CN116101326B

CN116101326B - Transverse control method, device and system for automatic driving vehicle and storage medium

Info

Publication number: CN116101326B
Application number: CN202310385315.1A
Authority: CN
Inventors: 徐亮; 韩鹏; 王博; 宋士佳; 孙超; 王文伟
Original assignee: Shenzhen Automotive Research Institute of Beijing University of Technology
Current assignee: Shenzhen Automotive Research Institute of Beijing University of Technology
Priority date: 2023-04-12
Filing date: 2023-04-12
Publication date: 2023-07-14
Anticipated expiration: 2043-04-12
Also published as: CN116101326A

Abstract

The embodiment of the invention discloses a transverse control method, a device and a system for an automatic driving vehicle and a storage medium. The method relates to the technical field of automatic driving, wherein the method comprises the following steps: acquiring vehicle control parameters, wherein the vehicle control parameters comprise vehicle wheelbase, planned path points, vehicle steering modes, pre-aiming distance control parameters, vehicle yaw angle, vehicle speed and vehicle reference points; determining a pre-aiming distance and a pre-aiming point according to the planned path point, the pre-aiming distance control parameter, the vehicle speed and the vehicle reference point; calculating an included angle between a connecting line of the pre-aiming point and the vehicle reference point and a longitudinal axis of the vehicle according to the pre-aiming point, the vehicle reference point and the vehicle yaw angle; and determining a wheel steering angle according to the included angle, the vehicle wheelbase, the pretightening distance, the vehicle steering mode and the vehicle yaw angle, and transversely controlling the vehicle according to the vehicle steering angle. The embodiment of the application can improve the running efficiency and stability of the transverse control of the automatic driving vehicle.

Description

Transverse control method, device and system for automatic driving vehicle and storage medium

Technical Field

The present invention relates to the field of autopilot technologies, and in particular, to a lateral control method, device, system, and storage medium for an autopilot vehicle.

Background

Path tracking of an autonomous vehicle may be defined as selecting a point on the vehicle as a control point to track a geometric curve independent of time parameters. In the prior art, when the lateral motion control of the vehicle is performed, a control method of a geometric model, a control method of a kinematic model, and a control method of a kinetic model are often used, for example, a pure tracking algorithm, a Stanley algorithm, a feedback linearization method, a model prediction control method, a PID control method, a full state feedback control method, a sliding mode control method, a fuzzy control method, and the like.

Autopilot vehicles are often equipped with various steering modes, such as front wheel steering (forward and reverse), in order to improve the mobility of the vehicle, especially in small spaces; rear wheel steering (forward and reverse); four-wheel steering (forward and reverse); front wheel steering (forward), rear wheel steering (reverse); in the automatic driving process, various special scenes such as a road with large curvature, large drift in positioning under certain conditions, planning of the tail end of a target path, and controlling the setting of the pretightening distance to be too small are always met. The existing automatic driving vehicle motion control method has the problems of low running efficiency and poor stability when coping with various steering modes and special scenes.

Disclosure of Invention

The embodiment of the invention provides a transverse control method, device and system for an automatic driving vehicle and a storage medium, aiming at solving the problems of poor running efficiency and stability of transverse control for the automatic driving vehicle in the prior art.

In a first aspect, an embodiment of the present invention provides a lateral control method of an autonomous vehicle, including:

acquiring vehicle control parameters, wherein the vehicle control parameters comprise a vehicle wheelbase, a planned path point, a vehicle steering mode, a pre-aiming distance control parameter, a vehicle yaw angle, a vehicle speed and a vehicle reference point;

determining a pretightening distance and a pretightening point according to the planned path point, the pretightening distance control parameter, the vehicle speed and the vehicle reference point;

calculating an included angle between a connecting line of the pre-aiming point and the vehicle reference point and a longitudinal axis of the vehicle according to the pre-aiming point, the vehicle reference point and the vehicle yaw angle;

and determining a wheel steering angle according to the included angle, the vehicle wheelbase, the pretightening distance, the vehicle steering mode and the vehicle yaw angle, and transversely controlling the vehicle according to the vehicle steering angle.

In a second aspect, an embodiment of the present invention further provides a lateral control device for an autonomous vehicle, including:

the vehicle steering control system comprises an acquisition unit, a control unit and a control unit, wherein the acquisition unit is used for acquiring vehicle control parameters, wherein the vehicle control parameters comprise a vehicle wheelbase, a planned path point, a vehicle steering mode, a pre-aiming distance control parameter, a vehicle yaw angle, a vehicle speed and a vehicle reference point;

the determining unit is used for determining a pretightening distance and a pretightening point according to the planned path point, the pretightening distance control parameter, the vehicle speed and the vehicle reference point;

the calculating unit is used for calculating an included angle between a connecting line of the pre-aiming point and the vehicle reference point and a longitudinal axis of the vehicle according to the pre-aiming point, the vehicle reference point and the vehicle yaw angle;

and the control unit is used for determining a wheel steering angle according to the included angle, the vehicle wheelbase, the pretightening distance, the vehicle steering mode and the vehicle yaw angle and transversely controlling the vehicle according to the vehicle steering angle.

In a third aspect, an embodiment of the present invention further provides a lateral control system of an autonomous vehicle, where the lateral control system of an autonomous vehicle includes a control device and a vehicle body, the control device is connected to the vehicle body, and the control device is configured to execute the above method.

In a fourth aspect, embodiments of the present invention also provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

The embodiment of the invention provides a transverse control method, device and system for an automatic driving vehicle and a storage medium. Wherein the method comprises the following steps: acquiring vehicle control parameters, wherein the vehicle control parameters comprise a vehicle wheelbase, a planned path point, a vehicle steering mode, a pre-aiming distance control parameter, a vehicle yaw angle, a vehicle speed and a vehicle reference point; determining a pretightening distance and a pretightening point according to the planned path point, the pretightening distance control parameter, the vehicle speed and the vehicle reference point; calculating an included angle between a connecting line of the pre-aiming point and the vehicle reference point and a longitudinal axis of the vehicle according to the pre-aiming point, the vehicle reference point and the vehicle yaw angle; and determining a wheel steering angle according to the included angle, the vehicle wheelbase, the pretightening distance, the vehicle steering mode and the vehicle yaw angle, and transversely controlling the vehicle according to the vehicle steering angle. According to the technical scheme, according to the obtained vehicle wheelbase, the planned path point, the vehicle steering mode, the pre-aiming distance control parameter, the vehicle yaw angle, the vehicle speed and the vehicle reference point, the pre-aiming distance and the pre-aiming point are calculated, then the included angle between the connecting line of the pre-aiming point and the vehicle reference point and the longitudinal axis of the vehicle is calculated, finally the wheel steering angle is determined based on the included angle and the pre-aiming distance, the vehicle is transversely controlled according to the vehicle steering angle, and the running efficiency and the stability of the automatic driving vehicle transverse control are improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a lateral control system for an autonomous vehicle according to an embodiment of the present invention;

fig. 2 is a schematic flow chart of a lateral control method of an automatic driving vehicle according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating the search of the pretightening point in FIG. 1;

FIG. 4 is a schematic diagram showing the distribution of pretightening points in the front wheel steering mode of FIG. 1;

FIGS. 5 and 6 are schematic diagrams of the pretightening point in the four-wheel steering mode of FIG. 1;

FIG. 7 is a schematic diagram of the geometric relationship of the four-wheel steering mode of FIG. 1;

fig. 8 is a schematic block diagram of a lateral control device of an autonomous vehicle according to an embodiment of the present invention;

fig. 9 is a schematic block diagram of an autonomous vehicle according to an embodiment of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be understood that the terms "comprises" and "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

As used in this specification and the appended claims, the term "if" may be interpreted as "when..once" or "in response to a determination" or "in response to detection" depending on the context. Similarly, the phrase "if a determination" or "if a [ described condition or event ] is detected" may be interpreted in the context of meaning "upon determination" or "in response to determination" or "upon detection of a [ described condition or event ]" or "in response to detection of a [ described condition or event ]".

Referring to fig. 1, fig. 1 is a schematic diagram of a lateral control system of an automatic driving vehicle according to an embodiment of the invention. The transverse control system comprises a control device and a vehicle body, wherein the control device is connected with the vehicle body, and the transverse control method of the automatic driving vehicle is applied to the control device, for example, the transverse control method of the automatic driving vehicle can be realized through a software program corresponding to the automatic driving vehicle, so that the running efficiency and stability of the transverse control of the automatic driving vehicle are improved.

Referring to fig. 2, fig. 2 is a flow chart of a lateral control method of an automatic driving vehicle according to an embodiment of the invention. As shown in fig. 2, the method includes the following steps S110 to S140.

S110, acquiring vehicle control parameters, wherein the vehicle control parameters comprise a vehicle wheelbase, a planned path point, a vehicle steering mode, a pre-aiming distance control parameter, a vehicle yaw angle, a vehicle speed and a vehicle reference point.

In the embodiment of the invention, the control device acquires vehicle control parameters, wherein the vehicle control parameters comprise a vehicle wheelbase, a planned path point, a vehicle steering mode, a pre-aiming distance control parameter, a vehicle yaw angle, a vehicle speed and a vehicle reference point. It should be noted that, the planned path point is generated by a path planning module, and includes a plurality of path points; the vehicle steering mode and the pretightening distance control parameter are modes and parameters configured by a user; the vehicle reference point, the vehicle yaw angle and the vehicle wheelbase are fixed parameters; the vehicle speed comprises a longitudinal vehicle speed of the vehicle and can be obtained through a vehicle speed module.

S120, determining a pretightening distance and a pretightening point according to the planned path point, the pretightening distance control parameter, the vehicle speed and the vehicle reference point.

In the embodiment of the invention, the pretightening distance is calculated according to the longitudinal speed of the vehicle and the pretightening distance control parameter. Specifically, the pretightening distance is calculated by the formula (1), in the formula (1), L _f For the pretarget distance L _o K is the pretightening distance control parameter; v (V) _x Is the vehicle longitudinal speed.

（1）

Further, the pre-aiming distance L is calculated _f Traversing the planned path points to find the path point closest to the vehicle reference point as a first reference pre-aiming point; acquiring the traveling direction of a vehicle, and performing forward search or backward search based on the traveling direction and the first reference pretightening point to find a path point which is larger than or equal to the pretightening distance for the first time as a second reference pretightening point; and determining a pretightening point according to the second reference pretightening point, the vehicle reference point and the pretightening distance. The step of determining the pre-aiming point according to the second reference pre-aiming point, the vehicle reference point and the pre-aiming distance includes: acquiring the sequence number of the second reference pre-aiming point, calculating the difference value between the sequence number and a preset value to be used as a target sequence number, and taking a path point corresponding to the target sequence number as a third reference pre-aiming point; inserting a plurality of reference path points between the second reference pre-aiming point and the third reference pre-aiming point; sequentially calculating stationsAnd the distance between the reference path point and the vehicle reference point is found out until the reference path point with the distance larger than the pretightening distance for the first time is used as a pretightening point. For ease of understanding, as shown in FIG. 3, it is assumed that the planned path point is (T ₁ 、……、T _n ) The vehicle reference point is O _c The first reference pre-aiming point is T _min From the first route point T ₁ Starting the traversal until T _n Find |O _c T _i Minimum to get distance O _c The nearest path point is the first reference pretightening point T _min The method comprises the steps of carrying out a first treatment on the surface of the According to the travelling direction of the vehicle, forward searching or backward searching is carried out to find that the first time is greater than or equal to L _f Is a path point T of (1) _p I.e. |O _c T _p |≥L _f I.e. the second reference pretightening point is T _p Recording the current path point sequence number p, and subtracting the p value by the preset value 1 to obtain a target sequence number p-1, wherein the third reference pretightening point is T _p-1 Understandably, |O _c T _p-1 |<L _f . To further lock the pretighted point, at T _p And T _p-1 Between which lambda reference path points are inserted, the x-coordinate x of the reference path points _i And y coordinate y _i In equation (2), x is as shown in equation (2) _Tq-1 ：y _Tq-1 Is T _p-1 X and y coordinates, x _Tq ：y _Tq Is T _p X-coordinate and y-coordinate of (c). Calculating reference Path Point and O _c The distance between the two points is found out until a reference path point with the distance being larger than the pretightening distance for the first time is taken as a pretightening point T _pst 。

（2）

S130, calculating an included angle between a connecting line of the pre-aiming point and the vehicle reference point and a longitudinal axis of the vehicle according to the pre-aiming point, the vehicle reference point and the vehicle yaw angle.

In the embodiment of the invention, after the pre-aiming point is determined, the coordinates of the vehicle reference point are obtained as the first sitting positionMarking; acquiring coordinates of the pre-aiming point as second coordinates; calculating a relative included angle according to the first coordinate and the second coordinate; and determining an absolute included angle according to the relative included angle, and taking the relative included angle and the absolute included angle as included angles between a connecting line of the pre-aiming point and the vehicle reference point and a longitudinal axis of the vehicle. For ease of understanding, assume that the pretightening point T _pst With the vehicle reference point O _c Is connected with the line of (a)

With longitudinal axis O of vehicle _c X _c The absolute angle of (2) is->

，/>

Positive value, range->

，

With O _c X _c The relative included angle of (a) is->

Understandably, <' > a->

In order to be based on the principle of a right-hand coordinate system, namely anticlockwise positive, O _c X _c Rotate to +.>

Is a function of the angle of (a). Specifically, when->

At O _c X _c Left side of (C)>

For positive, when->

At O _c X _c Right side of (2)

Is negative, i.e.)>

. Wherein->

And->

The relationship of (2) is shown in formula (3). />

The calculation formula of (2) is shown as formula (4), in formula (4), T _pst Is a coordinate of +.>

，O _c Is the coordinates in the geodetic coordinate system

. O-XY is the geodetic coordinate system (global coordinate system), O _c -X _c Y _c Is the vehicle coordinate system. O (O) _c X _c The included angle between the X and the global coordinate axis is->

According to the principle of a right-hand coordinate system, anticlockwise is positive, & lt/EN & gt>

The value range of (2) is->

. In other embodiments, the center of the rear axle of the vehicle may be defined as O _c 。

（3）

（4）

（5）

S140, according to the included angle, the vehicle wheelbase, the pretightening distance and the vehicle steering mode

And determining a wheel steering angle from the vehicle yaw angle, and laterally controlling the vehicle according to the vehicle steering angle.

In the embodiment of the invention, the wheel steering angle comprises a front wheel steering angle and a rear wheel steering angle, and if the vehicle steering mode is a front wheel steering mode or a front wheel steering mode during forward movement, the front wheel steering angle is calculated according to the vehicle wheelbase, the pretightening distance, the absolute included angle and the relative included angle. For ease of understanding, let L be the vehicle wheelbase, L _f For the pre-aiming distance,

for the absolute angle, ++>

For the relative angle, ++>

For controlling the absolute value of the quantity, a desired front wheel steering angle; />

To control the absolute value of the quantity, the desired rear wheel steering angle is obtained. Use->

And->

For expressing the signed front wheel steering angle and the rear wheel steering angle, the front wheel steering angle direction and the rear wheel steering angle are uniformly specified to be positive counterclockwise and negative clockwise, and the front wheel steering angle can be calculated by the formulas (6) to (9)>

Understandably, the rear wheel steering angle is +.>

，/>

Is 0. It should be noted that, as shown in fig. 4, all possible pre-aiming conditions of the autonomous vehicle in practice are shown, namely, T1 to T8.

（6）

（7）

（8）

（9）

Further, if the vehicle steering mode is a four-wheel steering mode, the front wheel steering angle and the rear wheel steering angle are calculated according to the vehicle wheelbase, the pretightening distance, the absolute included angle and the relative included angle. Specifically, a first four-wheel steering condition value is calculated through a first four-wheel steering condition formula according to the vehicle wheelbase, the pre-aiming distance, the absolute included angle and the preset proportion; calculating a second four-wheel steering condition value according to the vehicle wheelbase, the pretightening distance and the absolute included angle through a second four-wheel steering condition formula; if the first four-wheel steering condition value is larger than a first preset condition value and the second four-wheel steering condition value is larger than the first preset condition value, calculating an absolute front wheel steering angle and an absolute rear wheel steering angle through a first front wheel steering angle formula and a first rear wheel steering angle formula; if the first four-wheel steering condition value is not greater than the first preset condition value or the second four-wheel steering condition value is not greater than the first preset condition value, calculating the absolute front wheel steering angle and the absolute rear wheel steering angle through a second front wheel steering formula and a second rear wheel steering angle formula; and calculating the front wheel steering angle and the rear wheel steering angle according to the relative included angle, the absolute front wheel steering angle and the absolute rear wheel steering angle. Based on the above assumption, the first preset condition value and the second preset condition value are both 0.

When (when)

And->

When the pre-aiming point is shown as T in figure 5 ₁ 、T ₂ 、T ₃ 、T ₆ 、T ₇ 、T ₈ . That is, when the first four-wheel steering condition value is greater than 0 and the second four-wheel steering condition value is greater than 0, & gt is calculated by the formula (10) and the formula (11)>

And->

. The m/n represents a proportional relationship between the front and rear wheel rotation angles.

（10）

（11）

When (when)

Or->

When the first four-wheel steering condition value is not greater than 0 or the second four-wheel steering condition value is not greater than 0This occurs at a pretightening distance L _f When the value is small, T is as shown in FIG. 7 ₄ 、T ₅ 、T ₉ 、T ₁₀ These are the cases. Wherein T is ₄ And T ₉ Corresponding to->

，T ₅ And T ₁₀ Corresponding to

Calculating +.sup.th through equation (12) and equation (13)>

And->

。

（12）

（13）

For the first two cases of four-turn steering, the front wheel steering angle

And the rear wheel steering angle is +.>

From the equation (14) and the equation (15).

（14）

（15）

Further, if the vehicle steering mode is a rear wheel steering mode or a rear wheel steering mode during backward movement, the vehicle is steered according to the vehicle wheelbase and the pre-steering modeAnd calculating the steering angle of the rear wheel according to the aiming distance, the absolute included angle and the relative included angle. Specifically, calculating a first rear wheel steering condition value according to the vehicle wheelbase, the pretightening distance and the absolute included angle through a first rear wheel steering condition formula; calculating a second rear wheel steering condition value through a second rear wheel steering condition formula according to the vehicle wheelbase, the pretightening distance and the absolute included angle; if the first rear wheel steering condition value is larger than a second preset condition value and the second rear wheel steering condition value is larger than the second preset condition value, calculating an absolute rear wheel steering angle through a rear wheel steering angle formula; and calculating the rear wheel steering angle according to the relative included angle and the absolute rear wheel steering angle. Specifically, based on the above assumption, when the following is satisfied

And->

At this time, +.>

And->

。

（16）

（17）

When (when)

Or->

This occurs at a pretightening distance L _f When the value is smaller, the patient is treated with +.>

And->

All 0.

（18）

（19）

For both cases of the rear-wheel steering mode, the rear-wheel steering angle can be calculated as

。

（20）

For easy understanding, the derivation of the angle between the line connecting the pre-aiming point and the vehicle reference point and the longitudinal axis of the vehicle will be described as follows:

t is found in the vehicle coordinate system O _c -X _c Y _c Is used for the purpose of determining the coordinates of (a),

is expressed as coordinates of the geodetic coordinate system of (2)

Its coordinates in the vehicle coordinate system are expressed as

（1b）

Wherein,,

is a directional cosine matrix of the vehicle coordinate system Oc-XcYc with respect to the earth coordinate system O-XY.

According to T in the vehicle coordinate system O _c -X _c Y _c Is to calculate the angle

；

（2b）

Wherein,,

the value range of (2) is->

。

In the front wheel steering mode, the desired front wheel steering angle is derived as follows:

calculating the front wheel steering angle according to the geometric relationship

；

（1c）

Taking into account that

Is>

Therefore, the front wheel is turned +.>

And can be simplified as:

（2c）

in the four-wheel steering mode and the rear-wheel steering mode, the desired wheel steering angle is derived as follows:

as shown in fig. 6, the vehicle wheelbase is L, and the pretightening distance is L _f Turning radius R (intermediate unknowns); wherein,,

for turning center +.>

Is triangle->

At->

The plumpness on the edge; />

Is->

Length from the center of the front axle of the vehicle, +.>

Is->

The proportional relation between the front and rear wheel steering angles and the length of the center of the rear axle of the vehicle is m/n.

In a triangle shape

In (3) using the sine theorem:

（1.1a）

wherein at T ₁ And T ₆ In the case, as in FIG. 4, at this time

The method comprises the steps of carrying out a first treatment on the surface of the And at T ₂ 、T ₃ 、T ₇ 、T ₈ In the case where

。

Wherein, in

At the time of triangle->

In (3) using the sine theorem:

（1.2a）

in a triangle shape

In (3) using the sine theorem:

（2a）

（3a）

（4a）

（5）

（6a）

wherein,,

according to (1.1 a and 1.2 a) - (6 a), the following is found:

（7a）

when the vehicle turns, due to

Mostly less than->

Then can

（8a）

Substituting (8 a) into (7 a) can result in:

（9a）

（10a）

where m=0 is, the rear wheel steering mode is the case, where:

（11a）

（12a）

（13a）

（14a）

the final calculations (11 a) - (14 a) are for common cases, such as T ₁ 、T ₂ 、T ₃ And T ₆ 、T ₇ 、T ₈ And the like.

At T ₄ And T ₉ In the case where

And->

In triangle +.>

In which the sine theorem cannot be utilized, in which case, in the case of the four-wheel steering mode or the rear wheel steering mode, the stability is controlledIn consideration of the sex, set

（15a）

At T ₅ And T ₁₀ In the case where

In the case of the four-wheel steering mode or the rear-wheel steering mode, for control stability, setting is made

（16a）

Fig. 8 is a schematic block diagram of a lateral control device 200 for an autonomous vehicle according to an embodiment of the present invention. As shown in fig. 8, the present invention also provides a lateral control device 200 of an autonomous vehicle, corresponding to the above lateral control method of an autonomous vehicle. The lateral control device 200 of the autonomous vehicle comprises means for performing the lateral control method of the autonomous vehicle described above, which device may be arranged in the autonomous vehicle. Specifically, referring to fig. 8, the lateral control device 200 of the autonomous vehicle includes an acquisition unit 201, a determination unit 202, a calculation unit 203, and a control unit 204.

The acquiring unit 201 is configured to acquire vehicle control parameters, where the vehicle control parameters include a vehicle wheelbase, a planned path point, a vehicle steering mode, a pre-aiming distance control parameter, a vehicle yaw angle, a vehicle speed, and a vehicle reference point; the determining unit 202 is configured to determine a pretightening distance and a pretightening point according to the planned path point, the pretightening distance control parameter, the vehicle speed, and the vehicle reference point; the calculating unit 203 is configured to calculate an included angle between a line connecting the pre-aiming point and the vehicle reference point and a longitudinal axis of the vehicle according to the pre-aiming point, the vehicle reference point and the vehicle yaw angle; the control unit 204 is configured to control the steering mode of the vehicle according to the included angle, the wheelbase of the vehicle, the pre-aiming distance, and the steering mode.

In some embodiments, for example, the determining unit 202 includes a first calculating subunit, a traversal finding unit, a searching unit, and a determining subunit.

The first calculating subunit is used for calculating a pretightening distance according to the longitudinal speed of the vehicle and the pretightening distance control parameter; the traversal searching unit is used for traversing the planned path points to search the path point closest to the vehicle reference point as a first reference pre-aiming point; the searching unit is used for acquiring the travelling direction of the vehicle, and performing forward searching or backward searching based on the travelling direction and the first reference pretightening point so as to find a path point which is larger than or equal to the pretightening distance for the first time as a second reference pretightening point; the determining subunit is configured to determine a pretightening point according to the second reference pretightening point, the vehicle reference point, and the pretightening distance.

In some embodiments, for example, the determining subunit includes a second computing subunit, an inserting unit, and a searching unit.

The second calculating subunit is configured to obtain a sequence number of the second reference pre-aiming point, calculate a difference value between the sequence number and a preset value as a target sequence number, and use a path point corresponding to the target sequence number as a third reference pre-aiming point; the inserting unit is used for inserting a plurality of reference path points between the second reference pre-aiming point and the third reference pre-aiming point; the searching unit is used for sequentially calculating the distance between the reference path point and the vehicle reference point until the reference path point with the distance larger than the pretightening distance for the first time is found out and used as the pretightening point.

In some embodiments, for example, the computing unit 203 includes a first acquiring subunit, a second acquiring subunit, a third computing subunit, and as units.

The first acquisition subunit is used for acquiring coordinates of the vehicle reference point as first coordinates;

the second acquisition subunit is used for acquiring the coordinate of the pre-aiming point as a second coordinate; the third calculation subunit is used for calculating a relative included angle according to the first coordinate and the second coordinate; the unit is used for determining an absolute included angle according to the relative included angle, and taking the relative included angle and the absolute included angle as the included angle between the connecting line of the pre-aiming point and the vehicle reference point and the longitudinal axis of the vehicle.

In some embodiments, for example, the control unit 204 includes a fourth computing subunit, a fifth computing subunit, and a sixth computing subunit.

The fourth calculating subunit is configured to calculate, if the vehicle steering mode is a front wheel steering mode or a front wheel steering mode during forward movement, the front wheel steering angle according to the vehicle wheelbase, the pretightening distance, the absolute included angle and the relative included angle; the fifth calculating subunit is configured to calculate, if the vehicle steering mode is a rear-wheel steering mode or a rear-wheel steering mode during a backward movement, the rear-wheel steering angle according to the vehicle wheelbase, the pretightening distance, the absolute included angle, and the relative included angle, and specifically calculate a first rear-wheel steering condition value according to the vehicle wheelbase, the pretightening distance, and the absolute included angle by using a first rear-wheel steering condition formula; calculating a second rear wheel steering condition value through a second rear wheel steering condition formula according to the vehicle wheelbase, the pretightening distance and the absolute included angle; if the first rear wheel steering condition value is larger than a second preset condition value and the second rear wheel steering condition value is larger than the second preset condition value, calculating an absolute rear wheel steering angle through a rear wheel steering angle formula; calculating the rear wheel steering angle according to the relative included angle and the absolute rear wheel steering angle; the sixth calculating subunit is configured to calculate, if the vehicle steering mode is a four-wheel steering mode, the front-wheel steering angle and the rear-wheel steering angle according to the vehicle wheelbase, the pretightening distance, the absolute included angle, and the relative included angle, and specifically calculate a first four-wheel steering condition value according to a first four-wheel steering condition formula according to the vehicle wheelbase, the pretightening distance, the absolute included angle, and a preset proportion; calculating a second four-wheel steering condition value according to the vehicle wheelbase, the pretightening distance and the absolute included angle through a second four-wheel steering condition formula; if the first four-wheel steering condition value is larger than a first preset condition value and the second four-wheel steering condition value is larger than the first preset condition value, calculating an absolute front wheel steering angle and an absolute rear wheel steering angle through a first front wheel steering angle formula and a first rear wheel steering angle formula; if the first four-wheel steering condition value is not greater than the first preset condition value or the second four-wheel steering condition value is not greater than the first preset condition value, calculating the absolute front wheel steering angle and the absolute rear wheel steering angle through a second front wheel steering formula and a second rear wheel steering angle formula; and calculating the front wheel steering angle and the rear wheel steering angle according to the relative included angle, the absolute front wheel steering angle and the absolute rear wheel steering angle.

The specific implementation manner of the lateral control device 200 for an autonomous vehicle according to the embodiment of the present invention corresponds to the lateral control method for an autonomous vehicle described above, and will not be described herein.

The lateral control device of the autonomous vehicle described above may be implemented in the form of a computer program that can be run on the autonomous vehicle as shown in fig. 9.

Referring to fig. 9, fig. 9 is a schematic block diagram of an autonomous vehicle according to an embodiment of the present application.

Referring to fig. 9, the autonomous vehicle 300 includes a processor 302, a memory, and a network interface 305 connected by a system bus 301, where the memory may include a storage medium 303 and an internal memory 304.

The storage medium 303 may store an operating system 3031 and a computer program 3032. The computer program 3032, when executed, may cause the processor 302 to perform a lateral control method of an autonomous vehicle.

The processor 302 is used to provide computing and control capabilities to support the operation of the entire autonomous vehicle 300.

The internal memory 304 provides an environment for the execution of a computer program 3032 in the storage medium 303, which computer program 3032, when executed by the processor 302, causes the processor 302 to perform a lateral control method of an autonomous vehicle.

The network interface 305 is used for network communication with other devices. It will be appreciated by those skilled in the art that the structure shown in fig. 9 is merely a block diagram of a portion of the structure associated with the present application and does not constitute a limitation of the autonomous vehicle 300 to which the present application is applied, and that a particular autonomous vehicle 300 may include more or fewer components than shown, or may combine certain components, or may have a different arrangement of components.

Wherein the processor 302 is configured to execute a computer program 3032 stored in a memory to implement any of the embodiments of the lateral control method of an autonomous vehicle described above.

It should be appreciated that in embodiments of the present application, the processor 302 may be a central processing unit (Central Processing Unit, CPU), the processor 302 may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSPs), application specific integrated circuits (Application Specific Integrated Circuit, ASICs), off-the-shelf programmable gate arrays (Field-Programmable Gate Array, FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. Wherein the general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

Those skilled in the art will appreciate that all or part of the flow in a method embodying the above described embodiments may be accomplished by computer programs instructing the relevant hardware. The computer program may be stored in a storage medium that is a computer readable storage medium. The computer program is executed by at least one processor in the computer system to implement the flow steps of the embodiments of the method described above.

Accordingly, the present invention also provides a storage medium. The storage medium may be a computer readable storage medium. The storage medium stores a computer program. The computer program, when executed by the processor, causes the processor to perform any of the embodiments of the lateral control method of an autonomous vehicle described above.

The storage medium may be a U-disk, a removable hard disk, a Read-Only Memory (ROM), a magnetic disk, or an optical disk, or other various computer-readable storage media that can store program codes.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps described in connection with the embodiments disclosed herein may be embodied in electronic hardware, in computer software, or in a combination of the two, and that the elements and steps of the examples have been generally described in terms of function in the foregoing description to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the several embodiments provided by the present invention, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of each unit is only one logic function division, and there may be another division manner in actual implementation. For example, multiple units or components may be combined or may be integrated into another system, or some features may be omitted, or not performed.

The steps in the method of the embodiment of the invention can be sequentially adjusted, combined and deleted according to actual needs. The units in the device of the embodiment of the invention can be combined, divided and deleted according to actual needs. In addition, each functional unit in the embodiments of the present invention may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The integrated unit may be stored in a storage medium if implemented in the form of a software functional unit and sold or used as a stand-alone product. Based on such understanding, the technical solution of the present invention is essentially or partly contributing to the prior art or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium comprising several instructions for causing an autonomous vehicle (which may be a personal computer, a terminal, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention.

In the foregoing embodiments, the descriptions of the embodiments are focused on, and for those portions of one embodiment that are not described in detail, reference may be made to the related descriptions of other embodiments.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

While the invention has been described with reference to certain preferred embodiments, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made and equivalents will be apparent to those skilled in the art without departing from the scope of the invention. Therefore, the protection scope of the invention is subject to the protection scope of the claims.

Claims

1. A lateral control method of an autonomous vehicle, comprising:

determining a wheel steering angle according to the included angle, the vehicle wheelbase, the pretightening distance, the vehicle steering mode and the vehicle yaw angle, and transversely controlling the vehicle according to the vehicle steering angle;

the step of determining the pre-aiming distance and the pre-aiming point according to the planned path point, the pre-aiming distance control parameter, the vehicle speed and the vehicle reference point comprises the following steps:

calculating a pretightening distance according to the longitudinal speed of the vehicle and the pretightening distance control parameter;

traversing the planned path points to find the path point closest to the vehicle reference point as a first reference pre-aiming point;

acquiring the traveling direction of a vehicle, and performing forward search or backward search based on the traveling direction and the first reference pretightening point to find a path point which is larger than or equal to the pretightening distance for the first time as a second reference pretightening point;

and determining a pretightening point according to the second reference pretightening point, the vehicle reference point and the pretightening distance.

2. The method of claim 1, wherein the step of determining a pretighted point based on the second reference pretighted point, the vehicle reference point, and the pretighted distance comprises:

acquiring the sequence number of the second reference pre-aiming point, calculating the difference value between the sequence number and a preset value to be used as a target sequence number, and taking a path point corresponding to the target sequence number as a third reference pre-aiming point;

inserting a plurality of reference path points between the second reference pre-aiming point and the third reference pre-aiming point;

and sequentially calculating the distance between the reference path point and the vehicle reference point until the reference path point with the distance larger than the pretightening distance for the first time is found out as a pretightening point.

3. The method of claim 1, wherein the step of calculating an angle between a line connecting the pre-sight point and the vehicle reference point and a longitudinal axis of the vehicle based on the pre-sight point, the vehicle reference point, and the vehicle yaw angle comprises:

acquiring coordinates of the vehicle reference point as first coordinates;

acquiring coordinates of the pre-aiming point as second coordinates;

calculating a relative included angle according to the first coordinate and the second coordinate;

and determining an absolute included angle according to the relative included angle, and taking the relative included angle and the absolute included angle as included angles between a connecting line of the pre-aiming point and the vehicle reference point and a longitudinal axis of the vehicle.

4. A method according to claim 3, wherein the wheel steering angles include a front wheel steering angle and a rear wheel steering angle, and the step of determining the wheel steering angle from the included angle, the vehicle wheelbase, the pretighting distance, the vehicle steering mode, and the vehicle yaw angle comprises:

if the vehicle steering mode is a front wheel steering mode or a front wheel steering mode during forward movement, calculating the front wheel steering angle according to the vehicle wheelbase, the pretightening distance, the absolute included angle and the relative included angle;

if the vehicle steering mode is a rear wheel steering mode or a rear wheel steering mode during backward movement, calculating the rear wheel steering angle according to the vehicle wheelbase, the pretightening distance, the absolute included angle and the relative included angle;

and if the vehicle steering mode is a four-wheel steering mode, calculating the front wheel steering angle and the rear wheel steering angle according to the vehicle wheelbase, the pretightening distance, the absolute included angle and the relative included angle.

5. The method of claim 4, wherein the step of calculating the front wheel steering angle and the rear wheel steering angle from the vehicle wheelbase, the pretightening distance, the absolute angle, and the relative angle comprises:

calculating a first four-wheel steering condition value through a first four-wheel steering condition formula according to the vehicle wheelbase, the pretightening distance, the absolute included angle and the preset proportion;

calculating a second four-wheel steering condition value according to the vehicle wheelbase, the pretightening distance and the absolute included angle through a second four-wheel steering condition formula;

if the first four-wheel steering condition value is larger than a first preset condition value and the second four-wheel steering condition value is larger than the first preset condition value, calculating an absolute front wheel steering angle and an absolute rear wheel steering angle through a first front wheel steering angle formula and a first rear wheel steering angle formula;

if the first four-wheel steering condition value is not greater than the first preset condition value or the second four-wheel steering condition value is not greater than the first preset condition value, calculating the absolute front wheel steering angle and the absolute rear wheel steering angle through a second front wheel steering formula and a second rear wheel steering angle formula;

and calculating the front wheel steering angle and the rear wheel steering angle according to the relative included angle, the absolute front wheel steering angle and the absolute rear wheel steering angle.

6. The method of claim 4, wherein the step of calculating the rear wheel steering angle from the vehicle wheelbase, the pretightening distance, the absolute angle, and the relative angle comprises:

calculating a first rear wheel steering condition value through a first rear wheel steering condition formula according to the vehicle wheelbase, the pretightening distance and the absolute included angle;

calculating a second rear wheel steering condition value through a second rear wheel steering condition formula according to the vehicle wheelbase, the pretightening distance and the absolute included angle;

if the first rear wheel steering condition value is larger than a second preset condition value and the second rear wheel steering condition value is larger than the second preset condition value, calculating an absolute rear wheel steering angle through a rear wheel steering angle formula;

and calculating the rear wheel steering angle according to the relative included angle and the absolute rear wheel steering angle.

7. A lateral control device of an autonomous vehicle, characterized by comprising:

the vehicle steering control system comprises an acquisition unit, a control unit and a control unit, wherein the acquisition unit is used for acquiring vehicle control parameters, the vehicle control parameters comprise a vehicle wheelbase, a planned path point, a vehicle steering mode, a pre-aiming distance control parameter, a vehicle yaw angle, a vehicle speed and a vehicle reference point, and the vehicle speed comprises a vehicle longitudinal speed;

the control unit is used for determining a wheel steering angle according to the included angle, the vehicle wheelbase, the pretightening distance, the vehicle steering mode and the vehicle yaw angle and transversely controlling the vehicle according to the vehicle steering angle;

the determining unit comprises a first calculating subunit, a traversal searching unit, a searching unit and a determining subunit;

the first calculating subunit is used for calculating a pretightening distance according to the longitudinal speed of the vehicle and the pretightening distance control parameter;

the traversal searching unit is used for traversing the planned path points to search the path point closest to the vehicle reference point as a first reference pre-aiming point;

the searching unit is used for acquiring the travelling direction of the vehicle, and performing forward searching or backward searching based on the travelling direction and the first reference pretightening point so as to find a path point which is larger than or equal to the pretightening distance for the first time as a second reference pretightening point;

the determining subunit is configured to determine a pretightening point according to the second reference pretightening point, the vehicle reference point, and the pretightening distance.

8. A lateral control system of an autonomous vehicle, characterized in that the lateral control system of an autonomous vehicle comprises a control device and a vehicle body, the control device being connected to the vehicle body, the control device being adapted to perform the method according to any of claims 1-6.

9. A computer readable storage medium, characterized in that the storage medium stores a computer program which, when executed by a processor, implements the method according to any of claims 1-6.