CN110481551B - Automatic lane changing control method and device and vehicle - Google Patents

Automatic lane changing control method and device and vehicle Download PDF

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Publication number
CN110481551B
CN110481551B CN201910757839.2A CN201910757839A CN110481551B CN 110481551 B CN110481551 B CN 110481551B CN 201910757839 A CN201910757839 A CN 201910757839A CN 110481551 B CN110481551 B CN 110481551B
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lane
vehicle
target
point
determining
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CN110481551A (en
Inventor
陈志新
尚秉旭
刘洋
王洪峰
李宇寂
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FAW Group Corp
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FAW Group Corp
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60WCONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00Conjoint control of vehicle sub-units of different type or different function
    • B60W10/20Conjoint control of vehicle sub-units of different type or different function including control of steering systems
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60WCONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W30/00Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units, or advanced driver assistance systems for ensuring comfort, stability and safety or drive control systems for propelling or retarding the vehicle
    • B60W30/18Propelling the vehicle
    • B60W30/18009Propelling the vehicle related to particular drive situations
    • B60W30/18163Lane change; Overtaking manoeuvres
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06KRECOGNITION OF DATA; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K9/00Methods or arrangements for reading or recognising printed or written characters or for recognising patterns, e.g. fingerprints
    • G06K9/00624Recognising scenes, i.e. recognition of a whole field of perception; recognising scene-specific objects
    • G06K9/00791Recognising scenes perceived from the perspective of a land vehicle, e.g. recognising lanes, obstacles or traffic signs on road scenes
    • G06K9/00798Recognition of lanes or road borders, e.g. of lane markings, or recognition of driver's driving pattern in relation to lanes perceived from the vehicle; Analysis of car trajectory relative to detected road
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60WCONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2540/00Input parameters relating to occupants
    • B60W2540/18Steering angle

Abstract

The embodiment of the invention discloses a control method and device for automatic lane changing and a vehicle. The method comprises the following steps: determining a target lane to be changed of a current vehicle according to the acquired lane change request, acquiring lane line information of the target lane output by a vehicle-mounted camera on the current vehicle, determining a turning angle of a steering wheel on the current vehicle according to the lane line information, and controlling the steering wheel according to the turning angle so that the current vehicle drives into the target lane. Compared with the prior art, the steering wheel is controlled according to the corner determined by the embodiment of the invention according to the lane line information of the target lane, so that the current vehicle can drive into the target lane, the automatic lane change is realized, the manual control is not needed, and the automatic driving requirement is met.

Description

Automatic lane changing control method and device and vehicle
Technical Field
The embodiment of the invention relates to the technical field of automatic driving, in particular to a control method and device for automatic lane changing and a vehicle.
Background
In recent years, the automatic driving technology is receiving wide attention, and the automatic lane changing is a relatively complex driving behavior and is one of the core problems of automatic driving. At present, most manufacturers pay attention to the automatic driving behavior of an automatic driving vehicle following the vehicle on the road, and relatively few researches on automatic lane changing are carried out. When lane change driving is required, manual control is still required.
Even some manufacturers can realize automatic lane changing, the current vehicle cannot be effectively changed to a target lane due to large sudden change of the transverse deviation in the initial lane changing stage, and even potential safety hazards exist.
Disclosure of Invention
The embodiment of the invention provides a control method and device for automatic lane changing and a vehicle, which are used for effectively realizing the automatic lane changing of the vehicle and meeting the automatic driving requirement.
In a first aspect, an embodiment of the present invention provides a control method for automatically changing lanes, including:
determining a target lane to be changed of the current vehicle according to the acquired lane change request;
acquiring lane line information output by a vehicle-mounted camera on the current vehicle;
determining the turning angle of a steering wheel on the current vehicle according to the lane line information;
and controlling the steering wheel according to the turning angle to enable the current vehicle to drive into the target lane.
In a second aspect, an embodiment of the present invention further provides a control device for automatically changing lanes, including:
the target lane determining module is used for determining a target lane to be changed of the current vehicle according to the acquired lane changing request;
the information acquisition module is used for acquiring lane line information output by the vehicle-mounted camera on the current vehicle;
the corner determining module is used for determining the corner of a steering wheel on the current vehicle according to the lane line information;
and the control module is used for controlling the steering wheel according to the turning angle so that the current vehicle enters the target lane.
In a third aspect, an embodiment of the present invention further provides a vehicle, including:
the vehicle-mounted camera is used for acquiring lane line images and outputting lane line information according to the lane line images;
a steering wheel for controlling steering of the vehicle;
a vehicle speed sensor for measuring a vehicle speed of the vehicle;
an autonomous driving system for controlling the vehicle to be autonomously driven;
one or more controllers;
a processor for storing one or more programs;
the one or more programs, when executed by the controller, cause the controller to implement the automatic lane change control method according to the first aspect.
The embodiment of the invention provides a control method and a control device for automatic lane changing and a vehicle, wherein a target lane to be changed of a current vehicle is determined according to an obtained lane changing request, lane line information of the target lane output by a vehicle-mounted camera on the current vehicle is obtained, a turning angle of a steering wheel on the current vehicle is determined according to the lane line information, and the steering wheel is controlled according to the turning angle so that the current vehicle drives into the target lane. Compared with the prior art, the steering wheel is controlled according to the corner determined by the embodiment of the invention according to the lane line information of the target lane, so that the current vehicle can drive into the target lane, the automatic lane change is realized, the manual control is not needed, and the automatic driving requirement is met.
Drawings
Fig. 1 is a flowchart of a control method for automatically changing lanes according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a relationship between a current vehicle and a lane line according to an embodiment of the present invention;
fig. 3 is a flowchart of a control method for automatically changing lanes according to a second embodiment of the present invention;
fig. 4 is a schematic diagram of a target point according to a second embodiment of the present invention;
fig. 5 is a schematic diagram of positions of a current vehicle and a target point in a vehicle coordinate system according to a second embodiment of the present invention;
FIG. 6 is a schematic diagram of a lane change track according to a second embodiment of the present invention;
fig. 7 is a flowchart illustrating an implementation of automatic lane change according to a second embodiment of the present invention;
fig. 8 is a structural diagram of an automatic lane change control device according to a third embodiment of the present invention;
fig. 9 is a structural diagram of a vehicle according to a fourth embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures. In addition, the embodiments and features of the embodiments in the present invention may be combined with each other without conflict.
Example one
Fig. 1 is a flowchart of a control method for automatically changing lanes according to an embodiment of the present invention, where the embodiment is applicable to a situation that an automatically driven vehicle can automatically change lanes when the vehicle needs to drive a lane change lane, and the method may be executed by a control device for automatically changing lanes, where the device may be implemented by software and/or hardware, and may be integrated in the vehicle. Specifically, the method comprises the following steps:
and S110, determining a target lane to be changed of the current vehicle according to the acquired lane change request.
The lane change request is a request for changing the current vehicle to the left or the right, and whether the lane change request exists currently may be determined according to the state of the turn signal, for example, when the turn signal is on, it indicates that there is a lane change request, if the left turn signal is on, it indicates that there is a need for changing the lane to the left, if the right turn signal is on, it indicates that there is a need for changing the lane to the right, and when the turn signal is not on, it indicates that there is no need for changing the lane currently, and it is enough to keep driving in the lane. The target lane is a lane to be changed by the current vehicle, and it should be noted that the target lane of the embodiment is a lane adjacent to the lane where the current vehicle is located. The present vehicle is a vehicle having an automatic driving function.
And S120, acquiring lane line information of the target lane output by the vehicle-mounted camera on the current vehicle.
The vehicle-mounted camera is a front-view camera which is arranged on a current vehicle and is used for acquiring a road image in front of the current vehicle, the road image can be acquired in real time when the vehicle runs, and the road image comprises information such as other vehicles, the number of lanes, lane lines and the like. The embodiment does not limit the type and model of the front-view camera, and for example, a conventional camera may be used, or an intelligent camera integrating functions of recognition, calculation, and the like may be used. The embodiment takes an intelligent camera as an example, namely the lane line information of the target lane can be directly determined according to the acquired road image.
The lane line information is position information of two lane lines of a current vehicle and a target lane, and comprises a transverse deviation between the current vehicle and the two lane lines, a course angle between the current vehicle and the two lane lines and the like, wherein the transverse deviation is a distance between the current vehicle and the lane lines, a straight line corresponding to the distance is perpendicular to the advancing direction of the current vehicle, and the course angle is an included angle between the advancing direction of the current vehicle and the lane lines. Exemplarily, referring to fig. 2, fig. 2 is a schematic diagram illustrating a relationship between a current vehicle and a lane line according to an embodiment of the present invention. The lane where the current vehicle is located is the current lane, the lane on the left side of the current vehicle advancing direction is the left lane, the lane on the right side of the current vehicle advancing direction is the right lane, the first lane line and the second lane line are two lane lines corresponding to the left lane, the third lane line and the fourth lane line are two lane lines corresponding to the right lane, and the dotted line in fig. 2 represents the advancing direction of the current vehicle.
Assuming that the target lane is a left lane, the distance e of the current vehicle from the first lane line0The transverse deviation of the current vehicle from the first lane line is recorded as a first transverse deviation, and the distance e of the current vehicle from the second lane line2And the lateral deviation of the current vehicle from the second lane line is recorded as a second lateral deviation. The included angle theta between the advancing direction of the current vehicle and the first lane line0Recording the course angle of the current vehicle and the first lane line as a first course angle, and recording the included angle theta between the advancing direction of the current vehicle and the second lane line2And recording the current course angle between the vehicle and the second lane line as a second course angle. If the target lane is the right lane, the transverse deviation and the course angle of the current vehicle and the two lane lines can be determined according to the third lane line and the fourth lane line, and the process is similar to that of the left lane. The vehicle-mounted camera adopted by the embodiment can directly output information such as transverse deviation, course angle and the like of two lane lines corresponding to the current vehicle and the target lane, and provides basis for subsequent lane change. Of course, if a conventional camera is used, it may also be assisted by a thunderThe arrival device is determined by the vehicle control unit, and a specific determination process embodiment is not limited.
And S130, determining the turning angle of the steering wheel on the current vehicle according to the lane line information.
The steering wheel is used for controlling the driving direction of the current vehicle, when the current vehicle needs to be changed from the current lane to the target lane, the turning angle of the steering wheel needs to be determined, and the steering wheel is controlled to rotate by a corresponding angle according to the turning angle of the steering wheel so that the current vehicle can drive into the target lane from the current lane, wherein the turning angle of the steering wheel can be determined according to lane line information. For example, a target point may be selected on the target lane, the position information of the target point may be determined according to the lane line information, and the rotation angle of the steering wheel may be determined according to the position information of the target point. The target point is a point on a lane change reference line in the target lane, the lane change reference line is a straight line between two lane lines of the target lane, for example, a center line of the target lane may be used as the lane change reference line, or a certain lane line may be used as a reference, a distance from the lane change reference line to the lane line is a set proportion of the width of the target lane, a positional relationship between the lane change reference line and the two lane lines may be determined according to actual needs, and the embodiment is not limited.
After the lane change reference line is determined, a point on the lane change reference line can be selected as a target point, the embodiment does not limit the selection standard of the target point, for example, the association relationship between the vehicle speed and the position of the target point can be predetermined, and when the lane change is needed, the association relationship is searched according to the vehicle speed, so that the position of the target point can be determined. The association relationship is determined in a coordinate system established with the current vehicle as the origin, the direction in which the current vehicle advances as the Y-axis forward direction, and the direction pointed by the right hand facing the front of the current vehicle as the X-axis forward direction. The association relationship may be a one-to-one correspondence between the vehicle speed and the position of the target point, or a certain mathematical relationship between the vehicle speed and the position of the target point, and the position of the target point is determined by using the mathematical relationship in combination with the vehicle speed, which is not limited in the embodiments.
And S140, controlling the steering wheel according to the turning angle to enable the current vehicle to drive into the target lane.
After the turning angle of the steering wheel is determined, the steering wheel is automatically controlled to rotate according to the turning angle, so that the current vehicle is changed from the current lane to the target lane, manual control is not needed, automatic lane changing is realized, and the automatic driving requirement is met.
The embodiment of the invention provides an automatic lane changing control method, which comprises the steps of determining a target lane to be changed of a current vehicle according to an obtained lane changing request, obtaining lane line information of the target lane output by a vehicle-mounted camera on the current vehicle, determining a turning angle of a steering wheel on the current vehicle according to the lane line information, and controlling the steering wheel according to the turning angle so that the current vehicle drives into the target lane. Compared with the prior art, the steering wheel is controlled according to the corner determined by the embodiment of the invention according to the lane line information of the target lane, so that the current vehicle can drive into the target lane, the automatic lane change is realized, the manual control is not needed, and the automatic driving requirement is met.
Example two
Fig. 3 is a flowchart of a control method for automatically changing lanes according to a second embodiment of the present invention, which is embodied on the basis of the second embodiment, and specifically includes the following steps:
s210, determining a target lane to be changed of the current vehicle according to the acquired lane change request.
And S220, acquiring lane line information of the target lane output by the vehicle-mounted camera on the current vehicle.
And S230, determining parameter information of a target point on the target lane according to the lane line information.
Optionally, the lane line information includes: and under a vehicle coordinate system, a first transverse deviation and a first heading angle of the current vehicle and a first lane line corresponding to the target lane and a second transverse deviation and a second heading angle of the current vehicle and a second lane line corresponding to the target lane. The vehicle coordinate system is a coordinate system established by taking the current vehicle as a coordinate origin, taking the advancing direction of the current vehicle as a Y-axis forward direction and taking the direction pointed by the right hand facing the front of the current vehicle as an X-axis forward direction. The first transverse deviation, the first course angle, the second transverse deviation and the second course angle are values determined under the coordinate system, wherein the first course angle and the second course angle are included angles between a first lane line and a Y axis and between a second lane line and the Y axis respectively. Exemplarily, referring to fig. 4, fig. 4 is a schematic diagram of a target point provided in a second embodiment of the present invention. The target lane is a left lane, the lane change reference line 2 is a center line of the left lane, and the target point 1 is a point on the lane change reference line 2. The parameter information of the target point 1 is information representing a specific position of the target point 1, and may be, for example, coordinates of the target point 1 in the vehicle coordinate system and an angle between the target point 1 and the Y axis, where the angle between the target point 1 and the Y axis is an angle between the lane change reference line and the Y axis. Optionally, the parameter information of the target point 1 may be determined as follows:
determining the transverse coordinates of the target point under the vehicle coordinate system according to a transverse coordinate calculation formula, the first transverse deviation, the first course angle, the second transverse deviation, the second course angle and the longitudinal coordinates of the target point;
calculating a formula and the first course angle and the second course angle according to the course angle, and determining the course angle of the target point under the vehicle coordinate system;
and searching a first information association table according to the longitudinal coordinate of the target point according to the vehicle speed corresponding to the origin position of the current vehicle in the vehicle coordinate system to obtain the longitudinal coordinate of the target point.
Exemplarily, referring to fig. 5, fig. 5 is a schematic diagram of positions of a current vehicle and a target point in a vehicle coordinate system according to a second embodiment of the present invention, fig. 5 sets up a coordinate system with the current vehicle 3 as an origin, the target lane takes a left lane as an example, and a first lateral deviation e between the current vehicle 3 and a first lane line is shown0And a second lateral deviation e from the second lane line2A first course angle theta between the first lane line and the Y axis0And a second course angle theta between the second lane line and the Y axis2As shown in fig. 5, respectively. e is the transverse coordinate of the target point 1, when the target point 1 is located in the negative direction of the X axis, the target point 1 is negative, when the target point 1 is located in the positive direction of the X axis, the target point 1 is positive, l is the longitudinal coordinate of the target point 1, and the longitudinal coordinate of the target point 1 can be determined according to the current vehicleThe speed is obtained by searching a first information association table, the first information association table is used for storing the association relationship between the vehicle speed and the ordinate of the target point 1, and the embodiment does not limit the specific form of the association relationship. The speed of the current vehicle is the speed of the current vehicle at the origin. And the included angle theta between the lane changing reference line 2 and the Y axis is the heading angle of the target point 1. Optionally, the horizontal coordinate calculation formula of this embodiment is:
wherein e is the transverse coordinate of the target point 1 in the vehicle coordinate system, e0Is the first lateral deviation, e2Is the second lateral deviation, l is the longitudinal coordinate of the target point 1 in the vehicle coordinate system, θ0Is a first heading angle, θ2Is the second heading angle. The lateral coordinates of the target point 1 are obtained according to equation (1). The plus or minus of the lateral coordinate of the target point 1 depends on the positional relationship between the target point 1 and the X axis, for example, when the current vehicle changes lane to the right, the third lane line, the fourth lane line and the target point 1 are all located in the positive direction of the X axis, the lateral coordinate is positive, and the formula (1) can be expressed as follows:
when the current vehicle changes lane to the left, the first lane line, the second lane line, and the target point 1 are all located in the negative direction of the X axis, the lateral coordinate is negative, and equation (1) may be expressed as follows:
first heading angle theta during actual driving0And a second heading angle theta2Smaller, therefore, equation (1) can also be equivalent to:
the course angle of the target point 1 is an included angle between the lane change reference line 2 and the Y axis, and the course angle of the target point 1 can be determined according to the course angle calculation formula, the first heading angle and the second heading angle. Optionally, the heading angle calculation formula is as follows:
and theta is a course angle of the target point 1 in the vehicle coordinate system.
S240, determining a lane change track of the current vehicle changing to the target lane according to the parameter information of the target point.
And the lane changing track is a running track of the current vehicle changing from the current lane to the target lane, and is determined according to the position information and the course angle of the target point. For example, a limited number of coordinate points may be selected between the origin and the target point according to the current vehicle speed, and then the lane change trajectory and the trajectory equation corresponding to the lane change trajectory are obtained by fitting according to the origin, the limited number of coordinate points and the target point. The lane change track can also be determined in stages, and it can be understood that if the lateral acceleration of the vehicle changes suddenly in the lane change process, the lateral deviation is likely to change greatly suddenly, so that the vehicle cannot be accurately changed to the target lane, and even danger exists. For this reason, the track-changing track may be determined in segments, and the specific number of segments may be determined according to actual needs, for example, the track-changing track may be divided into two segments, a certain lateral acceleration is maintained for a certain time in the initial stage of track-changing, and then the second track segment and the track equation corresponding to the second track segment are determined according to the end point and the target point of the first track segment. Taking the two-segment method to determine the lane change trajectory as an example, optionally, S240 includes:
s2401, acquiring a vehicle speed corresponding to the original point position of the current vehicle in the vehicle coordinate system.
Specifically, the vehicle speed of the current vehicle at the origin of the coordinate system may be acquired by a vehicle speed sensor mounted on the current vehicle.
S2402, searching a second information association table according to the vehicle speed, and obtaining the lateral acceleration of the current vehicle.
The lateral acceleration is the component of the acceleration of the current vehicle on the X axis, the second information association table is used for storing the association relationship between the vehicle speed and the lateral acceleration, and after the vehicle speed of the current vehicle is determined, the second information association table is searched, so that the corresponding lateral acceleration can be obtained. The embodiment does not limit the determination process and the specific form of the correlation between the vehicle speed and the lateral acceleration. In order to ensure the stability of the lateral driving, the embodiment limits the lateral acceleration, which is optionally between-0.4 m/s2To +0.4m/s2Wherein "-" represents a negative direction of the lateral acceleration along the X-axis, and "+" represents a positive direction of the lateral acceleration along the X-axis.
S2403, determining a first track equation of a first track section of the current vehicle, coordinates of an end point of the first track section and a third course angle corresponding to the end point according to the vehicle speed, the lateral acceleration and the set running time.
The third course angle is an included angle between a tangent line of the first track segment at the end point and the Y axis. The set running time can be set according to actual needs, and the set running time is shorter due to the shorter lane changing distance, and optionally, the embodiment is set to be 0.5 s. Exemplarily, referring to fig. 6, fig. 6 is a schematic diagram of a lane change track according to a second embodiment of the present invention. Where O is the origin of the coordinate system, i.e., the current vehicle position. The point A is the terminal point of the first track segment, the track from the point O to the point A is the first track segment, and alpha is a third course angle.
The current vehicle is driven from the point O to the point A to be in uniform acceleration driving, the lateral acceleration is kept unchanged, and therefore the abscissa of the point A can be determined asWherein v is the speed of the current vehicle at the origin O, axFor the lateral acceleration corresponding to the vehicle speed, t is the set travel time, since t and axAll are smaller, then alpha is smaller, and the abscissa of the point A can be approximated toWherein v and axAre all vectors. Similarly, the ordinate of point A isSince α is small and the vehicle is currently traveling mainly sideways, i.e., the longitudinal acceleration is very small, and can be approximated to 0, the ordinate of the a point can be approximated to vt. From this, it can be found that the coordinates of the point A areThird course angleSince the current vehicle is running laterally at a uniform acceleration and the running time is short, the first trajectory segment OA can be processed approximately as a straight line, and the trajectory equation of the first trajectory segment OA, i.e. the first trajectory equation, can be determined according to the coordinates of the point a.
S2404, determining a second track equation of a second track segment of the current vehicle according to the coordinates of the end point, a third course angle corresponding to the end point and the parameter information of the target point, wherein the second track segment is a track segment from the end point of the first track segment to the target point.
The second track segment is a track segment from the end point of the first track segment to the target point, i.e., a track segment from point a to point B in fig. 6. In order to ensure the smoothness of the second trajectory segment and smooth the vehicle change-over process, the trajectory between the points a and B may be optionally determined in combination with the characteristics of the bezier curve. Bezier curves, also known as bezier curves or bezier curves, are curves applied to two-dimensional graphics applications. The curve is formed based on coordinates of known points, for example, two points are known, a formed bezier curve is a straight line between the two points, three points are known, a formed bezier curve is a quadratic bezier curve, four points are known, a formed bezier curve is a cubic bezier curve, and so on. Illustratively, taking the example of determining the second trajectory segment and the corresponding second trajectory equation in conjunction with the bezier curve, S2404 includes:
according to the coordinate of the terminal point, the third course angle and the parameter information of the target point, determining the coordinates of the first control point and the second control point respectively by combining a second track determination rule;
and determining a second track equation of a second track segment corresponding to the target point from the end point according to the end point, the coordinates of the first control point and the second control point and the parameter information of the target point.
In this embodiment, a cubic bezier curve is taken as an example, the curve needs coordinates of four known points, the coordinates of a point a and a point B are already determined, the point a and the point B are respectively a start point and an end point of the curve, coordinates of two other points need to be determined, and then a second trajectory equation corresponding to a second trajectory segment is determined according to the coordinates of the four points and a parametric expression of the cubic bezier curve.
In order to ensure the smoothness of the second track segment and ensure the smooth lane change process of the vehicle, the second track determination rule is set in the embodiment as the connection line of the point a and the first control point is the tangent line of the second track segment at the point a, that is, the included angle between the connection line of the point a and the first control point and the Y axis is the same as the course angle of the point a, and the connection line of the second track point and the point B is the tangent line of the second track segment at the point B, that is, the included angle between the connection line of the point B and the second control point and the Y axis is the same as the course angle of the point B. And according to the second track determination rule, combining the coordinates of the point A and the point B and the heading angle to determine the coordinates of the first control point and the second control point.
After the coordinates of the first control point and the second control point are determined, the shape of the second track segment and a corresponding second track equation can be determined according to the coordinates of the point A, the first control point, the second control point and the point B and the heading angles of the point A and the point B by combining the parameter expression of the cubic Betz curve. Illustratively, the parametric expression of the cubic bezier curve is:
P(t)=P0(1-t)3+3P1(1-t)2t+P2(1-t)t2+P3t3 (6)
wherein t is ∈ [0,1 ]],P0Is the start of the second track segment, P1Is a first control point, P2Is a second control point, P3Is the end point of the second trajectory segment, i.e. the target point. Assume a starting point state ofThe state of the target point isThen P is0=[x0,y0], P3=[xT,yT]Wherein d is1=k1(yT-y0),d2=k2(yT-y0) In this embodiment, x0Is the abscissa of point A, y0Is the ordinate of the point a and,course angle, x, of point ATIs the transverse coordinate of the target point, yTIs the longitudinal coordinate of the target point,is the course angle of the target point. k is a radical of1And k2For adjusting the shape of the second track segment, the size of the second track segment can be set according to actual needs, and optionally, k in the embodiment1=0.3,k2When the ratio is 0.3, P is added0、P1、P2And P3By substituting the coordinates of (A) into the formula (6)And obtaining a second track equation corresponding to the second track section.
And S250, determining the turning angle of the steering wheel on the current vehicle according to the lane changing track.
After the track equation corresponding to the track changing track is determined, the rotation angle of the steering wheel can be determined according to the speed of the current vehicle and the corresponding track equation. Specifically, the rotation angle of the steering wheel may be determined as follows:
s2501, searching a third information association table according to the speed of the current vehicle corresponding to the origin position, and obtaining a pre-aiming distance.
The pre-aiming distance is a longitudinal distance of a pre-aiming point on the track changing track, namely a longitudinal coordinate under a vehicle coordinate system, the pre-aiming distance is related to the vehicle speed of the current vehicle, the pre-aiming distance corresponding to the vehicle speed, namely the longitudinal coordinate of the pre-aiming point, can be obtained by searching a third information association table according to the vehicle speed, wherein the third information association table is used for storing the association relationship between the vehicle speed and the pre-aiming distance, and the embodiment does not limit the specific form of the association relationship.
S2502, determining a third transverse deviation corresponding to the pre-aiming distance according to the pre-aiming distance and by combining a track equation corresponding to the track changing track.
And substituting the value of the vertical coordinate corresponding to the pre-aiming distance into the track equation corresponding to the lane changing track to obtain the horizontal coordinate of the pre-aiming point, wherein the absolute value of the horizontal coordinate is the third transverse deviation. Therefore, the pre-aiming distance and the third transverse deviation of the pre-aiming point can be obtained, and a basis is provided for determining the rotation angle.
S2503, determining the rotation angle of the steering wheel according to a rotation angle calculation formula, the pre-aiming distance and the third transverse deviation.
Substituting the pre-aiming distance and the third lateral deviation into a rotation angle calculation formula to obtain a corresponding rotation angle, optionally, the rotation angle calculation formula provided in this embodiment is as follows:
of which the steering wheel isCorner epredIs the third lateral deviation, /)predAnd when the vehicle is determined, the corresponding wheelbase L is also determined. After the turning angle is determined, the steering wheel is controlled to rotate according to the turning angle, and the current vehicle can be changed from the current lane to the target lane.
And S260, controlling the steering wheel according to the turning angle to enable the current vehicle to drive into the target lane.
The following briefly describes an automatic lane change process, and referring to fig. 7, fig. 7 is a flowchart for implementing an automatic lane change according to a second embodiment of the present invention, after an automatic driving operation is started, a vehicle is automatically driven in a vehicle lane, during the driving operation, whether a lane change request is made is determined, if yes, a target lane and a target point corresponding to the target lane are determined according to the lane change request, then a lane change track is determined according to parameter information of the target point, a pre-aiming distance and a third lateral deviation of a pre-aiming point are determined according to the lane change track and a vehicle speed, the pre-aiming distance and the third lateral deviation are substituted into a corner calculation formula to determine a corner of a steering wheel, and the vehicle is controlled to change from the vehicle lane to the target lane according to the corner. And if the lane change request is not received in the driving process, the vehicle continues to run on the lane.
The second embodiment of the invention provides a control method for automatic lane changing, which is characterized in that on the basis of the first embodiment, the parameter information of a target is determined by using lane line information, and then the lane changing track is determined in two sections, so that the situation that the lane cannot be changed accurately due to large sudden change of lateral deviation in the initial stage of lane changing is avoided, the smoothness of the lane changing process is ensured, and the automatic driving requirement is met.
EXAMPLE III
Fig. 8 is a structural diagram of an automatic lane change control apparatus according to a third embodiment of the present invention, which is capable of executing the automatic lane change control method according to the third embodiment, and specifically, the apparatus includes:
the target lane determining module 310 is configured to determine a target lane to be changed of a current vehicle according to the acquired lane change request;
the information acquisition module 320 is configured to acquire lane line information of the target lane output by a vehicle-mounted camera on the current vehicle;
the corner determining module 330 is configured to determine a corner of a steering wheel on the current vehicle according to the lane line information;
and the control module 340 is configured to control the steering wheel according to the turning angle, so that the current vehicle enters the target lane.
The third embodiment of the invention provides a control device for automatically changing lanes, which determines a target lane to be changed of a current vehicle according to an acquired lane changing request, acquires lane line information of the target lane output by a vehicle-mounted camera on the current vehicle, determines a turning angle of a steering wheel on the current vehicle according to the lane line information, and controls the steering wheel according to the turning angle so that the current vehicle drives into the target lane. Compared with the prior art, the steering wheel is controlled according to the corner determined by the embodiment of the invention according to the lane line information of the target lane, so that the current vehicle can drive into the target lane, the automatic lane change is realized, the manual control is not needed, and the automatic driving requirement is met.
On the basis of the above embodiment, the rotation angle determining module 330 includes:
the parameter information determining unit is used for determining the parameter information of a target point on the target lane according to the lane line information;
the lane change track determining unit is used for determining a lane change track of the current vehicle to the target lane according to the parameter information of the target point;
and the corner determining unit is used for determining the corner of the steering wheel on the current vehicle according to the lane changing track.
On the basis of the above embodiment, the lane line information includes: under a vehicle coordinate system, a first transverse deviation and a first heading angle of the current vehicle and a first lane line corresponding to the target lane and a second transverse deviation and a second heading angle of the current vehicle and a second lane line corresponding to the target lane;
the parameter information determining unit is specifically used for determining the transverse coordinates of the target point under the vehicle coordinate system according to a transverse coordinate calculation formula, the first transverse deviation, the first course angle, the second transverse deviation, the second course angle and the longitudinal coordinates of the target point;
calculating a formula and the first course angle and the second course angle according to the course angle, and determining the course angle of the target point under the vehicle coordinate system;
and searching a first information association table according to the longitudinal coordinate of the target point according to the vehicle speed corresponding to the origin position of the current vehicle in the vehicle coordinate system to obtain the longitudinal coordinate of the target point.
On the basis of the above embodiment, the horizontal coordinate calculation formula is:
wherein e is the transverse coordinate of the target point in the vehicle coordinate system, e0Is the first lateral deviation, e2Is a second lateral deviation, l is the longitudinal coordinate of the target point in the vehicle coordinate system, θ0Is a first heading angle, θ2Is a second course angle;
the course angle calculation formula is as follows:
and theta is a course angle of the target point under the vehicle coordinate system.
On the basis of the above embodiment, the track change trajectory determination unit includes:
the vehicle speed obtaining subunit is used for obtaining a vehicle speed corresponding to the original point position of the current vehicle in the vehicle coordinate system;
the lateral acceleration obtaining subunit is used for searching a second information association table according to the vehicle speed to obtain the lateral acceleration of the current vehicle;
the first track equation determining subunit is used for determining a first track equation of a first track segment of the current vehicle, coordinates of an end point of the first track segment and a third course angle corresponding to the end point according to the vehicle speed, the lateral acceleration and the set running time;
and the second track equation determining subunit is configured to determine a second track equation of a second track segment of the current vehicle according to the coordinate of the end point, the third heading angle corresponding to the end point, and the parameter information of the target point, where the second track segment is a track segment from the end point of the first track segment to the target point.
On the basis of the above embodiment, the second trajectory equation determining subunit is specifically configured to determine, according to the coordinates of the end point, the third course angle, and the parameter information of the target point, coordinates of the first control point and the second control point, respectively, in combination with a second trajectory determination rule;
and determining a second track equation of a second track segment corresponding to the target point from the end point according to the end point, the coordinates of the first control point and the second control point and the parameter information of the target point.
On the basis of the above embodiment, the corner determining unit is specifically configured to search a third information association table according to the vehicle speed of the current vehicle corresponding to the origin position, and obtain a pre-aiming distance;
according to the pre-aiming distance, determining a third transverse deviation corresponding to the pre-aiming distance by combining a track equation corresponding to the track changing track;
and determining the rotation angle of the steering wheel according to a rotation angle calculation formula, the pre-aiming distance and the third transverse deviation.
On the basis of the above embodiment, the rotation angle calculation formula is as follows:
wherein is the angle of rotation of the steering wheel, epredIs the third lateral deviation, /)predAnd L is the pre-aiming distance, and is the wheelbase of the current vehicle.
The automatic lane changing control device provided by the third embodiment of the invention can execute the automatic lane changing control method described in the above embodiments, and has corresponding functions and beneficial effects.
Example four
Fig. 9 is a structural diagram of a vehicle according to a fourth embodiment of the present invention, and specifically, referring to fig. 9, the vehicle includes: the controller 410, the vehicle-mounted camera 420, the steering wheel 430, the vehicle speed sensor 440, the automatic driving system 450 and the memory 460, the controller 410 of the present embodiment is integrated in the automatic driving system 450 as an example, the controller 410, the vehicle-mounted camera 420, the steering wheel 430, the vehicle speed sensor 440, the automatic driving system 450 and the memory 460 may be connected by a bus or in other manners, and fig. 9 illustrates the connection by the bus as an example.
And the vehicle-mounted camera 420 is used for acquiring the lane line image and outputting lane line information according to the lane line image. And a steering wheel 430 for controlling steering of the vehicle. A vehicle speed sensor 440 for measuring a vehicle speed of the vehicle. An autopilot system 450 for controlling the vehicle to drive autonomously.
The memory 460 is a computer-readable storage medium, and can be used for storing software programs, computer-executable programs, and modules, such as program instructions/modules corresponding to the automatic lane changing control method in the embodiment of the present invention. The controller 410 executes various functional applications and data processing of the vehicle by executing software programs, instructions, and modules stored in the memory 460, that is, implements the automatic lane change control method of the above-described embodiment.
The memory 460 mainly includes a program storage area and a data storage area, wherein the program storage area can store an operating system and an application program required by at least one function; the storage data area may store data created according to the use of the terminal, and the like. Further, the memory 460 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some examples, the memory 460 may further include memory located remotely from the controller 410, which may be connected to the vehicle over a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.
The vehicle provided by the fourth embodiment of the present invention is the same as the control method for automatic lane changing provided by the foregoing embodiments, and the technical details that are not described in detail in the present embodiment can be referred to the foregoing embodiments, and the present embodiment has the same advantageous effects as the control method for performing automatic lane changing.
EXAMPLE five
Fifth embodiment of the present invention further provides a storage medium, on which a computer program is stored, where the computer program, when executed by a controller, implements the method for controlling automatic lane changing according to the fifth embodiment of the present invention.
Of course, the storage medium containing the computer-executable instructions provided by the embodiments of the present invention is not limited to the operations in the automatic lane changing control method described above, and may also perform related operations in the automatic lane changing control method provided by any embodiments of the present invention, and has corresponding functions and advantages.
From the above description of the embodiments, it is obvious for those skilled in the art that the present invention can be implemented by software and necessary general hardware, and certainly, can also be implemented by hardware, but the former is a better embodiment in many cases. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which may be stored in a computer-readable storage medium, such as a floppy disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a FLASH Memory (FLASH), a hard disk or an optical disk of a computer, and includes several instructions for enabling a computer device (which may be a robot, a personal computer, a server, or a network device) to execute the automatic lane changing control method according to the embodiments of the present invention.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims (8)

1. A control method for automatic lane changing is characterized by comprising the following steps:
determining a target lane to be changed of the current vehicle according to the acquired lane change request;
acquiring lane line information of the target lane output by a vehicle-mounted camera on the current vehicle;
determining the turning angle of a steering wheel on the current vehicle according to the lane line information;
controlling the steering wheel according to the turning angle to enable the current vehicle to drive into the target lane;
the determining the turning angle of the steering wheel on the current vehicle according to the lane line information includes:
determining parameter information of a target point on the target lane according to the lane line information; determining a lane changing track of the current vehicle changing to the target lane according to the parameter information of the target point; determining the turning angle of a steering wheel on the current vehicle according to the lane changing track;
wherein the lane line information includes: under a vehicle coordinate system, a first transverse deviation and a first heading angle of the current vehicle and a first lane line corresponding to the target lane and a second transverse deviation and a second heading angle of the current vehicle and a second lane line corresponding to the target lane;
the determining the parameter information of the target point on the target lane according to the lane line information includes:
determining the transverse coordinates of the target point under the vehicle coordinate system according to a transverse coordinate calculation formula, the first transverse deviation, the first course angle, the second transverse deviation, the second course angle and the longitudinal coordinates of the target point; calculating a formula and the first course angle and the second course angle according to the course angle, and determining the course angle of the target point under the vehicle coordinate system;
and searching a first information association table according to the longitudinal coordinate of the target point according to the vehicle speed corresponding to the origin position of the current vehicle in the vehicle coordinate system to obtain the longitudinal coordinate of the target point.
2. The method of claim 1, wherein the lateral coordinate calculation formula is:
wherein e is the transverse coordinate of the target point in the vehicle coordinate system, e0Is the first lateral deviation, e2Is a second lateral deviation, l is the longitudinal coordinate of the target point in the vehicle coordinate system, θ0Is a first heading angle, θ2Is a second course angle;
the course angle calculation formula is as follows:
and theta is a course angle of the target point under the vehicle coordinate system.
3. The method according to claim 1, wherein the determining a lane change trajectory of the current vehicle to change to the target lane according to the parameter information of the target point comprises:
acquiring the speed of the current vehicle corresponding to the original point position of the vehicle coordinate system;
searching a second information association table according to the vehicle speed to obtain the lateral acceleration of the current vehicle;
determining a first track equation of a first track section of the current vehicle, coordinates of a terminal point of the first track section and a third course angle corresponding to the terminal point according to the vehicle speed, the lateral acceleration and the set running time;
and determining a second track equation of a second track segment of the current vehicle according to the coordinates of the end point, a third course angle corresponding to the end point and the parameter information of the target point, wherein the second track segment is a track segment from the end point of the first track segment to the target point.
4. The method of claim 3, wherein determining the second trajectory equation for the second trajectory segment of the current vehicle according to the coordinates of the end point, the third heading angle corresponding to the end point, and the parameter information of the target point comprises:
according to the coordinate of the terminal point, the third course angle and the parameter information of the target point, determining the coordinates of the first control point and the second control point respectively by combining a second track determination rule;
and determining a second track equation of a second track segment corresponding to the target point from the end point according to the end point, the coordinates of the first control point and the second control point and the parameter information of the target point.
5. The method of claim 4, wherein said determining a steering angle of a steering wheel on the current vehicle based on the lane change trajectory comprises:
searching a third information association table according to the speed of the current vehicle corresponding to the original point position to obtain a pre-aiming distance;
according to the pre-aiming distance, determining a third transverse deviation corresponding to the pre-aiming distance by combining a track equation corresponding to the track changing track;
and determining the rotation angle of the steering wheel according to a rotation angle calculation formula, the pre-aiming distance and the third transverse deviation.
6. The method of claim 5, wherein the rotation angle calculation formula is:
wherein is the angle of rotation of the steering wheel, epredIs the third lateral deviation, /)predAnd L is the pre-aiming distance, and is the wheelbase of the current vehicle.
7. An automatic lane-changing control device, comprising:
the target lane determining module is used for determining a target lane to be changed of the current vehicle according to the acquired lane changing request;
the information acquisition module is used for acquiring lane line information of the target lane output by the vehicle-mounted camera on the current vehicle;
the corner determining module is used for determining the corner of a steering wheel on the current vehicle according to the lane line information;
the control module is used for controlling the steering wheel according to the turning angle so that the current vehicle drives into the target lane;
the rotation angle determination module includes:
the parameter information determining unit is used for determining the parameter information of a target point on the target lane according to the lane line information; the lane change track determining unit is used for determining a lane change track of the current vehicle to the target lane according to the parameter information of the target point; the turning angle determining unit is used for determining the turning angle of a steering wheel on the current vehicle according to the lane changing track;
wherein the lane line information includes: under a vehicle coordinate system, a first transverse deviation and a first heading angle of the current vehicle and a first lane line corresponding to the target lane and a second transverse deviation and a second heading angle of the current vehicle and a second lane line corresponding to the target lane;
the parameter information determining unit is specifically used for determining the transverse coordinates of the target point under the vehicle coordinate system according to a transverse coordinate calculation formula, the first transverse deviation, the first course angle, the second transverse deviation, the second course angle and the longitudinal coordinates of the target point; calculating a formula and the first course angle and the second course angle according to the course angle, and determining the course angle of the target point under the vehicle coordinate system;
and searching a first information association table according to the longitudinal coordinate of the target point according to the vehicle speed corresponding to the origin position of the current vehicle in the vehicle coordinate system to obtain the longitudinal coordinate of the target point.
8. A vehicle, characterized by comprising:
the vehicle-mounted camera is used for acquiring lane line images and outputting lane line information according to the lane line images;
a steering wheel for controlling steering of the vehicle;
a vehicle speed sensor for measuring a vehicle speed of the vehicle;
an autonomous driving system for controlling the vehicle to be autonomously driven;
one or more controllers;
a processor for storing one or more programs;
the one or more programs, when executed by the controller, cause the controller to implement the auto-lane-change control method of any one of claims 1-6.
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