RU2803579C1 - Driving assistance method and driving assistance device - Google Patents

Abstract

FIELD: driving assistance method and a driving assistance device.

SUBSTANCE: driving assistance method for controlling own vehicle with the controller includes obtaining level difference information for a height difference existing along a lane on which one's own vehicle is traveling. When it is determined from the level difference information that the own vehicle must overcome the level difference, generation of the target driving path occurs such that the angle (θs) of overcoming the level difference, which is the angle formed by the level difference and the target trajectory, is greater than a threshold value (Th). Moreover, a larger value is set as a threshold value when the level difference is higher or the slope of the level difference is larger.

EFFECT: reduced deviation from the target trajectory when the vehicle overcomes the level difference.

15 cl, 12 dwg

Description

TECHNICAL FIELD

[0001]

The present invention relates to a driving assistance method and a driving assistance device.

BACKGROUND OF THE INVENTION

[0002]

PTL 1 describes a map data storage unit that contains level difference information related to the level difference at the entrance to an object that a vehicle is required to pass when entering said object from a road, and object information related to that object stored in association with each other. It is described that for a vehicle to enter an object, stored level difference position information is provided along with information about the ground object.

LIST OF QUOTES

Patent literature

[0003]

PTL1: JP 2019-144030 A

The essence of the invention

Technical challenge

[0004]

When, while the vehicle is passing through a level difference, the driving direction of the vehicle is inclined with respect to the passing direction of the level difference, interference is applied to the steered wheels of the vehicle, and the driving direction of the vehicle is deviated. Therefore, when in autonomous driving the vehicle is forced to independently move along a preset target motion path, a deviation from the target motion path occurs.

The purpose of the present invention is to, when assisting driving, control one's own vehicle so that one's own vehicle moves along a target driving path, reduce the deviation from the target driving path when one's own vehicle overcomes a level difference.

SOLUTION

[0005]

According to an aspect of the present invention, there is provided a driving assistance method for controlling one's own vehicle using a controller so that the own vehicle moves along a target driving path, the method including: obtaining level difference information of a certain level difference existing along a lane traffic along which your own vehicle is moving; and when it is determined based on the level difference information that the own vehicle must overcome the level difference, generating a target driving path such that the level difference crossing angle, which is the angle formed by the level difference and the target driving path, is larger than the threshold value.

ADVANTAGEOUS EFFECTS OF THE INVENTION

[0006]

According to one aspect of the present invention, the assisted driving can control one's own vehicle so that one's own vehicle moves along a target driving path, reducing deviation from the target driving path when one's own vehicle overcomes a level difference.

The object and advantages of the invention will be realized and achieved by the elements and combinations specifically set forth in the claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and do not limit the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]

FIG. 1 is a schematic diagram of a configuration of a driving assistance device according to embodiments;

FIG. 2A is an explanatory diagram of an example of a driving assistance method according to the embodiments;

FIG. 2B is another explanatory diagram of an example of a driving assistance method according to the embodiments;

FIG. 3 is a block diagram illustrating an example of a functional configuration of a driving assistance device according to the embodiments;

FIG. 4 is an explanatory diagram of an example of calculating the angle θs of overcoming the level difference;

FIG. 5A is an explanatory diagram of an example of setting the threshold value Th of the level difference overcoming angle θs;

FIG. 5B is an explanatory diagram of another example of setting the threshold value Th of the level difference overcoming angle θs;

FIG. 6 is a flowchart of an example of a driving assistance method according to embodiments;

FIG. 7 is a flowchart of an example of the path generation processing of the first embodiment;

FIG. 8A is an explanatory diagram of an example of a situation in which the target speed at the time when the own vehicle passes a height difference is set to low;

FIG. 8B is an explanatory diagram of another example of a situation in which the target speed at the time when the own vehicle passes the level difference is set low; And

FIG. 9 is a flowchart of an example of path generation processing of the second embodiment.

Description of Embodiments

[0008]

(First embodiment)

(Configuration)

With reference to FIG. 1. The own vehicle 1 includes a driving assistance device 10 configured to perform driving assistance of the own vehicle 1. The driving assistance performed by the driving assistance device 10 may include autonomous control, which is, for example, based on the traffic environment around the own vehicle 1, forces the own vehicle 1 to perform unmanned driving without the participation of the driver.

An example of unmanned control by the driving assistance device 10 may be a driving control that causes the own vehicle 1 to drive unmanned along a preset target driving path in an urban area.

[0009]

The driving assistance device 10 includes object sensors 11, vehicle sensors 12, a positioning device 13, a map database 14, a communication device 15, a controller 16, and actuators 17. In the drawings, the map database is referred to as "map" BD").

The object sensors 11 include a plurality of different types of object detection sensors that are mounted on the own vehicle 1 and detect objects around the own vehicle 1, such as laser radar, millimeter wave radar, camera and light detection and ranging, or detection and ranging. laser imaging ranging (LIDAR).

[0010]

The vehicle sensors 12 are installed on the own vehicle 1 and detect various information (vehicle signals) that can be received from the own vehicle 1. The vehicle sensors 12 include a vehicle speed sensor for detecting a driving speed (vehicle speed) own vehicle 1, wheel speed sensors for detecting the rotation speeds of the respective tires of own vehicle 1, three-axis acceleration sensor (G sensor) for detecting acceleration (including deceleration) of own vehicle 1 in three axial directions, steering wheel angle sensor for detecting the steering angle (including the steering angle), a gyro sensor for detecting the angular velocity generated by own vehicle 1, a yaw rate sensor for detecting yaw speed, an accelerator sensor for detecting the opening of the accelerator of own vehicle, and a brake sensor for detecting the actuation amount driver brakes.

[0011]

The positioning device 13 includes a global navigation satellite system (GNSS) receiver, and by receiving radio waves from a plurality of navigation satellites, measures the current position of the own vehicle 1. The GNSS receiver may be, for example, a global positioning system (GPS) receiver or the like. The positioning device 13 may be, for example, an inertial navigation device.

The map database 14 can store high-definition map data (hereinafter simply referred to as “high-definition map”), which is suitable as a map for self-driving. A high-definition map is map data of higher precision than navigation map data (hereinafter referred to simply as a “navigation map”) and includes lane unit information that is more detailed than road unit information.

[0012]

For example, a high-definition map includes, as lane unit information, information about lane nodes, which indicate reference points on a lane reference line (eg, a line at the center of a lane), and information about lane links, which indicate shapes lane sections between lane nodes.

Information about each lane node includes the identification number and position coordinates of the lane node, the number of connected lane links (sections), and the identification numbers of connected lane links. Information about each lane link includes a lane link identification number, a lane type, a lane width, types of lane boundary lines, a lane shape, a lane marking shape, and a lane reference line shape. The high-resolution map further includes the types and position coordinates of ground objects such as traffic lights, stop lines, road signs, buildings, utility poles, curbs and crosswalks that exist in or near a traffic lane, and information about ground objects, such as identification numbers of lane nodes and identification numbers of lane links, which correspond to the coordinates of the positions of ground objects.

[0013]

Since the high-definition map includes node information and link information in units of lanes, it is possible to indicate the lane in which the own vehicle 1 is traveling along the traffic route. The high-resolution map has a coordinate system that can represent the positions in the driving direction and width direction of each lane. A high-resolution map has coordinates (eg, longitude, latitude, and height) that can represent positions in three-dimensional space, and traffic lanes and the above-described ground features can be described as shapes in three-dimensional space.

The communication device 15 communicates wirelessly with a communication device external to the own vehicle 1. The communication method used by the communication device 15 may be, for example, wireless communication via a public mobile telephone network, vehicle-to-vehicle communication, vehicle-to-vehicle communication means or satellite communications.

[0014]

The controller 16 is an electronic control unit (ECU) that controls the driving assistance system of the vehicle 1. The controller 16 includes a processor 18 and peripheral components such as a memory 19. The processor 18 may be, for example, a central processing unit (CPU). CPU) or microprocessor unit (MPU).

The memory device 19 may include a semiconductor memory device, a magnetic memory device, an optical memory device, and the like. The storage device 19 may include registers, a cache memory, and memory used as a main storage device, such as read-only memory (ROM) and random access memory (RAM).

[0015]

The functions of the controller 16, which will be described below, may be implemented, for example, by a processor 18 executing computer programs stored in a storage device 19.

It should be noted that the controller 16 may be configured with specialized hardware for performing information processing, which will be described below.

For example, controller 16 may include function logic circuitry implemented in a general purpose semiconductor integrated circuit. For example, controller 16 may include a programmable logic device such as a field programmable gate array (FPGA) or the like.

[0016]

The actuators 17 operate the steering wheel, the accelerator pedal and the brake device of the own vehicle in accordance with the control signals issued by the controller 16, and thereby generate the behavior of the own vehicle. The drives 17 include a steering drive, an accelerator opening drive, and a brake control drive. The steering actuator controls the steering direction and steering amount for steering the own vehicle.

The accelerator opening drive controls the opening of the accelerator of your own vehicle. Brake control drives control the braking action of the braking devices of the own vehicle 1.

[0017]

Next, an example of driving assistance control performed by the controller 16 will be described. FIG. 2A and 2B. Reference numeral 20 indicates the lane in which the own vehicle 1 is traveling, and reference numerals 21 and 22 indicate demarcation lines indicating the boundaries of the lane 20. In the example in the description of the present invention, the demarcation line 21 represents a traffic lane outside the traffic lane 20, and the demarcation line 22 represents the boundary line of a traffic lane. Demarcation lines 21 and 22 are examples of the “traffic path boundaries” described in the claims. The boundary of a traffic path is not limited to a demarcation line and can be a ground object, such as a curb and fence, or the side of a road.

[0018]

The passage 23 is connected to the side of the traffic lane 20 so as to face the traffic lane 20, and between the traffic lane 20 and the passage 23 parallel to the traffic lane 20 there is a difference of 24 levels. Passage 23 could, for example, be a driveway to enter a facility or private property. The passage 23 does not necessarily have to be a clearly shaped passage and may, for example, be part of a passage existing between the entrance to a facility or private property and the traffic lane 20.

It is now assumed that the controller 16, which performs the unmanned control, generates a target motion path 25, which, as shown in FIG. 2A, deviates from the traffic lane 20 and enters the passage 23. Own vehicle 1, moving along the target traffic path 25, overcomes the level difference 24 and enters the passage 23.

[0019]

The angle θs formed by the direction of movement of the own vehicle 1 and the direction of passage (extent) of the difference 24 levels while the own vehicle 1 overcomes the difference 24 levels is determined by the angle formed by a straight line parallel to the difference 24 levels and the target trajectory 25 of movement, that is the angle formed by the intersection of the difference 24 levels and the target trajectory 25 of movement. Hereinafter, the angle θs formed by the intersection of the level difference 24 and the target motion path 25 is called the “angle of overcoming the level difference.”

When the level difference overcoming angle θs is less than 90 degrees, that is, when the driving direction of the own vehicle 1 is inclined with respect to the passing direction of the 24 level difference, the steering shaft interference is applied to the steering wheels of the own vehicle 1 which is overcoming the 24 level difference. In the present invention, steered wheels mean wheels controlled by a steering mechanism.

[0020]

The interference increases as the angle θs of overcoming the level difference becomes further from 90 degrees. When a large disturbance is applied to the steered wheels, there is a possibility that the actual steering angle will deviate from the target steering angle set according to the target driving path 25, the own vehicle 1 will deviate from the target driving path 25, and the own vehicle 1 will likely approaches an obstacle near his own vehicle 1.

Accordingly, when generating a target motion path that overcomes the level difference 24, the controller 16 generates the target motion path such that the angle θs of overcoming the level difference exceeds a predetermined threshold value Th.

[0021]

In fig. 2B shows an example of a target motion path 27 generated such that the level difference overcoming angle θs is greater than a predetermined threshold value Th. Generating the target driving path 27 such that the level difference overcoming angle θs is greater than a predetermined threshold value Th allows the own vehicle 1 to overcome the level difference 24 at an angle close to 90 degrees.

[0022]

With this configuration, it is possible to reduce the steering shaft interference applied to the steered wheels while overcoming the level difference 24 and reduce the deviation from the target driving path 27. As a result, it is possible to prevent a close approach to an obstacle due to deviation from the target motion trajectory 27.

It should be noted that although the description of the present invention describes the case where there is a level difference 24 between the traffic lane 20 and the driveway 23, the present invention is not limited to this. The present invention is widely applicable to cases where self-driving control generates a target motion path that overcomes a difference of 24 levels.

[0023]

Next, the functional configuration of the controller 16 will be described in detail with reference to FIG. 3. The controller 16 includes an object detection unit 30, a own vehicle position estimation unit 31, a map acquisition unit 32, a detection integration unit 33, an object tracking unit 34, a map position calculation unit 35, a driving action plan determination unit 36, block 37 for determining the passable area, block 38 for generating the target movement trajectory, block 39 for determining the level difference, block 40 for calculating the angle of overcoming the level difference, block 41 for determining the recovery, and block 42 for controlling the vehicle.

[0024]

The object detection unit 30 detects, based on the detection signals from the object sensors 11, positions, angular positions, sizes, speeds, and the like. objects around own vehicle 1, such as a vehicle, motorcycle, pedestrian and obstacle. The object detection unit 30 outputs detection results representing two-dimensional positions, angular positions, sizes, velocities, and the like. objects, for example in a zenith view (also called a plan view) in which the own vehicle 1 is viewed from the air.

[0025]

The own vehicle position estimation unit 31 measures, based on the measurement result of the positioning and odometry device 13 using the detection results from the vehicle sensors 12, the absolute position of the own vehicle 1, that is, the position of the own vehicle 1 relative to a predetermined reference point, angular position and speed of own vehicle 1.

The map receiving unit 32 obtains map information indicating the structure of the road on which the own vehicle 1 is to travel from the map database 14 . The map receiving unit 32 can receive map information from an external map data server through the communication device 15.

[0026]

The detection integration unit 33 integrates a plurality of detection results that the object detection unit 30 respectively received from a plurality of object detection sensors, and outputs one detection result regarding each of the corresponding objects.

Specifically, the detection integration unit 33 calculates, from the behavior of objects respectively obtained from the object detection sensors, the most reasonable object behavior that minimizes the error, taking into account the error characteristics of the corresponding object detection sensors.

In particular, using the known sensor fusion technology, the detection integration unit 33 comprehensively evaluates the detection results obtained by multiple types of sensors and obtains a more accurate detection result.

[0027]

The object tracking unit 34 tracks objects detected by the object detection unit 30. Specifically, based on the detection results integrated by the detection integration unit 33, the object tracking unit 34 performs an identity (association) check of objects at different times based on the behavior of objects output at different times, and predicts the behavior of objects such as speed based on the association.

[0028]

The map position calculation unit 35 estimates the position and angular position of the own vehicle 1 on the map based on the absolute position of the own vehicle 1, which was obtained by the own vehicle position estimation unit 31, and the map information, which was obtained by the map acquisition unit 32.

The driving action plan determining unit 36 determines, based on the detection results obtained by the detection integration unit 33 and the object tracking unit 34, and the position of the own vehicle 1 identified by the map position calculation unit 35, a schematic driving action of the own vehicle 1, which must be performed by the driving assistance device 10.

[0029]

Examples of the driving action that the driving action plan determining unit 36 determines include, for example, stopping the own vehicle 1, temporarily stopping, driving speed, decelerating, accelerating, changing course, turning right, turning left, driving straight, changing lanes at a merge or between multiple lanes, lane keeping, overtaking, reacting to an obstacle, etc.

The driving action plan determination block 36 generates, based on the position and angular position of own vehicle 1, which was assessed by the position calculation block 35 on the map, the positions and angular positions of objects around own vehicle 1 and the high-definition map, a route space map that represents the presence or the absence of a route and object around one's own vehicle 1, and a risk map that quantifies the risk level of the traffic field. Block 36 for determining the driving action plan generates, based on the route space map and the risk map, an action plan when driving your own vehicle 1.

[0030]

The walkable area determination unit 37 determines, based on the driving action plan determined by the driving action plan determination unit 36, the moving characteristics of the own vehicle 1 and the route space map, a walkable area in which the own vehicle 1 can be forced to move.

The target motion trajectory generation block 38 generates, based on the driving action determined by the driving action plan determination block 36, and the traversable area determined by the traversable area determination block 37, candidates for the motion trajectory along which and the speed profile in accordance with which the own vehicle is forced to move remedy 1.

The target driving path generation unit 38 evaluates the future risks of the respective candidates based on the risk map, selects the optimal driving path and speed profile, and sets the selected driving path and speed profile as the target driving path and the target speed profile according to which the own vehicle 1 is forced move accordingly.

[0031]

With reference to FIG. 2A. When a target driving path that causes the own vehicle 1 to turn as the target driving path 25 is generated, the target driving path generating unit 38 gradually increases the curvature of the target driving path 25 to a maximum curvature, and then gradually decreases the curvature of the target driving path 25.

For example, the target motion path generating unit 38 generates a target motion path 25 generated in accordance with a clothoid curve or a spline curve. It should be noted, however, that the target motion path 25 is not limited to a curve that is calculated by a known calculation formula as described above. It is required that the target motion path 25 be only a curve whose curvature gradually increases to a maximum curvature and then gradually decreases.

[0032]

The target motion path generation unit 38 can determine the rate of change of curvature of the target motion path with specific parameters. The parameters by which the rate of change in the curvature of the target motion trajectory is determined are hereinafter called “curvature attenuation (relaxation) parameters.” An example of curvature attenuation parameters is the clothoid parameters of a clothoid curve. As the curvature attenuation parameters become larger, a target motion path 25 is generated whose curvature changes more smoothly. As the curvature attenuation parameters become smaller, a target motion path 25 is generated whose curvature changes more steeply.

[0033]

With reference to FIG. 3. The level difference determining unit 39 obtains the level difference information for the level difference 24, which exists parallel to the traffic lane 20. For example, the level difference determining unit 39 may obtain level difference information based on an image recognition result of a certain image captured by the camera. In addition, the level difference determining unit 39 can obtain level difference information based on the detection results of the laser radar, millimeter wave radar and lidar.

The level difference determining unit 39 can obtain, for example, the position, height and inclination (the inclination angle of the upper surface of the level difference 24 with respect to the road surface of the lane 20 or a horizontal plane) of the level difference 24 as level difference information.

[0034]

In addition, for example, the level difference determining unit 39 can, by detecting the boundary between a public road and a private property existing on the target driving path 25 based on the cartographic information in the map database 14, obtain the level difference information for the level difference 24 set at a location on the boundary between a public road and private property.

In addition, for example, the level difference determining unit 39 can obtain, based on the driving history stored when the own vehicle 1 or the other vehicle was actually moving, level difference information for the level difference 24 existing on the target driving path 25.

[0035]

The unit 40 for calculating the angle of overcoming the level difference determines whether the target movement path 25 overcomes the difference 24 levels (whether the target movement path 25 intersects the difference 24 levels). The level difference overcoming angle calculation unit 40 calculates the level difference overcoming angle θs when the target motion path 25 overcomes the level difference 24. With reference to FIG. 4. The reference numerals 2FL and 2FR indicate the steered wheels of the own vehicle 1, and the reference numerals 2RL and 2RR indicate wheels other than the steered wheels. In the example in the description of the present invention, the steered wheels 2FL and 2FR are the left front wheel and the right front wheel, respectively, and the steered wheels 2RL and 2RR are the left rear wheel and the right rear wheel, respectively.

[0036]

The level difference overcoming angle calculation unit 40, using the path that passes the center position C of the axis 3 of the steered wheels 2FL and 2FR as the target motion path 25, calculates the level difference overcoming angle θs formed by a straight line parallel to the level difference 24 and the target path 25 movement (the angle of overcoming the difference in levels formed by the intersection of the difference 24 levels and the target trajectory 25 of movement).

As described above, by calculating the angle formed by the path that passes the center position C of the axis 3 of the steered wheels 2FL and 2FR and the straight line parallel to the level difference 24 as the overcoming angle θs of the level difference, the angle formed by the direction of the steered wheels 2FL can be calculated and 2FR, and the direction in which the difference of 24 levels passes more appropriately.

[0037]

With reference to FIG. 3. The recovery determination unit 41 determines whether the target motion path should be restored depending on the level difference overcoming angle θs calculated with respect to the target motion path 25 that the target motion path generating unit 38 generated.

When the level difference overcoming angle θs is less than or equal to the predetermined threshold value Th, the restoration determination unit 41 decides to restore the target motion path. When the level difference overcoming angle θs exceeds a predetermined threshold value Th, the restoration determination unit 41 decides not to restore the target motion path. The recovery determination block 41 outputs the determination result to the target motion trajectory generating block 38.

[0038]

In addition, the recovery determination unit 41 may dynamically change the Th threshold value. For example, the recovery determination unit 41 may set a threshold value Th that changes in accordance with the level difference information for the level difference 24. For example, the recovery determination unit 41 may set a larger value as the Th threshold value the higher the difference of 24 levels. For example, the recovery determination unit 41 may set a larger value as the threshold value Th since the slope of the level difference 24 is larger.

[0039]

For example, the recovery determination unit 41 may set a threshold value Th that changes according to the aspect ratio or outer diameter of the tires of the own vehicle 1. For example, the recovery determination unit 41 may set a higher value as the threshold value Th because the aspect ratio of the tires is smaller . For example, the recovery determination unit 41 may set a larger value as the threshold value Th because the outer diameter of the tires is smaller.

In addition, the recovery determination unit 41 can obtain information about obstacles around the own vehicle 1 from the object sensors 11. For example, in the situation shown in FIG. 5A, there are posts 40a and 40b that are obstacles.

[0040]

When the obstacles 40a and 40b exist in the vicinity of the target driving path 27 along which the own vehicle 1 is to move after overcoming the level difference 24, the recovery determination unit 41 may set a larger value as the threshold value Th.

With reference to FIG. 5B. The recovery determination unit 41 can set a larger value as the threshold value Th because the lane width W1 of the driving lane 23 in which the own vehicle 1 must travel after overcoming the level difference 24 is narrower. Information about the lane width W1 can be obtained, for example, from the map database 14.

[0041]

With reference to FIG. 3. When the restoration determination unit 41 determines to restore the target motion path, the target motion path generation unit 38 restores the target motion path.

When restoring the target motion path, the target motion path generating unit 38 restores the target motion path in such a way that the angle θs of overcoming the level difference of the restored target motion path increases.

[0042]

For example, the target motion path generation unit 38, by reducing the curvature weakening parameters of the target motion path, which forces the own vehicle 1 to turn toward the level difference 24, restores the target motion path so that the angle θs of overcoming the level difference increases.

On the other hand, when the restoration determination unit 41 determines not to restore the target driving path, the target driving path generating unit 38 outputs the target driving path and the target speed profile to the vehicle control unit 42.

[0043]

Since, through this process, the target motion path generating unit 38 repeats restoring the target motion path until the level difference overcoming angle θs becomes larger than the threshold value Th, a target motion path whose level difference overcoming angle θs is larger than the threshold value Th is generated.

In addition, the target driving path generation unit 38 may set the target speed profile such that the target vehicle speed at the time when the own vehicle 1 passes the 24 level difference is less than or equal to a predetermined low speed (for example, 10 km /h).

[0044]

In addition, the target driving path generating unit 38 can dynamically change the target speed of the vehicle at the time when the own vehicle 1 passes the difference of 24 levels.

For example, the target driving path generation unit 38 may set the target speed profile such that the target vehicle speed at the time when the own vehicle 1 passes the level difference 24 is changed in accordance with the level difference information of said level difference 24.

For example, the target driving path generation unit 38 may set a lower target speed at the time when the own vehicle 1 passes the level difference 24 because the level difference 24 is higher. For example, the target driving path generation unit 38 may also set a lower target speed at the time when the own vehicle 1 passes the level difference 24 because the slope of the level difference 24 is larger.

[0045]

For example, the target driving path generation unit 38 may set the target speed profile such that the target vehicle speed at the time when own vehicle 1 passes the 24 level difference changes in accordance with the tire aspect ratio of own vehicle 1 or the outer diameter of the tires. . For example, the target driving path generation unit 38 may set a lower target speed at the time when the own vehicle 1 passes the 24 level difference because the aspect ratio is lower. For example, the target driving path generation unit 38 may also set a lower target speed at the time when the own vehicle 1 passes the 24 level difference because the outer diameter of the tires is smaller.

[0046]

In addition, the target motion trajectory generating unit 38 can receive information about obstacles around its own vehicle 1 from object sensors 11.

With reference to FIG. 5A. The target driving path generation unit 38 may set the target speed profile such that the target speed at the time when the own vehicle 1 passes the level difference 24 becomes lower when obstacles 40a and 40b exist in the vicinity of the target driving path 27 to be driven. own vehicle 1 after overcoming the difference of 24 levels.

[0047]

With reference to FIG. 5B. The target driving path generation unit 38 can set the target speed profile such that the target speed at the time when the own vehicle 1 passes the level difference 24 becomes smaller as the width W1 of the traffic lane 23 along which the own vehicle is to move means 1, having overcome the difference of 24 levels, becomes narrower.

In addition, the target driving path generation unit 38 can set the target speed profile such that the target vehicle speed at the time when the own vehicle 1 passes the level difference 24 changes in accordance with the level difference crossing angle θs.

[0048]

For example, the target driving path generation unit 38 may set a lower target speed at the time when the own vehicle 1 passes the level difference 24 because the level difference crossing angle θs is smaller.

With reference to FIG. 3. The vehicle control unit 42 actuates the actuators 17 such that the own vehicle 1 moves along the target motion path at a speed in accordance with the target speed profile output by the target motion path generating unit 38.

[0049]

(Exploitation)

Next, an operating example of the driving assistance device 10 in the embodiment will be described with reference to FIGS. 6.

In step S1, the object detection unit 30, using a plurality of object detection sensors, determines positions, angular positions, sizes, speeds, and the like. objects around your own vehicle 1.

In step S2, the detection integration unit 33 integrates a plurality of detection results obtained respectively from a plurality of object detection sensors, and outputs one detection result regarding each of the corresponding objects. The object tracking unit 34 tracks the corresponding objects that have been detected and integrated, and predicts the behavior of the objects around the own vehicle 1.

[0050]

In step S3, the own vehicle position estimation unit 31 measures, based on the measurement result of the positioning and odometry device 13 using the detection results from the vehicle sensors 12, the position, angular position and speed of the own vehicle 1 relative to a predetermined reference point.

In step S4, the map receiving unit 32 obtains map information indicating the structure of the road along which the own vehicle 1 should travel.

In step S5, the map position calculation unit 35 estimates the position and angular position of own vehicle 1 on the map based on the position of own vehicle 1 measured in step S3 and the map data obtained in step S4.

[0051]

In step S6, the driving action plan determination unit 36 determines, based on the detection results (behavior of objects around own vehicle 1) obtained in step S2 and the position of own vehicle 1 identified in step S5, the driving action of own vehicle 1. which the driving assistance device 10 must perform.

In step S7, the traversable area determination unit 37, the target motion path generation unit 38, the level difference determination unit 39, the level difference overcoming angle calculation unit 40, and the recovery determination unit 41 perform trajectory generation processing to generate the target motion path of the own vehicle 1.

[0052]

With reference to FIG. 7, the path generation processing of the first embodiment will be described. In step S10, the walkable area determining unit 37 determines, in accordance with the driving action plan determined by the driving action plan determination unit 36 and based on the driving characteristics of the own vehicle 1 and the route space map, a walkable area in which the own vehicle 1 can be forced to move. The target driving path generation unit 38 generates, based on the driving action determined by the driving action plan determining unit 36 and the traversable area determined by the traversable area determining unit 37, a target driving path and a target speed profile.

[0053]

In step S11, the level difference determining unit 39 obtains level difference information for the level difference 24, which exists in parallel with the traffic lane 20.

At step S12, the level difference overcoming angle calculation unit 40 determines whether the target movement path 25 overcomes the level difference 24 (whether the target movement path 25 crosses the level difference 24). When the target motion path 25 overcomes the level difference 24, the level difference overcoming angle calculation unit 40 calculates the level difference overcoming angle θs.

[0054]

The recovery determination unit 41 determines whether the level difference overcoming angle θs is less than or equal to the predetermined threshold value Th or not. When the level difference overcoming angle θs is less than or equal to the predetermined threshold value Th (step S12: Y), the process proceeds to step S13.

In step S13, the target driving path generation unit 38 reduces the curvature weakening parameters of the target driving path, which causes the own vehicle 1 to turn to a difference of 24 levels.

[0055]

In step S14, the target motion path generation unit 38, using the curvature weakening parameters set in step S13, reconstructs the target motion path that overcomes the difference of 24 levels. The process then returns to step S12.

On the contrary, when in step S12, the level difference overcoming angle θs is not less than or equal to the predetermined threshold value Th (step S12: N), the target driving path generation unit 38 outputs the target driving path and the target speed profile to the vehicle control unit 42, which completes the processing generating a trajectory, and the process proceeds to step S8 in FIG. 6.

With reference to FIG. 6. In step S8, the vehicle control unit 42 controls the own vehicle 1 such that the own vehicle 1 moves in accordance with the target driving path and speed profile generated in step S7.

[0056]

(Variation)

Although in the above example, it was determined whether the overcoming angle θs of the level difference of the target motion path generated by the target motion path generation unit 38 was less than or equal to the predetermined threshold value Th, and when the overcoming angle θs of the level difference was less than or equal to the predetermined threshold value Th, the target trajectory of movement was restored, the present invention is not limited to this. When generating a target motion path that overcomes the level difference 24, the target motion path generating unit 38 can generate the target motion path by appropriately setting the curvature weakening parameters so that the angle θs of overcoming the level difference is larger than the predetermined threshold value Th. In this case, the level difference overcoming angle calculation unit 40 and the recovery determination unit 41 shown in FIG. 3 may be omitted.

[0057]

For example, the target driving path generating unit 38 can determine based on the driving action plan generated by the driving action plan determining unit 36 and the level difference information obtained by the level difference determining unit 39 whether to generate a target driving path that overcomes the difference 24 levels.

When generating a target motion path that overcomes the level difference 24, the target motion path generating unit 38 can generate a target motion path whose level difference overcoming angle θs is larger than the predetermined threshold value Th by correspondingly setting smaller curvature weakening parameters than in the case of generating the target path movement, which does not overcome the difference of 24 levels.

[0058]

(Beneficial Effects of the First Embodiment)

(1) The controller 16 controls the own vehicle 1 with the help of the controller such that the own vehicle 1 moves along the target driving path. The level difference determining unit 39 obtains level difference information for a level difference 24 that exists parallel to the lane 20 along which the own vehicle 1 is moving. When generating a target driving path that overcomes the level difference 24, the target driving path generating unit 38 generates a target trajectory in such a way that the angle θs of overcoming the level difference exceeds a predetermined threshold value Th.

Because of this configuration, the angle at which the steered wheels of the own vehicle 1 overcome the difference of 24 levels becomes small and the interference becomes small, which makes it possible to reduce the tracking error with respect to the target driving path. Thanks to this effect, you can reduce the likelihood of colliding with an off-road obstacle.

[0059]

(2) The target driving path generation unit 38 generates a target driving path depending on the detection result of an object around the own vehicle 1. When the level difference overcoming angle θs formed by the generated target driving path and the straight line parallel to the level difference 24 is less than or equal to the threshold value Th, the target motion path generation unit 38 restores the target motion path so that the angle θs of overcoming the level difference is greater than the threshold value Th.

Because of this configuration, the angle at which the steered wheels of the own vehicle 1 overcome the difference of 24 levels becomes small and the interference becomes small, which makes it possible to reduce the tracking error with respect to the target driving path. Thanks to this effect, you can reduce the likelihood of colliding with an off-road obstacle.

[0060]

(3) The recovery determination unit 41 may set a larger value as the threshold value Th the higher the difference of the 24 levels or the larger the slope of the difference of the 24 levels.

Since the higher the level difference or the larger the inclination angle, the larger the resistance force supplied to the tires from the 24 level difference becomes, and the larger the tracking error relative to the target driving path becomes, setting the threshold value Th large can suppress the error.

[0061]

(4) The recovery determination unit 41 may set a larger value as the threshold value Th because the tire aspect ratio of the own vehicle 1 is lower or the outer diameter of the tires is smaller.

Since the probability of interference on the steering wheels is determined in such a way that the lower the aspect ratio of the tires and the smaller the outer diameter of the tires, the larger the tracking error relative to the target driving path becomes, setting the threshold value Th large can suppress the error.

[0062]

(5) The recovery determination unit 41 can obtain information about obstacles around the own vehicle 1, and, when an obstacle exists near the target driving path that the own vehicle 1 should follow after crossing the 24-level difference, set a larger value as the threshold value Th.

When there is an obstacle at a position close to the target motion path, after overcoming a difference of 24 levels, setting a larger threshold value Th can suppress the error and avoid a collision.

[0063]

(6) The recovery determination unit 41 can set a larger value as the threshold value Th because the lane width for the lane in which the own vehicle 1 must travel after crossing the difference of 24 levels is narrower.

When the width of the driving path after overcoming the difference of 24 levels is narrow, setting the threshold value Th larger can suppress the error and prevent the own vehicle 1 from deviating outward from the driving path and colliding with an obstacle.

[0064]

(7) The target driving path generation unit 38 can set the target vehicle speed at the time when the own vehicle 1 passes the 24 level difference to a low speed.

Reducing the vehicle speed can quickly make trajectory correction after overcoming the difference of 24 levels, prevent the repetition of a large error, and improve the tracking performance of the target driving trajectory.

[0065]

(8) The target driving path generation unit 38 may set a lower target speed at the time when the own vehicle 1 passes the level difference 24 because the level difference 24 is larger or the slope of the level difference 24 is larger.

Since the larger the 24-level difference or the larger its slope, the larger the deviation amount becomes after the 24-level difference is overcome, reducing the vehicle speed allows the trajectory correction to be carried out quickly after the 24-level difference is overcome, it is necessary to prevent the repetition of a large error and improve the tracking of the target driving path.

[0066]

(9) The target driving path generation unit 38 may set a lower target speed at the time when the own vehicle 1 passes the level difference 24 because the aspect ratio of the tires of the own vehicle 1 is smaller or the outer diameter of the tire is smaller.

Since the smaller the aspect ratio of the tires or the smaller the outer diameter of the tires, the larger the deviation amount becomes after crossing the 24-level difference, reducing the vehicle speed allows you to quickly make trajectory adjustments after crossing the 24-level difference, prevent the recurrence of a large error, and improve subsequent actions on the target trajectory movements.

[0067]

(10) The target driving path generation unit 38 can obtain information about obstacles around the own vehicle 1, and, when an obstacle exists near the target driving path along which the own vehicle 1, after overcoming a difference of 24 levels, should move, set a lower target speed at the time when own vehicle 1 passes the difference of 24 levels.

Since the risk of collision increases when there is an obstacle after a difference of 24 levels has been overcome, reducing the speed of the vehicle can quickly correct the trajectory after a difference of 24 levels has been overcome, preventing the repetition of a big mistake and avoiding a collision.

[0068]

(11) The target driving path generation unit 38 may set a lower target speed at the time when the own vehicle 1 passes the difference of 24 levels, when the lane width for the lane in which the own vehicle 1 should travel after passing the difference of 24 levels , it's getting narrower.

Since the narrower the lane width, the higher the risk of leaving the road after overcoming the difference of 24 levels, reducing the vehicle speed allows you to quickly correct the trajectory after overcoming the difference of 24 levels, preventing the repetition of a large mistake and avoiding a collision.

[0069]

(12) The target driving path generation unit 38 can set a lower target speed of the vehicle at the time when the own vehicle 1 passes the level difference 24 because the level difference crossing angle θs is smaller.

Even when the angle θs of overcoming the level difference is small, reducing the speed of the vehicle can quickly correct the route, prevent the repetition of a large mistake, and avoid a collision.

[0070]

(13) The level difference overcoming angle calculation unit 40 can calculate, using the path along which the center position of the steering wheel axis of the own vehicle 1 passes as the target driving path, the level difference overcoming angle θs formed by a straight line parallel to the level difference 24, and target trajectory of movement.

Taking into account the trajectory of the central position of the axis of the steered wheels instead of the center of the vehicle body makes it possible to increase the accuracy of the tire inclination angle at the moment the steered wheels overcome a difference of 24 levels.

[0071]

(Second embodiment)

Next, the second embodiment will be described. How close the level difference crossing angle θs can be brought to 90 degrees depends on the driving situation, environment, etc. own vehicle 1. That is, the permissible range of the curvature weakening parameters within which the curvature weakening parameters can be adjusted to bring the level difference overcoming angle θs closer to 90 degrees depends on the driving conditions, environment, and the like. own vehicle 1. Thus, there is a case where the target driving path cannot be generated such that the level difference overcoming angle θs exceeds the predetermined threshold value Th.

[0072]

With reference to FIG. 8A. A case is assumed where a target traffic trajectory 27 is generated, which from the traffic lane 20 overcomes the level difference 24 and produces a lane change to the fork traffic lane 28. In this case, after changing lanes to lane 28 of the fork, it is necessary to steer the wheels in the opposite direction, and when the angle θs of overcoming the level difference approaches 90 degrees, the curvature weakening parameter exceeds its permissible range, and the own vehicle 1, having overcome the difference of 24 levels, becomes unable move within the boundaries of the traffic path of lane 28 of the fork. Thus, the angle θs of overcoming the level difference cannot be brought closer to 90 degrees.

[0073]

With reference to FIG. 8B. In the case where the lane width W2 of the traffic lane 20 in which the own vehicle 1 travels before overcoming the level difference 24 is narrow, when the overcoming level difference angle θs approaches 90 degrees, the curvature weakening parameter also exceeds its permissible range, and the own vehicle 1 becomes unable to move within the boundaries of the driving path of the traffic lane 20 until the difference of 24 levels is overcome. In this case, the angle θs of overcoming the level difference also cannot be brought closer to 90 degrees.

[0074]

Accordingly, the target driving path generating unit 38 of the second embodiment determines whether the target driving path can be generated such that the own vehicle 1 moves within the limits of the driving path and the level difference overcoming angle θs is larger than the threshold value Th.

When no target driving path can be generated such that the own vehicle 1 moves within the boundaries of the driving path and the level difference overcoming angle θs is larger than the threshold value Th, the target driving path generation unit 38 sets the target vehicle speed at a time instant when own vehicle 1 passes a difference of 24 levels, at a predetermined low speed.

Due to this configuration, even if the target motion path cannot be generated such that the level difference overcoming angle θs is larger than the predetermined threshold value Th, it is possible to suppress the amount of deviation from the target motion path after overcoming the 24 level difference, and promptly carry out correction after overcoming the 24 level difference .

[0075]

With reference to FIG. 9, the path generation processing of the second embodiment will be described. The processing in steps S20 to S23 is the same as the processing in steps S10 to S13 described with reference to FIG. 7.

In step S24, the target motion path generation unit 38 determines whether the curvature weakening parameters reduced in step S23 are within a predetermined allowable range. For example, the target driving path generation unit 38 determines whether a target driving path along which the own vehicle 1 moves within the driving path boundaries can be generated using the curvature weakening parameters reduced in step S23.

When the curvature weakening parameters are not in the predetermined allowable range (step S24: N), the process proceeds to step S26.

[0076]

In step S26, the target driving path generation unit 38 sets the target speed profile such that the target speed at the time when the own vehicle 1 passes the level difference 24 becomes lower. For example, the target driving path generation unit 38 sets the target speed profile such that the target speed at the time when the own vehicle 1 passes the 24 level difference is a low speed. Thereafter, the path generation processing is completed, and the process proceeds to step S8 in FIG. 6.

When the curvature weakening parameters are in the predetermined allowable range (step S24: Y), the process proceeds to step S25. The processing in step S25 is the same as the processing in step S14 described with reference to FIG. 7. The process then returns to step S22.

[0077]

(Beneficial Effects of the Second Embodiment)

The object detection unit 30 detects the driving path boundaries of the driving lane 20 in which the own vehicle 1 is moving. When no target driving path can be generated such that the own vehicle 1 moves within the driving path boundaries and the overcoming level difference angle θs greater than the threshold value Th, the target motion path generating unit 38 sets the target speed of the vehicle at the time when the own vehicle 1 passes the difference of 24 levels to a low speed.

Due to this configuration, even if the target motion path cannot be generated such that the level difference overcoming angle θs is larger than the predetermined threshold value Th, it is possible to suppress the amount of deviation from the target motion path after overcoming the 24 level difference, and promptly carry out correction after overcoming the 24 level difference .

[0078]

All examples and conventions presented herein are intended for educational purposes to assist the reader in understanding the invention and the concepts brought by the inventor to the development of the art, and are not to be construed as limiting such examples and conditions specifically listed, but the organization of such examples in the description is not associated with demonstrating the superiority or inferiority of this invention. Although one or more embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions and modifications may be made to the invention without departing from the spirit and scope of the present invention.

LIST OF POSITIONAL SYMBOLS

[0079]

1 own vehicle

2FL, 2FR steering wheel

2RL, 2RR Wheel

3 axis

10 driving assistance device

11 object sensor

12 vehicle sensor

13 positioning device

14 map database

15 communication device

16 controller

17 drive

18 processor

19 storage device

30 object detection unit

31 blocks for estimating the position of your own vehicle

32 card receiving block

33 detection integration unit

34 object tracking unit

35 block for calculating the position on the map

36 block for determining the driving action plan

37 block for determining the passable area

38 block for generating target motion trajectory

39 block for determining the level difference

40 block for calculating the angle of overcoming the level difference

41 recovery detection blocks

42 vehicle control unit

Claims (27)

1. A driving assistance method for controlling one's own vehicle by means of a controller such that one's own vehicle moves along a target driving path, the method comprising: obtaining information about the level difference of a certain level difference existing along the lane along which the own vehicle is moving; And when determining, based on the level difference information, that the own vehicle must overcome the level difference, generating a target driving path such that the level difference overcoming angle, which is the angle formed by the level difference and the target driving path, is greater than a threshold value, wherein a larger value is set as the threshold when the level difference is higher or the level difference slope is larger. 2. The driving assistance method according to claim 1, wherein the method generates a target motion trajectory depending on the result of detecting an object around its own vehicle, and in the case of obtaining information about the level difference of a certain level difference existing along the lane along which the own vehicle is moving, and determining on the basis of the level difference information that the own vehicle must overcome the level difference when the angle of overcoming the level difference formed by the generated the target motion trajectory and a level difference less than or equal to said threshold value, the method restores or corrects the target motion path so that the angle of overcoming the level difference is greater than said threshold value. 3. The driving assistance method according to claim 1 or 2, characterized in that the method sets a larger value as a threshold value when the aspect ratio of the own vehicle's tires is smaller or the outer diameter of the tires is smaller. 4. The method of driving assistance according to any one of paragraphs. 1-3, additionally containing obtaining information about obstacles around your own vehicle, wherein, if there is an obstacle close to the target motion path along which the own vehicle should move after overcoming the level difference, the method sets a larger value as said threshold value. 5. The method of driving assistance according to any one of paragraphs. 1-4, characterized in that the method sets the target speed of the vehicle, at the time when the own vehicle passes the level difference, to a low speed. 6. The method of driving assistance according to any one of paragraphs. 1-5, characterized in that the method sets a lower target speed at the time when the own vehicle passes the level difference, when the level difference is larger or the slope of the level difference is larger. 7. The method of driving assistance according to any one of paragraphs. 1-6, characterized in that the method sets a lower target speed at a time when the own vehicle passes a level difference, when the aspect ratio of the own vehicle tires is smaller or the outer diameter of the tires is smaller. 8. The method of driving assistance according to any one of paragraphs. 1-7, additionally containing obtaining information about obstacles around your own vehicle, Moreover, if there is an obstacle near the target motion path along which the own vehicle must move after overcoming the level difference, the method sets a lower target speed at the time when the own vehicle passes the level difference. 9. The method of driving assistance according to any one of paragraphs. 1-8, characterized in that the method sets a lower target speed at the time when the own vehicle passes the level difference, when the lane width for the lane in which the own vehicle must travel after overcoming the level difference is narrower. 10. The method of driving assistance according to any one of paragraphs. 1-9, additionally containing detection of the path boundaries of the lane along which your own vehicle is moving, Moreover, when the target movement path cannot be generated in such a way that the own vehicle moves within the boundaries of the movement path, and the angle of overcoming the level difference is greater than the threshold value, the method sets the target vehicle speed at the time when the own vehicle passes the difference levels, at low speed. 11. The method of driving assistance according to any one of paragraphs. 1-10, wherein the method sets a lower target speed of the vehicle at the time when the own vehicle passes the level difference, when the angle of overcoming the level difference is smaller. 12. The method of driving assistance according to any one of paragraphs. 1-11, wherein the method, using the path along which the center position of the steering wheel axis of the own vehicle passes as the target motion path, calculates the angle of overcoming the level difference formed by the level difference and the target motion path. 13. A driving assistance device configured to control one's own vehicle in such a way that one's own vehicle moves along a target trajectory, comprising: a sensor configured to detect an object around the own vehicle; And a controller configured to obtain level difference information of some level difference existing along a lane in which the own vehicle is traveling, and when based on the level difference information it is determined that the own vehicle must overcome the level difference, thereby generating a target driving path , that the angle of overcoming the level difference, which is the angle formed by the level difference and the target movement trajectory, exceeds the threshold value, and a larger value is set as the threshold when the level difference is higher or the level difference slope is larger.