JP7569014B2 - Vehicle Driving Assistance Device - Google Patents

Description

The present invention relates to a vehicle driving assistance device.

There is known a vehicle driving assistance device that provides steering assistance to assist the driver of the vehicle in steering the vehicle by automatically steering the vehicle so that the vehicle travels along the center of the lane. This vehicle driving assistance device sets a line that passes through the center of the lane as a target driving line, and automatically steers the vehicle so that the vehicle travels along the target driving line.

When a vehicle travels near structures such as guardrails or buildings on the side of the road, the driver may feel pressured by the structures or may feel the risk of contact between the vehicle and the structures. When the driver feels pressured by the structures or feels the risk of contact between the vehicle and the structures, the driver may drive the vehicle away from the structures. However, when the above-mentioned steering assistance is performed, even if the driver steers the vehicle away from the structures, the steering assistance steers the vehicle closer to the structures. Therefore, a vehicle driving assistance device is known that performs steering assistance by offsetting (shifting) the target driving line in the steering assistance in a direction away from the structures when structures are present on the side of the road (see, for example, Patent Document 1).

JP 2009-230627 A

In conventional vehicle driving assistance devices, when a structure is present on the side of the road, steering assistance is always performed by offsetting the target driving line. However, depending on the structure, even if steering assistance is performed without offsetting the target driving line, the driver may not feel a sense of pressure from the structure or a risk of contact between the structure and the vehicle. In such cases, if steering assistance is performed by offsetting the target driving line, the driver may feel that the vehicle is traveling too far away from the structure, which may cause discomfort.

The object of the present invention is to provide a vehicle driving assistance device that can provide steering assistance to the driver with as little discomfort as possible.

One of the vehicle driving assistance devices according to the present invention executes steering assistance control to control the steering force applied to the host vehicle so that the host vehicle travels on a target driving line. When a structure is detected on the side of the host vehicle and the distance from the structure to the host vehicle's driving lane is longer than a predetermined distance threshold, or when the height of the structure is lower than a predetermined height threshold, the vehicle driving assistance device sets the target driving line based on the width of the host vehicle's driving lane. On the other hand, when a structure is detected on the side of the host vehicle and the distance from the structure to the host vehicle's driving lane is equal to or less than the predetermined distance threshold and the height of the structure is equal to or greater than the predetermined height threshold, the vehicle driving assistance device is configured to set the target driving line as a line that is shifted away from the structure from the target driving line set based on the width of the host vehicle's driving lane.

Generally, when a driver is traveling next to a tall structure such as a building, the driver tends to feel a sense of pressure from the structure and a risk of collision between the vehicle and the structure. However, even if the vehicle is traveling next to such a tall structure, if the structure is located away from the vehicle, the driver may not feel a sense of pressure from the structure or a risk of collision between the vehicle and the structure. In such a case, the steering assist control may shift (offset) the target driving line away from the structure, and the driver may feel uncomfortable when the vehicle travels on the target driving line.

In addition, if the structure is a low-height structure such as a guardrail, the driver tends not to feel a sense of pressure from the structure or a risk of contact between the vehicle and the structure even when the vehicle is traveling close to the structure. In such a case, if the steering assist control shifts (offsets) the target driving line away from the structure and the vehicle travels on the target driving line, the driver may feel uncomfortable.

In this way, whether or not the driver feels uncomfortable depends on the combination of the distance between the structure and the vehicle and the height of the structure.

According to the present invention, if the distance from the structure to the vehicle's driving lane is longer than a predetermined distance threshold, or if the height of the structure is lower than a predetermined height threshold, the target driving line set based on the width of the vehicle's driving lane is used as the target driving line and steering assist control is executed. In other words, if it is determined that the driver will not feel a sense of pressure from the structure or a risk of contact between the structure and the vehicle even if the vehicle is driving close to the structure, steering assist control is executed without shifting (offsetting) the target driving line away from the structure.

On the other hand, if the distance from the structure to the vehicle's driving lane is less than or equal to a predetermined distance threshold and the height of the structure is greater than or equal to a predetermined height threshold, steering assist control is executed by shifting the target driving line, set based on the width of the vehicle's driving lane, away from the structure, as the target driving line. In other words, if it is determined that the driver feels a sense of pressure from the structure or is in danger of contact between the structure and the vehicle when the vehicle is driving close to the structure, steering assist control is executed by shifting (offsetting) the target driving line away from the structure.

This allows steering assistance control to be performed without causing the driver any discomfort.

The vehicle driving assistance device according to the present invention may be configured to determine that the height of the structure is lower than a predetermined height threshold if the elevation angle of the upper end of the structure from the vehicle's driving lane is smaller than a predetermined elevation angle threshold, and to determine that the height of the structure is equal to or greater than the predetermined height threshold if the elevation angle is equal to or greater than the predetermined elevation angle threshold.

Even if a structure on the side of the vehicle is tall, the driver tends not to feel a sense of pressure from the structure or a risk of contact between the vehicle and the structure if the structure is located away from the vehicle's lane. Conversely, even if the structure is short, the driver tends to feel a sense of pressure from the structure or a risk of contact between the vehicle and the structure if the structure is close to the vehicle's lane.

When the heights of the structures are the same, the shorter the distance between the structure and the vehicle's lane, the larger the elevation angle of the structure's top end from the vehicle's lane. When the distance between the structure and the vehicle's lane is the same, the higher the structure's height, the larger the elevation angle of the structure's top end from the vehicle's lane.

Therefore, whether or not the driver feels a sense of pressure from the structure or senses the risk of contact between the structure and the vehicle depends on the elevation angle of the structure's top edge from the vehicle's lane.

According to the present invention, if the elevation angle of the upper end of the structure from the vehicle's driving lane is smaller than a predetermined elevation angle threshold, the height of the structure is determined to be lower than the predetermined height threshold. On the other hand, if the elevation angle of the upper end of the structure from the vehicle's driving lane is equal to or greater than the predetermined elevation angle threshold, the height of the structure is determined to be equal to or greater than the predetermined height threshold. This makes it possible to more appropriately determine whether the driver feels a sense of pressure from the structure or is at risk of contact between the structure and the vehicle.

Another vehicle driving assistance device according to the present invention executes steering assistance control for controlling a steering force applied to the host vehicle so that the host vehicle travels on a target driving line. The vehicle driving assistance device is configured to set the target driving line based on the width of the host vehicle's driving lane when a structure is detected to the side of the host vehicle and the elevation angle of the upper end of the structure from the host vehicle's driving lane is smaller than a predetermined elevation angle threshold. On the other hand, the vehicle driving assistance device is configured to set the target driving line as a line that is shifted away from the structure from the target driving line set based on the width of the host vehicle's driving lane when a structure is detected to the side of the host vehicle and the elevation angle is equal to or greater than the predetermined elevation angle threshold.

As mentioned above, whether the driver feels uncomfortable depends on the combination of the distance between the structure and the vehicle and the height of the structure. Also, whether the driver feels a sense of pressure from the structure or is in danger of contacting the structure with the vehicle depends on the elevation angle of the top of the structure from the vehicle's lane.

According to the present invention, if the elevation angle of the upper end of the structure from the vehicle's driving lane is smaller than a predetermined elevation angle threshold, steering assist control is executed using the target driving line set based on the width of the vehicle's driving lane as the target driving line. In other words, even if the vehicle is driving close to a structure, if it is determined that the driver will not feel a sense of pressure from the structure or a risk of contact between the structure and the vehicle, steering assist control is executed without shifting (offsetting) the target driving line away from the structure.

On the other hand, if the elevation angle of the upper end of the structure from the vehicle's lane is equal to or greater than a predetermined elevation angle threshold, steering assist control is executed by using a line that is a target driving line that is shifted away from the structure from the target driving line set based on the width of the vehicle's lane. In other words, if it is determined that the driver feels a sense of pressure from the structure or is in danger of contact between the vehicle and the structure when the vehicle is driving close to the structure, steering assist control is executed by shifting (offsetting) the target driving line away from the structure.

This allows steering assistance control to be performed without causing the driver any discomfort.

The steering assist control is, for example, a control that controls the steering force applied to the host vehicle so that the host vehicle travels on the target driving line when the host vehicle travels off the target driving line due to a steering operation by the driver of the host vehicle.

In cases where steering assist control is a control that assists the driver of the vehicle in steering the vehicle so that the vehicle travels along a target driving line, if the driver does not think that it is necessary to drive the vehicle very far from the structure, and steering assist control is executed such that the target driving line is shifted (offset) away from the structure, the driver will feel a greater sense of discomfort.

According to the present invention, in the case where the steering assist control is a control for controlling the steering force applied to the vehicle so that the vehicle travels on the target driving line when the vehicle deviates from the target driving line due to the driver's steering operation, when it is presumed that the driver does not think it is necessary to travel the vehicle very far away from the target driving line, the steering assist control is executed without shifting (offsetting) the target driving line, which is set based on the width of the lane in which the vehicle is traveling, away from the structure.

This allows steering assistance control to be performed without causing the driver any significant discomfort.

The components of the present invention are not limited to the embodiments of the present invention described below with reference to the drawings. Other objects, other features and associated advantages of the present invention will be easily understood from the description of the embodiments of the present invention.

FIG. 1 is a diagram showing a vehicle driving assistance device according to an embodiment of the present invention and a vehicle (host vehicle) on which the device is mounted. (A) of Figure 2 is a diagram showing a situation in which the steering force is controlled by steering assist control so that the vehicle travels along the target driving line, (B) of Figure 2 is a diagram showing a situation in which the steering force is controlled by steering assist control so that the vehicle, which has deviated to the left of the target driving line, moves to the right and travels along the target driving line, and (C) of Figure 2 is a diagram showing a situation in which the steering force is controlled by steering assist control so that the vehicle, which has deviated to the right of the target driving line, moves to the left and travels along the target driving line. FIG. 3A is a diagram showing a scene where a guard rail is present on the left side of the host vehicle, and FIG. 3B is a diagram showing a scene where a building is present on the left side of the host vehicle. FIG. 4A is a diagram showing a situation in which the vehicle is traveling on a target driving line shifted to the right when a guardrail is present on the left side of the vehicle, and FIG. 4B is a diagram showing a situation in which the vehicle is traveling on a target driving line shifted to the right when a building is present on the left side of the vehicle. FIG. 5 is a diagram showing the structure distance and the structure height. FIG. 6 is a diagram showing the structure distance, the structure height, and the structure elevation angle. FIG. 7 is a flowchart showing a routine executed by the vehicle driving assistance device according to the embodiment of the present invention. FIG. 8 is a flowchart showing a routine executed by the vehicle driving assistance device according to the embodiment of the present invention. FIG. 9 is a flowchart showing a routine executed by the vehicle driving assistance device according to the embodiment of the present invention.

The vehicle driving assistance device according to the embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the vehicle driving assistance device 10 according to the embodiment of the present invention is mounted on the host vehicle 100. In the following description, the driver of the host vehicle 100 will be referred to as "driver DR."

<ECU>
The vehicle driving assistance device 10 includes an ECU 90. ECU is an abbreviation for electronic control unit. The ECU 90 includes a microcomputer as a main component. The microcomputer includes a CPU, ROM, RAM, non-volatile memory, and an interface. The CPU executes instructions, programs, or routines stored in the ROM to realize various functions.

<Drive device, etc.>
In addition, the host vehicle 100 is equipped with a drive device 21, a braking device 22, and a steering device 23.

<Drive unit>
The drive device 21 is a device that outputs a drive torque TQd (drive force) that is applied to the host vehicle 100 to make the host vehicle 100 travel, and is, for example, an internal combustion engine, a motor, etc. The drive device 21 is electrically connected to the ECU 90. The ECU 90 can control the operation of the drive device 21 to control the drive torque TQd that is output from the drive device 21.

<Braking device>
The braking device 22 is a device, such as a brake device, that outputs a braking torque TQb (braking force) that is applied to the host vehicle 100 in order to brake the host vehicle 100. The braking device 22 is electrically connected to the ECU 90. The ECU 90 can control the braking torque TQb output from the braking device 22 by controlling the operation of the braking device 22.

<Steering device>
The steering device 23 is a device that outputs a steering torque TQs (steering force) that is applied to the host vehicle 100 in order to steer the host vehicle 100, and is, for example, a power steering device. The steering device 23 is electrically connected to the ECU 90. The ECU 90 can control the steering torque TQs output from the steering device 23 by controlling the operation of the steering device 23.

<Sensors, etc.>
Furthermore, the vehicle 100 is equipped with an accelerator pedal 31, an accelerator pedal operation amount sensor 32, a brake pedal 33, a brake pedal operation amount 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 41, a surrounding information detection device 50 and a driving assistance switch 61.

<Accelerator pedal operation amount sensor>
The accelerator pedal operation amount sensor 32 is a sensor that detects the operation amount of the accelerator pedal 31, and is electrically connected to the ECU 90. The accelerator pedal operation amount sensor 32 transmits information on the detected operation amount of the accelerator pedal 31 to the ECU 90. The ECU 90 obtains the operation amount of the accelerator pedal 31 as the accelerator pedal operation amount AP based on the information. The ECU 90 obtains a required drive torque TQd_req (required drive force) by calculation based on the accelerator pedal operation amount AP and the vehicle speed (host vehicle speed V) of the host vehicle 100. The required drive torque TQd_req is a drive torque TQd that is required to be output from the drive device 21. The ECU 90 controls the operation of the drive device 21 so that the required drive torque TQd_req is output.

<Brake pedal operation amount sensor>
The brake pedal operation amount sensor 34 is a sensor that detects the operation amount of the brake pedal 33, and is electrically connected to the ECU 90. The brake pedal operation amount sensor 34 transmits information on the detected operation amount of the brake pedal 33 to the ECU 90. The ECU 90 obtains the operation amount of the brake pedal 33 as a brake pedal operation amount BP based on the information. The ECU 90 obtains a required braking torque TQb_req (required braking force) by calculation based on the brake pedal operation amount BP. The required braking torque TQb_req is the braking torque TQb that is required to be output by the braking device 22. The ECU 90 controls the operation of the braking device 22 so that the required braking torque TQb_req is output.

<Steering angle sensor>
The steering angle sensor 37 is a sensor that detects the rotation angle of the steering shaft 36 with respect to the neutral position, and is electrically connected to the ECU 90. The steering angle sensor 37 transmits information on the detected rotation angle of the steering shaft 36 to the ECU 90. The ECU 90 obtains the rotation angle of the steering shaft 36 as a steering angle θs based on the information.

<Steering torque sensor>
The steering torque sensor 38 is a sensor that detects the torque input by the driver DR to the steering shaft 36 via the steering wheel 35, and is electrically connected to the ECU 90. The steering torque sensor 38 transmits information on the detected torque to the ECU 90. The ECU 90 acquires the torque input by the driver DR to the steering shaft 36 via the steering wheel 35 (driver input torque TQs_dr) based on the information.

<Vehicle speed detection device>
The vehicle speed detection device 41 is a device that detects the vehicle speed (host vehicle speed V) of the host vehicle 100, and is, for example, a wheel speed sensor. The vehicle speed detection device 41 is electrically connected to the ECU 90. The vehicle speed detection device 41 transmits information on the detected vehicle speed of the host vehicle 100 to the ECU 90. The ECU 90 obtains the host vehicle speed V based on the information.

The ECU 90 calculates and obtains the required steering torque TQs_req based on the steering angle θs, the driver input torque TQs_dr, and the vehicle speed V. The required steering torque TQs_req is the steering torque TQs that is requested to be output from the steering device 23. When the steering assist control described below is not being executed, the ECU 90 controls the operation of the steering device 23 so that the required steering torque TQs_req is output from the steering device 23.

<Peripheral information detection device>
The surrounding information detection device 50 is a device that detects information about the surroundings of the vehicle 100, and in this example, includes a radio wave sensor 51 and an image sensor 52. The radio wave sensor 51 is, for example, a radar sensor (such as a millimeter wave radar). The image sensor 52 is, for example, a camera. The surrounding information detection device 50 may also include a sonic sensor such as an ultrasonic sensor (clearance sonar) or an optical sensor such as a laser radar (LiDAR).

<Radio wave sensor>
The radio wave sensor 51 is electrically connected to the ECU 90. The radio wave sensor 51 transmits radio waves and receives radio waves (reflected waves) reflected by objects. The radio wave sensor 51 transmits information (detection results) related to the transmitted radio waves and received radio waves (reflected waves) to the ECU 90. In other words, the radio wave sensor 51 detects objects present in the vicinity of the vehicle 100 and transmits information (detection results) related to the detected objects to the ECU 90. The ECU 90 can obtain information (periphery detection information IS) related to objects present in the vicinity of the vehicle 100 based on the information (radio wave information).

<Image sensor>
The image sensor 52 is also electrically connected to the ECU 90. The image sensor 52 captures an image of the periphery of the vehicle 100 and transmits information related to the captured image to the ECU 90. The ECU 90 can obtain information (periphery detection information IS) related to the periphery of the vehicle 100 based on the image information.

For example, as shown in FIG. 2, when a structure ST such as a guard rail GR is present (see FIG. 2(A)), or when a structure ST such as a building BDG is present (see FIG. 2(B)), the ECU 90 detects such a structure ST based on the surrounding detection information IS.

As shown in FIG. 2, when there are marking lines LML and LMR on both sides of the vehicle 100, the ECU 90 recognizes the marking lines LML and LMR on the basis of the surrounding detection information IS, identifies the range of the vehicle's own lane LN on the basis of the recognized marking lines LML and LMR, and obtains the width WLN of the vehicle's own lane LN. The vehicle's own lane LN is the lane in which the vehicle 100 is traveling (the driving lane).

<Driving assistance switch>
The driving assist switch 61 is a switch for allowing the driver DR to select whether or not to execute steering assist control, which will be described later, and is electrically connected to the ECU 90. When the driving assist switch 61 is operated to an ON state, the ECU 90 determines that execution of steering assist control has been requested. On the other hand, when the driving assist switch 61 is operated to an OFF state, the ECU 90 determines that execution of operation assist control is no longer requested.

<Overview of operation of vehicle driving assistance device>
Next, an overview of the operation of the vehicle driving assistance device 10 will be described. In the following description, "left" refers to the left side in the traveling direction of the host vehicle 100, and "right" refers to the right side in the traveling direction of the host vehicle 100.

As shown in FIG. 2A, the vehicle driving assistance device 10 is configured to execute steering assistance control that performs steering assistance by controlling the steering force applied to the vehicle 100 so that the vehicle 100 travels along the target driving line Ltgt.

The vehicle driving assistance device 10 may be configured to execute steering assist control regardless of whether or not there is a request to execute steering assist control, but in this example, it is configured to execute steering assist control when there is a request to execute steering assist control.

In addition, the vehicle driving assistance device 10 may be configured to perform steering assistance control regardless of the operation (steering operation) of the steering wheel 35 by the driver DR, but in this example, it is configured to perform steering assistance when the operation (steering operation) of the steering wheel 35 by the driver DR causes the host vehicle 100 to deviate from the target driving line Ltgt.

As shown in FIG. 2B, when the vehicle 100 deviates from the target driving line Ltgt to the left during steering assist control, the vehicle driving assist device 10 controls the steering force applied to the vehicle 100 so that the vehicle 100 moves to the right, thereby providing steering assistance so that the vehicle 100 travels on the target driving line Ltgt.

On the other hand, as shown in FIG. 2C, when the vehicle 100 deviates from the target driving line Ltgt to the right while the steering assist control is being executed, the vehicle driving assist device 10 controls the steering force applied to the vehicle 100 so that the vehicle 100 moves to the left, thereby providing steering assistance so that the vehicle 100 travels on the target driving line Ltgt.

As shown in FIG. 3A, a structure ST such as a guard rail GR may be present on the side of the vehicle 100, or as shown in FIG. 3B, a structure ST such as a building BDG may be present on the side of the vehicle 100. In such cases, the driver DR may feel a sense of pressure from the structure ST or may feel a risk of contact between the vehicle 100 and the structure ST. As a measure to prevent the driver DR from feeling such pressure or danger when performing steering assist control, as shown in FIG. 4A and FIG. 4B, when a structure ST is present on the side of the vehicle 100, a possible measure is to perform steering assist control by offsetting (shifting) the target driving line Ltgt away from the structure ST.

However, when a structure ST is present to the side of the vehicle 100, if steering assist control is always performed by offsetting the target driving line Ltgt, depending on the structure ST, the driver DR may not feel a sense of pressure from the structure ST or a risk of contact between the vehicle 100 and the structure ST, even if steering assist control is performed without offsetting the target driving line Ltgt. In such a case, if steering assist control is performed by offsetting the target driving line Ltgt, the driver DR may feel that the vehicle 100 is traveling too far from the structure ST, which may cause discomfort.

Therefore, the vehicle driving assistance device 10 executes steering assistance control as follows:

While steering assist control is being performed, the vehicle driving assistance device 10 performs a process of obtaining a line passing through the center of the own lane LN as the reference driving line Lbase based on the width WLN of the own lane LN.

Furthermore, while the steering assist control is being performed, the vehicle driving assistance device 10 performs a process of determining whether or not a structure ST is present to the side of the vehicle 100 based on the surrounding detection information IS, and if it is determined that a structure ST is present to the side of the vehicle 100, the vehicle driving assistance device 10 obtains the structure distance W and structure height H based on the surrounding detection information IS.

The structure distance W is the distance from the structure ST to the own lane LN, and more specifically, the distance between the wall surface of the structure ST on the own lane LN side and the end of the demarcation line LML or LMR on the structure ST side. Therefore, as shown in FIG. 5, when the structure ST is located on the left side of the own lane LN, the structure distance W is the distance between the wall surface of the structure ST on the own lane LN side and the left end EL of the left demarcation line LML, and when the structure ST is located on the right side of the own lane LN, it is the distance between the wall surface of the structure ST on the own lane LN side and the right end of the right demarcation line LMR.

The structure height H is the height of the structure ST, and in this example, as shown in FIG. 5, is the height of the structure ST from the road surface on which the vehicle 100 is traveling.

When the vehicle driving assistance device 10 acquires the structure distance W and the structure height H, it determines whether the structure distance W is less than or equal to a predetermined distance (predetermined distance threshold Wth) and whether the structure height H is greater than or equal to a predetermined height (predetermined height threshold Hth).

When the vehicle driving assistance device 10 determines that the structure distance W is equal to or less than a predetermined distance threshold Wth and the structure height H is equal to or greater than a predetermined height threshold Hth, it determines that the target adjustment condition Cadj is satisfied.

When the vehicle driving assistance device 10 determines that the target adjustment condition Cadj is satisfied, it sets the target driving line Ltgt to a line that is shifted from the reference driving line Lbase by a predetermined distance ΔL away from the structure ST. That is, when the vehicle driving assistance device 10 determines that the target adjustment condition Cadj is satisfied, if the structure ST is on the left side of the vehicle 100, it sets the target driving line Ltgt to a line that is shifted from the reference driving line Lbase to the right by a predetermined distance ΔL, and if the structure ST is on the right side of the vehicle 100, it sets the target driving line Ltgt to a line that is shifted from the reference driving line Lbase to the left by a predetermined distance ΔL. Then, the vehicle driving assistance device 10 executes steering assistance control so that the vehicle 100 travels on the target driving line Ltgt thus set.

The predetermined distance ΔL may be set appropriately as long as the vehicle 100 does not travel outside the vehicle lane LN when the vehicle 100 travels on the target driving line Ltgt shifted by the predetermined distance ΔL.

On the other hand, if the vehicle driving assistance device 10 determines that the target adjustment condition Cadj is not satisfied, it sets the reference driving line Lbase as the target driving line Ltgt as is, and executes steering assistance control so that the host vehicle 100 travels along the target driving line Ltgt.

＜Effects＞
Generally, when a driver is driving next to a tall structure such as a building, the driver tends to feel a sense of pressure from the structure or a risk of contact between the vehicle and the structure. However, even if the vehicle is driving next to such a tall structure, if the structure is located away from the vehicle, the driver may not feel a sense of pressure from the structure or a risk of collision between the vehicle and the structure. In such a case, the steering assist control may shift (offset) the target driving line away from the structure, and the driver may feel uncomfortable when the vehicle drives on the target driving line.

In addition, if the structure is a low-height structure such as a guardrail, the driver tends not to feel a sense of pressure from the structure or a risk of contact between the vehicle and the structure even when the vehicle is traveling close to the structure. In such a case, if the steering assist control shifts (offsets) the target driving line away from the structure and the vehicle travels on the target driving line, the driver may feel uncomfortable.

In this way, whether or not the driver feels uncomfortable depends on the combination of the distance between the structure and the vehicle and the height of the structure.

According to the vehicle driving assistance device 10, when the structure distance W is longer than a predetermined distance threshold Wth or the structure height H is lower than a predetermined height threshold Hth, the reference driving line Lbase set based on the width WLN of the vehicle lane LN is used as the target driving line Ltgt and steering assistance control is executed. In other words, when it is determined that the driver DR will not feel a sense of pressure from the structure ST or a risk of contact between the structure ST and the vehicle 100 even if the vehicle 100 is driving close to the structure ST, the steering assistance control is executed without shifting (offsetting) the target driving line Ltgt away from the structure ST.

On the other hand, if the structure distance W is equal to or less than the predetermined distance threshold Wth and the structure height H is equal to or greater than the predetermined height threshold Hth, the steering assist control is executed by shifting the reference driving line Lbase, which is set based on the width WLN of the vehicle lane LN, away from the structure ST, as the target driving line Ltgt. In other words, if it is determined that the driver DR feels a sense of pressure from the structure ST when the vehicle 100 is traveling near the structure ST or feels a risk of contact between the structure ST and the vehicle 100, the target driving line Ltgt is shifted (offset) away from the structure ST and steering assist control is executed.

This allows steering assist control to be performed without causing any discomfort to the driver DR.

The vehicle driving assistance device 10 described above uses the structure distance W and the structure height H to determine whether the target adjustment condition Cadj is satisfied, but may be configured to use the structure distance W and the structure elevation angle θe.

The structure elevation angle θe is the elevation angle of the upper end of the structure ST from the vehicle lane LN. More specifically, when viewed on a vertical plane perpendicular to the traveling direction of the vehicle 100, it is the angle between a line along the road surface on which the vehicle 100 is traveling and a line connecting the end of the demarcation line LML or LMR on the structure ST side and the upper end of the wall of the structure ST on the road side on which the vehicle 100 is traveling. For example, in the example shown in FIG. 6, the structure elevation angle θe is the angle between a line L1 along the road surface on which the vehicle 100 is traveling and a line L2 connecting the left end EL of the left demarcation line LML and the upper end EU of the wall of the structure ST on the road side on which the vehicle 100 is traveling. In this example, the structure elevation angle θe is obtained based on the structure distance W and the structure height H.

In this case, the vehicle driving assistance device 10 determines whether the structure distance W is equal to or less than a predetermined distance threshold Wth and whether the structure elevation angle θe is equal to or greater than a predetermined elevation angle (predetermined elevation angle threshold θe_th).

When the vehicle driving assistance device 10 determines that the structure distance W is equal to or less than the predetermined distance threshold Wth and the structure elevation angle θe is equal to or greater than the predetermined elevation angle threshold θe_th, it determines that the target adjustment condition Cadj is satisfied. On the other hand, when the vehicle driving assistance device 10 determines that the structure distance W is longer than the predetermined distance threshold Wth or that the structure elevation angle θe is smaller than the predetermined elevation angle threshold θe_th, it determines that the target adjustment condition Cadj is not satisfied.

In this case, if the vehicle driving assistance device 10 determines that the structure elevation angle θe is equal to or greater than the predetermined elevation angle threshold θe_th, it determines that the structure height H is equal to or greater than the predetermined height threshold Hth. On the other hand, if the vehicle driving assistance device 10 determines that the structure elevation angle θe is smaller than the predetermined elevation angle threshold θe_th, it determines that the structure height H is lower than the predetermined height threshold Hth.

＜Effects＞
Even if a structure on the side of the vehicle is tall, the driver tends not to feel pressured by the structure or to feel the risk of contact between the vehicle and the structure if the structure is located far from the vehicle's lane. Conversely, even if the structure is short, the driver tends to feel pressured by the structure or to feel the risk of contact between the vehicle and the structure if the structure is close to the vehicle's lane.

When the height of a structure is the same, the elevation angle of the top end of the structure from the own lane increases as the distance between the structure and the own lane decreases, and when the distance between the structure and the own lane is the same, the elevation angle of the top end of the structure from the own lane increases as the height of the structure increases.

Therefore, whether or not the driver feels a sense of pressure from the structure or senses the risk of contact between the structure and the vehicle depends on the elevation angle of the structure's top edge from the vehicle's lane.

According to this vehicle driving assistance device 10, even if the vehicle 100 is traveling near a structure ST, if it is determined that the driver DR does not feel a sense of pressure from the structure ST or that there is no risk of contact between the vehicle 100 and the structure ST (i.e., if it is determined that the structure distance W is longer than a predetermined distance threshold Wth, or if it is determined that the structure elevation angle θe is smaller than a predetermined elevation angle threshold θe_th), steering assistance control is executed without shifting (offsetting) the target driving line Ltgt away from the structure.

On the other hand, when the vehicle 100 is traveling near a structure ST, if it is determined that the driver DR feels a sense of pressure from the structure ST or that there is a risk of contact between the vehicle 100 and the structure ST (i.e., when the structure distance W is less than or equal to the predetermined distance threshold Wth and the structure elevation angle θe is greater than or equal to the predetermined elevation angle threshold θe_th), steering assist control is executed by shifting (offsetting) the target driving line Ltgt away from the structure ST.

This allows steering assist control to be performed without causing any discomfort to the driver DR.

The vehicle driving assistance device 10 may also be configured to use only the structure elevation angle θe to determine whether the target adjustment condition Cadj is satisfied. In this case, the vehicle driving assistance device 10 determines whether the structure elevation angle θe is equal to or greater than a predetermined elevation angle threshold θe_th.

When the vehicle driving assistance device 10 determines that the structure elevation angle θe is equal to or greater than the predetermined elevation angle threshold θe_th, it determines that the target adjustment condition Cadj is satisfied. On the other hand, when the vehicle driving assistance device 10 determines that the structure elevation angle θe is smaller than the predetermined elevation angle threshold θe_th, it determines that the target adjustment condition Cadj is not satisfied.

＜Effects＞
As mentioned above, whether or not the driver feels a sense of pressure from the structure or senses the risk of contact between the structure and the vehicle depends on the elevation angle of the upper end of the structure from the vehicle's lane.

According to this vehicle driving assistance device 10, even if the vehicle 100 is traveling near a structure ST, if it is determined that the driver DR does not feel a sense of pressure from the structure ST or that there is no risk of contact between the structure ST and the vehicle 100 (i.e., if it is determined that the structure elevation angle θe is smaller than the predetermined elevation angle threshold θe_th), steering assistance control is executed without shifting (offsetting) the target driving line Ltgt away from the structure.

On the other hand, when the vehicle 100 is traveling near a structure ST, if it is determined that the driver DR feels a sense of pressure from the structure ST or that there is a risk of contact between the vehicle 100 and the structure ST (i.e., if it is determined that the structure elevation angle θe is equal to or greater than the predetermined elevation angle threshold θe_th), steering assist control is executed by shifting (offsetting) the target driving line Ltgt away from the structure ST.

This allows steering assist control to be performed without causing any discomfort to the driver DR.

<Specific Operation of Vehicle Driving Assistance Device>
Next, there will be described a specific operation of the vehicle driving support device 10. The CPU of the ECU 90 of the vehicle driving support device 10 executes the routine shown in Fig. 7, Fig. 8 or Fig. 9 at a predetermined calculation cycle.

Therefore, when the CPU is configured to execute the routine shown in FIG. 7, at a predetermined timing, it starts processing from step 700 in FIG. 7, proceeds to step 705, and determines whether or not execution of steering assist control is requested.

If the CPU judges "Yes" in step 705, the process proceeds to step 710, where the CPU acquires the reference driving line Lbase based on the width WLN of the vehicle's lane LN. Next, the CPU proceeds to step 715, where the CPU judges whether or not a structure ST is present to the side of the vehicle 100 based on the surrounding detection information IS.

If the CPU judges "Yes" in step 715, the process proceeds to step 720, where it determines whether the target adjustment condition Cadj is satisfied. Specifically, the CPU determines whether the structure distance W is equal to or less than a predetermined distance threshold Wth and the structure height H is equal to or greater than a predetermined height threshold Hth.

If the CPU judges "Yes" in step 720, it proceeds to step 725, corrects the reference driving line Lbase acquired in step 710 by shifting (offsetting) it a predetermined distance ΔL away from the structure ST, and sets the corrected reference driving line Lbase as the target driving line Ltgt. The CPU then proceeds to step 735.

On the other hand, if the CPU determines "No" in step 720, the process proceeds to step 730, where the reference driving line Lbase obtained in step 710 is set as the target driving line Ltgt. Next, the CPU proceeds to step 735.

Also, if the CPU determines "No" in step 715, the CPU proceeds to step 730 and sets the reference driving line Lbase obtained in step 710 to the target driving line Ltgt. Next, the CPU proceeds to step 735.

When the CPU advances the process to step 735, it performs steering assistance by controlling the steering force applied to the vehicle 100 so that the vehicle 100 travels along the target driving line Ltgt set in step 725 or step 730. Next, the CPU advances the process to step 795 and temporarily ends this routine.

If the CPU determines "No" in step 705, it proceeds directly to step 795 and ends this routine. In this case, no steering assistance is provided.

In addition, when the CPU is configured to execute the routine shown in FIG. 8, at a predetermined timing, it starts processing from step 800 in FIG. 8, proceeds to step 805, and determines whether or not execution of steering assist control is requested.

If the CPU judges "Yes" in step 805, the process proceeds to step 810, where the CPU acquires the reference driving line Lbase based on the width WLN of the vehicle's lane LN. Next, the CPU proceeds to step 815, where the CPU judges whether or not a structure ST is present to the side of the vehicle 100 based on the surrounding detection information IS.

If the CPU judges "Yes" in step 815, the process proceeds to step 820, where it judges whether the target adjustment condition Cadj is satisfied. Specifically, the CPU judges whether the structure distance W is equal to or less than a predetermined distance threshold Wth and the structure elevation angle θe is equal to or greater than a predetermined elevation angle threshold θe_th.

If the CPU judges "Yes" in step 820, it proceeds to step 825, corrects the reference driving line Lbase acquired in step 810 by shifting (offsetting) it a predetermined distance ΔL away from the structure ST, and sets the corrected reference driving line Lbase as the target driving line Ltgt. The CPU then proceeds to step 835.

On the other hand, if the CPU determines "No" in step 820, the process proceeds to step 830, where the reference driving line Lbase acquired in step 810 is set as the target driving line Ltgt. Next, the CPU proceeds to step 835.

Also, if the CPU determines "No" in step 815, the CPU advances the process to step 830 and sets the reference driving line Lbase acquired in step 810 to the target driving line Ltgt. Next, the CPU advances the process to step 835.

When the CPU advances the process to step 835, it performs steering assistance by controlling the steering force applied to the vehicle 100 so that the vehicle 100 travels along the target driving line Ltgt set in step 825 or step 830. Next, the CPU advances the process to step 895 and temporarily ends this routine.

If the CPU determines "No" in step 805, it proceeds directly to step 895 and ends this routine. In this case, no steering assistance is provided.

In addition, when the CPU is configured to execute the routine shown in FIG. 9, at a predetermined timing, it starts processing from step 900 in FIG. 9, advances the processing to step 905, and determines whether or not execution of steering assist control is requested.

If the CPU judges "Yes" in step 905, the process proceeds to step 910, where the CPU acquires the reference driving line Lbase based on the width WLN of the vehicle's lane LN. Next, the CPU proceeds to step 915, where the CPU judges whether or not a structure ST exists to the side of the vehicle 100 based on the surrounding detection information IS.

If the CPU judges "Yes" in step 915, the process proceeds to step 920, where it judges whether the target adjustment condition Cadj is satisfied. Specifically, the CPU judges whether the structure elevation angle θe is equal to or greater than a predetermined elevation angle threshold θe_th.

If the CPU judges "Yes" in step 920, it proceeds to step 925, corrects the reference driving line Lbase acquired in step 910 by shifting (offsetting) it a predetermined distance ΔL away from the structure ST, and sets the corrected reference driving line Lbase as the target driving line Ltgt. The CPU then proceeds to step 935.

On the other hand, if the CPU determines "No" in step 920, the process proceeds to step 930, where the reference driving line Lbase acquired in step 910 is set as the target driving line Ltgt. Next, the CPU proceeds to step 935.

Also, if the CPU determines "No" in step 915, the CPU advances the process to step 930 and sets the reference driving line Lbase acquired in step 910 to the target driving line Ltgt. Next, the CPU advances the process to step 935.

When the CPU advances the process to step 935, it performs steering assistance by controlling the steering force applied to the vehicle 100 so that the vehicle 100 travels along the target driving line Ltgt set in step 925 or step 930. Next, the CPU advances the process to step 995 and temporarily ends this routine.

If the CPU determines "No" in step 905, it proceeds directly to step 995 and ends this routine. In this case, no steering assistance is provided.

The above is the specific operation of the vehicle driving assistance device 10.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

10...vehicle driving assistance device, 50...peripheral information detection device, 90...ECU, 100...own vehicle, LN...own lane, LML...left side marking line, LMR...right side marking line, Ltgt...target driving line, ST...structure, GR...guardrail, BDG...building, W...structure distance, H...structure height, θe...elevation angle

Claims (4)

1. A vehicle driving assistance device that performs steering assistance control to control a steering force applied to a host vehicle so that the host vehicle travels along a target driving line,
when a structure is detected to the side of the host vehicle and the distance from the structure to the lane in which the host vehicle is traveling is longer than a predetermined distance threshold, or when the height of the structure is lower than a predetermined height threshold, the target driving line is set based on the width of the lane in which the host vehicle is traveling;
when a structure is detected to the side of the vehicle, if the distance from the structure to the vehicle's driving lane is equal to or less than the predetermined distance threshold and the height of the structure is equal to or greater than the predetermined height threshold, a target driving line is set by shifting a target driving line set based on the width of the vehicle's driving lane away from the structure,
The vehicle driving assistance device is configured as follows. The vehicle driving support device according to claim 1,
if an elevation angle of the upper end of the structure from the lane of travel of the host vehicle is smaller than a predetermined elevation angle threshold, it is determined that the height of the structure is lower than the predetermined height threshold;
If the elevation angle is equal to or greater than the predetermined elevation angle threshold, it is determined that the height of the structure is equal to or greater than the predetermined height threshold.
The vehicle driving assistance device is configured as follows. 1. A vehicle driving assistance device that performs steering assistance control to control a steering force applied to a host vehicle so that the host vehicle travels along a target driving line,
when a structure is detected to the side of the host vehicle and an elevation angle of an upper end of the structure from the lane of the host vehicle is smaller than a predetermined elevation angle threshold, the target driving line is set based on a width of the lane of the host vehicle;
when a structure is detected to the side of the vehicle and the elevation angle is equal to or greater than the predetermined elevation angle threshold, a target driving line is set by shifting a target driving line set based on a width of the lane in which the vehicle is traveling away from the structure,
The vehicle driving assistance device is configured as follows. The vehicle driving support device according to any one of claims 1 to 3,
The steering assist control is a control for controlling a steering force applied to the host vehicle so that the host vehicle travels on the target driving line when the host vehicle travels deviating from the target driving line due to a steering operation by a driver of the host vehicle.
Vehicle driving assistance device.

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