Vehicle driving support device

Abstract

A vehicle driving support device executes a lane departure prevention control to steer a host vehicle in a manner that a behavior parameter indicating a behavior of the host vehicle during execution of the lane departure prevention control does not exceed an upper limit value of the behavior parameter, in a case where an execution prohibition condition under which execution of the lane departure prevention control is prohibited based on a steering operation by a driver of the host vehicle does not hold while the host vehicle is likely to depart from a lane. The vehicle driving support device reduces the upper limit value of the behavior parameter when the host vehicle is traveling at a speed lower than a predetermined speed, or changes the execution prohibition condition in a manner that the execution prohibition condition does not become difficult to hold, as compared to when the host vehicle is traveling at a speed higher than the predetermined speed.

Description

Technical Field

[0001] This invention relates to a vehicle driving support device. Background Technology

[0002] A known vehicle driving assistance device performs lane departure prevention control, which autonomously steers the vehicle to prevent it from deviating from its lane. This device autonomously steers the vehicle to prevent it from veering outwards from lane markings such as white lines. However, when driving on regular roads, it is sometimes necessary to cross lane markings. If lane departure prevention control is activated in such situations, the driver cannot steer the vehicle as desired.

[0003] Therefore, there are also known vehicle driving support devices that, when the vehicle is traveling at low speed, do not perform lane departure prevention control even if the vehicle may cross the lane divider and deviate from the lane, but instead allow the vehicle to cross the lane divider (for example, see Japanese Patent Application Publication No. 2020-199808). Summary of the Invention

[0004] Compared to highways, ordinary roads are narrower. Therefore, when there are curbs (curb stones) or walls along the road, the distance between these curbs / walls and the vehicle is short. So, it is preferable to implement lane departure prevention control when the vehicle may come into contact with such curbs / walls or other three-dimensional objects (three-dimensional road ends).

[0005] However, as mentioned above, the road environment on ordinary roads is different from that on highways because they are narrower than highways and other vehicles stop in front of the vehicle when turning right. Therefore, if lane departure prevention control is performed on ordinary roads in the same way as when driving on highways, it may not be possible to ensure the driving safety of the vehicle.

[0006] Furthermore, even when your vehicle is traveling on a highway, there are situations where you are traveling at low speeds, such as when there is a traffic jam or when you are heading to a highway service area or exit. If you apply lane departure prevention control in the same way you would when you are traveling at high speed on the main line of the highway, it may not be possible to ensure the driving safety of your vehicle.

[0007] Of course, even when driving on ordinary roads, if a vehicle is sometimes traveling at high speeds, the likelihood of failing to ensure driving safety is small, even if lane departure prevention control is applied in the same way as when driving on a highway.

[0008] If lane departure prevention control is applied in the same way as when the vehicle is traveling at high speed, it may not be possible to ensure the driving safety of the vehicle, and the appropriate lane departure prevention control may not be implemented.

[0009] The purpose of this invention is to provide a vehicle driving support device that enables appropriate lane departure prevention control when the vehicle is traveling at low speeds.

[0010] The vehicle driving support device of the present invention includes a control device that performs lane departure prevention control by autonomously steering its own vehicle to prevent the vehicle from deviating from its lane.

[0011] The control device is configured to execute the lane departure prevention control autonomously when the lane departure prevention control is executed in a manner that prevents the execution of the lane departure prevention control from deviating from the lane and the execution prohibition condition based on the steering operation performed by the driver of the vehicle is not met. The lane departure prevention control is executed in such a manner that the action parameter representing the movement of the vehicle during the execution of the lane departure prevention control does not exceed the upper limit value of the action parameter.

[0012] Furthermore, the control device is configured to reduce the upper limit of the action parameter or change the execution prohibition condition in a manner that makes it difficult to meet the execution prohibition condition when the vehicle is traveling at a speed below a predetermined speed, compared to when the vehicle is traveling at a speed above the predetermined speed.

[0013] When a vehicle is traveling at low speed, the road it is traveling on is often narrow, and there are usually other vehicles and pedestrians nearby. Therefore, to ensure driving safety when the vehicle is traveling at low speed, it is preferable to implement lane departure prevention control in a way that does not significantly change the vehicle's behavior. Furthermore, it is preferable to implement lane departure prevention control in a way that is difficult to execute.

[0014] According to the present invention, when the vehicle is traveling at a speed below a predetermined speed, the upper limit of the action parameter is reduced, or modified in a way that makes it difficult to meet the prohibition conditions. Therefore, situations where the vehicle's behavior changes drastically when lane departure prevention control is executed are avoided, and lane departure prevention control becomes difficult to execute. Thus, appropriate lane departure prevention control can be implemented when the vehicle is traveling at low speeds.

[0015] Furthermore, in the vehicle driving support device of the present invention, the action parameter is, for example, the distance the vehicle moves in the lateral direction due to the lane departure prevention control, i.e., the lateral movement distance. Additionally, the action parameter is, for example, at least one of the vehicle's lateral acceleration, steering angle, and yaw rate.

[0016] Furthermore, in the vehicle driving support device of the present invention, the execution prohibition condition is, for example, a condition in which the driver of the vehicle inputs a steering force exceeding a steering force threshold into the vehicle. In this case, the control device is configured to change the execution prohibition condition in a manner that makes it difficult for the execution prohibition condition to be met by setting the steering force threshold to a small value.

[0017] Furthermore, in the vehicle driving support device of the present invention, the execution prohibition condition is, for example, a condition where the time elapsed since the execution of lane departure prevention control is prohibited due to the fulfillment of the execution prohibition condition is shorter than a predetermined time. In this case, the control device is configured to change the execution prohibition condition in a way that makes it difficult for the execution prohibition condition to be fulfilled by setting the predetermined time to a long time.

[0018] Furthermore, the vehicle driving support device of the present invention includes a control device that performs lane departure prevention control by autonomously steering its own vehicle to prevent the vehicle from deviating from its lane.

[0019] The control device is configured to execute the lane departure prevention control when the lane departure prevention control is prohibited from being executed based on steering operations performed by the driver of the vehicle, provided that the prohibition condition is not met. The lane departure prevention control is executed in such a way that the action parameters representing the actions of the vehicle during the execution of the lane departure prevention control are limited to a maximum value below the action parameter limit.

[0020] Furthermore, the control device is configured to, when the vehicle is traveling on a general road other than a dedicated motor vehicle road, reduce the upper limit of the action parameter or change the execution prohibition condition in a manner that makes it difficult for the execution prohibition condition to be met, compared to when the vehicle is traveling on the dedicated motor vehicle road.

[0021] Compared to dedicated motor vehicle lanes, general roads are narrower. Therefore, when a vehicle is traveling on a general road, there are often other vehicles and pedestrians nearby. Thus, to ensure driving safety when a vehicle is traveling on a general road, it is preferable to implement lane departure prevention control in a manner that does not significantly alter the vehicle's behavior. Furthermore, it is preferable to implement lane departure prevention control in a way that makes it difficult to execute.

[0022] According to the present invention, when the vehicle is traveling on a normal road, the upper limit of the behavior parameter is reduced, or modified in a way that makes it not difficult to meet the prohibition conditions. Therefore, it is possible to avoid situations where the vehicle's behavior changes drastically when lane departure prevention control is implemented, and furthermore, it is possible to prevent lane departure prevention control itself from becoming difficult to implement. Thus, it is possible to achieve appropriate lane departure prevention control when the vehicle is traveling on a normal road.

[0023] The constituent elements of this invention are not limited to the embodiments of the invention described below with reference to the accompanying drawings. Other objects, features, and incidental advantages of the invention should be readily understood from the description of the embodiments. Attached Figure Description

[0024] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which the same reference numerals denote the same elements, and wherein:

[0025] Figure 1 This is a diagram illustrating a vehicle driving support device according to an embodiment of the present invention, and a vehicle (the vehicle itself) equipped with the vehicle driving support device.

[0026] Figure 2 This is a diagram illustrating the implementation of lane departure prevention control.

[0027] Figure 3 This is a graph showing the distances to the left and right sides.

[0028] Figure 4 This is a diagram showing the target driving route set by lane departure prevention control.

[0029] Figure 5 This is a graph showing the lateral movement distance of the vehicle itself based on lane departure prevention control.

[0030] Figure 6 This diagram shows a situation where a vehicle overtakes a vehicle waiting to turn right.

[0031] Figure 7 This diagram shows a situation where a vehicle overtakes a vehicle waiting to turn right.

[0032] Figure 8 It is a diagram showing the situation where your vehicle is parked on the side of the road (shoulder).

[0033] Figure 9 This is a flowchart illustrating the routines executed by the vehicle driving support device according to an embodiment of the present invention.

[0034] Figure 10 This is a flowchart illustrating the routines executed by the vehicle driving support device according to an embodiment of the present invention.

[0035] Figure 11 This is a flowchart illustrating the routines executed by the vehicle driving support device according to an embodiment of the present invention.

[0036] Figure 12 This is a flowchart illustrating the routines executed by the vehicle driving support device according to an embodiment of the present invention.

[0037] Figure 13 This is a flowchart illustrating the routines executed by the vehicle driving support device according to an embodiment of the present invention. Detailed Implementation

[0038] Hereinafter, a vehicle driving support device according to an embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 As shown, the vehicle driving support device 10 of the embodiment of the present invention is mounted on its own vehicle 100.

[0039] <ecu>

[0040] The vehicle driving support device 10 includes an ECU 90 as a control device. ECU is short for Electronic Control Unit. The ECU 90 has a microcomputer as its main component. The microcomputer includes a CPU, ROM, RAM, non-volatile memory, and an interface. The CPU performs various functions by executing instructions, programs, or routines stored in the ROM.

[0041] <Drive devices, etc.>

[0042] In addition, the vehicle 100 is equipped with a drive unit 21, a braking unit 22 and a steering unit 23.

[0043] <Drive device>

[0044] The drive unit 21 is a device that outputs driving force (driving torque) to the vehicle 100 to enable the vehicle 100 to move, such as an internal combustion engine or a motor. The drive unit 21 is electrically connected to the ECU 90. The ECU 90 can control the driving force output from the drive unit 21 by controlling the operation of the drive unit 21.

[0045] Braking device

[0046] Braking device 22 is a device that outputs braking force (braking torque) to brake its own vehicle 100, such as a hydraulic brake device. Braking device 22 is electrically connected to ECU 90. ECU 90 can control the braking force output from braking device 22 by controlling the operation of braking device 22.

[0047] <Steering gear>

[0048] The steering device 23 is a device that outputs a steering force (steering torque) applied to the vehicle 100 to steer the vehicle 100, such as a power steering system. The steering device 23 is electrically connected to the ECU 90. The ECU 90 can control the steering force output from the steering device 23 by controlling the operation of the steering device 23.

[0049] <Sensors, etc.>

[0050] Furthermore, the vehicle 100 is equipped with an accelerator pedal 31, an accelerator pedal operation sensor 32, a brake pedal 33, a brake pedal operation sensor 34, a steering wheel 35, a steering shaft 36, a steering angle sensor 37, a steering torque sensor 38, a vehicle speed detection device 51, a lateral acceleration sensor 52, a yaw rate sensor 53, a surrounding information detection device 60, and a road information acquisition device 70.

[0051] <Accelerator pedal operation sensor>

[0052] The accelerator pedal operation amount sensor 32 is a sensor that detects the operation amount of the accelerator pedal 31. The accelerator pedal operation amount sensor 32 is electrically connected to the ECU 90. The accelerator pedal operation amount sensor 32 sends the detected operation amount information of the accelerator pedal 31 to the ECU 90. The ECU 90 obtains the operation amount of the accelerator pedal 31 (accelerator pedal operation amount AP) based on this information.

[0053] Based on the accelerator pedal operation amount AP and the vehicle speed (vehicle speed), ECU90 calculates the required driving force (required driving torque). The required driving force is the driving force that the drive unit 21 is required to output. ECU90 controls the operation of drive unit 21 to output a driving force equivalent to the required driving force.

[0054] Brake pedal operation sensor

[0055] The brake pedal operation amount sensor 34 is a sensor that detects the operation amount of the brake pedal 33. The brake pedal operation amount sensor 34 is electrically connected to the ECU 90. The brake pedal operation amount sensor 34 sends the detected operation amount information of the brake pedal 33 to the ECU 90. The ECU 90 obtains the operation amount of the brake pedal 33 (brake pedal operation amount BP) based on this information.

[0056] Based on the brake pedal operation amount BP, ECU90 calculates the required braking force (required braking torque). The required braking force is the braking force that the braking device 22 is required to output. ECU90 controls the operation of the braking device 22 to output a braking force equivalent to the required braking force.

[0057] <Steering Angle Sensor>

[0058] The steering angle sensor 37 is a sensor that detects the rotation angle of the steering shaft 36 relative to the neutral position. The steering angle sensor 37 is electrically connected to the ECU 90. The steering angle sensor 37 sends the detected rotation angle information of the steering shaft 36 to the ECU 90. The ECU 90 obtains the rotation angle (steering angle θs) of the steering shaft 36 based on this information.

[0059] <Steering torque sensor>

[0060] The steering torque sensor 38 is a sensor that detects the torque input by the driver of vehicle 100 to vehicle 100 (in this example, the torque input via steering wheel 35 to steering shaft 36). The steering torque sensor 38 is electrically connected to ECU 90. The steering torque sensor 38 sends the detected torque information to ECU 90. Based on this information, ECU 90 obtains the torque input by the driver via steering wheel 35 to steering shaft 36 (driver's steering force TQd).

[0061] <Vehicle speed detection device>

[0062] The vehicle speed detection device 51 is a device for detecting the driving speed (vehicle speed) of its own vehicle 100, such as a wheel speed sensor. The vehicle speed detection device 51 is electrically connected to the ECU 90. The vehicle speed detection device 51 sends the detected vehicle speed information of its own vehicle 100 to the ECU 90. The ECU 90 obtains the vehicle speed (vehicle speed V) of its own vehicle 100 based on this information.

[0063] Based on the acquired steering angle θs, the driver's steering force TQd, and the vehicle speed V, the ECU 90 calculates the required steering force (required steering torque). The required steering force is the steering force required to be output by the steering device 23. Except when performing lane departure prevention control as described later, the ECU 90 performs normal steering control, which controls the operation of the steering device 23 in a manner that outputs a steering force from the steering device 23 equivalent to the required steering force.

[0064] <Transverse Accelerometer>

[0065] The lateral acceleration sensor 52 is a sensor that detects the lateral acceleration of the vehicle 100. The lateral acceleration sensor 52 is electrically connected to the ECU 90. The lateral acceleration sensor 52 sends the detected acceleration information to the ECU 90. Based on this information, the ECU 90 obtains the lateral acceleration (lateral acceleration Gy) of the vehicle 100.

[0066] Yaw rate sensor

[0067] Yaw rate sensor 53 is a sensor that detects the yaw rate (yaw rate) of its own vehicle 100. Yaw rate sensor 53 is electrically connected to ECU 90. Yaw rate sensor 53 sends the detected yaw rate information to ECU 90. ECU 90 obtains the yaw rate (yaw rate dθy) of its own vehicle 100 based on this information.

[0068] <Surrounding Information Detection Device>

[0069] The surrounding information detection device 60 is a device for detecting information about the surroundings of its own vehicle 100. In this example, it includes an image sensor 61 and an electromagnetic wave sensor 62. The image sensor 61 is, for example, a camera. The electromagnetic wave sensor 62 is, for example, a radar sensor (millimeter-wave radar, etc.). In addition, the surrounding information detection device 60 may also include an ultrasonic sensor (gap sonar) or an optical sensor (LiDAR).

[0070] Image Sensor

[0071] The image sensor 61 is electrically connected to the ECU 90. The image sensor 61 captures images of the surroundings of the host vehicle 100, and transmits information of the captured images to the ECU 90. The ECU 90 can obtain information related to the surroundings of the host vehicle 100 (surrounding detection information IS) based on the information (image information II).

[0072] <Radio wave sensor>

[0073] The radio wave sensor 62 is electrically connected to the ECU 90. The radio wave sensor 62 transmits radio waves and receives radio waves reflected by an object (reflected waves). The radio wave sensor 62 transmits information (detection results) related to the transmitted radio waves and the received radio waves (reflected waves) to the ECU 90. In other words, the radio wave sensor 62 detects objects present around the host vehicle 100, and transmits information (detection results) related to the detected objects to the ECU 90. The ECU 90 can obtain information (surrounding detection information IS) related to objects such as structures present around the host vehicle 100 based on the information (radio wave information).

[0074] <Road information obtaining device>

[0075] The road information obtaining device 70 is a device that obtains information related to the road on which the host vehicle 100 is traveling, and in this example, includes a GPS device 71 and a map database 72.

[0076] <GPS device>

[0077] The GPS device 71 is a device that receives so-called GPS signals. The GPS device 71 is electrically connected to the ECU 90. The GPS device 71 transmits the received GPS signals to the ECU 90. The ECU 90 obtains the current position of the host vehicle 100 (the position of the host vehicle 100 in a GPS coordinate system) based on the received GPS signals.

[0078] <Map database>

[0079] The map database 72 is a database of map information. The map database 72 is electrically connected to the ECU 90. The ECU 90 can compare the current position of the host vehicle 100 obtained based on the GPS signals with the map information in the map database 72 to determine whether the road on which the host vehicle 100 is traveling is a general road or a motorway-only road.

[0080] <Outline of operation of vehicle driving support device>

[0081] Next, a summary of the operation of the vehicle driving support device 10 will be explained. During the driving of the vehicle 100, if a lane departure condition is met, such that the vehicle 100 may deviate from its lane LN, the vehicle driving support device 10 will, under the condition that the cancellation condition (execution prohibition condition) described later is not met, such as... Figure 2 As shown, lane departure prevention control is performed to autonomously steer the vehicle 100 to prevent it from deviating from its own lane LN.

[0082] The vehicle driving support device 10 sets a left lane departure determination line LL and a right lane departure determination line LR. When the vehicle 100 reaches the left lane departure determination line LL or the right lane departure determination line LR, it determines that the lane departure condition has been met.

[0083] The left deviation determination line LL is a line extending along the left end of its own lane LN. The vehicle driving support device 10 sets the left deviation determination line LL as the line extending along the "left dividing line 201L (flat road end)", "the boundary between the soil, grass, gravel, and stones and the road when there is soil, grass, gravel, and stones on the left side of its own lane LN (flat road end)", and "the boundary between the curb, guardrail, wall (fence), grass, bushes, ditch, and cones and the road when there is a curb, guardrail, wall (fence), grass, bushes, ditch, and cones on the left side of its own lane LN (grade-separated road end)".

[0084] In addition, when the line extending along the end of the flat road is set as the left deviation determination line LL, the vehicle driving support device 10 sets the line on the end of the flat road as the left deviation determination line LL. However, when the line extending along the end of the grade-separated road is set as the left deviation determination line LL, the line moving away from the end of the grade-separated road to the right by a predetermined distance is set as the left deviation determination line LL.

[0085] exist Figure 2 In the example shown, the line on the left dividing line 201L is set as the left deviation determination line LL.

[0086] Furthermore, the vehicle driving support device 10 determines that lane departure conditions have been met when the left distance DL becomes zero during the driving of its own vehicle 100. Figure 3 As shown, the left distance DL is the distance between the left front end of the vehicle 100 and the left deviation determination line LL.

[0087] Similarly, the right deviation determination line LR is a line extending along the right end of its own lane LN. The vehicle driving support device 10 sets the right deviation determination line LR as the line extending along the "right dividing line 201R (flat road end)", "the boundary between the soil, grass, gravel, and stones and the road when there is soil, grass, gravel, and stones on the right side of its own lane LN (flat road end)", and "the boundary between the curb, guardrail, wall (fence), grass, bushes, ditch, and cones and the road when there is a curb, guardrail, wall (fence), grass, bushes, ditch, and cones on the right side of its own lane LN (grade-separated road end)".

[0088] In addition, when the line extending along the end of the flat road is set as the right deviation determination line LR, the vehicle driving support device 10 sets the line on the end of the flat road as the right deviation determination line LR. However, when the line extending along the end of the grade-separated road is set as the right deviation determination line LR, the line that moves a predetermined distance to the left from the end of the grade-separated road is set as the right deviation determination line LR.

[0089] exist Figure 2 In the example shown, the line on the right dividing line 201R is set as the right deviation determination line LR.

[0090] Furthermore, if the right-hand distance DR becomes zero during the driving of the vehicle 100, the vehicle driving support device 10 determines that the lane departure condition has been met. Figure 3 As shown, the right distance DR is the distance between the right front end of the vehicle 100 and the right deviation determination line LR.

[0091] In addition, the vehicle driving support device 10 obtains both the planar road end and the elevated road end based on the surrounding detection information IS.

[0092] When the lane departure prevention control is initiated by the vehicle driving support device 10 if the lane departure condition is met but the cancellation condition is not met, such as... Figure 4 As shown, based on its own speed V and the lane departure warning line intersection angle θcross, the vehicle 100 is autonomously steered along a target driving route Ltgt by setting a lane departure prevention control system. The lane departure warning line intersection angle θcross is the angle between the longitudinal centerline of the vehicle 100 (a line passing through the center of the width of the vehicle 100 and extending in the longitudinal direction of the vehicle 100) and the left lane departure warning line LL or the right lane departure warning line LR.

[0093] Furthermore, the vehicle driving support device 10 sets an upper limit (action parameter limit Pmax) for the parameters (action parameters P) representing the actions of its own vehicle 100 when autonomously steering itself through lane departure prevention control, so as to set the target driving route Ltgt in a manner that the action parameters P do not exceed the action parameter limit Pmax. In this example, the action parameters P are the lateral movement distance Dy (lateral movement amount), lateral acceleration Gy, steering angle θs, and yaw rate dθy of the own vehicle 100.

[0094] like Figure 5 As shown, the lateral movement distance Dy is the point where the vehicle 100 deviates to the outside at the largest extent from the left deviation judgment line LL. Figure 5 The vehicle returns to its own lane LN from point P0 until lane departure prevention control ends. Figure 5 The distance that vehicle 100 moves in the lateral direction (width direction) of its own lane LN at location P1.

[0095] In addition, the vehicle driving support device 10 steers its own vehicle 100 in such a way that the action parameter P does not exceed the upper limit value Pmax of the action parameter during the period when the vehicle 100 is autonomously steered by lane departure prevention control.

[0096] <Cancellation Condition (Execution Prohibition Condition)>

[0097] In addition, drivers sometimes intentionally drive their vehicle 100 across the left departure warning line LL or the right departure warning line LR. In this case, the driver's steering force TQd is relatively large. Therefore, even if the lane departure condition is met, it is preferable not to execute lane departure prevention control when the driver's steering force TQd is relatively large. Furthermore, if a large driver's steering force TQd is input to the vehicle 100 during the execution of lane departure prevention control, it is preferable to stop lane departure prevention control.

[0098] Therefore, the vehicle driving support device 10 sets the driver's steering force TQd to a predetermined value (steering force threshold TQd_th) as a cancellation condition (execution prohibition condition). If the cancellation condition is met when the lane departure condition is met, lane departure prevention control is not executed. In addition, if the cancellation condition is met during the period from the start of lane departure prevention control to the end of lane departure prevention control, lane departure prevention control that is being executed is stopped.

[0099] In addition, in this example, the vehicle driving support device 10 is configured such that, even if the lane departure condition is not met but lane departure prevention control is not performed because the cancellation condition is met, lane departure prevention control is not performed during the period from the time when lane departure prevention control is not performed until a predetermined time (cancellation duration threshold Tth) has elapsed.

[0100] Furthermore, the vehicle driving support device 10 is configured such that, if lane departure prevention control is stopped due to the cancellation condition being met during the execution of lane departure prevention control, lane departure prevention control will not be executed even if the lane departure condition is met when the cancellation condition is not met, during the period from the time when lane departure prevention control is stopped until the cancellation duration threshold Tth has elapsed.

[0101] <Setting the upper limit of action parameters>

[0102] Roads are broadly divided into dedicated motor vehicle lanes, including highways, and general roads. Compared to dedicated motor vehicle lanes, general roads are narrower, and there are often other vehicles and pedestrians near the vehicle 100. Therefore, when the vehicle 100 is driving on a general road and lane departure prevention control is used to autonomously steer the vehicle 100, in order to ensure the driving safety of the vehicle 100, it is preferable to steer the vehicle 100 in a way that does not significantly change its movement, or to steer the vehicle 100 in a way that does not significantly move it in the lateral direction (the width direction of its own lane LN).

[0103] Therefore, when the vehicle's speed V is higher than the predetermined speed Vth, the vehicle driving support device 10 sets the upper limit value of the action parameter Pmax to a baseline value (the upper limit value of the action parameter Plarge at high speed). When the vehicle's speed V is lower than the predetermined speed Vth, the upper limit value of the action parameter Pmax is set to a predetermined value smaller than the upper limit value of the action parameter Plarge at high speed (the upper limit value of the action parameter Psmall at low speed). Alternatively, the vehicle driving support device 10 can also be configured such that when the vehicle 100 is traveling on a dedicated motor vehicle road, the upper limit value of the action parameter Pmax is set to the upper limit value of the action parameter Plarge at high speed, and when the vehicle 100 is traveling on a general road, the upper limit value of the action parameter Pmax is set to the upper limit value of the action parameter Psmall at low speed.

[0104] More specifically, in this example, when the vehicle speed V is higher than the predetermined speed Vth, the vehicle driving support device 10 sets the upper limit of the lateral movement distance Dy (lateral movement amount) of its own vehicle 100 (lateral movement distance upper limit value Dy_max) to the reference value (lateral movement distance upper limit value Dy_large at high speed), the upper limit of the lateral acceleration Gy of its own vehicle 100 (lateral acceleration upper limit value Gy_max) to the reference value (lateral acceleration upper limit value Gy_large at high speed), the upper limit of the steering angle θs of its own vehicle 100 (steering angle upper limit value θs_max) to the reference value (steering angle upper limit value θs_large at high speed), and the upper limit of the yaw rate dθy of its own vehicle 100 (yaw rate upper limit value dθy_max) to the reference value (yaw rate upper limit value dθy_large at high speed).

[0105] Furthermore, the vehicle driving support device 10 sets a target driving route Ltgt in such a way that the vehicle 100's motion parameter P does not exceed the upper limit value Plarge of the motion parameter at high speed when it autonomously steers itself through lane departure prevention control, and autonomously steers itself along the target driving route Ltgt.

[0106] On the other hand, when the vehicle speed V is below a predetermined speed Vth, the vehicle driving support device 10 sets the upper limit value of lateral movement distance Dy_max to a predetermined value smaller than the upper limit value of lateral movement distance Dy_large at high speed (the upper limit value of lateral movement distance Dy_small at low speed), sets the upper limit value of lateral acceleration Gy_max to a predetermined value smaller than the upper limit value of lateral acceleration Gy_large at high speed (the upper limit value of lateral acceleration Gy_small at low speed), sets the upper limit value of steering angle θs_max to a predetermined value smaller than the upper limit value of steering angle θs_large at high speed (the upper limit value of steering angle θs_small at low speed), and sets the upper limit value of yaw rate dθy_max to a predetermined value smaller than the upper limit value of yaw rate dθy_large at high speed (the upper limit value of yaw rate dθy_small at low speed).

[0107] Furthermore, the vehicle driving support device 10 sets a target driving route Ltgt in such a way that the vehicle 100's motion parameter P does not exceed the upper limit value Psmall of the motion parameter at low speed when autonomously steering the vehicle 100 through lane departure prevention control, and autonomously steering the vehicle 100 along the target driving route Ltgt.

[0108] This avoids situations where the vehicle 100, traveling at low speeds, experiences significant changes in its behavior or large lateral movements (in the width direction of its own lane LN) due to lane departure prevention control, thus ensuring the driving safety of the vehicle 100. Therefore, it enables appropriate lane departure prevention control when the vehicle 100 is traveling at low speeds.

[0109] <Setting the cancellation condition (setting the steering control force threshold)>

[0110] As described above, drivers sometimes intentionally drive their vehicle 100 past the left departure warning line LL or the right departure warning line LR. In this case, the driver's steering force TQd is relatively large. Therefore, even if the lane departure condition is met, it is preferable not to execute lane departure prevention control when the driver's steering force TQd is large. Furthermore, if a large driver's steering force TQd is input to the vehicle 100 during the execution of lane departure prevention control, it is preferable to stop lane departure prevention control.

[0111] Here, when the vehicle 100 is driving on a general road, compared to when the vehicle 100 is driving on a dedicated motor vehicle lane, even if the driver's steering force TQd is small, there is a possibility that the driver may intentionally cause the vehicle 100 to cross the left deviation judgment line LL or the right deviation judgment line LR.

[0112] Therefore, when the vehicle speed V is higher than the predetermined speed Vth, the vehicle driving support device 10 sets the steering force threshold TQd_th to a baseline value (steering force threshold TQd_large at high speed), and when the vehicle speed V is lower than the predetermined speed Vth, it sets the steering force threshold TQd_th to a predetermined value smaller than the steering force threshold TQd_large at high speed (steering force threshold TQd_small at low speed). Alternatively, the vehicle driving support device 10 can be configured such that when the vehicle 100 is traveling on a dedicated motor vehicle road, the steering force threshold TQd_th is set to the steering force threshold TQd_large at high speed, and when the vehicle 100 is traveling on a general road, the steering force threshold TQd_th is set to the steering force threshold TQd_small at low speed.

[0113] Therefore, when the vehicle 100 is traveling at a low speed, even if the driver's steering force TQd is small, lane departure prevention control will not be executed, and lane departure prevention control that is in operation will be stopped. Thus, appropriate lane departure prevention control can be executed when the vehicle 100 is traveling at a low speed.

[0114] Cancel the setting of the duration threshold.

[0115] Additionally, for example, such as Figure 6 and Figure 7 As shown, when vehicle 100 is traveling on a normal road, although it approaches the left curb 202L when passing right-turning vehicle 300 (other vehicles stopped for a right turn), if the cancellation condition is met and lane departure prevention control is not executed, a certain amount of time is required from the time the cancellation condition is met until vehicle 100 leaves curb 202L and returns to its own lane LN after passing right-turning vehicle 300. In such a case, if the cancellation duration threshold Tth is set to a short time, it is possible that the lane departure condition will be met and lane departure prevention control will be executed before vehicle 100 passes right-turning vehicle 300.

[0116] Therefore, when the vehicle speed V is higher than the predetermined speed Vth, the vehicle driving support device 10 sets the cancellation duration threshold Tth to a baseline value (high-speed cancellation duration threshold Tshort). When the vehicle speed V is lower than the predetermined speed Vth, the cancellation duration threshold Tth is set to a predetermined value larger than the high-speed cancellation duration threshold Tshort (low-speed cancellation duration threshold Tlong). Alternatively, the vehicle driving support device 10 can also be configured such that when the vehicle 100 is traveling on a dedicated motor vehicle lane, the cancellation duration threshold Tth is set to the high-speed cancellation duration threshold Tshort, and when the vehicle 100 is traveling on a general road, the cancellation duration threshold Tth is set to the low-speed cancellation duration threshold Tlong.

[0117] Therefore, when the vehicle 100 is traveling at a low speed, if lane departure prevention control is not executed when the lane departure condition is met but the cancellation condition is met, or if lane departure prevention control stops during the execution of lane departure prevention control due to the cancellation condition being met, lane departure prevention control will not be executed until a relatively long period of time has elapsed (lane departure prevention control will not be executed until a relatively long period of time has elapsed). Thus, appropriate lane departure prevention control can be implemented when the vehicle 100 is traveling at a low speed.

[0118] <Lane Departure Conditions Settings>

[0119] like Figure 6 and Figure 7 As shown, when vehicle 100 is driving on a normal road, there is a situation where vehicle 100 drives on the left side of its own lane LN in order to overtake vehicle 300 waiting to turn right. At this time, vehicle 100 may sometimes cross the left lane dividing line 201L. If lane departure prevention control is activated due to crossing the left lane dividing line 201L, vehicle 100 will not be able to overtake vehicle 300 smoothly.

[0120] In addition, such as Figure 8 As shown, when vehicle 100 is driving on a normal road, there are situations where the driver may stop vehicle 100 on the left side (shoulder) of its lane LN. In this case, vehicle 100 may sometimes cross the left lane dividing line 201L. If lane departure prevention control is activated because vehicle 100 has crossed the left lane dividing line 201L, the driver will not be able to stop vehicle 100 smoothly on the roadside.

[0121] In addition, when the vehicle 100 is driving on a normal road, there are also situations where the driver intentionally causes the vehicle 100 to cross the left dividing line 201L, the right dividing line 201R, or other parallel sections of the road. If lane departure prevention control is activated in this situation, it will be unnecessarily activated.

[0122] Therefore, although the vehicle driving support device 10 can be configured to set the left deviation judgment line LL and the right deviation judgment line LR based on both the plane road end and the grade-separated road end, regardless of whether the vehicle speed V is high or low, and determine whether the lane deviation condition is met, in this example, it is configured such that when the vehicle speed V is higher than the predetermined speed Vth, the left deviation judgment line LL and the right deviation judgment line LR are set based on both the plane road end and the grade-separated road end, and the lane deviation condition is determined; but when the vehicle speed V is lower than the predetermined speed Vth, the left deviation judgment line LL and the right deviation judgment line LR are set only based on the grade-separated road end.

[0123] Therefore, even if the vehicle 100 crosses the left lane marking 201L or the right lane marking 201R while traveling at a low speed, lane departure prevention control will not be activated. Thus, appropriate lane departure prevention control can be implemented when the vehicle 100 is traveling at a low speed.

[0124] The above is a summary of the operation of the vehicle driving support device 10.

[0125] <The specific operation of vehicle driving support devices>

[0126] Next, the specific operation of the vehicle driving support device 10 will be explained. The CPU of the ECU 90 of the vehicle driving support device 10 executes according to a predetermined calculation cycle. Figure 9 The example shown. Therefore, when the predetermined timing occurs, the CPU... Figure 9 The routine shown begins processing from step 900, which leads to step 905, where it is determined whether the values ​​of the flag Xexe_low during low-speed control execution and the flag Xexe_high during high-speed control execution are "0".

[0127] Regarding the flag Xexe_low during low-speed control execution, a value of "1" indicates that lane departure prevention control is being executed when the vehicle's speed V is below the predetermined speed Vth, while a value of "0" indicates that such lane departure prevention control is not being executed. Similarly, regarding the flag Xexe_high during high-speed control execution, a value of "1" indicates that lane departure prevention control is being executed when the vehicle's speed V is above the predetermined speed Vth, while a value of "0" indicates that such lane departure prevention control is not being executed.

[0128] If the CPU determines "yes" in step 905, the process proceeds to step 910, where it determines whether the cancellation duration Tcan exceeds the cancellation duration threshold Tth. The cancellation duration Tcan is the time elapsed since the point when lane departure prevention control is not executed, even though the lane departure condition is met but lane departure prevention control is not executed due to the cancellation condition being met. Alternatively, it is the time elapsed since the point when lane departure prevention control is stopped, even if lane departure prevention control is stopped during the execution of lane departure prevention control due to the cancellation condition being met.

[0129] If the CPU determines "yes" in step 910, the process proceeds to step 915 to determine whether the vehicle speed V is below the predetermined speed Vth. If the CPU determines "yes" in step 915, the process proceeds to step 920, setting the low-speed flag Xlow to "1". Regarding the low-speed flag Xlow, a value of "1" indicates that the vehicle speed V is below the predetermined speed Vth, and a value of "0" indicates that the vehicle speed V is not below the predetermined speed Vth. After executing step 920, the CPU proceeds to step 995, temporarily terminating the processing of this routine.

[0130] On the other hand, if the CPU determines "no" in step 915, it proceeds to step 925 and sets the value of the high-speed flag Xhigh to "1". Regarding the high-speed flag Xhigh, a value of "1" indicates that the vehicle speed V is higher than the predetermined speed Vth, and a value of "0" indicates that the vehicle speed V is not higher than the predetermined speed Vth. After executing step 925, the CPU proceeds to step 995, temporarily terminating the processing of this routine.

[0131] Alternatively, if the CPU determines "no" in step 905 or step 910, the process will proceed directly to step 995, temporarily terminating the processing of this routine.

[0132] Furthermore, the CPU executes according to a predetermined computation cycle. Figure 10 The example shown. Therefore, when the predetermined timing occurs, the CPU... Figure 10 The routine shown begins processing from step 1000, which leads to step 1005, where it is determined whether the value of the flag Xexe_low is "0" during the low-speed control execution.

[0133] If the CPU determines "yes" in step 1005, the process proceeds to step 1010 to determine whether the value of the low-speed indicator Xlow is "1". If the CPU determines "yes" in step 1010, the process proceeds to step 1015 to determine whether the lane departure condition is met. As described above, since the vehicle speed V is below the predetermined speed Vth, the CPU determines whether the lane departure condition is met based on the left departure determination line LL and the right departure determination line LR set at the end of the elevated road.

[0134] If the CPU determines "yes" in step 1015, the process proceeds to step 1020, where the steering force threshold TQd_th is set to the low-speed steering force threshold TQd_small. It then determines whether the driver's steering force TQd is smaller than this low-speed steering force threshold TQd_small, i.e., whether the cancellation condition is met. If the CPU determines "yes" in step 1020, the process proceeds to step 1025, where the upper limit value of the action parameter Pmax is set to the low-speed action parameter upper limit value Psmall. Next, the CPU proceeds to step 1030, using the low-speed action parameter upper limit value Psmall set in step 1025 to set the target driving route Ltgt. Next, the CPU proceeds to step 1035, setting the value of the flag Xexe_low during low-speed control execution to "1". Therefore, the determination in step 1005 is "no". When the process in step 1035 is executed, the CPU proceeds to step 1095, temporarily terminating the processing of this routine.

[0135] On the other hand, if the CPU determines "no" in step 1020, it proceeds to step 1040 and sets the cancellation duration threshold Tth to the low-speed cancellation duration threshold Tlong. Then, the CPU proceeds to step 1045 and sets the low-speed flag Xlow to "0". Next, the CPU proceeds to step 1095, temporarily terminating the processing of this routine.

[0136] Alternatively, if the CPU determines "no" in step 1010 or step 1015, the process will proceed directly to step 1095, temporarily terminating the processing of this routine.

[0137] Additionally, if the CPU determines "No" in step 1005, the process proceeds to step 1050, where the steering force threshold TQd_th is set to the low-speed steering force threshold TQd_small, and it is determined whether the driver's steering force TQd is greater than or equal to this low-speed steering force threshold TQd_small, i.e., whether the cancellation condition is met. If the CPU determines "Yes" in step 1050, the process proceeds to step 1055, stopping lane departure prevention control. Next, the CPU proceeds to step 1060, setting the cancellation duration threshold Tth to the low-speed cancellation duration threshold Tlong. Next, the CPU proceeds to step 1065, setting the values ​​of the flag Xexe_low and the low-speed flag Xlow during low-speed control execution to "0" respectively. Next, the CPU proceeds to step 1095, temporarily terminating the processing of this routine.

[0138] On the other hand, if the CPU determines "no" in step 1050, it causes the processing to proceed. Figure 11 Step 1105, as shown, determines whether the control termination condition is met. In this example, the control termination condition is met when, after the lane departure prevention control is initiated, the vehicle 100 returns to its own lane LN, and the yaw angle of the vehicle 100 becomes a value within the range of near zero.

[0139] If the CPU determines "yes" in step 1105, the process proceeds to step 1110 to execute autonomous steering control. That is, the CPU autonomously steers the vehicle 100 along the target driving route Ltgt. After executing step 1110, the CPU proceeds to step 1095 (see reference). Figure 10 This temporarily terminates the processing of this routine.

[0140] On the other hand, if the CPU determines "no" in step 1105, it proceeds to step 1115, ending lane departure prevention control. Next, the CPU proceeds to step 1120, setting the values ​​of the flag Xexe_low and the low-speed flag Xlow, which were executed during low-speed control, to "0". Then, the CPU proceeds to step 1095 (see...). Figure 10 This temporarily terminates the processing of this routine.

[0141] Furthermore, the CPU executes according to a predetermined computation cycle. Figure 12 The example shown. Therefore, when the predetermined timing occurs, the CPU... Figure 12 The routine shown begins processing from step 1200, which leads to step 1205, where it is determined whether the value of the flag Xexe_high is "0" during the high-speed control execution.

[0142] If the CPU determines "yes" in step 1205, the process proceeds to step 1210 to determine whether the value of the highway sign Xhigh is "1". If the CPU determines "yes" in step 1210, the process proceeds to step 1215 to determine whether the lane departure condition is met. As described above, since the vehicle speed V is higher than the predetermined speed Vth, the CPU determines whether the lane departure condition is met based on the left departure determination line LL and the right departure determination line LR set based on the horizontal road end and the vertical road end.

[0143] If the CPU determines "yes" in step 1215, the process proceeds to step 1220, where the steering force threshold TQd_th is set to the high-speed steering force threshold TQd_large. It then determines whether the driver's steering force TQd is smaller than this high-speed steering force threshold TQd_large, i.e., whether the cancellation condition is met. If the CPU determines "yes" in step 1220, the process proceeds to step 1225, where the upper limit value of the action parameter Pmax is set to the high-speed action parameter upper limit value Plarge. Next, the CPU proceeds to step 1230, using the high-speed action parameter upper limit value Plarge set in step 1225 to set the target driving route Ltgt. Next, the CPU proceeds to step 1235, setting the value of the flag Xexe_high during high-speed control execution to "1". Therefore, the determination in step 1205 is "no". After executing step 1235, the CPU proceeds to step 1295, temporarily ending the processing of this routine.

[0144] On the other hand, if the CPU determines "No" in step 1220, it proceeds to step 1240 and sets the cancellation duration threshold Tth to the high-speed cancellation duration threshold Tshort. Next, the CPU proceeds to step 1245 and sets the high-speed flag Xhigh to "0". Then, the CPU proceeds to step 1295, temporarily terminating the processing of this routine.

[0145] Alternatively, if the CPU determines "no" in step 1210 or step 1215, the process will proceed directly to step 1295, temporarily terminating the processing of this routine.

[0146] Additionally, if the CPU determines "No" in step 1205, the process proceeds to step 1250, where the steering force threshold TQd_th is set to the high-speed steering force threshold TQd_large, and it is determined whether the driver's steering force TQd is greater than or equal to this high-speed steering force threshold TQd_large, i.e., whether the cancellation condition is met. If the CPU determines "Yes" in step 1250, the process proceeds to step 1255, stopping lane departure prevention control. Next, the CPU proceeds to step 1260, setting the cancellation duration threshold Tth to the high-speed cancellation duration threshold Tshort. Next, the CPU proceeds to step 1265, setting the values ​​of the high-speed control execution flag Xexe_high and the high-speed flag Xhigh to "0" respectively. Next, the CPU proceeds to step 1295, temporarily terminating the processing of this routine.

[0147] On the other hand, if the CPU determines "no" in step 1250, it causes processing to proceed. Figure 13 Step 1305, as shown, determines whether the condition that the control termination condition is not met is met.

[0148] If the CPU determines "yes" in step 1305, the process proceeds to step 1310 to execute autonomous steering control. That is, the CPU autonomously steers the vehicle 100 along the target driving route Ltgt. After executing step 1310, the CPU proceeds to step 1295 (see reference). Figure 12 This temporarily terminates the processing of this routine.

[0149] On the other hand, if the CPU determines "no" in step 1305, it proceeds to step 1315, ending lane departure prevention control. Next, the CPU proceeds to step 1320, setting the values ​​of the flags Xexe_high and Xhigh during high-speed control execution to "0". Then, the CPU proceeds to step 1295 (see reference). Figure 12 This temporarily terminates the processing of this routine.

[0150] The above describes the specific operation of the vehicle driving support device 10.

[0151] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of the present invention.< / ecu>

Claims

1. A vehicle driving support device, comprising: A control device that autonomously steers its own vehicle to prevent it from deviating from its lane, wherein... The control device is configured such that, If the condition prohibiting the execution of lane departure prevention control based on steering operations performed by the driver of the vehicle is not met, then the lane departure prevention control is executed. The lane departure prevention control is executed in such a manner that the action parameters representing the vehicle's own movement during the execution of the lane departure prevention control do not exceed the upper limit value of the action parameters, thereby steering the vehicle itself. When the vehicle is traveling at a speed below a predetermined speed, compared to when the vehicle is traveling at a speed above the predetermined speed, the upper limit of the action parameter is reduced, or the execution prohibition condition is changed in a manner that makes it difficult for the execution prohibition condition to be met. The execution prohibition condition is that the time elapsed since the execution of lane departure prevention control is prohibited due to the fulfillment of the execution prohibition condition is shorter than a predetermined time. The control device is configured to change the execution prohibition condition in a way that makes it difficult to meet the execution prohibition condition by setting the predetermined time to a long time.

2. The vehicle driving support device according to claim 1, The action parameter is the distance the vehicle moves laterally, i.e., the lateral movement distance, due to the lane departure prevention control.

3. The vehicle driving support device according to claim 1, The action parameter is at least one of the vehicle's lateral acceleration, steering angle, and yaw rate.

4. A vehicle driving support device, comprising: A control device that autonomously steers its own vehicle to prevent it from deviating from its lane, wherein... The control device is configured such that, If the condition prohibiting the execution of lane departure prevention control based on steering operations performed by the driver of the vehicle is not met, then the lane departure prevention control is executed. The lane departure prevention control is performed by autonomously steering the vehicle itself, limiting the action parameters representing the vehicle's own actions during the execution of the lane departure prevention control to below an upper limit value. When the vehicle is traveling on a general road other than a dedicated motor vehicle lane, compared to when the vehicle is traveling on a dedicated motor vehicle lane, the upper limit of the action parameter is reduced, or the execution prohibition condition is changed in a manner that makes it difficult for the execution prohibition condition to be met. The execution prohibition condition is that the time elapsed since the execution of lane departure prevention control is prohibited due to the fulfillment of the execution prohibition condition is shorter than a predetermined time. The control device is configured to change the execution prohibition condition in a way that makes it difficult to meet the execution prohibition condition by setting the predetermined time to a long time.

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