Driving assistance systems

Abstract

To properly execute lane-keeping assistance control even when driving through sharp curves.SOLUTION: A driving assistance device supports driving of a vehicle by a driver. The driving assistance device includes a recognition sensor, a steering actuator, and an electronic control unit. The recognition sensor recognizes the situation in front of the vehicle. The steering actuator steers the vehicle. The electronic control unit controls the steering actuator so as to suppress lane deviation of the vehicle from a traveling lane. The electronic control unit uses the recognition sensor to recognize a curve sign that prompts the driver's attention to a curve ahead of the vehicle, and increases the steering assist amount of the steering actuator for suppressing the lane deviation during passage through the curve in comparison to a case of passing through the curve without recognition of the curve sign when the curve sign is recognized.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a driving assistance device that suppresses lane departure.

Background Art

[0002] Patent Document 1 discloses a vehicle control device that executes lane-keeping assist control for maintaining the traveling lane of a vehicle on a target traveling lane. When the steering work rate calculated by adding the product of the steering speed and the steering torque and the product of the steering angle and the differential value of the steering torque exceeds a predetermined value, the control amount by the lane-keeping assist control is made smaller than when the steering work rate is less than the predetermined value.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the technique described in Patent Document 1, when there is a sharp curve ahead of the vehicle, it may be difficult to continue the lane-keeping assist control without changing the control amount in advance.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a driving assistance device that can appropriately execute lane maintenance support control even when traveling on a sharp curve.

Means for Solving the Problems

[0006] The driver assistance device described herein assists the driver in operating a vehicle. The driver assistance device comprises a recognition sensor, a steering actuator, and an electronic control unit. The recognition sensor recognizes the situation in front of the vehicle. The steering actuator steers the vehicle. The electronic control unit controls the steering actuator to suppress lane departure of the vehicle from the driving lane. The electronic control unit uses the recognition sensor to recognize a curve sign to alert the driver to a curve ahead of the vehicle, and when a curve sign is recognized, it increases the amount of steering assist from the steering actuator to suppress lane departure while passing through the curve compared to when passing through the curve without recognizing the curve sign. [Effects of the Invention]

[0007] According to this disclosure, even when driving on a sharp curve, lane keeping assist control can be appropriately performed using curve signs recognized by recognition sensors. [Brief explanation of the drawing]

[0008] [Figure 1] This diagram schematically shows an example of the configuration of a vehicle equipped with a driver assistance device according to an embodiment. [Figure 2] This diagram illustrates the challenges of lane keeping assist control, as well as the first and second specific examples. [Figure 3] Figure 1 is a flowchart showing the processing of the sign determination unit. [Figure 4] Figure 1 is a flowchart showing the processing of the travel path calculation unit. [Figure 5] Figure 1 is a flowchart showing the processing of the assist amount calculation unit. [Figure 6] This is a diagram showing curve markers S1 to S3. [Modes for carrying out the invention]

[0009] 1. Example of vehicle configuration Figure 1 is a schematic diagram showing an example of the configuration of a vehicle 1 equipped with a driver assistance device according to an embodiment.

[0010] Vehicle 1 is equipped with a driver assistance electronic control unit (driver assistance ECU) 10. The driver assistance ECU (or simply ECU) 10 performs driver assistance control to support the driver's operation of vehicle 1. The ECU 10 includes a processing circuit 11 and a memory 12. The processing circuit 11 executes various processes related to driver assistance for vehicle 1. The memory 12 stores various information necessary for the processing by the processing circuit 11. Various processes by the processing circuit 11 are realized by the processing circuit 11 executing various computer programs. Various computer programs are stored in the memory 12 or recorded on a computer-readable recording medium. Note that the ECU 10 may be configured by combining multiple ECUs.

[0011] Vehicle 1 is also equipped with sensors 20. Sensors 20 include, for example, a camera 21, a vehicle speed sensor 22, and a steering angle sensor 23. The camera 21 is located at the front of Vehicle 1 and recognizes the situation in front of Vehicle 1. The “recognition sensor” in this disclosure includes, for example, a camera 21, a sensor that can be used for sign recognition by the ECU 10. The vehicle speed sensor 22 detects the speed of Vehicle 1. The steering angle sensor 23 detects the steering angle of Vehicle 1.

[0012] Vehicle 1 also includes a steering actuator 30 and an EPS-ECU 31. The steering actuator 30 generates a force to steer the wheels of vehicle 1 (for example, the front wheels). The steering actuator 30 can assist the driver in steering, and can also steer the wheels independently of the driver. As an example, the steering actuator 30 is a steering assist motor of an electric power steering system (EPS). The steering actuator 30 is controlled, for example, by an EPS-ECU 31 included in the EPS. Control of the steering actuator 30 by the EPS-ECU 31 also includes control based on commands from the driver assistance ECU 10 to the EPS-ECU 31.

[0013] Furthermore, Vehicle 1 is equipped with a brake ECU 40, an instrument panel 50, and a navigation device 60. The brake ECU 40 controls the brake actuator that generates the braking force of Vehicle 1. The control of the brake actuator by the brake ECU 40 also includes control based on commands from the driver assistance ECU 10 to the brake ECU 40. The instrument panel 50 is located inside the cabin of Vehicle 1 and is an example of a display device that shows information to the driver. The navigation device 60 is configured to communicate with external systems via a wireless communication network and can acquire various information such as road information and vehicle location information from external systems.

[0014] In the example of vehicle 1 having the above-described configuration, the "driving assistance device" according to this disclosure comprises a driving assistance ECU 10, a camera 21, and a steering actuator 30.

[0015] 2. Lane keeping assist control The driver assistance control of vehicle 1, performed by the driver assistance ECU 10, includes "lane keeping assist control." In the following description, lane keeping assist control will be referred to as LTA (Lane Tracing Assist). LTA includes controlling the steering actuator 30 to suppress vehicle 1 from deviating from its driving lane (lane departure).

[0016] 2-1.Basic configuration When LTA is requested by the driver through the operation of a predetermined control device, the driver assistance ECU 10 executes LTA. In LTA, the ECU 10 assists the driver's steering operation by applying steering torque to the steering mechanism so that the position of vehicle 1 (the vehicle itself) is maintained near the target driving line TL within the driving lane L (see Figure 1). The target driving line TL is, for example, the lane center line CL, but may be offset in the lane width direction by a predetermined distance from the lane center line CL.

[0017] The ECU 10 calculates the target steering angle δt of the LTA at a predetermined calculation cycle based on, for example, the curvature R, the yaw angle θy, and the lateral deviation Dy. The curvature R is the curvature R of the curve of the lane center line CL (see FIG. 2(B) described later). The yaw angle θy is the angle formed between the direction of the lane center line CL and the direction in which the vehicle 1 is facing. The lateral deviation Dy is the distance in the lane width direction between the center of gravity point P of the vehicle 1 and the lane center line CL. The ECU 10 can acquire information on the left and right white lines WL that demarcate the traveling lane L of the vehicle 1, the lane center line CL, the curvature R, the yaw angle θy, and the lateral deviation Dy based on the image information of the camera 21. Note that for the yaw angle θy and the lateral deviation Dy, the left - right direction with respect to the lane center line CL is specified by the sign (positive or negative). Also, for the curvature R, the turning direction (right or left) of the curve is specified by the sign (positive or negative).

[0018] The calculation formula for the target steering angle δt includes, for example, the product of the curvature R and the control gain (the first term), the product of the yaw angle θy and the control gain (the second term), and the product of the lateral deviation Dy and the control gain (the third term). The first term is a steering angle component that is determined according to the curvature R of the road and acts in a feed - forward manner. The second term is a steering angle component that acts in a feedback manner so as to reduce the yaw angle θy (that is, so as to reduce the deviation of the direction of the vehicle 1 with respect to the lane center line CL). That is, it is a steering angle component calculated by feedback control with the target value of the yaw angle θy set to zero. The third term is a steering angle component that acts in a feedback manner so as to reduce the lateral deviation Dy, which is the deviation (position deviation) of the vehicle 1 in the lane width direction with respect to the lane center line CL. That is, it is a steering angle component calculated by feedback control with the target value of the lateral deviation Dy set to zero.

[0019] According to the LTA, for example, when the center line CL of the lane curves to the left, when the vehicle 1 has a lateral displacement to the right with respect to the center line CL of the lane, or when the vehicle 1 is facing to the right with respect to the center line CL of the lane, the target steering angle δt is calculated so that the target steering angle δ becomes a steering angle in the left direction. The target steering angle δt calculated in this way, or the target steering torque for obtaining the target steering angle δt, corresponds to the steering amount by the LTA. And the steering amount by the LTA corresponds to an example of the "steering assist amount" according to the present disclosure.

[0020] 2-2. Correction of Steering Assist Amount Using Curve Sign FIG. 2(A) is a diagram for explaining the problems of lane keeping support control. FIG. 2(A) illustrates a driving scene in which a curve C1 exists in front of the vehicle 100 on a traveling road such as a mountain road. The curve C1 is a sharp curve. For this reason, a curve sign (warning sign) S1 for prompting the driver's attention with respect to the curve C1 is installed on the side of the road in front of the vehicle 100 before entering the curve C1.

[0021] In the vehicle 100 according to the comparative example shown in FIG. 2(A), different from the present embodiment, an LTA that does not utilize the recognition of the curve sign S1 of the curve C1 by the camera is executed. As a result, although a sharp curve C1 where the curve sign S1 is installed is in front of the vehicle 100, the steering assist amount of the LTA is not appropriately changed in advance considering the existence of the curve C1, and the vehicle 100 enters the curve C1. As a result, in this comparative example, the LTA cannot be continued during the passage of the curve C1, and the LTA has ended. Additionally, from the image information of the camera, the curvature R of the curve C1 can be obtained before entering the curve C1. However, for example, when the curve C1 is a curve that turns significantly, it may be difficult to grasp the entire curvature R of the curve C1 before entering the curve C1 only with the above traveling road information.

[0022] In light of the above-mentioned challenges, the driver assistance ECU 10 performs a "recognition process" to recognize the curve sign S using the camera 21. Specifically, in this recognition process, the ECU 10 recognizes the curve sign S by analyzing the image from the camera 21, for example, using an image recognition AI (Artificial Intelligence) that has been generated in advance by machine learning.

[0023] Then, when the ECU 10 recognizes a curve sign S, it performs an "assistance increase process" that increases the amount of steering assist AS of the steering actuator 30, which is used to suppress lane departure while passing through a curve, compared to when passing through curve C without recognizing the curve sign S.

[0024] 2-2-1. First Specific Example Figure 2(B) is a diagram illustrating a first specific example of lane keeping support control according to the embodiment. In the first specific example, the target steering angle δt, calculated as "the amount of steering in the direction of turning the wheels toward the inside of curve C1," corresponds to the steering assist amount AS in the assist increase process described above.

[0025] In the first specific example, if there is a sharp curve C1 in front of vehicle 1, the curve marker S1 is recognized by the recognition process as shown in Figure 2(B). Then, the assist increase process calculates the target steering angle δt to be a larger value than when the curve marker S1 is not recognized (Figure 2(A)). As a result, the amount of steering assist AS when vehicle 1 passes through curve C1 is increased compared to when passing through curve C1 without the recognition of the curve marker S1.

[0026] According to the first specific example, it is possible to maintain LTA appropriately even when driving on a sharp curve C1.

[0027] 2-2-2. Second specific example Figure 2(C) is a diagram illustrating a second specific example of lane keeping support control according to the embodiment. In the second specific example, the "offset amount OS for offsetting the driving position of vehicle 1 in the lane width direction on the driving lane L to the inside of curve C1 relative to the center of the driving lane L" corresponds to the steering assist amount AS in the assist increase process described above. The offset amount OS is determined by the target driving line TL.

[0028] In the second specific example, if a sharp curve C1 exists in front of vehicle 1, a curve marker S1 is recognized by the recognition process as shown in Figure 2(C). The increase in steering assist amount AS due to the assist increase process in the second specific example is achieved by setting an offset amount OS1 that is significantly offset to the inside of curve C1 compared to the offset amount OS0 identified by the target driving line TL0 when the curve marker S1 is not recognized, prior to entering curve C1. In the example shown in Figure 2(C), the offset amount OS0 of the target driving line TL0 is zero. That is, the target driving line TL0 is equal to the lane center line CL. However, the target driving line TL0 may be different from the lane center line CL.

[0029] According to the second specific example, by increasing the offset amount OS prior to entering curve C1, it becomes easier to maintain LTA even if the lateral deviation Dy expands towards the outside of curve C1 while passing through the sharp curve C1.

[0030] As explained using the first and second specific examples, the driving assistance device according to this embodiment can appropriately perform lane keeping assistance control using the curve marker S recognized by the camera 21, even when driving on a sharp curve.

[0031] Furthermore, this method, which utilizes the recognition information of curve markers S, has the following advantages compared to the method that utilizes road information from the navigation device 60. Specifically, for example, when a new curve marker S is installed, it takes time for the information of the newly installed curve marker S to be reflected in the road information of the navigation device 60. In contrast, this method allows for the recognition of the newly installed curve marker S and its reflection in the LTA without such a delay. Also, in areas with poor communication environments, such as mountainous regions, it may not be possible to use the information from the navigation device 60. This method avoids such problems.

[0032] Furthermore, the steering assist amount AS may be both (or a combination of) the steering amount (target steering angle δt) and the offset amount OS.

[0033] 2-2-3. Processing Flow To perform LTA-related processing, the driver assistance ECU 10 includes, as functional blocks, a sign determination unit 13, a driving path calculation unit 14, and an assist amount calculation unit 15 (see Figure 1). These functional blocks are realized through the cooperation of a processing circuit 11 that executes a computer program and a memory 12.

[0034] Figure 3 is a flowchart showing the processing of the sign determination unit 13 shown in Figure 1. The processing in this flowchart and the flowcharts shown in Figures 4 and 5, which will be described later, are executed in parallel by the ECU 10 (processing circuit 11). Here, the first specific example described above, in which the steering assist amount AS is the target steering angle δt as "the amount of steering in the direction of turning the wheels toward the inside of the curve C1", will be mainly explained.

[0035] The sign determination unit 13 determines and classifies what kind of sign the sign recognized using the camera 21 is.

[0036] Specifically, in step S100, it is determined whether or not a sign has been detected based on the image information from camera 21. If no sign is detected, the process in step S100 is repeated. On the other hand, if a sign is detected, the process proceeds to step S102.

[0037] In step S102, it is determined whether the detected sign is a curve sign S. If the detected sign is not a curve sign S, the process returns to step S100. On the other hand, if the detected sign is a curve sign S, the process proceeds to step S104. In addition, the processes in steps S100 and S102 correspond to the "recognition process" described above.

[0038] In step S104, a process is executed to display an icon representing the curve marker S on the meter panel 50. Specifically, the memory 12 of the ECU 10 stores data for the icon representing the curve marker S. The process in step S104 includes reading the data for the icon representing the curve marker S from the memory 12. The icon displayed on the meter panel 50 is, for example, a specific icon. Furthermore, in step S104, a process is also executed to send "curve marker information Ic" to the assist amount calculation unit 15. The curve marker information Ic includes at least information indicating that the curve marker S has been recognized by the marker determination unit 13.

[0039] Furthermore, as illustrated in Figures 6(A) to 6(C) described later, there are various types of curve markers S. Therefore, the process in step S104 may include, for example, a process to identify the type of curve marker S using an image recognition AI. This process of identifying the type of curve marker S also corresponds to the "recognition process" described above. The memory 12 may store data of icons representing various types of curve markers S. The process in step S104 may include a process of reading the icon data of the identified type of curve marker S from the memory 12 and displaying it on the meter panel 50.

[0040] Furthermore, the curve marking information Ic transmitted from the marking determination unit 13 to the assist amount calculation unit 15 may include marking type information Ic1 indicating the type of curve marking S identified as described above. Specifically, the marking type information Ic1 may include, for example, information on the total angle a, which will be described in detail later with Figures 6(A) to 6(C), for each type of curve marking S. In addition, the marking type information Ic1 may include, for example, information on the curving direction, indicating whether the curve marking S is a curve that curves only to the left or right, or a curve that curves to both the left and right, for each type of curve marking S.

[0041] Figure 4 is a flowchart showing the processing of the road path calculation unit 14 shown in Figure 1. The road path calculation unit 14 uses road path information based on the image from the camera 21 to calculate the curvature R of the road in front of the vehicle 1. The road path information includes, for example, the left and right white lines WL that demarcate the road lane L, and the lane center line CL. As already explained, the curvature R is the curvature of the curve of the lane center line CL of the road lane L of the vehicle 1.

[0042] Specifically, in step S200, road information is acquired from camera 21. Then, in step S202, it is determined whether or not there is road information for the navigation device 60 (i.e., whether or not the road information has been received by ECU 10).

[0043] As a result, if the navigation device 60 also has road information, the curvature R is calculated from the road information of both the camera 21 and the navigation device 60 (step S204). On the other hand, if the navigation device 60 does not have road information, the curvature R is calculated only from the road information of the camera 21 (step S206). These calculations of curvature R can be performed using known methods. The curvature R calculated in step S204 or S206 is transmitted from the road calculation unit 14 to the assist amount calculation unit 15.

[0044] Figure 5 is a flowchart showing the processing of the assist amount calculation unit 15 shown in Figure 1. When the sign determination unit 13 recognizes that the sign is a curve sign S, the assist amount calculation unit 15 increases the steering assist amount AS to a value greater than the normal value AS0 based on the curvature R calculated by the driving path calculation unit 14.

[0045] Specifically, in step S300, curve sign information Ic transmitted from the sign determination unit 13 is acquired. Next, in step S302, the curvature R transmitted from the road calculation unit 14 is acquired.

[0046] Next, in step S304, it is determined whether or not a curve marker S exists (i.e., whether or not the curve marker S has been recognized) based on the curve marker information Ic. If the curve marker S does not exist, the process proceeds to step S306.

[0047] In step S306, the normal value AS0 of the steering assist amount AS of the LTA is calculated. Specifically, in the first example above, the normal value δt0 of the target steering angle δt corresponding to the normal value AS0 is calculated based on the curvature R, lateral deviation Dy, and yaw angle θy, for example, by the method described in Section 2-1 of the basic configuration of the LTA. In the second example above, where the steering assist amount AS is the offset amount OS, the normal value OS0 of the offset amount OS corresponding to the normal value AS0 is determined based on the target driving line TL0. For example, if the target driving line TL0 is equal to the lane center line CL, then the offset amount OS0, which is zero, corresponds to the normal value AS0.

[0048] On the other hand, if a curve marker S exists (step S304; Yes), the process proceeds to step S308. In step S308, the corrected steering assist amount AS1 using the curve marker S is calculated. Specifically, the normal value AS0 is calculated in the same way as in step S306, and then the steering assist amount AS1 is calculated by multiplying the normal value AS0 by the correction coefficient K. In the second specific example where the steering assist amount AS is the offset amount OS, the offset amount OS1 corresponding to the corrected steering assist amount AS1 is calculated by multiplying the offset amount OS0 corresponding to the normal value AS0 by the correction coefficient K.

[0049] (Examples of various settings for the correction coefficient K) The correction factor K is a positive value and can be set using various methods, such as the following:

[0050] The first example setting described is a first specific case in which the target steering angle δt is used as the steering assist amount AS. Under conditions where the vehicle speed can be considered constant, the lateral acceleration Gy of vehicle 1 during a turn can be determined by the steering angle δ. In this example setting, the relationship between vehicle speed, steering angle δ, and lateral acceleration Gy is used. Specifically, the correction coefficient K is determined such that, under the current vehicle speed, the target steering angle δt1 corresponding to the corrected steering assist amount AS1 is a steering angle value that produces a lateral acceleration Gy1 (e.g., 0.3G) that is a predetermined amount higher than the normal lateral acceleration Gy0 (e.g., 0.2G). The normal lateral acceleration Gy0 is the value of the lateral acceleration Gy that occurs when steering is performed with the normal value δt0.

[0051] Alternatively, the correction factor K may be a fixed value set in advance, for example.

[0052] Furthermore, in the example where the curve sign information Ic includes sign type information Ic1, the correction coefficient K may be set using, for example, the following method. Figures 6(A) to 6(C) show specific examples of curve signs S1 to S3, respectively. The curve mark M1 in curve sign S1 illustrates a curve that turns only to one side (for example, left). The curve mark M2 in curve sign S2 illustrates a curve that turns only to one side (for example, right), or more specifically, a curve that curves sharply to the right. The curve mark M3 in curve sign S3 illustrates a curve that turns to both sides, or more specifically, a curve that curves sharply to both sides.

[0053] In Figure 6(A), angle a1 represents the angle of the arc included in curve mark M1 (= total angle). In Figure 6(B), angle a2 represents the angle of the arc included in curve mark M2 (= total angle). In Figure 6(C), angles a3_1 and a3_2 represent the angles of the two arcs included in curve mark M2, and the sum of angles a3_1 and a3_2 is the total angle a3. As can be seen by comparing each figure, the total angle a of the arcs is largest for curve mark M3, followed by curve marks M2 and M1. In other words, the total angle a represents the degree of curvature of the curve represented by the curve mark M. This degree of curvature is largest for curve mark M3, followed by curve marks M2 and M1.

[0054] The correction coefficient K may be set as follows, taking into consideration the type of curve marker S. That is, the correction coefficient K may be set to be larger when the total angle a is greater than a predetermined threshold (e.g., a2 and a3) compared with the case when the total angle a is less than or equal to the threshold (e.g., a1). Alternatively, the correction coefficient K may be set to be larger the larger the total angle a is. According to these setting examples, the corrected steering assist amount AS1 will be larger when the total angle a is large compared with the case when the total angle a is small. This makes it possible to appropriately determine the steering assist amount AS1 according to the degree of curving around the curve C using the recognition result of the curve marker S. As a result, LTA can be continued more appropriately compared to the example in which this point is not considered. In addition, the total angle a can be obtained, for example, by reading the information of the total angle a for the recognized curve marker S from the marker type information Ic1 in memory 12. Alternatively, the total angle a may be obtained directly, for example, by analyzing the image of the curve mark M of the curve marker S obtained by camera 21.

[0055] Furthermore, the correction coefficient K may be set as follows, taking into consideration the type of curve marking S. That is, when the curve mark M indicates a curve that turns in both directions (e.g., M3), it may be set to be larger than when the curve mark M indicates a curve that turns in only one direction (e.g., M1 and M2). As a result, the corrected steering assist amount AS1 will be larger when the curve mark M indicates a curve that turns in both directions compared to when the curve mark M indicates a curve that turns in only one direction. According to this example setting, the steering assist amount AS1 can be appropriately determined depending on whether the curve C is a continuous curve or not (more specifically, depending on whether the curve C is a series of sharp curves that require a change in steering direction) by utilizing the recognition result of the curve marking S. As a result, the LTA can be continued more appropriately compared to the example where this point is not considered. In addition, the turning direction information of the curve C can be obtained, for example, by reading the turning direction information for the recognized curve marking S from the marking type information Ic1 in memory 12. Alternatively, the direction of the curve may be directly obtained, for example, by analyzing the image of the curve mark M of the curve sign S obtained by the camera 21.

[0056] In Figure 5, in step S310 following step S306 or S308, the steering assist amount AS (i.e., AS0 or AS1) is transmitted to the EPS-ECU 31. As a result, the EPS-ECU 31 controls the steering actuator 30 to realize the steering assist amount AS. The driver assistance control of the vehicle 1 may also include, for example, automatic acceleration / deceleration control (e.g., adaptive cruise control) that automatically accelerates and decelerates the vehicle 1, along with the LTA. When automatic acceleration / deceleration control is performed along with the LTA, the information on the steering assist amount AS may also be transmitted to the brake ECU 40 for the control of deceleration of the vehicle 1. [Explanation of Symbols]

[0057] 1 Vehicle, 10 Driving assistance ECU, 11 Processing circuit, 12 Memory, 13 Sign recognition unit, 14 Driving path calculation unit, 15 Assist amount calculation unit, 21 Camera, 30 Steering actuator

Claims

1. A driver assistance device that assists the driver in operating a vehicle, A recognition sensor that recognizes the situation in front of the vehicle, A steering actuator for steering the vehicle, An electronic control unit that controls the steering actuator to suppress lane departure of the vehicle from the driving lane, Equipped with, The aforementioned electronic control unit is Using the aforementioned recognition sensor, a curve sign is recognized to alert the driver to a curve ahead of the vehicle. When the curve sign is recognized, the amount of steering assist from the steering actuator to suppress lane departure while passing through the curve is increased compared to when passing through the curve without recognizing the curve sign. If the sum of the angles of the arcs included in the curve mark in the recognized curve marker is large, the amount of steering assist is increased compared to when the sum of angles is small. A driving assistance device characterized by the following features.

2. A driver assistance device that assists the driver in operating a vehicle, A recognition sensor that recognizes the situation in front of the vehicle, A steering actuator for steering the vehicle, An electronic control unit that controls the steering actuator to suppress lane departure of the vehicle from the driving lane, Equipped with, The aforementioned electronic control unit is Using the aforementioned recognition sensor, a curve sign is recognized to alert the driver to a curve ahead of the vehicle. When the curve sign is recognized, the amount of steering assist from the steering actuator to suppress lane departure while passing through the curve is increased compared to when passing through the curve without recognizing the curve sign. When the curve mark in the recognized curve marker indicates a curve that turns to both the left and the right, the amount of steering assist is increased compared to when the curve mark indicates a curve that turns to only one side. A driving assistance device characterized by the following features.

3. A driving support device according to claim 1 or 2, The steering assist amount is at least one of the following: a steering amount in the direction of turning the wheels toward the inside of the curve, and an offset amount that offsets the vehicle's position in the lane width direction on the driving lane toward the inside of the curve relative to the center of the driving lane. A driving assistance device characterized by the following features.

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