CN114954470A

CN114954470A - Lane changing control method and storage medium for automatic driving vehicle

Info

Publication number: CN114954470A
Application number: CN202210740550.1A
Authority: CN
Inventors: 潘元承; 俞剑斌; 邵志文; 侯学锋; 林雅婷; 王鸿源
Original assignee: Fujian Zhongke Spruce Information Technology Co ltd
Current assignee: Fujian Zhongke Spruce Information Technology Co ltd
Priority date: 2022-06-27
Filing date: 2022-06-27
Publication date: 2022-08-30

Abstract

The invention provides a lane change control method and a storage medium of an automatic driving vehicle, wherein the method comprises the following steps: when changing lanes, if the distance S between the vehicle and the center line of the target lane is greater than a preset distance threshold S1, the linear length L of the target lane is greater than a preset length threshold L1, and no obstacle exists on an inclined path, an inclined flag is established, and the vehicle is controlled to enter an inclined steering mode; otherwise, the oblique running zone bit is not established, and the vehicle is controlled to enter a front axle steering mode; and the oblique steering mode is that all tires of the vehicle steer according to the target steering angle. The invention designs a lane change control scheme which can flexibly and autonomously switch the front axle steering mode and the diagonal steering mode according to the actual vehicle condition on the basis of an IGV vehicle, can improve the lane change efficiency and the success rate of the vehicle under the condition that the vehicle has obstacles on the side edge, simultaneously ensures the lane change safety, and has wide and good application prospect in other fields which have automatic driving requirements on the vehicle, such as ports and the like.

Description

Lane changing control method and storage medium for automatic driving vehicle

Technical Field

The invention relates to the technical field of automatic driving, in particular to a lane change control method and a storage medium of an automatic driving vehicle.

Background

An autonomous vehicle is an intelligent vehicle that is unmanned via a computer system. With the popularization of the automatic driving vehicle, the automatic driving vehicle has good application in various fields, is particularly used for transporting heavy goods, and is called as an unmanned truck in the industry.

The port is used as a transportation hub and plays a very important role in promoting international trade and regional development, about 90% of global trade is carried by sea, and the operation efficiency is important for the port. Under the era background of great development of industrial 4.0 and Internet +, digital and full-automatic transformation and upgrading are carried out in ports. Nowadays, port operation develops toward automation, and automatic wharf is constantly increased, and automatic operation constantly accelerates work efficiency, and this practices thrift the cost of labor again when increasing the new vitality in port, and in the future, the improvement of automation can further promote the intellectuality of port operation.

In the course of automatic transformation of harbors, unmanned trucks are continuously introduced for operation, and in recent years, in order to improve the flexibility of vehicles, some harbors have begun to introduce Intelligent Guided Vehicles (IGV) with four-wheel steering.

Most of the conventional unmanned trucks only have a front wheel steering mode, and when a vehicle changes lanes, if the vehicle or other objects exist on the side, the tail of the vehicle is easy to collide (as shown in the left side of fig. 1). In order to avoid the situation, the vehicle should limit the maximum turning angle at the moment, but the limitation can increase the lane changing duration and the driving distance, further influences the operation of other vehicles on the target lane and reduces the overall operation efficiency; meanwhile, if there is an obstacle in front at this time, limiting the maximum rotation angle may cause the vehicle to collide with the obstacle in front (as illustrated on the right in fig. 1), and thus the lane change operation cannot be completed.

In order to solve the problems, the invention provides an efficient and safe lane change control method based on the existing IGV.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the art described above. Therefore, an object of the present invention is to provide a lane change control method for an automatically driven vehicle, which can automatically change lanes according to a crab steer mode under a condition that a road condition allows, thereby improving lane change efficiency and success rate of the vehicle in a condition that an obstacle is present on a side of the vehicle, and simultaneously ensuring lane change safety.

A second objective of the present invention is to provide a computer-readable storage medium, wherein a program of the computer-readable storage medium, when being executed by a processor, can implement lane changing automatically according to a crab steer mode under a condition that a road condition allows, thereby improving lane changing efficiency and success rate of a vehicle in a situation that an obstacle is present on a side of the vehicle, and simultaneously ensuring lane changing safety.

In order to achieve the above object, an embodiment of a first aspect of the present invention provides a lane change control method for an autonomous vehicle, including: when changing lanes, if the distance S between the vehicle and the center line of the target lane is greater than a preset distance threshold S1, the linear length L of the target lane is greater than a preset length threshold L1, and no obstacle exists on an inclined path, an inclined flag is established, and the vehicle is controlled to enter an inclined steering mode; otherwise, the oblique running zone bit is not established, and the vehicle is controlled to enter a front axle steering mode; and the oblique steering mode is that the front wheels and the rear wheels of the vehicle are steered according to the target steering angle.

According to the lane change control method of the automatic driving vehicle, the current road condition can be automatically judged when the lane change requirement exists, and the lane change is carried out by automatically selecting the diagonal steering mode under the condition that the road condition allows, so that the lane change efficiency and the lane change success rate of the vehicle are improved, and the lane change safety is ensured.

In addition, the lane change control method for the automatic driving vehicle according to the above embodiment of the present invention may further have the following additional technical features:

further comprising:

after entering the oblique steering mode, if the distance S between the vehicle and the center line of the target lane is smaller than a preset distance threshold S3 or the distance between any corner of the vehicle and the boundary of the target lane is smaller than a preset distance threshold Q3, the current vehicle speed is smaller than a preset vehicle speed V4, and the current corner is smaller than a preset corner alpha 1, the oblique flag bit is not established, and the vehicle is controlled to exit the oblique steering mode.

Preferably, after entering the crab steer mode, performing includes:

s1: judging whether the target lane is on the right side of the vehicle; if yes, go to S2; if not, go to S3;

s2: if the included angle beta between the vehicle and the central line of the target lane is larger than 0, taking the distance between the upper right corner of the vehicle and the right boundary of the target lane as the boundary distance Q, and otherwise, taking the distance between the lower right corner of the vehicle and the right boundary of the target lane as the boundary distance Q; execution of S4;

s3: if the included angle beta between the vehicle and the central line of the target lane is larger than 0, taking the distance between the lower left corner of the vehicle and the left boundary of the target lane as the boundary distance Q, and otherwise, taking the distance between the upper left corner of the vehicle and the left boundary of the target lane as the boundary distance Q, and executing S4;

s4, calculating the distance S;

s5: if the distance S is smaller than a preset distance threshold S1 or the boundary distance Q is smaller than a preset distance threshold Q1, then S6 is performed; otherwise, setting the target vehicle speed as the preset vehicle speed V1, and returning to execute S4;

s6: if the distance S is smaller than a preset distance threshold S2 or the boundary distance Q is smaller than a preset distance threshold Q2, then S7 is performed; otherwise, setting the target vehicle speed as the preset vehicle speed V2, and returning to execute S4;

s7: if the distance S is smaller than the preset distance threshold S3, or the boundary distance Q is smaller than the preset distance threshold Q3, go to S8; otherwise, setting the target vehicle speed as the preset vehicle speed V3, and returning to execute S4;

s8: setting the target speed and the target corner to be 0;

s9: judging whether the current vehicle speed is less than a preset vehicle speed V4 and whether the current turning angle is less than a preset turning angle alpha 1;

if not, returning to execute S8; if so, the inclined running zone bit is not established, and the vehicle is controlled to exit the inclined running steering mode.

Preferably, the preset threshold length L1 is k × S, where k is a driving characteristic of the vehicle and S is a distance from a center line of the target lane.

Preferably, the length P of the diagonal path is L1/cos (α); wherein α is a target rotation angle.

Preferably, the distance threshold S1 is 4 m; the distance threshold Q1 is 4 m; the distance threshold Q2 is 2 m; the distance threshold Q3 is 0.5 m; the vehicle speed V1 is 4 km/h; the vehicle speed V2 is 2 km/h; the vehicle speed V3 is 0.5 m/s; the vehicle speed V4 is 0.1 m/s; the rotational angle alpha 1 is 2 DEG

To achieve the above object, a second embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored, the program, when being executed by a processor, being capable of implementing the steps included in the above-mentioned lane change control method for an autonomous vehicle.

According to the computer-readable storage medium of the embodiment of the invention, after being executed by the processor of the vehicle, the program on the computer-readable storage medium can automatically judge the current road condition when the vehicle has a lane change requirement, and automatically select the diagonal steering mode for lane change under the condition that the road condition allows, so that the lane change efficiency and the lane change success rate of the vehicle are improved, and the lane change safety is ensured.

Drawings

FIG. 1 illustrates two collision situations that may easily occur when a front-wheel steering mode is used during a lane change of a conventional unmanned truck;

FIG. 2 is a graphical representation of two steering modes of the vehicle;

FIG. 3 is a graphical representation of the calculated parameters involved in a lane-change control method for an autonomous vehicle in accordance with an embodiment of the present invention;

FIG. 4 is a general flowchart illustration of a lane-change control method of an autonomous vehicle in accordance with an embodiment of the present invention;

FIG. 5 is a flowchart illustrating a determination process of entering a crab steer mode in a lane change control method of an autonomous vehicle in accordance with an embodiment of the present invention;

fig. 6 is a flowchart illustrating execution of the crab steer mode control in the lane change control method of the autonomous vehicle according to the embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

The lane change control method of the automatic driving vehicle can automatically judge the current road condition when the lane change is required, and automatically select the diagonal steering mode for lane change under the condition that the road condition allows, thereby improving the lane change efficiency and the lane change success rate of the vehicle and ensuring the lane change safety.

In order to better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In order to better understand the technical solution, the technical solution will be described in detail with reference to the drawings and the specific embodiments.

The embodiment of the invention provides a lane change control method of an automatic driving vehicle, and particularly relates to judgment of entering a diagonal steering mode, control of the diagonal steering mode and judgment and control of exiting the diagonal steering mode. As shown in fig. 2, the right side indicates the tire steering when the vehicle is controlled by using the diagonal steering mode, that is, the diagonal steering mode is that all tires of the vehicle are steered according to the target steering angle; the left side is the tire steer indication when the vehicle is controlled using front axle steer mode.

As shown in fig. 4, an embodiment provides a lane change control method for an autonomous vehicle, including:

SS 1: presetting a target rotation angle alpha when a vehicle changes lanes;

SS 2: judging whether the diagonal zone bit is established; when the inclined mark bit is established, the vehicle is controlled to enter the inclined steering mode, and all tires of the vehicle steer;

if the diagonal zone bit is true, SS3 is executed; if the diagonal flag bit is not true, SS4 is executed;

SS 3: controlling the vehicle to steer according to a diagonal steering mode, and judging whether the exiting diagonal zone bit is established in real time;

if the exiting diagonal flag bit is true, SS4 is executed; if the exiting diagonal flag bit is not true, returning to execute SS 3;

SS 4: and controlling the vehicle to steer according to the front axle steering mode.

Referring to fig. 3, in the present embodiment, the determination basis for the establishment of the skew flag, i.e. the determination basis for entering the skew steering mode, is:

if the distance S between the vehicle and the center line of the target lane is greater than a preset distance threshold S1, the straight length L of the target lane is greater than a preset length threshold L1, and no obstacle exists on the inclined path, the inclined flag bit is established, and the vehicle is controlled to enter an inclined steering mode; otherwise, the oblique running zone bit is not established, and the vehicle is controlled to enter a front axle steering mode.

In this embodiment, the determination criterion for the establishment of the exit-diagonal flag bit, that is, the determination criterion for the exit-diagonal steering mode, is as follows:

and if the distance S between the vehicle and the center line of the target lane is smaller than a preset distance threshold value S3 or the distance between any corner of the vehicle and the boundary of the target lane is smaller than a preset distance threshold value Q3, the current vehicle speed is smaller than a preset vehicle speed V4, and the current corner is smaller than a preset corner alpha 1, the exiting inclined-running flag bit is established, and the vehicle is controlled to exit the inclined-running steering mode.

That is to say, when the vehicle has a lane change requirement, whether the 'diagonal zone bit' is established or not is detected in real time, if so, the vehicle enters a diagonal steering mode to control steering, and otherwise, the vehicle enters a front axle steering mode to control steering.

In some embodiments, referring to fig. 3 and 5, the specific determination process for entering the crab steer mode at the current time is as follows:

s01: detecting whether the 'diagonal zone bit' at the previous moment is established or not; if yes, go to S02; if not, executing S03;

s02: detecting whether the 'exiting diagonal flag bit' is established or not; if yes, exiting the diagonal steering mode; if not, entering a diagonal steering mode;

s03: detecting whether the distance S of the vehicle from the center line of the target lane is larger than a preset distance threshold value S1 (preferably, S1 is 3 m); if yes, go to S04; if not, the 'diagonal zone bit' is not true;

s04: detecting whether the linear length L of the target lane is greater than a preset length threshold value L1; if yes, go to step S05; if not, the 'diagonal zone bit' is not true; l1 is related to the distance S in S03, and L1 is k × S (k depends on the running characteristic of the vehicle, and k is 3.3 in the present embodiment);

s05: detecting whether an obstacle exists on the diagonal path; if yes, the 'diagonal zone bit' is not established; if not, the 'diagonal zone bit' is established; the included angle between the diagonal path and the vehicle body is equal to the target rotation angle alpha of the vehicle, and the length P of the diagonal path can be calculated by the target rotation angle alpha and L1 in S04, wherein P is L1/cos (alpha).

In some embodiments, referring to fig. 3 and 6, the specific control flow after the vehicle enters the crab steer mode, i.e. the control of the crab process, includes the following steps:

s0: setting a steering mode of a vehicle as a diagonal steering mode, and setting a target turning angle of the vehicle as a fixed value alpha; preferably said α is 20 °;

s1: detecting whether the target lane is on the right side of the vehicle; if yes, go to S2; if not, go to S3;

s2: if the included angle beta between the vehicle and the central line of the target lane is larger than 0, defining the boundary distance Q as the distance between the upper right corner of the vehicle and the right boundary of the target lane, otherwise defining the boundary distance Q as the distance between the lower right corner of the vehicle and the right boundary of the target lane; execution of S4;

s3: if the included angle beta between the vehicle and the center line of the target lane is larger than 0, defining the boundary distance Q as the distance between the lower left corner of the vehicle and the left boundary of the target lane, otherwise defining the boundary distance Q as the distance between the upper left corner of the vehicle and the left boundary of the target lane, and executing S4;

s4, calculating the distance S between the vehicle and the center line of the target lane;

s5: if the distance S is less than a preset distance threshold S1 (e.g., S1 ═ 4m), or the boundary distance Q is less than a preset distance threshold Q1 (e.g., Q1 ═ 4m), then S6 is performed; otherwise, setting the target vehicle speed as a preset vehicle speed V1 (such as the vehicle speed V1 being 4km/h), and returning to execute S4;

s6: if the distance S is less than a preset distance threshold S2 (e.g., S2 ═ 2m), or the boundary distance Q is less than a preset distance threshold Q2 (e.g., Q2 ═ 2m), then S7 is performed; otherwise, setting the target vehicle speed as a preset vehicle speed V2 (for example, the vehicle speed V2 is 2km/h), and returning to execute S4;

s7: if the distance S is smaller than the preset distance threshold S3 (e.g., 0.3m in case of S3), or the boundary distance Q is smaller than the preset distance threshold Q3 (e.g., 0.5m in case of Q3), then S8 is performed; otherwise, setting the target vehicle speed as a preset vehicle speed V3 (if the vehicle speed V3 is 0.5m/S), and returning to execute S4;

s8: setting the target speed and the target turning angle to be 0;

s9: judging whether the current actual vehicle speed of the vehicle is less than a preset vehicle speed V4 (for example, the vehicle speed V4 is 0.1m/s) and whether the current actual steering angle is less than a preset steering angle alpha 1 (for example, alpha 1 is 2 degrees);

if not, returning to execute S8; if yes, the exit diagonal zone bit is established, and the vehicle is controlled to exit the diagonal steering mode.

On the basis of the above embodiment, the present invention provides another embodiment:

a computer-readable storage medium, having stored thereon a computer program enabling, when executed by a processor, implementing the steps involved in a method of lane change control for an autonomous vehicle as described in the above embodiments. The specific steps are not repeated here.

The invention provides a lane change control method of an automatic driving vehicle and a computer readable storage medium, on the basis of an IGV vehicle, a lane change control scheme which can flexibly and autonomously switch a front axle steering mode and an inclined steering mode according to actual vehicle conditions is designed, and a mode which can accurately judge the establishment of an inclined mark position and the exit of the inclined mark position is provided, therefore, the lane change efficiency and the success rate of the vehicle under the condition of side obstacles can be improved, and the lane change safety is ensured; furthermore, the device has wide and good application prospect in other fields such as ports and the like which have automatic driving requirements on vehicles.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It should be noted that in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The usage of the words first, second and third, etcetera do not indicate any ordering. These words may be interpreted as names.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above should not be understood to necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Moreover, various embodiments or examples and features of various embodiments or examples described in this specification can be combined and combined by one skilled in the art without being mutually inconsistent.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A lane change control method of an autonomous vehicle, characterized by comprising:

when changing lanes, if the distance S between the vehicle and the center line of the target lane is greater than a preset distance threshold S1, the linear length L of the target lane is greater than a preset length threshold L1, and no obstacle exists on an inclined path, an inclined flag is established, and the vehicle is controlled to enter an inclined steering mode; otherwise, the oblique running zone bit is not established, and the vehicle is controlled to enter a front axle steering mode; and the oblique steering mode is that all tires of the vehicle steer according to the target steering angle.

2. The lane change control method of an autonomous vehicle as claimed in claim 1, further comprising:

after entering the oblique steering mode, if the distance S between the vehicle and the center line of the target lane is smaller than a preset distance threshold S3 or the distance between any corner of the vehicle and the boundary of the target lane is smaller than a preset distance threshold Q3, the current vehicle speed is smaller than a preset vehicle speed V4, and the current corner is smaller than a preset corner alpha 1, the exit oblique flag is established, and the vehicle is controlled to exit the oblique steering mode.

3. The lane change control method of an autonomous vehicle as claimed in claim 1, wherein after entering the crab steer mode, performing comprises:

s4, calculating the distance S;

s7: if the distance S is smaller than a preset distance threshold S3 or the boundary distance Q is smaller than a preset distance threshold Q3, then S8 is performed; otherwise, setting the target vehicle speed as the preset vehicle speed V3, and returning to execute S4;

s8: setting the target speed and the target corner to be 0;

4. The lane-change control method of an autonomous vehicle as claimed in claim 1, wherein said preset threshold length L1 is k × S, where k is a driving characteristic of the vehicle and S is a distance of the vehicle from a center line of the target lane.

5. A lane change control method of an autonomous vehicle as set forth in claim 1, characterized in that the length P of said diagonal path is L1/cos (α); wherein α is a target rotation angle.

6. A lane change control method of an autonomous vehicle as claimed in claim 3, characterized in that said distance threshold S1 is 4 m; the distance threshold Q1 is 4 m; the distance threshold Q2 is 2 m; the distance threshold Q3 is 0.5 m; the vehicle speed V1 is 4 km/h; the vehicle speed V2 is 2 km/h; the vehicle speed V3 is 0.5 m/s; the vehicle speed V4 is 0.1 m/s; the rotation angle α 1 is 2 °.

7. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, is able to carry out the steps included in a method for lane change control of an autonomous vehicle as claimed in any one of the claims 1 to 6.