CN114684200A - Initial trajectory planning method, device, equipment and storage medium - Google Patents

Abstract

The invention discloses an initial trajectory planning method, an initial trajectory planning device, an initial trajectory planning equipment and a storage medium, wherein the method comprises the following steps: acquiring vehicle initial position information, a vehicle running speed and a first target track of a host vehicle in response to a target control instruction for causing the host vehicle to run along the first target track in a target lane; generating a second target track based on the vehicle initial position information, the vehicle running speed and the first target track so that the vehicle merges into the first target track from the vehicle initial position along the second target track; and after the second target track is generated, updating the second target track according to the initial position information of the vehicle, the running speed of the vehicle acquired in real time and the first target track. The method is not limited by the condition of the initial state of the vehicle, and the second target track planned along the lane can be quickly and stably merged into the first target track after the initial track planning function is activated at any position of the lane.

Description

An initial trajectory planning method, device, equipment and storage medium

technical field

The invention relates to the technical field of automatic driving, in particular to an initial trajectory planning method, device, equipment and storage medium.

Background technique

The lane centering control function in the intelligent driving industry will calculate the target trajectory according to the detection results of the lane line and the preceding vehicle trajectory and update the target trajectory in real time. The vehicle eventually needs to drive along the target trajectory. At the initial moment of activation of such functions, the current position of the vehicle may be far from the lateral position of the target trajectory.

Most of the existing schemes limit the initial activation conditions of the lane activation function, so that the vehicle is only allowed to activate the corresponding function when the lateral position of the vehicle is very small from the target trajectory and the heading deviation from the target trajectory heading is very small. restrictions are too strict.

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the first aspect of the present invention proposes an initial trajectory planning method, including:

In response to the target control instruction for causing the ego vehicle to travel along the first target trajectory in the target lane, obtain the vehicle initial position information of the ego vehicle, the vehicle speed and the first target trajectory; wherein the vehicle initial position The information includes the initial position of the vehicle and the driving direction of the vehicle; the first target trajectory is obtained according to the lane line of the target lane and the trajectory detection result of the target vehicle, and the target vehicle is traveling in the target lane;

A second target trajectory is generated based on the vehicle initial position information, the vehicle travel speed, and the first target trajectory, so that the ego vehicle merges into the first target trajectory along the second target trajectory from the vehicle initial position. a target trajectory;

After the second target trajectory is generated, the second target trajectory is updated according to the vehicle initial position information, the vehicle traveling speed and the first target trajectory acquired in real time.

Further, the generating a second target trajectory based on the initial position information of the vehicle, the driving speed of the vehicle and the first target trajectory includes:

Extract the target point position information at the end of the first target trajectory, and construct an auxiliary line according to the position information of the target point; wherein, the end is the end of the first target trajectory away from the initial position of the vehicle, and the The position information of the target point includes the coordinates of the target point and the heading angle of the target point;

determining a final curvature according to the initial position of the vehicle and the traveling speed of the vehicle;

calculating a minimum turning radius based on the vehicle speed and the final curvature;

Curves passing through the initial position of the vehicle and tangent to the driving direction of the vehicle and the auxiliary line are constructed with the minimum turning radius as a radius to obtain the second target trajectory.

Further, the extracting target point position information at the end of the first target trajectory includes:

Extract the position information of several points at the end of the first target trajectory;

The target point position information is obtained according to the position information of the several points.

Further, determining the final curvature according to the initial position of the vehicle and the traveling speed of the vehicle includes:

acquiring a first curvature corresponding to the initial position of the vehicle; wherein, the first curvature is a lane curvature;

query the allowable lateral acceleration corresponding to the speed of the vehicle;

calculating a second curvature based on the vehicle travel speed and the allowable lateral acceleration;

The final curvature is obtained from the first curvature and the second curvature.

Further, constructing a curve passing through the initial position of the vehicle and tangent to the driving direction of the vehicle and the auxiliary line respectively by using the minimum turning radius as a radius to obtain the second target trajectory, including:

An auxiliary coordinate system is constructed with the initial position of the vehicle as the origin; wherein, the x-axis direction of the auxiliary coordinate system is determined according to the driving direction of the vehicle or the heading angle of the target point, and the y-axis of the auxiliary coordinate system perpendicular to the x-axis;

A first circle center is determined on the y-axis of the auxiliary coordinate system according to the initial position of the vehicle and the minimum turning radius; wherein, the first circle center is the center of the first auxiliary circle, and the first circle center is located in the between the initial position of the vehicle and the auxiliary line;

constructing the first auxiliary circle based on the first circle center and the minimum turning radius;

A second center is determined based on the auxiliary line and the first auxiliary circle; wherein, the second center is the center of the second auxiliary circle;

constructing the second auxiliary circle based on the second center and the minimum turning radius;

The shortest S-shaped curve connecting the initial position of the vehicle, the position of the middle point and the position of the end point on the first auxiliary circle and the second auxiliary circle is used as the second target trajectory, wherein the position of the middle point is the tangent point between the first auxiliary circle and the second auxiliary circle, and the position of the end point is the tangent point between the second auxiliary circle and the auxiliary line.

Further, constructing a curve passing through the initial position of the vehicle and tangent to the driving direction of the vehicle and the auxiliary line respectively by using the minimum turning radius as a radius to obtain the second target trajectory, including:

The center of a third auxiliary circle is determined based on the initial position of the vehicle, the driving direction of the vehicle, the minimum turning radius and the auxiliary line; wherein the third auxiliary circle is tangent to the driving direction of the vehicle and the the initial position of the vehicle, the radius of the third auxiliary circle is the minimum turning radius, and the third auxiliary circle is tangent to the auxiliary line;

Constructing the third auxiliary circle with the minimum turning radius as the radius based on the determined circle center;

The shortest circular curve connecting the initial position of the vehicle and the position of the end point on the third auxiliary circle is used as the second target trajectory; wherein, the position of the end point is the third auxiliary circle and the auxiliary line cut point.

Further, after the second target trajectory is generated based on the vehicle initial position information, the vehicle speed and the first target trajectory, the method further includes:

A number of auxiliary points are respectively taken at preset time intervals on both sides of the calculated point on the second target trajectory; wherein, the auxiliary points are on the second target trajectory; the calculated The point includes the initial position of the vehicle, and the middle point or the end point of the second target trajectory;

The second target trajectory is smoothed according to the calculated position of the point and the several auxiliary points to obtain the smoothed second target trajectory.

A second aspect of the present invention provides an initial trajectory planning device, comprising:

an acquisition module, configured to acquire the vehicle initial position information, the vehicle speed and the first target trajectory of the self-vehicle in response to the target control instruction for causing the self-vehicle vehicle to travel along the first target trajectory in the target lane; wherein, The initial position information of the vehicle includes the initial position of the vehicle and the driving direction of the vehicle; the first target trajectory is obtained according to the lane line of the target lane and the trajectory detection result of the target vehicle, and the target vehicle is in the target lane drive;

a trajectory generation module, configured to generate a second target trajectory based on the vehicle initial position information, the vehicle running speed and the first target trajectory, so that the self-vehicle moves along the second target from the vehicle initial position the trajectory is merged into the first target trajectory;

A trajectory updating module, configured to update the second target trajectory according to the vehicle initial position information and the vehicle speed and the first target trajectory acquired in real time after the second target trajectory is generated

A third aspect of the present invention provides an electronic device, the electronic device includes a processor and a memory, the memory stores at least one instruction or at least a piece of program, and the at least one instruction or the at least one piece of program is processed by the The controller is loaded and executed to realize the initial trajectory planning method proposed in the first aspect of the present invention.

A fourth aspect of the present invention provides a computer-readable storage medium, where at least one instruction or at least one piece of program is stored, and the at least one instruction or at least one piece of program is loaded and executed by a processor to implement the present invention The initial trajectory planning method proposed in the first aspect.

Implementing the present invention has the following beneficial effects:

The embodiment of the present invention is not limited by the initial state conditions of the vehicle, the initial trajectory planning function can be activated at any position in the lane, and the planned second target trajectory can be moved directly to the first target trajectory quickly and smoothly without generating redundant action.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a flowchart of an initial trajectory planning method provided by an embodiment of the present invention;

2 is a schematic diagram of a second target trajectory at a moment provided by an embodiment of the present invention;

3 is a schematic diagram of a second target trajectory at another moment provided by an embodiment of the present invention;

4 is a planning effect diagram of a second target trajectory provided by an embodiment of the present invention;

5 is a flowchart of updating a second target trajectory provided by an embodiment of the present invention;

6 is a schematic diagram of planning a second target trajectory provided by an embodiment of the present invention;

7 is another schematic diagram of planning a second target trajectory provided by an embodiment of the present invention;

FIG. 8 is a structural block diagram of an initial trajectory planning apparatus provided by an embodiment of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Examples of such embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout.

It should be noted that the terms "first", "second", etc. in the description and claims of the present application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It is to be understood that data so used may be interchanged under appropriate circumstances so that the embodiments of the application described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having" and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or server comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

The lane centering control function in the intelligent driving industry will calculate the target trajectory according to the detection results of the lane line and the preceding vehicle trajectory and update the target trajectory in real time. The vehicle eventually needs to drive along the target trajectory. In view of the situation that the current position of the vehicle may be far from the lateral position of the target trajectory line at the initial moment of activation of such a function, the embodiment of the present invention plans an additional initial trajectory path between the current position of the vehicle and the target trajectory line, so as to Smoothly merge the vehicle into the target trajectory along the initial trajectory.

It should be noted that the initial trajectory planning method provided by the embodiment of the present invention can be used in path planning in various scenarios, including but not limited to similar scenarios such as lane keeping, high-level automatic driving lane change, and merging of two paths.

Example

FIG. 1 is a flowchart of an initial trajectory planning method provided by an embodiment of the present invention. This specification provides the operation steps of the method as described in the embodiment or the flowchart, but based on conventional or non-creative work, it may include more or more Fewer steps. The sequence of steps enumerated in the embodiments is only one of the execution sequences of many steps, and does not represent the only execution sequence. When an actual system or server product is executed, it can be executed sequentially or in parallel (for example, in a parallel processor or multi-threaded processing environment) according to the embodiments or the methods shown in the accompanying drawings. Specifically, as shown in Figure 1, the method may include:

S101: In response to the target control instruction for causing the own vehicle to travel along the first target trajectory in the target lane, obtain the vehicle initial position information, the vehicle speed and the first target trajectory of the own vehicle;

Wherein, the initial position information of the vehicle includes the initial position of the vehicle and the driving direction of the vehicle; the first target trajectory is obtained according to the lane line of the target lane and the trajectory detection result of the target vehicle, and the target vehicle is driving in the target lane;

Specifically, the target control instruction can be a lane change instruction, a lane keeping instruction, etc. According to the actual needs of the application scenario, other target control instructions can also be applied in this paper.

Specifically, in a vehicle lane changing scenario, the target lane may be a lane other than the own vehicle lane, such as an adjacent lane; in a lane keeping scenario, the target lane may be the own vehicle lane.

S102: Generate a second target trajectory based on the vehicle initial position information, the vehicle speed and the first target trajectory, so that the self-vehicle merges into the first target trajectory along the second target trajectory from the vehicle initial position;

The second target trajectory is a line segment starting from the current position of the ego vehicle and finally merged into the first target trajectory. The line type of the second target trajectory includes, but is not limited to, a straight line, a broken line, a curved line, and the like.

S103: After generating the second target trajectory, update the second target trajectory according to the vehicle initial position information, the vehicle traveling speed and the first target trajectory acquired in real time.

That is to say, after the second target trajectory is generated, the initial position information of the vehicle is kept unchanged, and the second target trajectory is updated according to the initial position information of the vehicle, the vehicle driving direction and the first target trajectory acquired in real time.

2 is a schematic diagram of a second target trajectory at one moment provided by an embodiment of the present invention, and FIG. 3 is a schematic diagram of a second target trajectory at another moment provided by an embodiment of the present invention. Please refer to FIG. 2 and FIG. After the second target trajectory line is generated, the auxiliary line will be updated in real time with the path of the first eye path. At subsequent moments, the initial position S2 of the vehicle and the driving direction of the vehicle are kept unchanged, and only the real _- time self-vehicle coordinate system is converted to calculate in real time. Update M ₁ , M ₂ , M ₃ , E ₁ , E ₂ , E ₃ . As shown in Figures 2 and 3, the initial position of the vehicle at one moment is the same as the initial position of the vehicle at another moment, and the position, heading angle, and auxiliary line of the end of the first target trajectory at one moment are the same as the other. The vehicle position at a moment, the position of the end of the first target trajectory, the heading angle, and the auxiliary line are different.

4 is a planning effect diagram of a second target trajectory provided by an embodiment of the present invention, wherein the dotted line is the first target trajectory, the solid lines on both sides of the dotted line are lane lines, and the lower left corner is the initial vehicle position Num2 (ie S ₂ ) and the auxiliary points Num1 (ie S ₁ ) and Num3 (ie S ₃ ) on the front and back sides, and the upper right corner is the point Num7 (ie P ₃ ), Num8 (ie P ₂ ), Num9 near the end on the first target trajectory (ie P ₁ ), the end is far away from the initial position Num2 of the vehicle, and an intermediate point Num4 (ie M ₃ ) and its auxiliary points Num5 (ie M ₂ ) and Num6 (ie M ) are also set between the start point and the end point and the end point ₁ ), the rectangular box is the real-time position of the vehicle. After the second target trajectory line is generated, the points Num7, Num8, Num9 and the auxiliary lines determined according to the points Num7, Num8, and Num9 will be updated in real time with the first eye path path. The driving direction is unchanged, and M ₁ , M ₂ , M ₃ , E ₁ , E ₂ , and E ₃ are calculated and updated in real time according to the initial vehicle position Num2 and the initial vehicle driving direction, as well as the vehicle driving speed and the auxiliary line acquired in real time.

Compared with the existing method without an initial trajectory, the method provided by the embodiment of the present invention is not limited by the initial state conditions of the vehicle, and can smoothly merge into the target trajectory after any position of the lane is activated.

5 is a flowchart of updating the second target trajectory provided by an embodiment of the present invention. Specifically, as shown in FIG. 5 , generating a second target trajectory based on the initial vehicle position information, the vehicle speed and the first target trajectory includes the following steps:

S201: extracting target point position information at the end of the first target trajectory, and constructing an auxiliary line according to the position information of the target point;

Wherein, the end is the end of the first target trajectory away from the initial position of the vehicle, and the position information of the target point includes the coordinates of the target point and the heading angle of the target point; here, the extraction position of the target point position information is set at the end of the first target trajectory: In order to avoid that the path from the initial position of the vehicle to merge into the first target trajectory is too long, the vehicle can quickly transition to the first target trajectory.

In some embodiments, extracting target point position information at the end of the first target trajectory includes:

Extract the position information of several points at the end of the first target trajectory; the position information here includes the coordinates and heading angles corresponding to the points;

After the location information of several points is extracted, the location information of the target point is obtained according to the location information of several points. Specifically, the average value of the coordinates and the average value of the heading angle of the above-mentioned points can be calculated according to the position information of the several points, the average value of the coordinates of the several points is used as the coordinate of the target point, and the average value of the heading angle of the several points is used as the heading of the target point. horn.

In an example, P1, P2..., Pn are points on the planned first target trajectory, please continue to refer to Figure 2 and Figure 3, take three points at the end P1, P2, P3, calculate the average heading angle α; α=(α1+α2+α3)/3, wherein the heading angle of P1 is α1, the heading angle of P2 is α2, and the heading angle of P3 is α3.

The auxiliary line is constructed according to the position information of the target point. After obtaining the average value of the coordinates and the average heading angle α, tan(α) is used as the slope, and a straight line is calculated by the least square method as the auxiliary line. A*x+B* y+C=0 means.

S202: Determine the final curvature according to the initial position of the vehicle and the speed of the vehicle;

In some embodiments, the final curvature is determined based on the initial position of the vehicle and the speed of the vehicle, including:

Obtain the first curvature corresponding to the initial position of the vehicle; wherein, the first curvature is the curvature of the lane;

Query the allowable lateral acceleration corresponding to the vehicle speed;

Calculate the second curvature according to the vehicle speed and the allowable lateral acceleration; specifically, the formula for calculating the second curvature is: Curvature=a/v^2; where, Curvature is the second curvature; a is the allowable lateral acceleration; v is the vehicle's Driving speed.

The final curvature is obtained from the first curvature and the second curvature.

It should be noted that the minimum turning radius is calculated according to the second curvature, so that the method is suitable for both straight roads and curved roads. However, the calculation of the minimum turning radius only based on the road curvature is not suitable for the situation where the road is a straight road, because the curvature of the straight road is infinitely small, and the minimum turning radius calculated directly from the road curvature tends to be infinitely large, which makes the planned second target trajectory too large. The need for vehicles to merge quickly along the target line cannot be met. Here, the road curvature (ie, the first curvature) is added on the basis of the second curvature because the curve needs to plan a sharper circle to the auxiliary line than the straight road, so as to quickly transition to the auxiliary line.

The embodiment of the present invention does not use body attitude signals such as yaw rate YawRate and steering angle to calculate, but adjusts the final curvature by limiting the real-time lateral acceleration through the queried allowable lateral acceleration, so as to realize the adjustment of the second target trajectory, so that the entire parallel The entry process is smooth.

S203: Calculate the minimum turning radius according to the vehicle speed and the final curvature;

The maximum lateral acceleration a _max can be reversed according to the final curvature and the vehicle speed; that is, the maximum lateral acceleration a _max = final curvature * v^2, and then the minimum turning radius R=V^ can be calculated according to the vehicle speed and the maximum lateral acceleration 2/a _max .

In some embodiments, steps S202 and S203 may be replaced by the following steps:

Query the _allowable lateral acceleration a corresponding to the driving speed of the vehicle;

According to the traveling speed of the vehicle and the allowable lateral acceleration a _{allow to} calculate the minimum turning radius R=V^2/a _allow .

S204: Using the minimum turning radius as a radius, construct a curve passing through the initial position of the vehicle and tangent to the driving direction of the vehicle and the auxiliary line, respectively, to obtain a second target trajectory.

The embodiment of the present invention does not limit the point that is finally merged into the target trajectory, but dynamically solves the tangent point between the second target trajectory and the auxiliary line determined according to the position information of the target point in real time, so that the tangent point of the second target trajectory can be quickly merged under the condition of ensuring stability. target line.

In some embodiments, a minimum turning radius is used as a radius to construct a curve passing through the initial position of the vehicle and tangent to the driving direction of the vehicle and the auxiliary line, respectively, to obtain the second target trajectory, including:

Build an auxiliary coordinate system with the initial position of the vehicle as the origin;

6 is a schematic diagram of planning a second target trajectory provided by an embodiment of the present invention, please refer to FIG. 6 , the x-axis direction of the auxiliary coordinate system is determined according to the driving direction of the vehicle, and the y-axis of the auxiliary coordinate system is perpendicular to the x-axis;

The first circle center is determined on the y-axis of the auxiliary coordinate system according to the initial position of the vehicle and the minimum turning radius; as shown in Figure 6, the first circle center is the center of the first auxiliary circle, and the first circle center is located between the initial position of the vehicle and the auxiliary line ;The minimum turning radius is R, and the coordinates of the first circle center are (0, -R);

Construct a first auxiliary circle based on the first circle center and the minimum turning radius;

The second center is determined based on the auxiliary line and the first auxiliary circle; wherein, the second center is the center of the second auxiliary circle; wherein, the coordinates of the second center are (a, b);

Construct a second auxiliary circle based on the second circle center and the minimum turning radius;

The shortest S-shaped curve connecting the initial position of the vehicle, the position of the intermediate point and the position of the end point on the first auxiliary circle and the second auxiliary circle is used as the second target trajectory, and the obtained S-shaped second target trajectory conforms to the driver's steering wheel. Habit.

Among them, the position of the middle point is the tangent point between the first auxiliary circle and the second auxiliary circle, and its coordinates are (M _x , M _y )=(aR*cosβ, b+R*sinβ); the position of the end point is the second auxiliary circle The tangent point with the auxiliary line, its coordinates are (E _x , E _y )=(a+R*sinα, b+R*cosα), where α is the angle between the auxiliary line and the driving direction of the vehicle, α is Negative value with direction.

That is to say, the radius of the first auxiliary circle is the above-mentioned minimum turning radius, the radius of the second auxiliary circle is also the above-mentioned minimum turning radius, and the first auxiliary circle is tangent to the vehicle's driving direction at the initial position of the vehicle (ie point S ₂ ) , the second auxiliary circle and the auxiliary line are tangent to the point E ₂ , and the first auxiliary circle and the second auxiliary circle circumscribe M ₂ . The second target trajectory is an S-shaped curve passing through S ₃ , S ₂ , S ₁ , M ₃ , M ₂ , M ₁ , E ₃ , E ₂ , and E ₁ in sequence as shown in the figure.

As the auxiliary line is updated in real time at every moment, the points S ₃ , S ₂ , S ₁ , M ₃ , M ₂ , M ₁ , E ₃ , E ₂ , and E ₁ are also updated in real time, and the S-shaped curve determined according to these points is also updated in real time. Update in real time.

Substitute the coordinates of the trajectory end point ( _{Ex, E y )} =(a+R*sinα, b+R*cosα) into the auxiliary line expression to get:

sinα·E _x -cosα·E _y +C ₀ =0 (Equation 1)

According to formula 1, formula 2 can be obtained

sinα·(a+R*sinα)-cosα·(b+R*cosα)+C ₀ =0 (Equation 2)

Convert Equation 2 into Equation 3, Equation 3 is the expression of b with respect to a

b=tanα·(a+R*sinα)-R·cosα+C ₀ /cosα (Equation 3)

According to the geometric relationship between the first circle center and the second circle center, Equation 4 is obtained

a ² +(R+b) ² =(2R) ² (Equation 4)

Substitute Equation 3 into Equation 4 to obtain Equation 5, which is the quadratic equation in one variable with respect to a

(1+tan ² α)·α ² +(2·R·tanα+2·R·tan ² α·sinα-2·R·sinα+2·tanα·C0/cosα·α+2R2·tαna·sinα- 2R2·cosα+2RC0/cosα+R·tαnα·sinα-R·cosα+C0/cosα2=0 (Formula 5)

Using C ₁ , C ₂ , and C ₃ to represent the coefficients of the quadratic equations, the simplified equation 6 is obtained

C ₁ ·a ² +C ₂ ·a+C ₃ =0 (Formula 6)

Solve Equation 7 in a general way, Equation 7 is the expression of a

Substitute Equation 7 into Equation 3 to find b, and get the coordinates (a, b)

Then substitute the solved coordinates (a, b) back to the coordinates of the end point (E _x , E _y )=(a+R*sinα, b+R*cosα), and find the coordinates of the end point (E _x , E _y )

Construct the expression of β sinβ=(R+b)/2R, cosβ=a/2R,

Substitute the expression of β back into the coordinate expression of the intermediate point M _x == aR*cosβ, My ₌ b+R*sinβ, and obtain (M _x , _My ).

FIG. 7 is another schematic diagram of planning a second target trajectory provided by an embodiment of the present invention. Please refer to FIG. 7. In some embodiments, the minimum turning radius is used as the radius to construct the initial position of the passing vehicle and is respectively related to the driving direction of the vehicle and the auxiliary vehicle. The curve of the line tangent to obtain the second target trajectory, including:

The auxiliary coordinate system is constructed with the initial position of the vehicle as the origin (S _x , S _y ); the x' axis direction of the auxiliary coordinate system is determined according to the heading angle of the target point, and the y' axis of the auxiliary coordinate system is perpendicular to the x'axis;

The first circle center is determined on the y' axis of the auxiliary coordinate system according to the initial position of the vehicle and the minimum turning radius; wherein, the first circle center is the center of the first auxiliary circle whose coordinates are (0, -R), and the first circle center is located in the vehicle Between the initial position and the auxiliary line; the expression of the auxiliary line is sinα·x-cosα·y+C ₀ =0, and the auxiliary line is parallel to the x' axis.

Construct a first auxiliary circle based on the first circle center and the minimum turning radius;

The second center is determined based on the auxiliary line and the first auxiliary circle; wherein, the second center is the center of the second auxiliary circle;

Construct a second auxiliary circle based on the second circle center and the minimum turning radius;

The shortest S-shaped curve connecting the initial position of the vehicle, the position of the intermediate point (M _x , My _y ) and the position of the end point (E _x , E _y ) on the first auxiliary circle and the second auxiliary circle is used as the second target trajectory, where , the middle point is the tangent point between the first auxiliary circle and the second auxiliary circle, and the end point is the tangent point between the second auxiliary circle and the auxiliary line.

The lateral distance from the origin along the auxiliary line normal to the auxiliary line is

L _lateral direction=sinα·S _x −cosα·S _y +C ₀ (Equation 8)

The longitudinal distance from the origin along the auxiliary line to the auxiliary line is

-cosα·x-sinα·y+C ₁ =0

The translation method calculates M _x , _{My y} , Ex and E _y

M _x =S _x -cosα*L _vertical /2-sinα*L _horizontal /2

M _y =S _y -sinα*L _{vertical direction} /2+cosα*L _horizontal direction/2

E _x =S _x -cosα*Llongitudinal- _sinα * _Ltransverse

E _y =S _y -sinα*L _{vertical direction} +cosα*L _horizontal direction

Compared with the calculation method shown in FIG. 6 , the calculation method shown in FIG. 7 can simplify the solution process, and the finally solved trajectory lines are relatively close, which can achieve an approximate effect.

The above-mentioned embodiment discloses a method for obtaining the second target trajectory by using two auxiliary circles, and a method for obtaining the second target trajectory by using one assistant is also feasible.

For example, in some embodiments, a minimum turning radius is used as a radius to construct a curve passing through the initial position of the vehicle and tangent to the driving direction of the vehicle and the auxiliary line, respectively, to obtain the second target trajectory, including:

The center of the third auxiliary circle is determined based on the initial position of the vehicle, the driving direction of the vehicle, the minimum turning radius and the auxiliary line; wherein, the third auxiliary circle is tangent to the driving direction of the vehicle at the initial position of the vehicle, and the radius of the third auxiliary circle is the minimum turning radius , the third auxiliary circle is tangent to the auxiliary line;

Based on the determined circle center, the third auxiliary circle is constructed with the minimum turning radius as the radius;

The shortest circular curve connecting the initial position of the vehicle and the position of the end point on the third auxiliary circle is used as the second target trajectory; wherein, the position of the end point is the tangent point between the third auxiliary circle and the auxiliary line.

In some alternative embodiments, the second target trajectory may be a straight line from the initial position of the vehicle to the end point. Compared with the above example of the S-shaped curve, the straight second target trajectory can shorten the length of the second target trajectory. The length of the line segment makes the vehicle transition from the current vehicle position to the first target trajectory line more quickly. However, the straight second target trajectory is not smooth enough, which reduces the comfort of the driver and passengers, and the user experience is not good and does not meet the The driver's habit of turning the steering wheel.

It should be noted that the embodiment of the present invention preferentially adopts the above-mentioned scheme of obtaining the second target trajectory by using an auxiliary circle, rather than auxiliary graphics of other shapes such as ellipses, etc., because the circular curve can smoothly transition to the target trajectory line, and the circular curve is similar to the target trajectory. Easier to compute than other shapes such as ellipses, etc. In addition to the several preferred embodiments listed above, the second target trajectory in this embodiment of the present invention may also have other shapes and other planning methods, which are not limited in this embodiment.

In some alternative embodiments, the position of the end point may be a fixed position on the first target trajectory. Compared with the above solution in which the position of the end point is updated in real time, the planned path of the second target trajectory in this solution is longer and less frequent. Can quickly or smoothly transition to the first target trajectory.

Please continue to refer to FIG. 2 and FIG. 3 , in some embodiments, after generating the second target trajectory based on the vehicle initial position information, the vehicle speed and the first target trajectory, the method further includes:

A number of auxiliary points are respectively taken at preset time intervals on both sides of the calculated point on the second target trajectory; the auxiliary point is on the second target trajectory; the calculated points include the initial position of the vehicle and the first The middle point or end point of the two target trajectories; for example, a point S ₃ and S ₁ are taken 1s before and 1s after the current vehicle position S2, and a point M is taken 1s before and _1s after the middle point position _{M2 3.} M ₁ , take a point E ₃ and E ₁ at the first 1 s and the last 1 s of the end point position E ₂ . It should be noted that, according to actual needs, the preset time interval can also be other numerical values, and the number of auxiliary points can also be other numerical values, for example, two auxiliary points are taken before and after, which is not limited in this embodiment.

The second target trajectory is smoothed according to the calculated position of the point and several auxiliary points to obtain a smoothed second target trajectory.

The embodiment of the present invention is not limited by the initial state conditions of the vehicle, the initial trajectory planning function can be activated at any position in the lane, and the planned second target trajectory can move directly to the first target trajectory quickly and smoothly, and the real vehicle performance effect good.

It should be noted that the present invention is not limited by the described sequence of actions, because according to the present invention, certain steps may be performed in other sequences or simultaneously.

FIG. 8 is a structural block diagram of an initial trajectory planning apparatus provided by an embodiment of the present invention. Specifically, as shown in FIG. 8 , the apparatus includes:

The acquiring module 301 is configured to acquire the vehicle initial position information, the vehicle speed and the first target trajectory of the self-vehicle in response to the target control instruction for causing the self-vehicle vehicle to travel along the first target trajectory in the target lane; wherein, the vehicle The initial position information includes the initial position of the vehicle and the driving direction of the vehicle; the first target trajectory is obtained according to the lane line of the target lane and the trajectory detection result of the target vehicle, and the target vehicle is driving in the target lane;

a trajectory generation module 302, configured to generate a second target trajectory based on the vehicle initial position information, the vehicle speed and the first target trajectory, so that the self-vehicle merges into the first target trajectory along the second target trajectory from the vehicle initial position;

The trajectory updating module 303 is configured to, after generating the second target trajectory, update the second target trajectory according to the initial position information of the vehicle, the vehicle traveling speed and the first target trajectory acquired in real time.

Embodiments of the present invention further provide a vehicle, which has the initial trajectory planning device provided by the above device embodiments. It should be noted that the vehicle of the present invention may be a truck, sport utility vehicle, van, motorhome or any other type of vehicle without departing from the scope of the present disclosure.

An embodiment of the present invention also provides an electronic device, the electronic device includes a processor and a memory, and the memory stores at least one instruction, at least one piece of program, code set or instruction set, at least one instruction, at least one piece of program, code set or The instruction set is loaded and executed by the processor to implement the initial trajectory planning method as in the method embodiment.

Embodiments of the present invention further provide a storage medium, which can be set in a server to store at least one instruction, at least one piece of program, code set, or at least one relevant instruction for implementing the initial trajectory planning method in the method embodiment. An instruction set, the at least one instruction, the at least one piece of program, the code set or the instruction set is loaded and executed by the processor to implement the initial trajectory planning method provided by the above method embodiments.

Optionally, in this embodiment, the above-mentioned storage medium may be located in at least one network server among multiple network servers of a computer network. Optionally, in this embodiment, the above-mentioned storage medium may include but is not limited to: a U disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a mobile hard disk, a magnetic Various media that can store program codes, such as discs or optical discs.

It can be seen from the above-mentioned embodiments of the initial trajectory planning method, device, electronic device or storage medium provided by the present invention that the embodiments of the present invention are not limited by the initial state conditions of the vehicle, and the initial trajectory planning function can be activated at any position in the lane, and the initial trajectory planning function can be activated along the lane. The planned second target trajectory moves directly to the first target trajectory quickly and smoothly without any unnecessary actions.

It should be noted that: the above-mentioned order of the embodiments of the present invention is only for description, and does not represent the advantages and disadvantages of the embodiments. And the foregoing describes specific embodiments of the present specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that in the embodiments and still achieve desirable results. Additionally, the processes depicted in the figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the apparatus and server embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and for related parts, please refer to the partial descriptions of the method embodiments.

Those of ordinary skill in the art can understand that all or part of the steps of implementing the above embodiments can be completed by hardware, or can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium. The storage medium mentioned may be a read-only memory, a magnetic disk or an optical disk, etc.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection of the present invention. within the range.

Claims (10)

1. An initial trajectory planning method, comprising:

acquiring vehicle initial position information, a vehicle running speed and a first target track of a host vehicle in response to a target control instruction for causing the host vehicle to run along the first target track in a target lane; the vehicle initial position information comprises a vehicle initial position and a vehicle driving direction; the first target track is obtained according to a lane line of the target lane and a track detection result of a target vehicle, and the target vehicle runs in the target lane;

generating a second target track based on the vehicle initial position information, the vehicle running speed and the first target track so that the self vehicle is merged into the first target track from the vehicle initial position along the second target track;

after the second target track is generated, the second target track is updated according to the vehicle initial position information, the vehicle running speed and the first target track which are acquired in real time.

2. The method of claim 1, wherein generating a second target trajectory based on the vehicle initial position information, the vehicle travel speed, and the first target trajectory comprises:

extracting target point position information at the tail end of the first target track, and constructing an auxiliary line according to the position information of the target point; the terminal is one end of the first target track far away from the initial position of the vehicle, and the position information of the target point comprises the coordinates of the target point and the course angle of the target point;

determining a final curvature according to the initial position of the vehicle and the running speed of the vehicle;

calculating a minimum turning radius according to the vehicle running speed and the final curvature;

and constructing curves which pass through the initial position of the vehicle and are respectively tangent to the driving direction of the vehicle and the auxiliary line by taking the minimum turning radius as a radius to obtain the second target track.

3. The method of claim 2, wherein said extracting target point location information at the end of the first target trajectory comprises:

extracting position information of a plurality of points at the tail end of the first target track;

and obtaining the position information of the target point according to the position information of the points.

4. The method of claim 2, wherein determining the final curvature based on the initial vehicle position and the vehicle travel speed comprises:

acquiring a first curvature corresponding to the initial position of the vehicle; wherein the first curvature is a lane curvature;

inquiring the allowable lateral acceleration corresponding to the vehicle running speed;

calculating a second curvature from the vehicle running speed and the allowable lateral acceleration;

and obtaining the final curvature according to the first curvature and the second curvature.

5. The method according to claim 2, wherein said constructing a curve passing through the initial position of the vehicle and tangent to the vehicle driving direction and the auxiliary line, respectively, with the minimum turning radius as a radius, to obtain the second target trajectory comprises:

constructing an auxiliary coordinate system by taking the initial position of the vehicle as an origin; the direction of the x axis of the auxiliary coordinate system is determined according to the vehicle running direction or the course angle of the target point, and the y axis of the auxiliary coordinate system is vertical to the x axis;

determining a first circle center on a y axis of the auxiliary coordinate system according to the initial position of the vehicle and the minimum turning radius; the first circle center is the circle center of a first auxiliary circle and is located between the initial position of the vehicle and the auxiliary line;

constructing the first auxiliary circle based on the first circle center and the minimum turning radius;

determining a second circle center based on the auxiliary line and the first auxiliary circle; the second circle center is the circle center of a second auxiliary circle;

constructing the second auxiliary circle based on the second circle center and the minimum turning radius;

and taking the shortest S-shaped curve connecting the initial position of the vehicle, the middle point position and the end point position on the first auxiliary circle and the second auxiliary circle as the second target track, wherein the middle point position is the tangent point of the first auxiliary circle and the second auxiliary circle, and the end point position is the tangent point of the second auxiliary circle and the auxiliary line.

6. The method according to claim 2, wherein said constructing a curve passing through the initial position of the vehicle and tangent to the vehicle driving direction and the auxiliary line, respectively, with the minimum turning radius as a radius, to obtain the second target trajectory comprises:

determining a center of a third auxiliary circle based on the vehicle initial position, the vehicle traveling direction, the minimum turning radius, and the auxiliary line; wherein the third auxiliary circle is tangent to the vehicle driving direction at the vehicle initial position, the radius of the third auxiliary circle is the minimum turning radius, and the third auxiliary circle is tangent to the auxiliary line;

constructing the third auxiliary circle by taking the minimum turning radius as a radius based on the determined circle center;

taking the shortest circular curve connecting the initial position and the end position of the vehicle on the third auxiliary circle as the second target track; wherein the end point position is a tangent point of the third auxiliary circle and the auxiliary line.

7. The method of claim 1, wherein after generating a second target trajectory based on the vehicle initial position information, the vehicle travel speed, and the first target trajectory, further comprising:

respectively taking a plurality of auxiliary points on two sides of the position of the calculated point on the second target track according to a preset time interval; wherein the auxiliary point is on the second target track; the calculated points include the vehicle initial position, and a middle point or an end point of the second target trajectory;

and smoothing the second target track according to the calculated positions of the points and the auxiliary points to obtain the smoothed second target track.

8. An initial trajectory planning apparatus, comprising:

the vehicle control method comprises an acquisition module, a control module and a control module, wherein the acquisition module is used for responding to a target control instruction for enabling a vehicle to run along a first target track in a target lane, and acquiring vehicle initial position information, vehicle running speed and the first target track of the vehicle; the vehicle initial position information comprises a vehicle initial position and a vehicle driving direction; the first target track is obtained according to a lane line of the target lane and a track detection result of a target vehicle, and the target vehicle runs in the target lane;

a track generation module, configured to generate a second target track based on the vehicle initial position information, the vehicle running speed, and the first target track, so that the host vehicle merges into the first target track from the vehicle initial position along the second target track;

and the track updating module is used for updating the second target track according to the vehicle initial position information, the vehicle running speed and the first target track which are acquired in real time after the second target track is generated.

9. An electronic device, comprising a processor and a memory, wherein at least one instruction or at least one program is stored in the memory, and the at least one instruction or the at least one program is loaded and executed by the processor to implement the initial trajectory planning method according to any one of claims 1 to 7.

10. A computer-readable storage medium, having stored therein at least one instruction or at least one program, which is loaded and executed by a processor to implement the initial trajectory planning method according to any one of claims 1 to 7.

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