] When the magnitude (|θ|) of the steering angle θ is smaller than the threshold angle θth (that is, when the override condition is not satisfied), the CPU makes a “NO” determination in step 335 , and the process proceeds to step 340 .

[0054] In step 340, the CPU sets the target steering angle θtgt to the above-mentioned departure suppression 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 terminates this routine.

[0055] When the magnitude (|θ|) of the steering angle θ is greater than or equal to the threshold angle θth when the process enters step 335 (ie, when the override condition is satisfied), the CPU makes a “yes” determination in step 335 and executes steps 345 and 350 .

[0056] Step 350: 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. Therefore, the steering angle of the steering wheel of the own vehicle is not controlled according to the disengagement suppression steering angle θdev but is controlled according to the manual steering angle θman based on the steering operation of the driver. Thus, the disengagement control is interrupted when the override condition is satisfied. Then, the processing proceeds to step 395, and the CPU temporarily terminates this routine.

[0057] When the value of the override flag Xovr is "1" when the process enters step 325, the CPU determines "No" in step 325, and the process enters step 355. In step 355, the CPU determines whether a predetermined time has passed from the establishment time point when the override condition is established. As an example, the predetermined time is set to a value shorter than the end time Tend.

[0058] If the predetermined time has not passed since the establishment time point, the CPU determines "No" in step 355, and the process proceeds to step 350. On the other hand, if the predetermined time has passed since the establishment time point, 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.

[0059] When the end condition is satisfied when the process enters step 320, the CPU determines "yes" in step 320, and the process enters step 365. In step 365, the CPU sets the value of the execution flag Xexe to "0" and the value of the override flag Xovr to "0". Then, the process enters step 395, and the CPU temporarily ends this routine.

[0060] <Threshold angle setting>

[0061] When processing enters Figure 3 At step 330, the CPU Figure 4 The process starts at step 400 and proceeds to step 405. In step 405, the CPU determines whether there is a rear approaching vehicle RV based on the rear image data.

[0062] When there is no rear approaching vehicle RV, the CPU makes a "No" determination 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. Then, the process proceeds to step 495, and the CPU temporarily terminates this routine.

[0063] If there is a rear approaching vehicle RV, 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 larger than the first threshold angle θth1". Then, the process proceeds to step 495, and the CPU temporarily ends this routine.

[0064] As described above, according to the present embodiment, when there is a rear approaching vehicle RV, the override condition (specifically, the override condition on both sides) is less likely to be satisfied than when there is no rear approaching vehicle RV. Thus, the possibility of collision between the own vehicle SV and the rear approaching vehicle RV can be reduced.

[0065] (First Modification)

[0066] The ECU 20 of this modified example obtains the magnitude of the steering angle θ having a negative value as the right steering angle θR, and obtains the magnitude of the steering angle θ having a positive value as the left steering angle θL. The ECU 20 determines that the overriding condition is satisfied when the right steering angle θR is greater than or equal to the right threshold angle θRth (when the right overriding condition is satisfied), or when the left steering angle θL is greater than or equal to the left threshold angle θLth (when the left overriding condition is satisfied).

[0067] 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.

[0068] When there is a rear approaching vehicle RV and the rear approaching vehicle RV intends to change lanes to the right, the ECU 20 sets the right threshold angle θRth to "the second right threshold angle θRth2 larger than the first right threshold angle θRth1" and sets the left threshold angle θLth to the first left threshold angle θLth1. In addition, when the rear approaching vehicle RV intends to change lanes to the left, the ECU 20 sets the left threshold angle θLth to "the 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. That is, when the rear approaching vehicle RV intends to change lanes, the ECU 20 makes it difficult for the overriding condition of the lane change target side of the rear approaching vehicle RV to be established than when there is no rear approaching vehicle RV.

[0069] The ECU 20 makes it difficult for the override condition to be satisfied only on the side where the possibility of the own vehicle SV colliding with the rear approaching vehicle RV is high. Thus, the possibility of the own vehicle SV colliding with the rear approaching vehicle RV can be reduced. Furthermore, when the driver performs a steering operation to the side where the possibility of the own vehicle SV colliding with the rear approaching vehicle RV is low, the override condition is satisfied as usual, thereby reducing the possibility of causing discomfort (discomfort) to the driver.

[0070] When there is a passing lane adjacent to the driving area TA when the rear approaching vehicle RV has no intention to change lanes, the ECU 20 makes the threshold angle θth on the passing lane side of the right threshold angle θRth and the left threshold angle θLth larger than when there is no rear approaching vehicle RV. In countries where traffic is on the left, the passing lane exists on the right side of the driving area TA, so the ECU 20 sets the right threshold angle θRth to the second right threshold angle θRth2. In countries where traffic is on the right, the passing lane exists on the left side of the driving area TA, so the ECU 20 sets the left threshold angle θLth to the second left threshold angle θLth2. In the following description, the country where traffic is on the left is assumed.

[0071] The rear approaching vehicle RV may suddenly change lanes without showing the intention to change lanes. In this case, the rear approaching vehicle RV is likely to change lanes to the passing lane side. When the rear approaching vehicle RV has no intention to change lanes, the ECU 20 only makes it difficult for the overriding condition on the passing lane side to be satisfied, thereby reducing the possibility of causing discomfort to the driver and reducing the possibility of a collision between the own vehicle SV and the rear approaching vehicle RV.

[0072] The CPU of the ECU 20 of this modification executes Figure 5 The threshold angle setting subroutine shown is replaced by Figure 4 The threshold angle setting subroutine is shown.

[0073] When processing enters Figure 3 At step 330, the CPU Figure 5 The processing starts at step 500. In step 505, the CPU determines whether there is a rear approaching vehicle RV.

[0074] 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 the first right threshold angle θRth1, and sets the left threshold angle θLth to the first left threshold angle θLth1. After executing step 510, the process proceeds to step 595, and the CPU temporarily ends this routine. Then, the process proceeds to step 596. Figure 3 In step 335, the CPU determines whether either a right override condition, that is, the right steering angle θR is greater than a right threshold angle θRth, or a left override condition, that is, the left steering angle θL is greater than a left threshold angle θLth, is satisfied.

[0075] When either the right override condition or the left override condition is satisfied, the CPU makes a “Yes” determination in step 335 . When neither the right override condition nor the left override condition is satisfied, the CPU makes a “No” determination in step 335 .

[0076] When there is a rear approaching vehicle RV when the processing enters step 505, the CPU determines "yes" in step 505, and the processing enters step 515. In step 515, the CPU determines whether the rear approaching vehicle RV has the intention to change lanes. As an example, when the CPU determines that the turn signal of the rear approaching vehicle RV is working based on the rear image data, it determines that the rear approaching vehicle RV has the intention to change lanes. As another example, when the lateral speed of the rear approaching vehicle RV obtained based on multiple rear image data is above the threshold speed, the CPU determines that the rear approaching vehicle RV has the intention to change lanes. In addition, the lateral acceleration can also be used instead of the lateral speed. As another example, when the inter-vehicle communication interface 38 receives a "lane change signal indicating that a lane change is about to be made" from the rear approaching vehicle RV, the CPU determines that the rear approaching vehicle RV has the intention to change lanes.

[0077] 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 lane change direction of the rear approaching vehicle RV is the right side.

[0078] 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. Then, the process proceeds to step 595, and the CPU temporarily terminates this routine and executes Figure 3 Step 335.

[0079] If the lane change direction is the left side, 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. Then, the process proceeds to step 595, and the CPU temporarily terminates this routine and executes Figure 3 Step 335.

[0080] When there is no rear approaching vehicle RV when the process enters step 515, the CPU determines "No" in step 515, and the process enters step 535. In step 535, the CPU determines whether there is an overtaking lane on the right side of the driving area TA based on the front image data. The overtaking lane is a lane adjacent to the driving area TA and allows driving in the same direction as the traveling direction of the own vehicle SV.

[0081] If there is a passing lane, the CPU makes a “Yes” determination in step 535 , and the process proceeds to step 525 . If there is no passing lane, the CPU makes a “No” determination in step 535 , and the process proceeds to step 510 .

[0082] As described above, according to this variation, the override condition is only made difficult to be satisfied on the side where the rear approaching vehicle RV is more likely to change lanes, thereby reducing the possibility of causing discomfort to the driver and reducing the possibility of a collision between the own vehicle SV and the rear approaching vehicle RV.

[0083] Furthermore, the overtaking condition on the lane change target side (or the side opposite to the overtaking lane) that is not the rear approaching vehicle RV can be easily satisfied. When the rear approaching vehicle RV overtakes the own vehicle SV, the driver of the own vehicle SV may intentionally perform a steering operation to the "side opposite to the side where the rear approaching vehicle RV overtakes the own vehicle SV" in order to avoid the rear approaching vehicle RV that is about to overtake the own vehicle SV. When the disengagement control is executed during such a steering operation, the disengagement control is immediately stopped, so the possibility that the disengagement control will cause discomfort to the driver can be reduced.

[0084] Furthermore, when the CPU makes a “No” determination in step 505 , the CPU may determine whether or not there is a passing lane adjacent to the traveling area TA, and proceed to step 515 only when there is a passing lane.

[0085] (Second Modification)

[0086] The ECU 20 may execute the departure warning as the departure control instead of the vehicle control, or may execute both the vehicle control and the departure warning as the departure control. That is, the ECU 20 executes at least one of the vehicle control and the departure warning as the departure control.

[0087] In the departure warning, the ECU 20 causes the display device 44 to display a departure warning screen for notifying the driver that the own vehicle SV may depart from the driving area TA (or is departing from this meaning). The ECU 20 may also cause the speaker 46 to emit a departure warning sound for notifying the driver that the own vehicle SV may depart from the driving area TA (or is departing from this meaning).

[0088] (Third Modification)

[0089] ECU20 makes it difficult for the override condition to be established by increasing the threshold angle θth (right threshold angle θRth and left threshold angle θLth), but the present invention is not limited thereto. For example, ECU20 may make the steering angle θ compared with the threshold angle θth smaller than the actual steering angle θ in order to make it difficult for the override condition to be established. Specifically, ECU20 uses the value obtained by multiplying the actual steering angle θ by a weight coefficient α (0≤α<1) as the steering angle θ to be compared with the threshold angle θth.

[0090] (Fourth Modification)

[0091] The ECU 20 determines that the override condition is satisfied when the steering angle θ is greater than or equal to the threshold angle θth, but the present invention is not limited thereto. Instead of the steering angle θ, at least one of the steering torque Tr, the steering angular velocity, the steering angle of the steering wheel, the steering angular velocity, the lateral velocity of the own vehicle SV, and the lateral acceleration Gy of the own vehicle SV may be used. These values ​​are values ​​related to the steering operation performed by the driver and are also referred to as steering index values.

[0092] (Fifth Modification)

[0093] ECU20 determines that the termination condition is satisfied when a predetermined termination time Tend has passed since the execution condition is satisfied, but the present invention is not limited thereto. For example, ECU20 may determine that the termination condition is satisfied when the vehicle SV is located inside the "termination reference line set inside the reference line RL". As another example, ECU20 may determine that the termination condition is satisfied when the predicted travel route PR no longer intersects the reference line RL or the termination reference line.

[0094] (Sixth Modification)

[0095] When the override condition is satisfied, the ECU 20 may set the value of the execution flag Xexe to “0” to terminate the disengagement control.

[0096] (Seventh Modification)

[0097] The ECU 20 may set the reference line RL outside the boundary BL. The device 10 may include a sensor (such as a laser radar, a millimeter wave radar, and a sonar) capable of detecting an object of the own vehicle SV instead of the rear camera 24 .

[0098] The device 10 can be applied to vehicles such as engine vehicles, hybrid vehicles, plug-in hybrid vehicles, fuel cell vehicles, and electric vehicles. Moreover, the device 10 can be applied to autonomous driving vehicles. Moreover, the present invention can also be regarded as a non-transient storage medium that stores a program for realizing the functions of the device 10 and is readable by a computer.

Claims

1. A driving assistance device that, when a vehicle is likely to deviate from a driving area in which the vehicle is traveling or when the vehicle has deviated from the driving area, performs at least one of a departure warning for notifying a driver of the departure from the driving area and a vehicle control for controlling the driving state of the vehicle so as not to deviate from the driving area as departure control, The driving assistance device is configured as follows: During the execution of the disengagement control, if an override condition that a steering index value related to the steering operation performed by the driver is equal to or greater than a threshold value is satisfied, interrupting or terminating the disengagement control, When there is a rear approaching vehicle approaching the own vehicle from behind the own vehicle in the traveling area, the override condition is less likely to be satisfied than when there is no rear approaching vehicle.

2. The driving assistance device according to claim 1, The override condition includes a right-side override condition and a left-side override condition. The driving assistance device is configured as follows: When a right steering index value related to the 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 satisfied, When a left-side steering index value related to the left-side steering operation performed by the driver is equal to or greater than the threshold value, it is determined that the left-side override condition is satisfied, When there is a rear approaching vehicle and the rear approaching vehicle intends to change lanes, the overriding condition on the lane change target lane side of the right overriding condition and the left overriding condition is made less likely to be satisfied than when there is no rear approaching vehicle.

3. The driving assistance device according to claim 2, wherein: In the case where there is a vehicle approaching from behind and the vehicle has no intention of changing lanes, if the own vehicle is traveling in a driving area adjacent to a passing lane, the overriding condition on the overtaking lane side of the right overriding condition and the left overriding condition is made more difficult to establish than when there is no vehicle approaching from behind.

4. A driving assistance method, wherein, when a vehicle is likely to deviate from a driving area in which the vehicle is traveling or the vehicle has deviated from the driving area, a computer mounted on the vehicle executes, as a departure control, at least one of a departure alarm for notifying a driver of the departure from the driving area and a vehicle control for controlling the driving state of the vehicle so as not to deviate from the driving area, The driving assistance method comprises the following steps: During the execution of the disengagement control, when an override condition that a steering index value related to the steering operation performed by the driver is equal to or greater than a threshold value is satisfied, the computer interrupts or ends the disengagement control; and The computer makes it difficult for the override condition to be satisfied when there is a rear approaching vehicle approaching the own vehicle from behind the own vehicle in the travel area, compared to when there is no rear approaching vehicle.

5. A program for causing a computer mounted on the own vehicle to execute at least one of a departure alarm for notifying a driver of departure from the driving area and a vehicle control for controlling the driving state of the own vehicle so as not to depart from the driving area, when the own vehicle is likely to depart from a driving area in which the own vehicle is traveling or when the own vehicle has departed from the driving area, as departure control, The procedure comprises the following steps: During the execution of the disengagement control, when an override condition that a steering index value related to the steering operation performed by the driver is equal to or greater than a threshold value is satisfied, causing the computer to interrupt or terminate the disengagement control; and A step of causing the computer to make it difficult for the override condition to be satisfied when there is a rear approaching vehicle approaching the host vehicle from behind the host vehicle in the travel area, compared to when there is no rear approaching vehicle.

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