Vehicle driving assistance device

Abstract

To provide a driving support device for a vehicle capable of performing appropriate driving support control without giving an incongruity or discomfort to a driver.SOLUTION: A driving support device for a vehicle includes: surrounding condition information acquisition devices 21 and 23 for acquiring surrounding condition information of the vehicle; a steering angle detection sensor 15 for detecting a steering angle and a steering direction of the vehicle; and a travel control unit 24 that totally controls the entire vehicle and includes a steering support control unit 11 that performs travel control according to steering support control based on each output information of the surrounding condition information acquisition device and the steering angle detection sensor. The steering support control unit recognizes an oncoming vehicle and an object to be avoided on a roadside based on the output information of the surrounding condition information acquisition device, estimates an avoidance priority of the oncoming vehicle and the object to be avoided, and sets a new lane keeping target travel route according to the avoidance priority.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a driving assistance device for a vehicle that performs lane keeping control and lane departure prevention control to assist a driver in driving. [Background technology]

[0002] In recent years, development of automatic driving control technology for vehicles such as automobiles that allows the vehicle to travel automatically without the need for driver operation has been progressing. In addition, various driving assistance devices that utilize this type of automatic driving control technology to perform various controls to assist the driver in driving operations have been proposed and are becoming generally put into practical use.

[0003] Among conventional driving assistance devices, for example, there are some that are equipped with an Active Lane Keeping (ALK) driving control function that constantly recognizes the vehicle's surroundings using various sensor devices, etc., and keeps the vehicle traveling along the lane it is traveling in based on the various information data acquired.

[0004] In addition, some conventional driving assistance devices are equipped with a lane departure prevention (LDP) control function that, when it is determined that the vehicle is tending to deviate from the lane in which it is traveling, intervenes a predetermined steering assistance control as appropriate to prevent the vehicle from deviating from the lane in which it is traveling or to suppress lane departure.

[0005] Generally, on roads on which vehicles travel, such as general roads that do not have a central median or other three-dimensional structure in the middle of the road, there are various obstacles, such as curbs, guardrails, side walls (including snow walls on snowy roads), utility poles, and other three-dimensional structures located at the boundary between the roadway and the sidewalk, as well as other vehicles parked or stopped on the side of the road (shoulder), other vehicles stopped on the left or right of the vehicle's lane (own lane) just before an intersection and attempting to turn right or left, and road cones installed to restrict road construction or to separate the lane from other construction areas.

[0006] Here, these various obstacles are collectively referred to as "objects to be avoided." Such objects to be avoided may impede the travel of a vehicle, so the vehicle must avoid collisions with these obstacles. Therefore, on this type of general road, the area in which a vehicle can travel is determined by the presence of the various obstacles.

[0007] Therefore, in order for a vehicle equipped with a conventional driving assistance device to continue driving reliably and safely on the road while performing lane keeping control and lane departure prevention control, it is required to recognize the situation around the vehicle (such as the situation of obstacles on the road) and constantly recognize the area in which the vehicle can travel.

[0008] Furthermore, especially on public roads where there are no three-dimensional structures such as central medians, the vehicle's driving assistance device must also recognize the presence of other vehicles traveling in the oncoming lane and vehicles parked or stopped in the oncoming lane (hereinafter collectively referred to as vehicles in the oncoming lane) as surrounding conditions and take these into consideration when controlling the vehicle's driving.

[0009] To this end, in conventional driving assistance devices, various proposals have been made, for example, in International Publication WO2019 / 043847, Patent Publication No. 2020-158090, and Patent Publication No. 2013-043563, regarding technologies for recognizing the surrounding conditions of a vehicle while it is traveling on a road and appropriately controlling the vehicle's driving in accordance with the recognized surrounding conditions.

[0010] The driving assistance device disclosed in the above-mentioned International Publication No. WO2019 / 043847 and the like recognizes other vehicles traveling alongside the vehicle, and sets the driving path of the vehicle by appropriately adjusting the lateral distance between the vehicle and the other vehicle traveling alongside the vehicle depending on the relative positional relationship between the vehicle and the other vehicle traveling alongside and the type of the other vehicle traveling alongside the vehicle.

[0011] The driving assistance device disclosed in the above-mentioned Patent Publication No. 2020-158090, etc., recognizes road dividing lines and other vehicles traveling parallel to the vehicle, and sets the vehicle's driving path by appropriately adjusting the lateral distance in the width direction between the vehicle and the other vehicles traveling parallel to the vehicle in accordance with the relative positional relationship between the vehicle and the other vehicles traveling parallel to the vehicle and the road dividing lines.

[0012] The driving assistance device disclosed in the above-mentioned Patent Publication No. 2013-043563, etc., recognizes the surrounding conditions, estimates the level of collision risk with various recognized objects, and sets the vehicle's driving path by appropriately adjusting the lateral distance in the width direction between the vehicle and surrounding objects according to the estimated level of collision risk. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] International Publication No. WO2019 / 043847 [Patent Document 2] Japanese Patent Publication No. 2020-158090 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-043563 Summary of the Invention [Problem to be solved by the invention]

[0014] Generally, when a vehicle is traveling on an ordinary road or the like that does not have a three-dimensional structure such as a median strip, and there is a vehicle in the oncoming lane, the closer the lateral distance between the vehicle and the oncoming vehicle, the more likely the driver is to feel intimidated or oppressed by the oncoming vehicle. Therefore, in such a situation, the driver may steer the vehicle in a direction that moves it laterally away from the oncoming vehicle.

[0015] In this case, the direction away from the vehicle on the oncoming lane is the direction opposite the oncoming lane, i.e., the direction toward the shoulder. Specifically, the direction opposite the oncoming lane corresponds to the left side area of the road, for example, in the case of a road with left-hand traffic regulations. An object to be avoided may exist in the direction of this area (the direction opposite the oncoming lane; the shoulder).

[0016] For this reason, in the above-mentioned situation, if the driver, while traveling, is aware of the presence of a vehicle in the oncoming lane and steers in a direction to avoid the vehicle in the oncoming lane, that is, toward the opposite side of the oncoming lane (shoulder), the vehicle will head in the direction opposite the oncoming lane (shoulder). At this time, the driving assistance device of the vehicle will respond to the object to be avoided that exists on the shoulder, and in some cases, may activate lane keeping control or lane departure prevention control.

[0017] However, in this situation, the steering performed by the driver is the result of a driving maneuver performed to avoid the oncoming vehicle due to a sense of intimidation or pressure from the oncoming vehicle, and therefore the driver recognizes the steering as a necessary driving maneuver.

[0018] However, the lane departure prevention control that may be activated in response to such steering is a control that intervenes to correct the steering in the direction of the oncoming lane, contrary to the driver's intended steering (steering toward the opposite side of the oncoming lane (toward the shoulder)). Therefore, such intervention of the lane departure prevention control is a behavior that is not intended by the driver, and there is a problem in that the driver feels strange or uncomfortable.

[0019] Similarly, when a vehicle is traveling on an ordinary road or the like that does not have a three-dimensional structure such as a median strip, there may be a situation in which the surrounding obstacles on the road shoulder are, for example, a high side wall or the like running along the road. Even in such a situation, the driver may feel intimidated or oppressed by the obstacle such as the high side wall. Therefore, in this case too, the driver may recognize the side wall or the like as an object to be avoided and may steer the vehicle in a direction away from the high side wall or the like in the lateral direction.

[0020] In this case, there is a possibility that an oncoming lane exists on the opposite side of the object to be avoided, such as a high side wall, and that an oncoming vehicle as the object to be avoided is traveling on the oncoming lane. Therefore, in this case, the vehicle's driving assistance device may recognize these objects to be avoided and activate lane keeping control or lane departure prevention control. Furthermore, the intervention of lane keeping control or lane departure prevention control in such a case also poses the same problem of the possibility that the driver may feel uncomfortable or uneasy.

[0021] In conventional driving assistance devices disclosed in the above-mentioned International Publication WO2019 / 043847, the above-mentioned Japanese Patent Application Publication No. 2020-158090, the above-mentioned Japanese Patent Application Publication No. 2013-043563, etc., all of them only control the setting of a driving route taking into consideration other vehicles traveling alongside or obstacles with the possibility of collision, and no particular consideration is given to driving control in the event that, for example, the driver steers in a direction that deviates from the set driving route at their will.

[0022] An object of the present invention is to provide a driving assistance device for a vehicle that can perform more appropriate driving assistance control without causing discomfort or annoyance to the driver. [Means for solving the problem]

[0023] In order to achieve the above object, a driving assistance device for a vehicle according to one aspect of the present invention is a driving assistance device for a vehicle that can perform at least lane keeping driving control for driving a vehicle along a driving lane and lane departure prevention control for preventing the vehicle from departing from the driving lane, and includes a surrounding situation information acquisition device that acquires surrounding situation information for the vehicle, a steering angle detection sensor that detects the steering angle and steering direction of the vehicle, and a driving control unit that includes a steering assistance control unit that performs driving control involving steering assistance control based on output information from the surrounding situation information acquisition device and the steering angle detection sensor, and that performs overall control of the entire vehicle, a determination of a tendency of the vehicle to deviate from a driving lane based on output information from the surrounding situation information acquisition device and the steering angle detection sensor; Based on the output information of the surrounding situation information acquisition device, Oncoming vehicles and an object to be avoided on the shoulder side of the lane of the vehicle. Oncoming car Estimate the avoidance priority of both the object and the object to be avoided. If it is determined that the vehicle has a tendency to depart from its lane, a new lane departure prevention target driving route is set for the vehicle in accordance with the avoidance priority. If it is determined that the vehicle does not have a tendency to depart from its lane, A new lane-keeping target driving route for the vehicle is set according to the avoidance priority. [Effects of the Invention]

[0024] According to the present invention, it is possible to provide a driving assistance device for a vehicle that can perform more appropriate driving assistance control without causing discomfort or annoyance to the driver. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a vehicle equipped with a driving assistance device according to an embodiment of the present invention. [Figure 2] FIG. 1 is a block diagram showing the schematic configuration of a camera unit and a cruise control unit (MCU) in a driving assistance device according to an embodiment of the present invention. [Figure 3] 1 is a flowchart showing the operation of a driving assistance device according to an embodiment of the present invention (when there is a tendency for the vehicle to deviate from its lane); [Figure 4] 1 is a flowchart showing the operation of a driving assistance device according to an embodiment of the present invention (when there is no tendency for the vehicle to depart from the lane). [Figure 5]FIG. 1 is a conceptual diagram illustrating a situation in which lane keeping control is performed when there is no tendency for the vehicle to depart from the lane to the left in a driving assistance device according to an embodiment of the present invention. [Figure 6] FIG. 1 is a conceptual diagram illustrating a situation in which lane departure prevention control intervenes when there is a tendency for the vehicle to depart from the lane to the left in a driving assistance device according to an embodiment of the present invention. [Figure 7] FIG. 1 is a conceptual diagram illustrating a situation in which lane keeping control is performed when there is no tendency for the vehicle to depart from the lane to the right in a driving assistance device according to an embodiment of the present invention. [Figure 8] FIG. 1 is a conceptual diagram illustrating a situation in which lane departure prevention control intervenes when there is a tendency for the vehicle to depart from the lane to the right in a driving assistance device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention will be described below with reference to the illustrated embodiments. The drawings used in the following description are schematic, and the dimensional relationships and scales of the components may be different for each component in order to show each component at a size that allows it to be recognized on the drawing. Therefore, the present invention is not limited to the illustrated embodiments in terms of the number of components shown in the drawings, the shapes of the components, the size ratios of the components, the relative positional relationships of the components, and so on.

[0027] A driving assistance device according to one embodiment of the present invention is a device that is mounted on a vehicle such as an automobile and that executes driving assistance control to assist the driver of the vehicle in driving operations. The driving assistance device according to this embodiment acquires information about the surrounding conditions of the vehicle using various sensor devices, such as an image sensor of a camera unit or a radar sensor of a radar device. These various sensor devices are autonomous sensor devices that operate autonomously.

[0028] Here, information about the surrounding conditions of the vehicle refers to information about various objects to be avoided that exist around the vehicle while it is moving, such as a preceding vehicle, a following vehicle, an oncoming vehicle, a vehicle traveling alongside the vehicle, other vehicles including motorcycles, pedestrians, bicycles, and other moving objects, as well as various three-dimensional structures such as curbs, guardrails, side walls, and utility poles, and stationary objects such as other vehicles parked or stopped on the side of the road (shoulder). Hereinafter, information about the surrounding conditions of the vehicle will be referred to as surrounding condition information, etc. As described above, this surrounding condition information is acquired using various sensor devices.

[0029] The driving assistance device of this embodiment appropriately uses surrounding situation information, etc. acquired using various sensor devices, etc. as information when executing driving assistance control to assist the driving operation of the driver of the vehicle.

[0030] Examples of driving assistance control executed by the driving assistance device of this embodiment include active lane keeping (ALK) driving control and lane departure prevention (LDP) control.

[0031] The schematic configuration of a driving assistance device according to one embodiment of the present invention will be described below with reference to Figures 1 and 2. Figure 1 is a block diagram showing the schematic configuration of a vehicle equipped with a driving assistance device according to one embodiment of the present invention. Figure 2 is a block diagram showing the schematic configuration of a camera unit and a cruise control unit (MCU) in the driving assistance device according to one embodiment of the present invention.

[0032] As described above, the driving assistance device 1 of this embodiment is a device mounted on a vehicle M such as an automobile. The driving assistance device 1 basically has substantially the same configuration as conventional driving assistance devices of the same type. Therefore, in FIGS. 1 and 2, only the components of the driving assistance device 1 of this embodiment that are directly related to the present invention are shown, and components that are not directly related to the present invention are not shown. In the following description, detailed description of components other than those directly related to the present invention will be omitted, assuming that they are substantially the same as those of conventional driving assistance devices, and only the components directly related to the present invention will be described in detail below.

[0033] As shown in FIG. 1, the driving assistance device 1 of this embodiment is configured to include a camera unit 21 and a radar device 23, which are surrounding situation information acquisition devices, a driving control unit 24, which is a driving control unit including a steering assistance control unit 11, an electric power steering (EPS) device 6 (hereinafter abbreviated as the EPS device 6), and the like.

[0034] As shown in Figures 1 and 2, the camera unit 21 is composed of a stereo camera consisting of a main camera 22a and a sub-camera 22b, and is composed of an on-board camera 22 which is an ambient condition acquisition sensor and an autonomous sensor device, an image processing unit (IPU) 21c (not shown in Figure 1; hereinafter abbreviated as IPU21c) connected to the on-board camera 22 (22a, 22b), and an image recognition processing unit 21d (not shown in Figure 1) to which the IPU21c is connected.

[0035] The vehicle-mounted camera 22 is installed, for example, in a position above and in front of the rearview mirror at the front of the vehicle interior of the vehicle M, close to the inner surface of the windshield of the vehicle M. In this case, the two cameras (22a, 22b) of the vehicle-mounted camera 22 are arranged horizontally at approximately equal intervals on the left and right sides of the center position in the vehicle width direction of the vehicle M.

[0036] The on-board camera 22 is, for example, an autonomous sensor device that senses the real space ahead of the vehicle M and acquires image information of the surrounding conditions mainly ahead of the vehicle M. As described above, the main camera 22a and the sub-camera 22b of the on-board camera 22 are arranged at symmetrical positions on either side of the center in the vehicle width direction. As a result, the on-board camera 22 acquires two sets of image data obtained by capturing an area of a predetermined range ahead of the vehicle M from different viewpoints using the two cameras (22a, 22b).

[0037] The IPU 21c is a circuit unit that performs predetermined image processing based on two sets of image data acquired by the on-board cameras 22 (22a, 22b). That is, the IPU 21c generates stereo image information (three-dimensional image information) based on the two sets of image data acquired by the on-board cameras 22 (22a, 22b), and generates image information (hereinafter referred to as distance image information) containing distance information calculated from the amount of positional deviation between the two images of the same object captured in each of the two sets of image data. The distance image information generated in this manner is sent to the image recognition processing unit 21d.

[0038] The image recognition processing unit 21d receives distance image information and the like transmitted from the IPU 21c, and functions as a surrounding situation recognition processing unit that recognizes the surrounding situation of the vehicle M based on the distance image information and the like.

[0039] The image recognition processing unit 21d, for example, recognizes the lane dividing lines that separate the left and right lane of the road on which the vehicle M is traveling, and obtains various information such as the road curvature [1 / m] of each of the left and right lane dividing lines and the width between the left and right lane dividing lines (lane width).

[0040] Furthermore, the image recognition processing unit 21d performs predetermined pattern matching and the like based on the distance image information to recognize various three-dimensional objects (objects to be avoided), such as curbs, guardrails, side walls, utility poles, etc. that exist along the road, as well as other vehicles, including pedestrians, bicycles, and motorcycles, that exist on the road on which the vehicle M is traveling. Here, the recognition of objects performed by the image recognition processing unit 21d includes the acquisition of various information, such as the type of object, the distance to the object, the moving speed of the object, and the relative speed between the object and the vehicle M.

[0041] In this way, in the driving assistance device 1 of this embodiment, the camera unit 21 functions as a surrounding situation information acquisition device that recognizes the surrounding situation of the vehicle M based on image data of the surrounding situation acquired by the on-board camera 22, which is an autonomous sensor device serving as a surrounding situation acquisition sensor, and acquires it as surrounding situation information.

[0042] The cruise control unit 24 is configured by a processor including hardware configured by a well-known microcontroller unit (MCU) and its peripheral devices, which includes, for example, a central processing unit (CPU), random access memory (RAM), read-only memory (ROM), non-volatile memory, non-volatile storage, and non-transitory computer readable medium. The ROM, non-volatile memory, non-volatile storage, etc. store software programs executed by the MCU and fixed data such as data tables. The MCU reads the software programs stored in the ROM, etc., expands them into the RAM, and executes them. The software programs appropriately refer to various data, etc., to realize the predetermined functions of the constituent units, etc., of the driving assistance device 1 of this embodiment.

[0043] The processor may be configured with a semiconductor chip such as an FPGA (Field Programmable Gate Array).The software program may be in a form in which the whole or part of the software program is recorded as a computer program product on a portable storage medium such as a flexible disk, CD-ROM, or DVD-ROM, or on a non-transitory computer readable medium such as a card-type memory, HDD (Hard Disk Drive), or SSD (Solid State Drive).

[0044] Various component units including various sensor devices such as the camera unit 21 described above and the radar device 23 described later are connected to the cruise control unit (MCU) 24. As a result, the cruise control unit 24 controls the operating conditions of the various connected component units, receives detection results (surrounding situation information) from the various sensor devices, performs predetermined cruise control as appropriate, and comprehensively controls the entire driving assistance device 1 of this embodiment.

[0045] In addition, various sensor devices for recognizing the surrounding conditions of vehicle M include, for example, the on-board camera 22 included in the camera unit 21 described above and the radar sensors (23fl, 23fr, 23rl, 23rr) included in the radar device 23 described later, as well as, for example, a vehicle speed sensor 13 that detects the current vehicle speed of vehicle M by detecting the rotational speed of each of the front, rear, left and right wheels of vehicle M, a lateral acceleration sensor or yaw rate sensor 14 that detects the yaw rate and lateral acceleration of vehicle M, a steering angle detection sensor 15 that detects the steering angle of vehicle M, a gyro sensor (not shown) that detects the angular velocity or angular acceleration of vehicle M, and a GNSS (Global Navigation Satellite System) receiver (not shown) that receives positioning signals transmitted from multiple positioning satellites.

[0046] The driving assistance device 1 of this embodiment is provided with a radar device 23 as a surrounding situation information acquisition device, as shown in Fig. 2. The radar device 23 is connected to a cruise control unit 24, acquires data on the surrounding situation, performs predetermined processing, and outputs the data to the cruise control unit 24 as recognition data in a predetermined format including the surrounding situation information.

[0047] The radar device 23 is configured with a plurality of radar sensors. The radar device 23 illustrated in this embodiment is an example configuration in which the vehicle M is equipped with four radar sensors. Here, the plurality (four) radar sensors include, for example, a left front-side radar sensor 23fl, a right front-side radar sensor 23fr, a left rear-side radar sensor 23rl, and a right rear-side radar sensor 23rr.

[0048] Of the four radar sensors (23fl, 23fr, 23rl, 23rr) in the radar device 23, the left front-side radar sensor 23fl and the right front-side radar sensor 23fr are provided, for example, on the left and right sides, respectively, of the front bumper of the vehicle M. These left front-side radar sensor 23fl and right front-side radar sensor 23fr recognize objects in areas diagonally forward and to the left and right of the vehicle M that cannot be recognized by the two image data acquired by the on-board cameras 22 (22a, 22b). Note that a portion of each of the areas recognized by the left front-side radar sensor 23fl and the right front-side radar sensor 23fr is set to overlap a portion of each of the areas recognized by the on-board cameras 22 (22a, 22b). As a result, the on-board camera 22 (22a, 22b), the left front side radar sensor 23fl, and the right front side radar sensor 23fr can recognize almost the entire area from the left and right sides near the front of the vehicle M to the front.

[0049] Of the four radar sensors (23fl, 23fr, 23rl, 23rr) in the radar device 23, the left rear-side radar sensor 23rl and the right rear-side radar sensor 23rr are provided, for example, on the left and right sides of the rear bumper of the vehicle M. These left rear-side radar sensor 23rl and right rear-side radar sensor 23rr recognize objects in an area extending from the left and right sides toward the rear of the vehicle M, which cannot be recognized by the above-mentioned left front-side radar sensor 23fl and right front-side radar sensor 23fr. Note that the areas recognized by the left rear-side radar sensor 23rl and the right rear-side radar sensor 23rr are set to partially overlap each other. As a result, the left rear-side radar sensor 23rl and the right rear-side radar sensor 23rr can recognize almost the entire area extending from the left and right sides toward the rear of the vehicle M.

[0050] In this case, the radar device 23 recognizes the positions and relative speeds of three-dimensional objects in front of, behind, and on the left and right sides of the vehicle M, as well as the size of the three-dimensional objects, and functions as a surrounding situation information acquisition device that acquires information about the surrounding situation of the vehicle M.

[0051] Information about three-dimensional objects recognized by the radar device 23 is input to the cruise control unit 24. In response to this, the cruise control unit 24 recognizes as three-dimensional objects other vehicles around the vehicle M, such as other preceding vehicles in front, other vehicles running parallel to the left and right sides, other following vehicles behind, and other intersecting vehicles approaching the vehicle M from a direction intersecting the path of travel of the vehicle M at an intersection, as well as various moving bodies around the vehicle M, such as pedestrians and bicycles.

[0052] As the radar device 23, for example, a millimeter wave radar device, a laser radar device, a LiDAR (Light Detection and Ranging) device, or the like is applied.

[0053] On the other hand, the cruise control unit 24 is configured to include a steering assist control unit 11. Here, the steering assist control unit 11 is configured by, for example, an electronic circuit formed in the cruise control unit 24.

[0054] In addition, instead of being provided within the driving control unit 24 as described above, the steering assist control unit 11 may also be configured by a processor including hardware that is separate and independent from the driving control unit 24.

[0055] The steering assist control unit 11 in the driving assist device 1 of this embodiment performs driving control involving steering assist control, such as lane keeping driving control and lane departure prevention control, among various controls that can be executed by the driving assist device 1 of this embodiment. To this end, the steering assist control unit 11 has, for example, a lane keeping driving control unit (hereinafter referred to as ALK_ECU) 11a and a lane departure prevention control unit (hereinafter referred to as LDP_ECU) 11b.

[0056] The ALK_ECU 11a is a control unit that contributes to steering assist control (lane keeping control) for stably driving the vehicle M within the driving lane. Here, the lane keeping driving control is driving control that recognizes the left and right dividing lines of the driving lane in which the vehicle M is traveling, as well as three-dimensional structures and the like (objects to be avoided such as curbs, guardrails, side walls, utility poles, etc.) that exist in the surroundings based on the surrounding conditions mainly in front and to the sides of the vehicle M recognized by surrounding condition acquisition sensors such as the on-board camera 22 of the camera unit 21 and the radar sensors (23fl, 23fr, 23rl, 23rr) of the radar device 23, and includes steering control for driving the vehicle M along the center of the left and right dividing lines.

[0057] The LDP_ECU 11b is also a control unit that contributes to steering assist control (lane departure prevention control) that assists the driver in steering when avoiding a dangerous situation that the vehicle M may encounter while traveling, such as a collision or contact between the vehicle M and an obstacle on the road while traveling. Here, the lane departure prevention control recognizes the surrounding conditions of the vehicle M, mainly in front and to the sides, of the lane in which the vehicle M is traveling, as well as the left and right dividing lines of the lane in which the vehicle M is traveling, as well as surrounding three-dimensional structures and the like (objects to be avoided, such as curbs, guardrails, side walls, and utility poles), based on the surrounding conditions mainly in front and to the sides of the vehicle M recognized by surrounding condition acquisition sensors such as the on-board camera 22 of the camera unit 21 and the radar sensors (23fl, 23fr, 23rl, 23rr) of the radar device 23, and when it is determined that the traveling direction of the vehicle M tends to deviate from the lane, it controls the steering torque and intervenes a predetermined steering control to make the vehicle M parallel to the left and right dividing lines, thereby preventing the vehicle M from deviating from the lane or suppressing the lane departure.

[0058] The configurations of the ALK_ECU 11a and the LDP_ECU 11b applied to the driving assistance device 1 of this embodiment are substantially the same as those applied to conventional driving assistance devices of the same type, etc. Therefore, further detailed description of the configurations of these control units will be omitted.

[0059] Here, the EPS device 6 is a component unit for intervening predetermined steering assist control at predetermined timing as needed.

[0060] As shown in FIG. 1, vehicle M has left and right front wheels FL, FR and left and right rear wheels RL, RR, and the left and right front wheels FL, FR are connected to a steering mechanism 2 consisting of a rack and pinion mechanism or the like via tie rods 3. Also, a steering shaft 5 having a handlebar 4 fixed to its tip is connected to the steering mechanism 2. With this configuration, when the driver operates the handlebar 4, the left and right front wheels FL, FR are steered via the steering shaft 5 and steering mechanism 2. In this way, the steering mechanism of vehicle M is made up of the steering mechanism 2, tie rods 3, handlebar 4, steering shaft 5, etc. Note that a steering mechanism of this type has a configuration substantially similar to that of steering mechanisms generally provided in conventional vehicles such as automobiles.

[0061] The EPS device 6 acts on the steering shaft 5 in such a steering mechanism. The EPS device 6 is configured to include an EPS motor 7, an EPS control unit (EPS_ECU) 8, a steering torque sensor 12, and the like.

[0062] In addition to the EPS_ECU 8, the driving control unit 24, the camera unit 21, etc., the vehicle M also includes various control units (not shown) that control the driving state of the vehicle, such as a drive source control unit that controls a drive source such as an engine or an electric motor, a transmission control unit, a brake control unit, etc. These various control units are connected to each other via an in-vehicle network using a CAN (Controller Area Network) communication 10 or the like, for free two-way communication.

[0063] The EPS motor 7 of the EPS device 6 is connected to the steering shaft 5 via a transmission mechanism (not shown). The EPS_ECU 8 controls the steering torque applied to the steering shaft 5 by the EPS motor 7.

[0064] The steering torque sensor 12 is a sensor device that detects the steering torque applied to the steering wheel 4 as the amount of driving operation by the driver. For this purpose, the steering torque sensor 12 is attached to the steering shaft 5. The steering torque sensor 12 is connected to the EPS_ECU 8. As a result, the detection result of the steering torque sensor 12 is output to the EPS_ECU 8.

[0065] The EPS_ECU 8 sets a torque (assist torque) that assists the steering torque applied by the driver to the steering wheel 4, according to various data such as the steering torque detected by the steering torque sensor 12 and the speed of the vehicle M detected by a vehicle speed sensor 13 (described later). By applying the assist torque to the steering shaft 5, the burden on the driver in operating the steering wheel is reduced, and steering assistance is provided to the driver.

[0066] In addition, the driving control unit 24 is connected to sensor devices that detect the behavior of the vehicle M, such as a vehicle speed sensor 13 that detects the vehicle speed, a yaw rate sensor 14 that detects the yaw rate and lateral acceleration generated in the vehicle body, and a steering angle detection sensor 15 that detects the steering angle and steering direction from the rotation angle of the steering shaft 5.

[0067] The ALK_ECU 11a and LDP_ECU 11b in the cruise control unit 24 receive outputs from the various sensor devices described above and execute cruise control including predetermined steering control as appropriate. The schematic configuration of the driving assistance device 1 of this embodiment has been described above.

[0068] Next, the operation of the driving assistance device of this embodiment when lane keeping control and lane departure prevention control are performed will be described below with reference to Figs. 3 to 8. Fig. 3 is a flowchart showing the operation of the driving assistance device of one embodiment of the present invention when lane keeping control and lane departure prevention control are mainly performed when there is a tendency for the vehicle to depart from the lane to the left. Fig. 4 is a flowchart showing the operation of the driving assistance device of one embodiment of the present invention when lane keeping control and lane departure prevention control are mainly performed when there is no tendency for the vehicle to depart from the lane. Fig. 5 is a flowchart showing the operation of the driving assistance device of one embodiment of the present invention when lane keeping control and lane departure prevention control are mainly performed when there is a tendency for the vehicle to depart from the lane to the right.

[0069] Fig. 5 is a diagram conceptually showing a situation in which lane keeping control is performed when there is no tendency for the vehicle to depart from the lane to the left in a driving assistance device according to an embodiment of the present invention. Fig. 6 is a diagram conceptually showing a situation in which lane departure suppression control is performed when there is a tendency for the vehicle to depart from the lane to the left in a driving assistance device according to an embodiment of the present invention.

[0070] Fig. 7 is a diagram conceptually showing a situation in which lane keeping control is performed when there is no tendency for the vehicle to depart to the right in a driving assistance device according to an embodiment of the present invention. Fig. 8 is a diagram conceptually showing a situation in which lane departure suppression control is performed when there is a tendency for the vehicle to depart to the right in a driving assistance device according to an embodiment of the present invention.

[0071] In the following description of this embodiment, as shown in Figures 5 to 8, a road system based on left-hand traffic where vehicles are allowed to drive on the left side is exemplified. Therefore, the configuration of the present invention can be easily applied to a road system based on right-hand traffic by simply switching the left and right. In addition, in the following description of this embodiment, the terms "left" and "right" refer to the left and right when facing an object.

[0072] First, consider a situation in which a vehicle M (hereinafter referred to as the host vehicle M) equipped with a driving assistance device 1 according to one embodiment of the present invention is traveling on an ordinary road without a three-dimensional structure such as a median strip while executing lane keeping driving control. At this time, the host vehicle M is in a state in which it can further execute lane departure prevention control at any time (i.e., a standby state for lane departure prevention control). In this case, the driving control unit 24 in the driving assistance device 1 of the host vehicle M while traveling continuously receives a signal from the steering torque sensor 12. Therefore, for example, when the steering torque sensor 12 detects a steering torque generated by a steering operation (steering) by the driver of the host vehicle M, the driving control unit 24 appropriately executes a predetermined driving control based on the received detection result of the steering torque.

[0073] Here, for example, assume the situations shown in Figures 5 to 8. Details will be described later, but the outline of the example situations shown in Figures 5 and 7 assumes the following situation. That is, for example, when the driver of the host vehicle M executing lane keeping control is aware of an oncoming vehicle (M1 or M2) or a vehicle parked or stopped in the oncoming lane (not shown; in the following description, oncoming vehicles that are traveling and vehicles parked or stopped in the oncoming lane will be abbreviated as "vehicles on the oncoming lane") and steers the vehicle to the left (towards the shoulder) in a direction to avoid the vehicle on the oncoming lane (see, for example, the symbol M1 or M2), or when the driver of the host vehicle M steers to the right (towards the center line of the road) while being aware of a side wall or the like 204 on the left side (the shoulder side of the host lane), and it is determined that the host vehicle M does not have a tendency to depart from the lane, this is an example of lane keeping control that is performed.

[0074] In addition, the outline of the example situation shown in Figures 6 and 8 is an example of when, for example, the driver of vehicle M while performing lane keeping driving control is aware of a vehicle (M1 or M2, etc.) in the oncoming lane and steers to the left (towards the shoulder) to avoid the vehicle (M1 or M2, etc.) in the oncoming lane, or when the driver of vehicle M is aware of a side wall, etc. 204 on the left side (the shoulder side of the vehicle's lane) and steers to the right (towards the center line of the road), it is determined that vehicle M is prone to deviating from its lane and lane departure prevention control intervenes.

[0075] 6 to 9, the lane in which the host vehicle M is traveling is indicated by reference numeral 201 (hereinafter referred to as the host lane 201). Reference numeral 202 indicates an oncoming lane that is provided adjacent to and parallel to the host lane 201. Reference numeral 203 indicates a road centerline that is a dividing line that separates the host lane 201 from the oncoming lane 202. In this case, the road centerline 203 is indicated by a white dashed line. Also, a sidewall 204 or the like is provided along the host lane 201 at the left edge (hereinafter referred to as the shoulder side) of the host lane 201. Similarly, a sidewall 204 or the like is provided in the oncoming lane 202 on the shoulder side of oncoming vehicles (M1, M2; described in detail later) traveling in the oncoming lane 202.

[0076] The host vehicle M traveling on such a road travels within the host lane 201 by lane keeping driving control as described above. At this time, the driving assistance device 1 of the host vehicle M sets a lane keeping target driving path (a virtual line indicated by reference numeral 205; a two-dot chain line) at a predetermined position on the host lane 201, and executes driving control to make the host vehicle M travel along the lane keeping target driving path 205. This lane keeping target driving path 205 is a virtual line that is set in consideration of the surrounding conditions of the host vehicle M. Normally, the lane keeping target driving path 205 is set at approximately the center position of the host lane 201.

[0077] 6 to 9, oncoming vehicles traveling in the oncoming lane 202 are indicated by the symbols M1 and M2. In the following description, the term "oncoming vehicle" refers to, for example, not only oncoming vehicles traveling indicated by the symbols M1 and M2 in the figures, but also vehicles parked and stopped on the oncoming lane (not shown). Therefore, in the following description, the terms "oncoming vehicle," "oncoming vehicle M1," "oncoming vehicle M2," "oncoming vehicles (M1, M2)," etc., can be replaced with "vehicles parked and stopped on the oncoming lane" or "vehicles on the oncoming lane," etc., and can be considered the same. In this case, the oncoming vehicle M1 indicated by the dashed line in FIGS. 6 to 9 is traveling on the oncoming lane 202 along the lane keeping target traveling path 205x set at approximately the center of the oncoming lane 202.

[0078] At this time, the distance between the vehicle M and the oncoming vehicle M1 (the distance lateral to the direction of travel of each vehicle M, M1, i.e., the distance in the vehicle width direction) is indicated by the lateral distance G1, for example, between an extension line 206a in the direction of travel along the right side position of the vehicle M (shown by a dashed line in Figures 5 to 8) and an extension line 206b in the direction of travel along the right side position of the oncoming vehicle M1 (shown by a dashed line in Figures 5 to 8).

[0079] 5 to 8, the oncoming vehicle M2 shown by a dashed line is traveling in an oncoming lane 202, close to the road center line 203. At this time, the distance between the host vehicle M and the oncoming vehicle M2 (the distance laterally with respect to the traveling direction of each vehicle, i.e., the distance in the vehicle width direction) is shown as the lateral distance G2 between, for example, a line 206a (shown by a dashed line in FIGS. 5 to 8) along the right side of the host vehicle M and an extension line 206c (shown by a dashed line in FIGS. 5 to 8) in the traveling direction that is also along the right side of the oncoming vehicle M2.

[0080] 5 to 8 do not indicate that the oncoming vehicles M1 and M2 are simultaneously present at the positions shown in the drawings on the road, but are depicted on the same drawing to indicate the difference in the lateral (vehicle width) positional relationship between the host vehicle M and each of the oncoming vehicles M1 and M2. In this case, the longitudinal (vehicle travel direction) positional relationship between the host vehicle M and each of the oncoming vehicles M1 and M2 is depicted shifted in the front-to-rear direction to avoid cluttering the drawings and avoiding overlapping on the drawings. Therefore, the longitudinal (vehicle travel direction) positional relationship between the host vehicle M and each of the oncoming vehicles M1 and M2 is not limited to the depicted representation.

[0081] In such a situation, the cruise control unit 24 in the driving assistance device 1 of the host vehicle M checks whether the host vehicle M is prone to deviate to the left or right from the driving lane in which the host vehicle M is currently traveling (host lane 201) in step S11 of Fig. 3. Here, the determination of whether the host vehicle M is prone to deviate from the lane is made based on the output result of the steering angle detection sensor 15.

[0082] For example, if the output result (steering angle) of the steering angle detection sensor 15 does not exceed a predetermined value, it can be assumed that the host vehicle M is traveling along the predicted traveling route to the left indicated by reference numeral 207aa (two-dot chain line) in Fig. 5 or the predicted traveling route to the right indicated by reference numeral 207ab (two-dot chain line) in Fig. 7. Here, the predicted traveling route 207aa in Fig. 5 indicates that the host vehicle M will intersect with the left-side imaginary lateral position line 208L (dotted line) for deviation determination that is set in advance within the host vehicle lane 201 after a relatively long predetermined time (see the situation in Fig. 5). Also, the predicted traveling route 207ab in Fig. 7 indicates that the host vehicle M will intersect with the right-side imaginary lateral position line 208R (dotted line) for deviation determination that is set in advance within the host vehicle lane 201 after a relatively long predetermined time (see the situation in Fig. 7).

[0083] This means that it can be estimated that even if the host vehicle M continues traveling while maintaining the current steering angle (which does not exceed the predetermined value), it will take a relatively long predetermined time before it deviates from the host vehicle lane 201. In other words, it can be determined that the host vehicle M is not in a situation where it is likely to deviate within the predetermined time. Therefore, in this case, the driving assistance device 1 determines that the host vehicle M is not prone to deviating from the lane (see the situations in FIGS. 5 and 7).

[0084] On the other hand, for example, when the output result (steering angle) of the steering angle detection sensor 15 exceeds a predetermined value, it can be inferred that the host vehicle M is traveling along a predicted traveling route to the left indicated by reference numeral 207ac (two-dot chain line) in Fig. 6 or a predicted traveling route to the right indicated by reference numeral 207ad (two-dot chain line) in Fig. 8. Here, the predicted traveling route 207ac in Fig. 6 indicates that the host vehicle M will intersect with a left-side imaginary lateral position line 208L (dotted line) for deviation determination that is set in advance within the host vehicle lane 201 within a relatively short predetermined time (see the situation in Fig. 6). Also, the predicted traveling route 207ad in Fig. 8 indicates that the host vehicle M will intersect with a right-side imaginary lateral position line 208R (dotted line) for deviation determination that is set in advance within the host vehicle lane 201 within a relatively short predetermined time (see the situation in Fig. 8).

[0085] This means that if the host vehicle M continues traveling while maintaining the current steering angle (exceeding the predetermined value), it can be estimated that the host vehicle M will deviate from the host vehicle lane 201 within a relatively short predetermined time. In other words, it can be determined that the host vehicle M is in a situation where it is likely to deviate within the predetermined time. Therefore, in this case, the driving assistance device 1 determines that the host vehicle M has a tendency to deviate from the lane (see the situations in FIGS. 6 and 8).

[0086] The departure determination lateral position virtual lines 208L, 208R are virtual lines set at a position a predetermined distance toward the host vehicle lane 201 from the shoulder side (for example, the side wall 204, etc.) or the center line 203 of the host vehicle lane 201, and along the shoulder side (for example, the side wall 204, etc.) or the center line 203. If the travel path of the host vehicle M is expected to deviate from the departure determination lateral position virtual lines 208L, 208R toward the shoulder side or the center line 203, it is determined that the host vehicle M is prone to departure from the lane.

[0087] Returning to FIG. 3, first, if it is determined in the processing of step S11 that the host vehicle M is in a situation where it is likely to deviate from the host vehicle lane 201, the processing proceeds to the next step S12. In this case, in the processing steps from step S12 onwards, lane departure suppression control intervenes, and a predetermined driving route is set as appropriate according to the surrounding conditions. However, in this case, if there is a tendency for the host vehicle to depart the lane to the left, the situation corresponds to that in FIG. 6. Also, if there is a tendency for the host vehicle to depart the lane to the right, the situation corresponds to that in FIG. 8. Note that the control itself is the same for both the left and right directions. Therefore, the left and right cases are respectively described in the explanation of the flowchart.

[0088] On the other hand, if it is determined in the processing of step S11 that the vehicle M is not in a situation where it is likely to deviate from the lane 201, the process proceeds to the processing of step S21 in Fig. 4 (see circle 4 in Figs. 3 and 4). In this case, in the processing steps after step S21 in Fig. 4, a predetermined driving route is set appropriately according to the surrounding conditions by lane keeping driving control (see the situations in Figs. 5 and 7).

[0089] If it is determined in the processing of step S11 in Fig. 3 that the host vehicle M is in a situation where it is likely to deviate from the host vehicle lane 201 (the situation in Fig. 6), the process proceeds to the processing of step S12, in which the cruise control unit 24 checks whether or not an oncoming vehicle (M1 or M2) has been recognized based on the output information of the surrounding situation information acquisition device (22, 23, etc.). If an oncoming vehicle (M1 or M2) has been recognized, the process proceeds to the next step S13. If an oncoming vehicle (M1 or M2) has not been recognized, the process proceeds to the processing of step S18.

[0090] In this situation, the oncoming vehicles in the oncoming lane recognized by the driving assistance device 1 of the host vehicle M are shown as examples of oncoming vehicles indicated by symbols M1 and M2 in Figures 6 and 8. In the situation assumed in this case, the oncoming vehicle recognized by the host vehicle M is assumed to be either symbol M1 or M2. In addition, although the situation in which an oncoming vehicle is not recognized is omitted from the illustration, a situation in which the oncoming vehicle (M1 or M2) in Figures 6 and 8 does not exist is assumed.

[0091] Next, in step S13, the driving control unit 24 detects the lateral distance (G1 or G2) between the host vehicle M and the recognized oncoming vehicle (M1 or M2) and the relative speed between the host vehicle M and the oncoming vehicle (M1 or M2) based on the output information of the surrounding situation information acquisition device (22, 23, etc.), and makes a judgment on the detected distance value and relative speed value.

[0092] An example of the determination made here is whether the lateral distance (G1 or G2) between the vehicle M and the oncoming vehicle (M1 or M2) is less than a predetermined threshold, and whether the relative speed between the vehicle M and the oncoming vehicle (M1 or M2) is greater than or equal to a predetermined threshold.

[0093] Here, the predetermined threshold value for the lateral distance (G1 or G2) between the host vehicle M and the oncoming vehicle (M1 or M2) and the predetermined threshold value for the relative speed between the host vehicle M and the oncoming vehicle (M1 or M2) are set to a distance that does not cause the driver of the host vehicle to feel intimidated or oppressed by the oncoming vehicle when the host vehicle M and the oncoming vehicle (M1 or M2) pass each other.

[0094] A specific example of the threshold value for the lateral distance between the host vehicle and an oncoming vehicle is assumed to be approximately the width of the vehicle (for example, approximately 1.5 m). Also, a specific example of the threshold value for the relative speed between the host vehicle and the oncoming vehicle is assumed to be, for example, a situation in which the host vehicle and the oncoming vehicle are traveling at a normal traveling speed on an ordinary road (for example, approximately 50 km / h), in which case the relative speed when the host vehicle and the oncoming vehicle pass each other is assumed to be approximately 100 km / h.

[0095] In this case, a situation that meets the above two conditions (lateral distance and relative speed) is assumed to be a case where an oncoming vehicle M2 is recognized in Figures 6 and 8. In this situation, the lateral distance G2 between the host vehicle M and the oncoming vehicle M2 is closer than a predetermined threshold, and the relative speed is higher than a predetermined threshold, so when the host vehicle M passes the oncoming vehicle M2, the oncoming vehicle M2 is likely to give the driver of the host vehicle M a sense of intimidation or oppression. This means that the closer the distance to the oncoming vehicle M2 and the higher the relative speed, the greater the sense of intimidation or oppression the driver will feel from the oncoming vehicle M2.

[0096] Furthermore, when the host vehicle M passes an oncoming vehicle M2 that is also traveling, if the above two conditions are met, it can be estimated that the avoidance priority is high, taking into consideration the possibility of a collision, etc. Therefore, if the above two conditions are met in step S13, the process proceeds to the next step S14.

[0097] On the other hand, in the above-mentioned step S13, a situation where the above two conditions are not met is assumed to be a case where an oncoming vehicle M1 is recognized in Figures 6 and 8. In this situation, the lateral distance G1 between the host vehicle M and the oncoming vehicle M1 is greater than a predetermined threshold, or the relative speed is lower than a predetermined threshold. From this, when the host vehicle M passes the oncoming vehicle M1 in a situation where the above two conditions are not met, it can be estimated that the sense of intimidation or pressure felt by the driver of the host vehicle M is relatively low, and the avoidance priority is low.

[0098] Therefore, if the above two conditions are not met in step S13, the process proceeds to step S16.

[0099] In step S16, the cruise control unit 24 determines whether the height of the sidewalls, etc. 204 existing along the shoulder side of the lane 201 in which the host vehicle is traveling exceeds a predetermined threshold. In the example shown in this embodiment, the height of the sidewalls, etc. 204 is compared with the height of the outer rear-view mirrors (not shown; in FIG. 3, they are referred to as mirrors; hereinafter, simply referred to as mirrors) of the host vehicle M to determine whether the height of the sidewalls, etc. 204 is higher than the height position of the mirrors of the host vehicle M.

[0100] In this case, the height of the sidewalls etc. 204 is information obtained based on output information of the surrounding situation information acquisition device (22, 23 etc.). In addition, the height position of the mirrors of the vehicle M is numerical information specific to the vehicle M, and is obtained by referring to data stored in advance in a storage device etc. (not shown) included in the cruise control unit 24, for example.

[0101] In general, the height position of a mirror in a vehicle is set at a position approximately equal to the driver's line of sight in the horizontal direction. Therefore, in a situation where the height of the side wall or the like 204 on the shoulder side of the vehicle M while traveling is higher than the height position of the mirror of the vehicle M (i.e., the driver's line of sight), the driver may feel a sense of intimidation or oppression from the side wall or the like 204. This means that the higher the side wall or the like 204, the greater the sense of intimidation or oppression the driver will feel from the oncoming vehicle M2.

[0102] When the host vehicle M travels along the side wall or the like 204 on the road shoulder side, if the height of the side wall or the like 204 is high, it can be estimated that the avoidance priority is high in consideration of the possibility of a collision, etc. Therefore, if it is determined in the above-mentioned step S16 that the height of the side wall or the like 204 is higher than the height position of the mirror of the host vehicle M, the driving assistance device 1 of the host vehicle M recognizes the side wall or the like 204 as a collision avoidance target, and proceeds to the processing of the next step S17. On the other hand, if it is determined that the height of the side wall or the like 204 is lower than the height position of the mirror of the host vehicle M, the processing proceeds to the processing of step S18.

[0103] In step S17, the driving control unit 24 performs control to create a new lane departure prevention target driving path (abbreviated as lane departure prevention path in FIG. 3) at a position where the host vehicle M is laterally farther away from the side wall, etc. 204 than the lane departure prevention target driving path during normal control. Thereafter, the process returns to step S11, and lane keeping driving control is continued.

[0104] Here, for example, the processing of step S17 (creation of a lane departure prevention path corresponding to side walls, etc.) is performed in the following circumstances when there is a tendency for the vehicle to depart from the lane to the left. That is, in Fig. 6, the driving path indicated by reference symbol 207bl indicates the lane departure prevention target driving path during normal control. Also, the driving path indicated by reference symbol 207dl indicates the lane departure prevention target driving path corresponding to the side wall, etc. 204, an object to be avoided on the shoulder side of the road, when the driver steers left due to being aware of an oncoming vehicle, etc., and the predicted driving path is shifted to the left (see reference symbol 207ac in Fig. 6). This lane departure prevention target driving path 207dl is generated at a position farther away from the side wall, etc. 204 in the lateral direction than the lane departure prevention target driving path 207bl during normal control.

[0105] That is, the situation at this time is that the host vehicle M is in a situation where it is about to deviate leftward from the host vehicle lane 201 (Y in step S11), an oncoming vehicle (M1 or M2) is recognized (Y in step S12), and further, the situation does not match the above two conditions (lateral distance and relative speed) in the processing of step S13 (N in step S13) (therefore, the recognized oncoming vehicle is symbol M1), and it has been determined that the height of the side wall, etc. 204 on the shoulder side is higher than the height position of the mirror of the host vehicle M (Y in step S16). In other words, this is a situation where the oncoming vehicle M1 is recognized, and the side wall, etc. 204 is higher than the height of the mirror of the host vehicle M.

[0106] At this time, control is performed to create a new lane departure prevention target driving path 207dl in which the host vehicle M travels at a position away from the side wall, etc. 204 relative to the lane departure prevention target driving path 207bl during normal control. At this time, the oncoming vehicle M1 recognized by the driving assistance device 1 of the host vehicle M is at a lateral distance greater than a predetermined threshold or the relative speed is lower than a predetermined threshold, so it can be estimated that the avoidance priority for the oncoming vehicle M1 is low. On the other hand, the side wall, etc. 204 is determined to be higher than the predetermined threshold, so it can be estimated that the avoidance priority for the side wall, etc. 204 is high. For this reason, even if the new lane departure prevention target driving path 207dl is set at a position farther away from the side wall, etc. 204 than the lane departure prevention target driving path 207bl during normal control (i.e., a predetermined position closer to the oncoming lane 202), it is considered that the driver will feel less intimidated or oppressed by the oncoming vehicle M1. On the other hand, the new lane departure prevention target driving path 207dl is set at a position farther away from the side walls, etc. 204 than the lane departure prevention target driving path 207bl during normal control, so the driver can reduce the sense of intimidation and pressure he or she feels from the side walls, etc. 204.

[0107] Furthermore, the processing of step S17 (creation of a lane departure prevention path corresponding to a side wall, etc.) when there is a tendency for the vehicle to depart from the lane to the right is performed as follows: In other words, in Fig. 8, the driving path indicated by reference symbol 207br indicates a lane departure prevention target driving path corresponding to the object to be avoided on the shoulder side of the road, i.e., the side wall, etc. 204, when the driver steers right due to being aware of the side wall, etc., and the predicted driving path is shifted to the right (see reference symbol 207ad in Fig. 8). This lane departure prevention target driving path 207dr is generated at a position farther away from the side wall, etc. 204 in the lateral direction than the lane departure prevention target driving path 207br in normal times.

[0108] That is, in this situation, the oncoming vehicle M1 recognized by the driving assistance device 1 of the host vehicle M is at a lateral distance greater than a predetermined threshold or at a relative speed lower than a predetermined threshold, so it can be estimated that the avoidance priority for the oncoming vehicle M1 is low. On the other hand, the side wall, etc. 204 is determined to be higher than the predetermined threshold, so it can be estimated that the avoidance priority for the side wall, etc. 204 is high. For this reason, by setting the new lane departure prevention target driving path 207dr as described above, the driver can reduce the sense of intimidation or oppression he or she feels from the oncoming vehicle M2 and the side wall, etc. 204.

[0109] Then, the driving control unit 24 controls the driving of the host vehicle M along the new lane departure prevention target driving paths 207dl, 207dr. After that, when the side walls, etc. 204 are no longer recognized, driving control is performed to return the host vehicle M to the original lane keeping target driving path 205, as shown by reference symbol 207r in Figures 6 and 8.

[0110] As a result, when the lane departure prevention control intervenes when the driver steers left while being aware of an oncoming vehicle, or when the driver steers right while being aware of a side wall or the like 204, if the presence of a side wall or the like 204 is recognized on the road shoulder side, or if the presence of an oncoming vehicle M1 is recognized, new lane departure prevention target driving paths 207dl, 207dr are created that take into account the height of the side wall or the like 204 and the oncoming vehicle M1. These new lane departure prevention target driving paths 207dl, 207dr are set at positions where the host vehicle M is further away from the side wall or the like 204 than the normal lane departure prevention target driving paths 207bl, 207br, so the driver can avoid a sense of intimidation or oppression from the oncoming vehicle M1 and can also reduce a sense of intimidation or oppression from the side wall or the like 204. In this case, the driver does not experience any discomfort or annoyance due to the further intervention of the lane departure prevention control.

[0111] On the other hand, if it is confirmed in step S13 that the situation satisfies the two conditions (lateral distance and relative speed) and the process proceeds to step S14, in step S14, the cruise control unit 24 determines whether the height of the side wall, etc. 204 is higher than the height position of the mirror of the host vehicle M, as in step S16. If it is determined that the height of the side wall, etc. 204 is higher than the height position of the mirror of the host vehicle M, the process proceeds to step S18 (see circle A in FIG. 3). If it is determined that the height of the side wall, etc. 204 is lower than the height position of the mirror of the host vehicle M, the process proceeds to the next step S15.

[0112] In step S15, the driving control unit 24 performs control to create a new lane departure prevention target driving path (abbreviated as lane departure prevention path in FIG. 3) at a position where the host vehicle M is laterally separated from the oncoming vehicle M2. Thereafter, the process returns to step S11, and the lane keeping driving control is continued.

[0113] For example, the processing of step S15 (creation of an oncoming vehicle-compatible lane departure prevention path) is performed in the following circumstances when there is a tendency for the vehicle to depart from the lane to the left. That is, in Fig. 6, the driving path indicated by reference symbol 207cl indicates the lane departure prevention target driving path during oncoming vehicle response control when the driver steers left due to being aware of an oncoming vehicle or the like and the predicted driving path is shifted to the left (see reference symbol 207ac in Fig. 6). This lane departure prevention target driving path 207cl is generated at a position farther away from the oncoming vehicle M2 in the lateral direction than the normal lane departure prevention target driving path 207bl. That is, the situation at this time is that the host vehicle M is in a situation where it is about to deviate leftward from the host vehicle lane 201 (Y in step S11), an oncoming vehicle (M1 or M2) is recognized (Y in step S12), and furthermore, the situation satisfies the above two conditions (lateral distance and relative speed) in the processing of step S13 (Y in step S13) (therefore, the recognized oncoming vehicle is symbol M2), and it has been determined that the height of the side wall etc. 204 on the road shoulder side is lower than the height position of the mirror of the host vehicle M (N in step S14). In other words, this is a situation where the oncoming vehicle M2 is recognized, and the side wall etc. 204 is lower than the mirror height of the host vehicle M.

[0114] In such a case, control is performed to create a new lane departure prevention target driving path 207cl in which the host vehicle M travels at a position away from the oncoming vehicle M, relative to the lane departure prevention target driving path 207bl during normal control. At this time, the oncoming vehicle M2 recognized by the driving assistance device 1 of the host vehicle M is closer in lateral distance than a predetermined threshold and its relative speed is higher than the predetermined threshold, so it can be estimated that the avoidance priority for the oncoming vehicle M2 is high. On the other hand, since the side wall 204 is determined to be lower than the predetermined threshold, it can be estimated that the avoidance priority for the side wall 204 is low. For this reason, even if the new lane departure prevention target driving path 207cl is set at a position away from the oncoming vehicle M2 than the lane departure prevention target driving path 207bl during normal control (i.e., a predetermined position closer to the side wall 204), it is considered that the driver will feel less intimidated or oppressed by the side wall 204. On the other hand, the new lane departure prevention target driving path 207cl is set at a position farther away from the oncoming vehicle M2 than the lane departure prevention target driving path 207bl during normal control, so the driver can reduce the sense of intimidation and pressure he or she feels from the oncoming vehicle M2.

[0115] Furthermore, for example, the situation in which the process of step S15 (creation of an oncoming vehicle-compatible lane departure prevention path) is performed when there is a tendency for the vehicle to deviate to the right is as follows: In other words, in Fig. 8, the driving path indicated by reference symbol 207cr indicates the lane departure prevention target driving path during oncoming vehicle response control when the driver steers right due to being aware of a side wall or the like and the predicted driving path is shifted to the right (see reference symbol 207ad in Fig. 8). This lane departure prevention target driving path 207cr is generated at a position where the host vehicle M is laterally farther away from the oncoming vehicle M2 (i.e., a predetermined position closer to the side wall or the like 204) than the lane departure prevention target driving path 207br under normal conditions.

[0116] That is, in this situation, the oncoming vehicle M2 recognized by the driving assistance device 1 of the host vehicle M is closer in lateral direction than a predetermined threshold and its relative speed is higher than the predetermined threshold, so it can be estimated that the avoidance priority for the oncoming vehicle M2 is high. On the other hand, the side wall, etc. 204 is determined to be lower than the predetermined threshold, so it can be estimated that the avoidance priority for the side wall, etc. 204 is low. For this reason, by setting the new lane departure prevention target travel path 207cr as described above, the driver can reduce the sense of intimidation and oppression he or she feels from the oncoming vehicle M2 and the side wall, etc. 204.

[0117] Then, the cruise control unit 24 controls the host vehicle M to travel along the new lane departure prevention target travel paths 207cl, 207cr. After that, when the oncoming vehicle M2 is no longer recognized, cruise control is performed to return the host vehicle M to the original lane keeping target travel path 205, as shown by reference symbol 207r in FIGS. 6 and 8.

[0118] As a result, when the lane departure prevention control intervenes when the driver steers left while being conscious of an oncoming vehicle, or when the driver steers right while being conscious of the side wall or the like 204, if the presence of the oncoming vehicle M2 is recognized, new lane departure prevention target driving paths 207cl, 207cr are created that take into account the height of the oncoming vehicle M2 as well as the height of the side wall or the like 204. These new lane departure prevention target driving paths 207cl, 207cr are set at positions where the host vehicle M is further away from the oncoming vehicle M2 than the normal lane departure prevention target driving paths 207bl, 207br, so the driver can avoid feeling intimidated or oppressed by the side wall or the like 204 and the oncoming vehicle M2, and further, the driver does not experience any strange or uncomfortable sensations due to the intervention of the lane departure prevention control.

[0119] Furthermore, if an oncoming vehicle is not recognized in the processing of step S12 described above, or if the processing of step S14 described above determines that the height of the side wall etc. 204 on the shoulder side of the vehicle M is higher than the height position of the mirror of the vehicle M (see circle A in Figure 3), or if the processing of step S16 described above determines that the height of the side wall etc. 204 on the shoulder side of the vehicle M is lower than the height position of the mirror of the vehicle M, when the processing proceeds to step S18, in this step S18, the driving control unit 24 performs normal lane departure suppression control.

[0120] In addition, here, if the processing of the above-mentioned step S14 determines that the height of the side wall etc. 204 on the shoulder side of the vehicle M is higher than the height position of the mirror of the vehicle M (see circle symbol A in Figure 3), the processing of the previous step S13 determines that the above two judgment conditions (lateral distance and relative speed) regarding the oncoming vehicle (M1 or M2) are met (i.e., the recognized amount of oncoming vehicle is symbol M2).

[0121] Therefore, in the driving assistance device 1 of this embodiment, in addition to the oncoming vehicle M2, the side wall 204 on the road shoulder side must be taken into consideration at the same time. In this case, it can be estimated that both the oncoming vehicle M2 and the side wall 204 have a high priority for avoidance for the host vehicle M. Therefore, in this case, normal lane departure suppression control is executed instead of a driving route that pulls the host vehicle to either the left or right. Then, a normal lane departure suppression target driving route 207bl is created, and driving control is executed to follow this route.

[0122] On the other hand, if the processing of step S16 above determines that the height of the side wall etc. 204 on the shoulder side of vehicle M is lower than the height position of the mirror of vehicle M, the processing of the previous step S13 determines that the above two judgment conditions (lateral distance and relative speed) regarding the oncoming vehicle (M1 or M2) do not match.

[0123] Therefore, in the driving assistance device 1 of this embodiment, it can be estimated that it is a situation in which it is not necessary to take into consideration either the oncoming vehicle M2 or the sidewall 204 on the road shoulder side. In such a situation, normal lane departure prevention control is naturally executed. Then, a normal lane departure prevention target driving path 207bl is created, and driving control is executed to follow this path.

[0124] Furthermore, if an oncoming vehicle is not recognized in the process of step S12, it can be assumed that the steering is not intentional, for example, due to carelessness of the driver, etc. In this case, it is only necessary to create a normal lane departure prevention target driving path 207bl and perform driving control to follow this path.

[0125] Thereafter, driving control is performed to return the host vehicle M to the original lane keeping target driving path 205, as in the driving path indicated by reference symbol 207r in Fig. 6. In this case, if an oncoming vehicle has been recognized in the processing steps before step S18 (Y in step S12), driving control is performed to return the host vehicle M to the original lane keeping target driving path 205 after the oncoming vehicle is no longer recognized. Thereafter, the process returns to step S11, and lane keeping driving control is continued.

[0126] Furthermore, if it is determined in the processing of step S11 in Figure 3 described above that the vehicle M is unlikely to deviate from the vehicle's lane 201, the process proceeds to step S21 in Figure 4, and as described above, in the processing steps after step S21, a predetermined driving route is set appropriately according to the surrounding conditions by lane keeping driving control when there is no tendency for the vehicle to deviate from the lane.

[0127] 4, the cruise control unit 24 performs the same process as step S12 described above. That is, the cruise control unit 24 checks whether an oncoming vehicle (M1 or M2) has been recognized. If an oncoming vehicle (M1 or M2) has been recognized, the process proceeds to the next step S22. If an oncoming vehicle (M1 or M2) has not been recognized, the process proceeds to step S27.

[0128] In this situation, the oncoming vehicles in the oncoming lane recognized by the driving assistance device 1 of the host vehicle M are shown as oncoming vehicles indicated by symbols M1 and M2 in Fig. 5 and Fig. 7, as in the situation in Fig. 6 and Fig. 8 (step S12 in Fig. 3) described above. That is, the oncoming vehicle recognized by the host vehicle M in the situation assumed in this case is assumed to be either symbol M1 or M2. Furthermore, although a situation in which an oncoming vehicle is not recognized is not shown, a situation in which no oncoming vehicle (M1 or M2) exists in Fig. 5 and Fig. 7 is assumed.

[0129] 4, the cruise control unit 24 performs the same process as in step S13 described above. That is, in step S22, the cruise control unit 24 detects the lateral distance (G1 or G2) between the host vehicle M and the oncoming vehicle (M1 or M2) and the relative speed between the host vehicle M and the oncoming vehicle (M1 or M2), and makes a determination on the detected distance value and relative speed value.

[0130] If it is confirmed in step S22 that the above two conditions (lateral distance and relative speed) are met, the process proceeds to the next step S23. If the above two conditions are not met, the process proceeds to step S25.

[0131] In step S23, the cruise control unit 24 performs the same processing as in step S14 described above. That is, in step S23, it is determined whether or not the height of the side wall, etc. 204 is higher than the height position of the mirror of the host vehicle M. If it is determined here that the height of the side wall, etc. 204 is higher than the height position of the mirror of the host vehicle M, the process proceeds to step S27 (see circle B in FIG. 4). On the other hand, if it is determined that the height of the side wall, etc. 204 is lower than the height position of the mirror of the host vehicle M, the process proceeds to step S24.

[0132] In step S24, the cruise control unit 24 performs control to create a new lane keeping target driving path (abbreviated as lane keeping path in FIG. 4) at a position where the host vehicle M moves away from the oncoming vehicle M2. Thereafter, the process returns to step S11, and the lane keeping driving control is continued (see circled symbol 3 in FIGS. 4 and 3).

[0133] For example, the processing of step S24 (creation of an oncoming vehicle-compatible lane keeping path) when the host vehicle M is traveling along predicted traveling path 207aa (FIG. 5) to the left is performed as follows. That is, in FIG. 5, the traveling path indicated by reference numeral 205 indicates a lane keeping target traveling path under normal control. Also, in FIG. 5, the traveling path indicated by reference numeral 205al indicates a lane keeping target traveling path under oncoming vehicle-compatible control when the driver steers left due to being aware of an oncoming vehicle, etc., and the predicted traveling path shifts to the left (see reference numeral 207aa in FIG. 5). This lane keeping target traveling path 205al is generated at a position farther away from the oncoming vehicle M2 in the lateral direction than the lane keeping target traveling path 205 under normal conditions. That is, the situation at this time is that the host vehicle M is not in a situation where it is likely to deviate from the host vehicle lane 201 (N in step S11 in FIG. 3), an oncoming vehicle (M1 or M2) is recognized (Y in step S21 in FIG. 4), and further, the situation satisfies the above two conditions (lateral distance and relative speed) in the processing of step S22 (Y in step S22) (therefore, the recognized oncoming vehicle is symbol M2), and it is determined that the height of the side wall, etc. 204 on the road shoulder side is lower than the height position of the mirror of the host vehicle M (N in step S23). In other words, this is a situation where the oncoming vehicle M2 is recognized, and the side wall, etc. 204 is lower than the mirror height of the host vehicle M.

[0134] In such a case, control is performed to create a new lane keeping target driving path 205al in which the host vehicle M travels at a position away from the oncoming vehicle M2, in addition to the lane keeping target driving path 205 during normal control. At this time, the oncoming vehicle M2 recognized by the driving assistance device 1 of the host vehicle M is closer in lateral distance than a predetermined threshold and the relative speed is higher than a predetermined threshold, so it can be estimated that the avoidance priority of the oncoming vehicle M2 is high.

[0135] On the other hand, since the side wall, etc. 204 is determined to be lower than the predetermined threshold, it can be estimated that the avoidance priority for the side wall, etc. 204 is low. For this reason, even if the new lane keeping target driving path 205al is set at a position farther away from the oncoming vehicle M2 than the lane keeping target driving path 205 during normal control (i.e., a predetermined position closer to the side wall, etc. 204), it is considered that the sense of intimidation or oppression that the driver receives from the side wall, etc. 204 is low.

[0136] In addition, the new lane keeping target driving path 205al is set at a position farther away from the oncoming vehicle M2 than the lane keeping target driving path 205 during normal control, so the driver can reduce the sense of intimidation and pressure he or she feels from the oncoming vehicle M2.

[0137] Furthermore, for example, the processing of step S24 (creation of an oncoming vehicle-compatible lane keeping path) when the host vehicle M is traveling along a predicted traveling path 207ab (FIG. 7) in a rightward direction is performed as follows. That is, in FIG. 7, the traveling path indicated by reference symbol 205 indicates a lane keeping target traveling path during normal control. Also, in FIG. 7, the traveling path indicated by reference symbol 205ar indicates a lane keeping target traveling path during oncoming vehicle-compatible control when the driver steers right due to being aware of a side wall or the like and the predicted traveling path becomes reference symbol 207ab in FIG. 7. This lane keeping target traveling path 205ar is generated at a position where the host vehicle M is farther away from the side wall or the like 204 in the lateral direction than the lane keeping target traveling path 205 under normal conditions, and farther away from the oncoming vehicle M2 than the lane keeping target traveling path 205br under side wall or the like (described in detail later)

[0138] In this situation, the oncoming vehicle M2 recognized by the driving assistance device 1 of the vehicle M is closer in lateral distance than a predetermined threshold and its relative speed is higher than a predetermined threshold, so it can be estimated that the avoidance priority for the oncoming vehicle M2 is high.

[0139] On the other hand, since the side wall etc. 204 is determined to be lower than the predetermined threshold, it can be estimated that the avoidance priority for the side wall etc. 204 is low. Therefore, by setting the new lane keeping target driving path 205ar as described above, the driver can reduce the sense of intimidation and oppression that he or she receives from the oncoming vehicle M2 and the side wall etc. 204.

[0140] Then, the cruise control unit 24 controls the host vehicle M to travel along the new lane keeping target travel paths 205al, 205ar. After that, when the oncoming vehicle M2 is no longer recognized, cruise control is performed to return the host vehicle M to the original lane keeping target travel path 205, as shown by reference symbol 205r in FIGS. 5 and 7.

[0141] As a result, if it is determined that the vehicle is unlikely to deviate from the lane (N in step S11 in Figure 3), and the processing steps from Figure 4 onwards, i.e., lane keeping control, are performed, if an oncoming vehicle (M1 or M2) is recognized (Y in step S21), and the relationship between the recognized oncoming vehicle (M1 or M2) and the host vehicle M satisfies the above two conditions (lateral distance and relative speed) (Y in step S22), the oncoming vehicle is recognized as the oncoming vehicle corresponding to symbol M2 shown in Figures 5 and 7.

[0142] At this time, if the side wall etc. 204 is lower than the mirror height of the host vehicle M (N in step S23) and the predicted driving path is as indicated by reference symbol 207aa in Fig. 5, a new lane keeping target driving path 205al is created that reflects the driver's intention and moves the host vehicle M closer to the shoulder than the normal lane keeping target driving path 205. This new lane keeping target driving path 205al is created at a position that is farther away in the lateral direction from the oncoming vehicle M2 than the lane keeping target driving path 205 under normal control.

[0143] Also, at this time, if the side wall etc. 204 is lower than the mirror height of the vehicle M (N in step S23) and the predicted driving route is symbol 207ab in Figure 5, a new lane keeping target driving route 205ar is created at a position closer to the right than the lane keeping target driving route 205 in normal times (more specifically, a position away from the side wall etc. 204 relative to the lane keeping target driving route 205 in normal times, and away from the oncoming vehicle M2 relative to the lane keeping target driving route 205br (described in detail later) during side wall etc. response control).

[0144] In short, when the driver steers left while being aware of an oncoming vehicle, or when the driver steers right while being aware of a side wall or the like 204, it is determined that there is no tendency for the vehicle to depart from the lane and lane keeping control is performed, and when an oncoming vehicle M2 is recognized and the side wall or the like 204 is low, the host vehicle M is moved closer to the shoulder or to the right than the normal lane keeping target driving path 205, and new lane keeping target driving paths 205al, 205ar are created at a predetermined position laterally away from the oncoming vehicle M2 or the side wall or the like 204. These new lane keeping target driving paths 205al, 205ar become the lane keeping target driving paths during oncoming vehicle response control.

[0145] In this case, the host vehicle M behaves in accordance with the driver's steering intention (driving the host vehicle M to the left or right) while appropriately performing lane keeping control along the new lane keeping target driving paths 205al, 205ar set in a position away from the oncoming vehicle M2 in the lateral direction, thereby preventing the driver from feeling strange or uncomfortable.

[0146] On the other hand, if the situation is such that the above two conditions are not met in step S22, the process proceeds to step S25, where the cruise control unit 24 performs the same process as step S16. That is, in step S25, it is determined whether the height of the side wall, etc. 204 is higher than the height position of the mirror of the host vehicle M. If it is determined that the height of the side wall, etc. 204 is higher than the height position of the mirror of the host vehicle M, the process proceeds to step S26. If it is determined that the height of the side wall, etc. 204 is lower than the height position of the mirror of the host vehicle M, the process proceeds to step S27.

[0147] In step S26, the cruise control unit 24 performs control to create a new lane keeping target driving path (abbreviated as lane keeping path in FIG. 4) at a position that is farther laterally from the oncoming vehicle M2 than the lane keeping target driving path 205a1, 205a1 during the oncoming vehicle response control described above, and at a position where the host vehicle M is farther laterally from the side wall or the like 204 than the lane keeping target driving paths 205a1, 205a1 during the oncoming vehicle response control described above. Thereafter, the process returns to step S11, and the lane keeping driving control continues (see circled symbol 3 in FIGS. 4 and 3).

[0148] For example, the processing of step S26 (creation of a lane keeping path corresponding to a side wall, etc.) when the host vehicle M is traveling along a predicted traveling path 207aa (FIG. 5) in a leftward direction is as follows: In other words, in FIG. 5, the traveling path indicated by reference symbol 205bl indicates a lane keeping target traveling path corresponding to the shoulder-side object to be avoided, i.e., the side wall, etc. 204, when the driver steers left due to being aware of an oncoming vehicle, etc., and the predicted traveling path is shifted to the left (see reference symbol 207aa in FIG. 5). This lane keeping target traveling path 205bl is generated in response to steering to the left, at a position farther away from the oncoming vehicle M2 in the lateral direction than the lane keeping target traveling path 205 in normal operation, and at a position where the host vehicle M is farther away in the lateral direction from the side wall, etc. 204 than the lane keeping target traveling path 205al during the above-mentioned oncoming vehicle response control. That is, the situation at this time is that the host vehicle M is not in a situation where it is likely to deviate from the host vehicle lane 201 (N in step S11 in FIG. 3), an oncoming vehicle (M1 or M2) is recognized (Y in step S21 in FIG. 4), and further, the situation is such that the above two conditions (lateral distance and relative speed) in the processing of step S22 are not met (N in step S22) (therefore, the recognized oncoming vehicle is symbol M1), and it is determined that the height of the side wall, etc. 204 on the road shoulder side is higher than the height position of the mirror of the host vehicle M (Y in step S25). In other words, this is a situation where the oncoming vehicle M1 is recognized, and the side wall, etc. 204 is higher than the height of the mirror of the host vehicle M.

[0149] In such a case, the oncoming vehicle M1 recognized by the driving assistance device 1 of the host vehicle M is at a lateral distance greater than a predetermined threshold or at a relative speed lower than a predetermined threshold, so it can be estimated that the avoidance priority for the oncoming vehicle M1 is low. On the other hand, the side wall 204 is determined to be higher than the predetermined threshold, so it can be estimated that the avoidance priority for the side wall 204 is high.

[0150] For this reason, in response to the driver steering leftward with the oncoming vehicle M1 in mind, the cruise control unit 24 sets a new lane keeping target driving path 205bl at a predetermined position closer to the shoulder of the road than the lane keeping target driving path 205 during normal control (a position away from the oncoming vehicle M1). In this case, the new lane keeping target driving path 205bl is set at a position farther away from the side wall or the like 204 (i.e., a position closer to the oncoming vehicle M1) than the lane keeping target driving path 205al during oncoming vehicle response control, taking into consideration the presence of the oncoming vehicle M1 (low avoidance priority) and the side wall or the like 204 (high avoidance priority).

[0151] The new lane keeping target driving path 205al set in this manner takes into consideration both the oncoming vehicle M1 and the side walls, etc. 204, and therefore reduces the sense of intimidation and pressure that the driver feels from the side walls, etc. 204 and the oncoming vehicle M1.

[0152] For example, the processing of step S26 (creation of a side wall or other corresponding lane keeping path) when the host vehicle M is traveling along predicted traveling path 207ab (FIG. 7) in a rightward direction is performed as follows: That is, in FIG. 7, the traveling path indicated by reference symbol 205br indicates the lane keeping target traveling path during side wall or other corresponding control when the driver steers right due to being aware of a side wall or other similar object and the predicted traveling path is shifted to the right (see reference symbol 207ab in FIG. 7). This lane keeping target traveling path 205br is generated at a predetermined position where the host vehicle M is laterally separated from the side wall or other similar object 204, relative to the lane keeping target traveling path 205 during normal control.

[0153] In this situation, the oncoming vehicle M1 recognized by the driving assistance device 1 of the host vehicle M is either farther away in the lateral direction than a predetermined threshold or has a relative speed lower than a predetermined threshold, so it can be estimated that the avoidance priority for the oncoming vehicle M1 is low. On the other hand, the side wall, etc. 204 is determined to be higher than the predetermined threshold, so it can be estimated that the avoidance priority for the side wall, etc. 204 is high. For this reason, by setting a new lane keeping target driving path 205br as described above, the driver can reduce the sense of intimidation or oppression he or she feels from the side wall, etc. 204 and the oncoming vehicle M1.

[0154] Then, the cruise control unit 24 controls the host vehicle M to travel along these new lane keeping target travel paths 205bl, 205br. After that, when the side walls, etc. 204 are no longer recognized, cruise control is performed to return the host vehicle M to the original lane keeping target travel path 205, as shown by reference symbol 205r in Figures 5 and 7. Thereafter, the process returns to step S11 in Figure 3, and lane keeping travel control is continued (see circled reference symbol 3 in Figures 4 and 3).

[0155] As a result, if it is determined that the vehicle is unlikely to deviate from the lane (N in step S11 in Figure 3), and the processing steps from Figure 4 onwards, i.e., lane keeping control, are performed, if an oncoming vehicle M1 is recognized and the side wall etc. 204 is higher than the mirror height of the vehicle M, a new lane keeping target driving path 205bl, 205br is created that reflects the driver's intention and moves the vehicle M closer to the shoulder or to the right than the normal lane keeping target driving path 205.

[0156] Here, the new lane keeping target driving path 205bl is created at a position farther away from the oncoming vehicle M1 in the lateral direction than the lane keeping target driving path 205 during normal control, and farther away from the side wall, etc. 204 than the lane keeping target driving path 205al during oncoming vehicle response control. In addition, the new lane keeping target driving path 205br is created at a position farther away from the side wall, etc. 204 in the lateral direction than the lane keeping target driving path 205 during normal control.

[0157] In short, even if the driver steers left while being aware of an oncoming vehicle, it is determined that there is no tendency for the vehicle to depart from the lane, and lane keeping control is performed. In this case, if the oncoming vehicle M1 is recognized and the side wall or the like 204 is high, the host vehicle M is moved closer to the shoulder than the normal lane keeping target driving path 205, and a new lane keeping target driving path 205bl is created at a position away from the oncoming vehicle M1 and away from the side wall or the like 204, relative to the lane keeping target driving path 205al. This new lane keeping target driving path 205bl becomes the lane keeping target driving path during side wall or the like response control.

[0158] Similarly, even if the driver steers to the right while being aware of an oncoming vehicle, it is determined that there is no tendency for the vehicle to depart from the lane, and lane keeping control is performed. In this case, if an oncoming vehicle M1 is recognized and the side wall or the like 204 is high, the host vehicle M is moved to the right of the normal lane keeping target driving path 205, and a new lane keeping target driving path 205br is created in a position away from the side wall or the like 204. This new lane keeping target driving path 205br becomes the lane keeping target driving path during side wall or the like response control.

[0159] In this case, the host vehicle M appropriately performs lane keeping control along the new lane keeping target driving paths 205bl, 205br while behaving in accordance with the driver's steering intention (driving to the left or right), thereby preventing the driver from feeling strange or uncomfortable.

[0160] Furthermore, if it is determined in the processing of step S23 above that the height of the sidewall, etc. 204 on the shoulder side of the host vehicle M is higher than the height position of the mirror of the host vehicle M (see circle B in FIG. 4), or if it is determined in the processing of step S25 above that the height of the sidewall, etc. 204 on the shoulder side of the host vehicle M is lower than the height position of the mirror of the host vehicle M, the process proceeds to step S27, in which the cruise control unit 24 executes normal lane keeping control. Thereafter, when an oncoming vehicle or sidewall, etc. 204 is no longer recognized, cruise control is executed to return the host vehicle M to the original lane keeping target travel path 205, as indicated by reference symbol 205r in FIG. 5. Thereafter, the process returns to the processing of step S11 in FIG. 3, and lane keeping travel control is continued (see circle 3 in FIGS. 4 and 3).

[0161] The normal lane keeping driving control executed here is, for example, driving control along the lane keeping target driving path 205 shown in Fig. 5. The situation at this time is when it is determined that the vehicle is unlikely to deviate from the lane, as described above (N in step S11 in Fig. 3). Therefore, at this time, the host vehicle M may be traveling at a position slightly deviated toward the shoulder from the lane keeping target driving path 205 on which the host vehicle M is currently traveling. Therefore, here, steering intervention is performed to correct the deviation from the lane keeping target driving path 205, and driving control is performed to return the host vehicle to the lane keeping target driving path 205. In this way, lane keeping driving control is continuously performed.

[0162] As described above, according to the above embodiment, when a host vehicle M equipped with a vehicle driving assistance device 1 capable of performing at least lane keeping driving control to make the host vehicle M travel along the host vehicle lane 201 and lane departure prevention control to prevent the host vehicle M from deviating from the host vehicle lane 201 is traveling on a general road that does not have a three-dimensional structure such as a central median while performing lane keeping driving control, if it is detected that the driver has steered to the left or right with an object to be avoided, such as an oncoming vehicle or a side wall on the shoulder side 204, the steering direction and the lane departure tendency of the host vehicle M are determined from information such as the steering torque and steering angle obtained based on the output from the steering torque sensor 12 and the steering angle detection sensor 15.

[0163] Here, if steering to the left (towards the shoulder) is detected and it is determined that there is a tendency for the vehicle to depart from the lane, and if lane departure prevention control is to intervene, the lane departure prevention target driving path is set as follows.

[0164] When an oncoming vehicle (M1 or M2) and a side wall or the like 204 on the road shoulder side are recognized and the oncoming vehicle (M2) has a higher avoidance priority than the side wall or the like 204 (step S15 in FIG. 3), a lane departure prevention target driving path 207cl (see FIG. 6) is set according to the oncoming vehicle M2. This lane departure prevention target driving path 207cl is set at a position that is farther away from the oncoming vehicle M2 in the lateral direction than the lane departure prevention target driving path 207bl during normal control.

[0165] Furthermore, when the side wall or the like 204 on the road shoulder side has a higher avoidance priority than the oncoming vehicle (M1) (step S17 in FIG. 3), a lane departure prevention target driving path 207dl (see FIG. 6) is set according to the side wall or the like 204. This lane departure prevention target driving path 207dl is set at a position that is farther away from the side wall or the like 204 in the lateral direction than the lane departure prevention target driving path 207bl during normal control.

[0166] In addition, if steering to the left (towards the road shoulder) is detected and it is determined that there is no tendency for the vehicle to depart from the lane, and if lane keeping control is to be performed, the lane keeping target driving path is set as follows.

[0167] When an oncoming vehicle (M1 or M2) and a side wall or the like 204 on the road shoulder side are recognized and the oncoming vehicle (M2) has a higher avoidance priority than the side wall or the like 204 (step S24 in FIG. 4), a lane keeping target driving path 205al (see FIG. 5) is set according to the oncoming vehicle M2. This lane keeping target driving path 205al is set at a position that is farther away from the oncoming vehicle M2 in the lateral direction than the lane keeping target driving path 205 during normal control.

[0168] In addition, if the side wall, etc. 204 on the shoulder side of the road has a higher avoidance priority than the oncoming vehicle (M1) (step S26 in Figure 4), a lane keeping target driving path 205bl (see Figure 5) is set according to the side wall, etc. 204.

[0169] This lane keeping target driving path 205bl is set at a position that is laterally farther from the oncoming vehicle M2 than the lane keeping target driving path 205 during normal control, and at a position where the vehicle M is laterally farther from the side wall, etc. 204 than the lane keeping target driving path 205al during oncoming vehicle response control.

[0170] On the other hand, if steering to the right (towards the center of the road) is detected and it is determined that there is a tendency for the vehicle to depart from the lane, and if lane departure prevention control is to intervene, the lane departure prevention target driving path is set as follows.

[0171] When an oncoming vehicle (M1 or M2) and a side wall or the like 204 on the road shoulder side are recognized and the oncoming vehicle (M2) has a higher avoidance priority than the side wall or the like 204 (step S24 in FIG. 4), a lane departure prevention target driving path 207cr (see FIG. 8) is set according to the oncoming vehicle M2. This lane departure prevention target driving path 207cr is set at a position that is farther away from the oncoming vehicle M2 in the lateral direction than the lane departure prevention target driving path 207br during normal control.

[0172] Furthermore, when the side wall or the like 204 on the road shoulder side has a higher avoidance priority than the oncoming vehicle (M1) (step S26 in FIG. 4), a lane departure prevention target driving path 207dr (see FIG. 8) is set according to the side wall or the like 204. This lane departure prevention target driving path 207dr is set at a position that is farther away from the side wall or the like 204 in the lateral direction than the lane departure prevention target driving path 207br during normal control.

[0173] In addition, if steering to the right (towards the center of the road) is detected and it is determined that there is no tendency for the vehicle to depart from the lane, and if lane keeping control is to be performed, the lane keeping target driving path is set as follows.

[0174] When an oncoming vehicle (M1 or M2) and a side wall or the like 204 on the side of the road are recognized and the oncoming vehicle (M2) has a higher avoidance priority than the side wall or the like 204 (step S24 in Figure 4), a lane keeping target driving path 205ar (see Figure 7) corresponding to the oncoming vehicle M2 is set.

[0175] This lane keeping target driving path 205ar is set at a position that is laterally farther from the oncoming vehicle M2 than the lane keeping target driving path 205 under normal control, and at a position where the vehicle M is laterally farther from the side wall, etc. 204 than the lane keeping target driving path 205 under normal control.

[0176] In addition, if the side wall, etc. 204 on the shoulder side of the road has a higher avoidance priority than the oncoming vehicle (M1) (step S26 in Figure 4), a lane keeping target driving path 205br (see Figure 7) is set according to the side wall, etc. 204.

[0177] This lane keeping target driving path 205br is set at a position that is farther laterally from the side wall or the like 204 than the lane keeping target driving path 205 during normal control.

[0178] In this way, the driving assistance device 1 of this embodiment detects the relative relationship between the host vehicle and an object to be avoided based on various information such as the surrounding situation information of the host vehicle M acquired by the surrounding situation information acquisition device and the steering direction and steering angle of the host vehicle M acquired by the steering torque sensor and steering angle detection sensor, estimates the avoidance priority for objects to be avoided, including oncoming vehicles recognized around the host vehicle M, and sets a lane maintenance target driving path or a lane departure prevention target driving path according to the avoidance priority.

[0179] With this configuration, when the driver of the vehicle M traveling on a public road steers to the left or right, for example, while being aware of an oncoming vehicle or a side wall on the side of the road, the driving assistance device 1 of this embodiment can perform lane keeping control or lane departure prevention control that reflects the driver's steering intention, while preventing the lane keeping control or lane departure prevention control from intervening more than necessary.Therefore, it is possible to perform appropriate driving assistance control and achieve smooth driving control without causing the driver any sense of discomfort or annoyance.

[0180] The present invention is not limited to the above-described embodiments, and various modifications and applications can be made without departing from the spirit and scope of the invention. Furthermore, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining the disclosed multiple constituent elements. For example, if the problem to be solved by the invention can be solved and the effects of the invention can be obtained even if some constituent elements are deleted from all the constituent elements shown in one embodiment, the configuration from which these constituent elements are deleted can be extracted as the invention. Furthermore, constituent elements from different embodiments may be appropriately combined. The present invention is not limited by specific embodiments other than as limited by the appended claims. [Explanation of symbols]

[0181] 1...Driving assistance device 2...Steering mechanism 3...Tie rod 4...Handle 5...Steering axis 6...Electric power steering (EPS) device 7...EPS motor 8…EPS control unit (EPS_ECU) 10...CAN communication 11...Steering assist control unit 11a...Lane keeping control unit (ALK_ECU) 11b...Lane Departure Prevention Control Unit (LDP_ECU) 12...Steering torque sensor 13...Vehicle speed sensor 14...Yaw rate sensor 15...Steering angle detection sensor 21...Camera unit 21c...Image Processing Unit (IPU) 21d...Image recognition processing section 22...In-car camera 22a...Main camera 22b...Sub camera 23...Radar equipment 23fl...Left front side radar sensor 23fr...Right front side radar sensor 23rl...Left rear side radar sensor 23rr...Right rear side radar sensor 24...Drive control unit 201…own lane 202...Oncoming traffic 203...Road center line 204...Curb 205, 205x...Lane keeping target driving route 205al, 205ar...Lane keeping target driving route (when controlling for oncoming vehicles) 205bl, 205br...Lane keeping target driving path (when controlling against side walls, etc.) 206a...extension of the right side of the vehicle 206b...extension of the right side of the oncoming vehicle M1 206c...extension of the right side of the oncoming vehicle M2 207aa, 207ab...Predicted driving route (small steering angle) 207ac, 207ad...Predicted driving route (large steering angle) 207bl, 207br...Lane departure prevention target driving path (normal control) 207cl, 207cr...Lane departure prevention target driving path (when controlling for oncoming vehicles) 207dl, 207dr... Lane departure prevention target driving path (when controlling against side walls, etc.) 208L, 208R...Departure detection horizontal position virtual line FL, FR…Left and right front wheels RL, RR…Left and right rear wheels G1: Lateral distance between your vehicle and oncoming vehicle M1 G2: Lateral distance between your vehicle and oncoming vehicle M2 M...own vehicle M1, M2...Oncoming vehicles

Claims

1. A driving assistance device for a vehicle that can perform at least a lane keeping control that causes a vehicle to travel along a driving lane and a lane departure suppression control that suppresses the vehicle from deviating from the driving lane, a surrounding situation information acquisition device for acquiring surrounding situation information of the vehicle; a steering angle detection sensor for detecting a steering angle and a steering direction of the vehicle; a driving control unit that includes a steering assist control unit that performs driving control including steering assist control based on output information from the surrounding situation information acquisition device and the steering angle detection sensor, and that performs overall control of the vehicle; Equipped with the steering assist control unit determines a tendency of the vehicle to deviate from its driving lane based on output information from the surrounding situation information acquisition device and the steering angle detection sensor, recognizes an oncoming vehicle in an oncoming lane adjacent to the driving lane of the vehicle and an object to be avoided on a shoulder side of the driving lane of the vehicle based on the output information from the surrounding situation information acquisition device, and estimates avoidance priorities of the oncoming vehicle and the object to be avoided, When it is determined that the vehicle has a tendency to depart from its lane, setting a new lane departure prevention target driving route for the vehicle in accordance with the avoidance priority; If it is determined that the vehicle does not have a tendency to depart from its lane, A new lane-keeping target driving route for the vehicle is set according to the avoidance priority. A vehicle driving assistance device characterized by:

2. The avoidance priority of the oncoming vehicle is The vehicle is determined to be high when the lateral distance between the vehicle and the oncoming vehicle is less than a predetermined threshold and the relative speed between the vehicle and the oncoming vehicle is higher than a predetermined threshold, The avoidance priority of the object to be avoided is The height of the object to be avoided is determined to be high when it is higher than the height of the exterior rearview mirror of the vehicle.

2. The vehicle driving assistance device according to claim 1.

3. When the oncoming vehicle is recognized, When either the avoidance priority of the oncoming vehicle or the avoidance priority of the object to be avoided is higher, The new lane keeping target driving route or the new lane departure prevention target driving route is 3. The vehicle driving assistance device according to claim 2, wherein the vehicle driving assistance device is set at a position laterally away from the oncoming vehicle or the object to be avoided that has a high avoidance priority.

4. When the oncoming vehicle is recognized, When the avoidance priority of the oncoming vehicle and the avoidance priority of the object to be avoided are both high, The new lane keeping target driving route or the new lane departure prevention target driving route is The driving route is the same as the lane keeping target driving route or the lane departure prevention target driving route when the oncoming vehicle is not recognized.

4. The vehicle driving assistance device according to claim 2 or 3.

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