Driving assistance device, driving assistance method, and driving assistance program

Abstract

To solve the problem that there is the risk that optimal driving support may not be performed if out-of-lane suppression control is prohibited uniformly according to a location where a vehicle travels.SOLUTION: A driving support device executes one or more kinds of control for suppressing deviation of a vehicle from a travel lane. In a case where both a first condition that a vehicle speed is equal to or lower than a predetermined speed and a second condition that the vehicle is traveling in a predetermined area are established, the driving support device suppresses at least one of the control.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a driving assistance device mounted on a vehicle, and more particularly to a driving assistance device having a lane departure prevention function that prevents the vehicle from departing from the lane in which it is currently traveling. [Background technology]

[0002] In recent years, in order to assist drivers in driving a vehicle, driving assistance devices have been developed that determine whether or not there is a possibility that the vehicle will deviate from its driving lane, and if there is a possibility of deviation, issue an alarm using audio or a display device, and in addition, perform lane deviation prevention control, such as generating a steering force using the vehicle's steering device in the direction opposite to the direction in which the vehicle will deviate.

[0003] On the other hand, if the driver intentionally deviates from the driving lane, the driver may find the activation of the lane departure prevention control annoying. In consideration of this issue, a technology has been disclosed that, when detecting a toll booth, an interchange, a branch point to a parking or service area on a highway, determines that there is a high possibility that the driver will intentionally deviate from the driving lane, and prohibits the lane departure prevention control (see, for example, Patent Document 1 and Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-116436 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-18211 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if lane departure suppression control is uniformly prohibited depending on the location where the vehicle is traveling, there is a risk that optimal driving assistance will not be achieved. [Means for solving the problem]

[0006] First Aspect The driving assistance device according to the present invention prevents a vehicle from deviating from its driving lane. Complex A driving assistance device that performs control of the number of vehicles, The control includes at least a warning to the driver and steering assistance, and the vehicle is driven at a speed faster than Vth based on a radius of curvature R of a curve on a road on which the vehicle is traveling. The vehicle speed small The first condition is that the vehicle is traveling in a specified area. 、 If both of the above are true, prohibiting at least the warning, and prohibiting at least the warning and the steering assistance when all of the first condition, the second condition, and a third condition that the driver performs a predetermined brake operation or the deceleration of the host vehicle is equal to or greater than a predetermined value are satisfied; It is characterized by:

[0007] Second Aspect The driving assistance device according to the present invention before The first condition and the second condition, The aforementioned If both of the third and third conditions are met, multiple of The present invention is characterized in that all of the above controls are suppressed.

[0008] Third Aspect The driving assistance device according to the present invention is characterized in that the predetermined area is an area from an exit of a highway to a toll gate.

[0011] Fourth Aspect The driving assistance control method according to the present invention is a method for preventing a vehicle from deviating from a driving lane. Complex A driving assistance control method for performing control of a number of The control includes at least a warning to the driver and steering assistance, and the vehicle is driven at a speed faster than Vth based on a radius of curvature R of a curve on a road on which the vehicle is traveling. The vehicle speed small The first condition is that the vehicle is traveling in a specified area. 、 If both of the above are true, prohibiting at least the warning, and prohibiting at least the warning and the steering assistance when all of the first condition, the second condition, and a third condition that the driver performs a predetermined brake operation or the deceleration of the host vehicle is equal to or greater than a predetermined value are satisfied; It is characterized by:

[0012] Fifth Aspect The driving assistance control program according to the present invention is a program for preventing a vehicle from deviating from its driving lane. Complex A driving assistance control program for performing control of a number of The control includes at least a warning to the driver and steering assistance, and the vehicle is driven at a speed faster than Vth based on a radius of curvature R of a curve on a road on which the vehicle is traveling. The vehicle speed small The first condition is that the vehicle is traveling in a specified area. 、 If both of the above are true, prohibiting at least the warning, and prohibiting at least the warning and the steering assistance when all of the first condition, the second condition, and a third condition that the driver performs a predetermined brake operation or the deceleration of the host vehicle is equal to or greater than a predetermined value are satisfied; It is characterized by: [Effects of the Invention]

[0013] According to the driving assistance device of the present invention, when traveling through a location where lane departure prevention control is not required, some or all of the lane departure prevention control is suppressed only in certain situations, thereby eliminating the annoyance felt by the driver and allowing driving assistance to continue. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a block diagram showing a configuration of a driving assistance device according to an embodiment; [Figure 2] 1 is a table summarizing conditions and concepts according to examples. [Figure 3] FIG. 10 is a diagram illustrating the relationship between the radius of curvature of a driving lane and a vehicle speed threshold. [Figure 4] 10 is a flowchart illustrating an execution procedure according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a lane departure prevention device for a moving vehicle according to the present embodiment will be described by way of example with reference to the drawings. The configurations according to the following embodiments are merely examples, and the respective components, flowcharts, etc. are not intended to limit the technical scope of the invention to those only.

[0016] <Outline of the driving assistance device> The configuration of a driving assistance device according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing the configuration of a driving assistance device according to an embodiment.

[0017] The driving assistance device 100 is composed of a lane departure prevention assistance unit 1001 that performs lane departure prevention assistance to prevent the vehicle 1 from departing from the lane in which it is currently traveling, and a lane departure prevention assistance suppression unit 1002 that suppresses the lane departure prevention assistance based on predetermined conditions.

[0018] A camera 101, a navigation system 102, a vehicle speed sensor 103, and a brake pedal 104 are electrically connected to the driving assistance device 100. An alarm device 105 and a steering device 106 are also electrically connected to the driving assistance device 100. Each function of the driving assistance device 100 in FIG. 1 is realized by a CPU and memory (ROM, RAM, etc.) of one or more ECUs (not shown).

[0019] The periphery recognition unit 101 recognizes the situation around the vehicle 1 based on the output of a detection means capable of detecting the situation outside the vehicle 1, such as a millimeter wave radar, a camera, or a LiDAR (Light Detection and Ranging). In particular, the periphery recognition unit 101 recognizes white lines that define lanes based on camera images.

[0020] An example of a white line recognition method based on camera images will be described below. The camera is, for example, a CCD camera or a CMOS camera, and is installed, for example, above the center of the windshield inside the vehicle so that its optical axis is aligned forward. The camera captures an image of the road surface ahead of the vehicle, including the white lines on both sides of the lane, and outputs the captured road image data to the surroundings recognition unit 101.

[0021] The surroundings recognition unit 101 performs image processing on the road image data. After performing well-known binarization and edge extraction processing on the road image data, it performs pattern matching processing and performs pattern recognition of white lines based on a model corresponding to a white line template.

[0022] The location information acquisition unit 102 includes, for example, a navigation device including a map database and an infrastructure information receiving device that externally acquires traffic volume information and the like. The navigation device can acquire the location information of the vehicle with high accuracy by matching the results of measurements of the vehicle's location using GPS or autonomous navigation with roads recorded in the map database. Alternatively, the infrastructure information receiving device may receive traffic information and the like from infrastructure and estimate the location information of the vehicle based on that information.

[0023] The vehicle state acquisition unit 103 acquires the vehicle speed and acceleration from a vehicle speed sensor and an acceleration sensor mounted on the vehicle. The braking device 104 has a brake pedal and decelerates the vehicle through the driver's operation of the brake pedal. Operation information such as whether the driver has operated the brake pedal, the amount of depression, and the depression speed is transmitted to the driving assistance device.

[0024] The warning device 105 is, for example, a display device or a speaker. The driving assistance device issues a warning to the driver by displaying a predetermined indicator or character on the display device or controlling the speaker to emit a warning sound. The driving assistance device may also issue a warning to the driver by vibrating the steering wheel.

[0025] The steering device 106 has, for example, a steering actuator, and the driving assistance device controls the steering actuator to generate a steering force in the vehicle.

[0026] <Lane Departure Prevention Assist> The operation of the lane departure prevention support performed by the lane departure prevention support unit 1001 to prevent the vehicle 1 from departing from the lane in which it is currently traveling will now be described. In this embodiment, the lane departure prevention support is performed by the CPU executing a control program stored in the memory of an ECU (not shown). The control program may also be acquired from an external server or the like via a communication device (not shown).

[0027] The lane departure prevention support unit 1001 uses a known method to calculate the distance in the width direction of the road between the white lines pattern-recognized by the periphery recognition unit 101 and the vehicle 1. For example, it calculates the distance in the width direction of the vehicle 1 from each of the left and right white lines.

[0028] Next, the lane departure prevention support unit 1001 compares the widthwise distance of the vehicle 1 from each of the left and right white lines with a preset first threshold value, and determines whether both are equal to or greater than the first threshold value. The first threshold value is a threshold value that can determine that the possibility of the vehicle 1 deviating from its travel lane is sufficiently low if the distance between the white lines and the vehicle 1 is equal to or greater than this value.

[0029] Therefore, if the lane departure prevention support unit 1001 determines that at least one of the widthwise distances of the vehicle 1 relative to the left and right white lines is narrower than the first threshold value, it is determined that there is a risk that the vehicle 1 will deviate from the driving lane.

[0030] If the lane departure prevention support unit 1001 determines that there is a risk that the vehicle 1 will deviate from the driving lane, it controls the steering device 106 of the vehicle 1 so that a steering force is generated in the direction opposite to the direction of deviation of the vehicle 1. However, if it is determined that the widthwise distance of the vehicle 1 from each of the left and right white lines is equal to or greater than the first threshold, the control of the steering device 106 is terminated.

[0031] Furthermore, in this embodiment, priority is given to the steering operation by the driver over the control of the steering device 106 by the driving assistance device 100. Therefore, even if lane departure prevention assistance that controls the steering device 106 is performed, if the driver performs a steering operation in the lane departure direction, the distance in the width direction of the vehicle 1 from the white line will become even narrower than the first threshold value, increasing the risk that the vehicle 1 will depart from the traveling lane.

[0032] If the widthwise distance of the vehicle 1 from the white lines becomes narrower than the first threshold, the lane departure prevention support unit 1001 compares the widthwise distance of the vehicle 1 from each of the left and right white lines with a second threshold that is smaller than the first threshold, and determines whether both distances are equal to or greater than the second threshold. The second threshold is a threshold that can determine that there is a high possibility that the vehicle 1 will deviate from its travel lane if the distance between the white lines and the vehicle 1 is not equal to or greater than this value.

[0033] Therefore, when the lane departure prevention support unit 1001 determines that at least one of the widthwise distances of the vehicle 1 from the left and right white lines is narrower than the second threshold, it issues a warning to the driver via the warning device 105. For example, it outputs a warning message to the display indicating that the vehicle 1 may depart from the driving lane, and outputs a warning sound from the speaker. It may also vibrate the steering wheel to alert the driver.

[0034] In the above embodiment, lane departure prevention assistance is performed in the order of "controlling the steering device" and "issuing a warning to the driver" as the widthwise distance of the vehicle 1 from the white line narrows, but the order of "controlling the steering device" and "issuing a warning to the driver" may be reversed, or they may be performed simultaneously. Also, a configuration may be adopted in which the control of the steering device or the warning to the driver is changed based on the widthwise distance.

[0035] <Lane Departure Prevention Assist Unit> However, if lane departure prevention assistance is always implemented in a situation where the vehicle 1 deviates from the driving lane at the driver's will, there is a concern that an alarm will be activated even when the driver deviates from the driving lane at the driver's will, which will be a cause of annoyance for the driver.

[0036] Therefore, the lane departure prevention assist suppression unit 1002 suppresses unnecessary lane departure prevention assist when a predetermined condition is satisfied while traveling through a predetermined point. However, as shown in the following examples, the embodiments of the present invention also include a mode in which suppression is prohibited.

[0037] Specific processing contents of the lane departure prevention support suppression unit 1002 will be explained below with reference to Fig. 2. Fig. 2 is a table summarizing conditions and concepts for suppressing lane departure prevention support according to this embodiment.

[0038] The shaded area in Figure 2 represents the content of the lane departure prevention assist suppression, which changes from A to D depending on the conditions. Condition A is when the driving area of ​​the host vehicle is outside a predetermined area, and lane departure prevention assist is not prohibited or suppressed, but normal lane departure prevention assist is executed. Outside the predetermined area, it is unlikely that a situation will occur in which the driver will cause the vehicle 1 to deviate from the driving lane, so by executing normal lane departure prevention assist, lane departure can be suppressed and the driver's driving can be appropriately supported.

[0039] In the condition B in FIG. 2, when the vehicle is traveling in a predetermined area and the vehicle speed is equal to or greater than a predetermined speed Vth, the lane departure prevention assist is not prohibited or suppressed, and normal lane departure prevention assist is performed. The speed Vth means the maximum vehicle speed at which the vehicle can safely turn in the traveling lane. Under the condition B, Do Although a situation may arise in which the driver intends to cause the vehicle 1 to deviate from its lane, the system determines that the vehicle is traveling at a high speed and cannot safely complete the curve, and so normal lane departure prevention assistance is performed.

[0040] 3, the larger the radius of curvature R, the gentler the curve, and therefore the higher the maximum vehicle speed (speed Vth) at which the vehicle can safely complete the turn. The radius of curvature R can be obtained by calculation using a known method based on the vehicle's position information from the navigation device of the position information acquisition unit 102, road information in a map database, and camera information from the surroundings recognition unit 101.

[0041] In C of Fig. 2, the operation of both "controlling the steering device" and "issuing a warning to the driver" of the lane departure prevention assist is prohibited or suppressed under the conditions that the driving area of ​​the host vehicle is a predetermined area, the vehicle speed is less than a predetermined speed Vth, and the driver is braking or the deceleration of the host vehicle is equal to or greater than a predetermined value. Under condition C, the lane departure prevention assist is prohibited or suppressed in a situation where the vehicle can be driven safely and it is determined that the driver intends to decelerate, so it is possible to eliminate the annoyance felt by the driver due to the lane departure prevention assist while also allowing the continuation of driving assistance.

[0042] In D of FIG. 2, the lane departure prevention assist function "issue warning to driver" is prohibited or suppressed under the following conditions: the driving area of ​​the host vehicle is a predetermined area, the vehicle speed is less than a predetermined speed Vth, and the driver is not braking or the deceleration of the host vehicle is less than a predetermined value. Under condition D, the vehicle speed is such that the driver can safely complete the turn by operating the driver, but it cannot be determined that the driver intends to decelerate. Therefore, by activating the lane departure prevention assist function "control the steering device," it is possible to continue driving assistance while at the same time alleviating, to some extent, the annoyance felt by the driver by the lane departure prevention assist.

[0043] Alternatively, an embodiment may be adopted in which, among the lane departure prevention assistance functions, "controlling the steering device" is prohibited or suppressed, and "issuing an alert to the driver" is activated. In this case, the driving assistance cannot be continued, but the driver can be informed that the host vehicle is about to depart while suppressing any discomfort felt by the driver due to the driving assistance.

[0044] Specific processing contents of the lane departure prevention assist suppression unit 1002 will be described below using a flowchart. Fig. 4 is a flowchart showing processing contents of lane departure prevention control according to this embodiment. A program according to the flowchart is stored in advance in an ECU (not shown) and is repeatedly executed by the ECU. The control program may also be acquired from an external server or the like via a communication device (not shown).

[0045] In S500, the lane departure prevention support described above is executed. Specifically, the lane departure prevention support unit 1001 controls the steering device 106 to generate a steering force in the direction opposite to the direction in which the vehicle 1 is departing, and issues a warning to the driver.

[0046] In S501, it is determined whether the vehicle 1 is traveling in a predetermined area. The predetermined area is, for example, the area from the exit of a highway to the toll gate, and the determination is made based on the position information of the vehicle 1 obtained by the position information acquisition unit 102. If the determination is negative, the process returns to S500 (A in FIG. 2) and normal lane departure prevention assistance is executed. On the other hand, if the determination is positive, the process proceeds to S502.

[0047] In S502, it is determined whether the vehicle speed of the vehicle 1 is lower than the speed Vth based on the radius of curvature R. If the determination is negative, the vehicle speed is high and there is a high possibility that the vehicle will not be able to safely complete the curve without lane departure prevention assistance, so the process returns to S500 (B in FIG. 2) and normal lane departure prevention assistance is performed. On the other hand, if the determination is positive, the process proceeds to S503.

[0048] In S503, it is determined whether the driver is performing a brake operation or whether the deceleration of the vehicle 1 is equal to or greater than a predetermined value. Specifically, it is determined whether the driver is performing a brake operation based on information such as the amount of depression of the brake pedal and the depression speed sent from the brake device 104 to the driving assistance device 100. Alternatively, the deceleration of the vehicle 1 may be calculated based on acceleration information of the vehicle 1 sent from the vehicle state acquisition unit 103 to the driving assistance device 100, and it may be determined whether the deceleration is equal to or greater than a predetermined value. The predetermined value is set to a value that allows it to be determined that the driver has the intention to decelerate. If a positive determination is made, the process proceeds to S504 (C in FIG. 2), and if a negative determination is made, the process proceeds to S505 (D in FIG. 2).

[0049] In S504, the lane departure prevention assist is prohibited from both "controlling the steering device" and "issuing a warning to the driver." Since lane departure prevention assist is prohibited in a safe situation and when it is determined that the driver intends to decelerate, it is possible to eliminate the annoyance felt by the driver due to lane departure prevention assist while also allowing driving assistance to continue.

[0050] In S505, the lane departure prevention assist function "issue a warning to the driver" is prohibited. Although the vehicle speed is such that the driver can safely complete the turn by operating the vehicle, S503 does not determine that the driver intends to decelerate. Therefore, by activating the lane departure prevention assist function "control the steering device," it is possible to continue driving assistance while at the same time alleviating, to some extent, the annoyance felt by the driver by the lane departure prevention assist.

[0051] The flowchart in Figure 4 mainly describes a form in which lane departure prevention assist, which can be a nuisance to the driver, is prohibited, but it may also be a form in which some or all of the lane departure prevention assist is suppressed, and is not necessarily limited to the above embodiment.

[0052] For example, when "controlling the steering device" in the lane departure prevention assist is suppressed, the steering force in the direction opposite to the direction of departure may be made smaller than the steering force in normal lane departure prevention assist. Also, by making the first threshold smaller than the normal value, the control of the steering device may be delayed compared to normal lane departure prevention assist.

[0053] For example, when suppressing the "warning to the driver" in the lane departure prevention assist, whereas in normal lane departure prevention assist, an alarm sound is emitted and a predetermined indicator or character is displayed on the display device, the alarm may be prohibited and only the alarm on the display device may be displayed. Also, by setting the second threshold value smaller than the normal value, the warning to the driver may be delayed compared to normal lane departure prevention assist.

[0054] Although the embodiments of the present invention have been described above, the present invention is not limited to the above examples and can be modified in various ways. [Explanation of symbols]

[0055] 100 Driving Assistance Equipment 101 Surrounding Recognition Unit 102 Location information acquisition unit 103 Vehicle status acquisition unit 104 Brake equipment 105 Alarm device 106 Steering device

Claims

1. A driving assistance device that performs a plurality of controls to prevent a vehicle from deviating from a driving lane, The control includes at least a warning to the driver and steering assistance, prohibiting at least the warning when both a first condition that the vehicle speed is lower than a speed Vth based on a curvature radius R of a curve on a road on which the vehicle is traveling and a second condition that the vehicle is traveling in a predetermined area are satisfied; a driving assistance device that prohibits at least the warning and the steering assistance when all of the first condition, the second condition, and a third condition that the driver performs a predetermined brake operation or the deceleration of the vehicle is equal to or greater than a predetermined value are satisfied.

2. If the first condition, the second condition, and the third condition are all met, The driving assistance device according to claim 1 , wherein all of the plurality of controls are suppressed.

3. The driving assistance device according to claim 1 , wherein the predetermined area is an area from an exit of a highway to a toll gate.

4. A driving assistance control method that executes a plurality of controls to suppress deviation of a vehicle from a driving lane, The control includes at least a warning to the driver and steering assistance, prohibiting at least the warning when both a first condition that the vehicle speed is lower than a speed Vth based on a curvature radius R of a curve on a road on which the vehicle is traveling and a second condition that the vehicle is traveling in a predetermined area are satisfied; a driving assistance control method characterized by prohibiting at least the warning and the steering assistance when all of the first condition, the second condition, and a third condition that the driver performs a predetermined braking operation or the deceleration of the vehicle is equal to or greater than a predetermined value are satisfied.

5. A driving assistance control program that executes a plurality of controls to prevent a vehicle from deviating from a driving lane, The control includes at least a warning to the driver and steering assistance, prohibiting at least the warning when both a first condition that the vehicle speed is lower than a speed Vth based on a curvature radius R of a curve on a road on which the vehicle is traveling and a second condition that the vehicle is traveling in a predetermined area are satisfied; A driving assistance control program characterized by prohibiting at least the warning and the steering assistance when all of the first condition, the second condition, and a third condition that the driver performs a predetermined brake operation or the deceleration of the vehicle is equal to or greater than a predetermined value are met.

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