An Initial Trajectory Planning Method, Device, Equipment and Storage Medium

Abstract

The present invention discloses an initial trajectory planning method, device, equipment and storage medium. The method includes: in response to a target control instruction for causing a host vehicle to travel along a first target trajectory within a target lane, acquiring the initial position information of the vehicle, the vehicle traveling speed and the first target trajectory; generating a second target trajectory based on the initial position information of the vehicle, the vehicle traveling speed and the first target trajectory, so that the host vehicle merges into the first target trajectory along the second target trajectory from the initial position of the vehicle; after generating the second target trajectory, updating the second target trajectory according to the initial position information of the vehicle and the vehicle traveling speed and the first target trajectory obtained in real time. The present invention is not limited by the initial state conditions of the vehicle, and can quickly and smoothly merge into the first target trajectory along the planned second target trajectory after activating the initial trajectory planning function at any position in the lane.

Description

Technical Field

[0001] The present invention relates to the technical field of autonomous driving, and particularly to an initial trajectory planning method, device, equipment and storage medium. Background Art

[0002] In the lane centering control function of the intelligent driving industry, the target trajectory is calculated based on the lane line and the detected result of the leading vehicle's trajectory and updated in real time, and the vehicle finally needs to drive along the target trajectory. At the initial moment when such a function is activated, the lateral position of the vehicle's current position from the target trajectory line may be relatively far.

[0003] Most of the existing solutions restrict the initial activation conditions of the lane activation and maintenance functions, so that the vehicle is only allowed to activate the corresponding function when the lateral position from the target trajectory is very small and the deviation between the heading and the target trajectory heading is very small. The restriction on the initial state conditions of the vehicle is too strict. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, a first aspect of the present invention provides an initial trajectory planning method, including:

[0005] Responding to a target control instruction for causing a host vehicle to travel along a first target trajectory in a target lane, acquiring vehicle initial position information, vehicle traveling speed and the first target trajectory of the host vehicle; wherein, the vehicle initial position information includes a vehicle initial position and a vehicle traveling direction; the first target trajectory is obtained according to the lane line of the target lane and the detected result of the target vehicle's trajectory, and the target vehicle travels in the target lane;

[0006] Generating a second target trajectory based on the vehicle initial position information, the vehicle traveling speed and the first target trajectory, so that the host vehicle merges from the vehicle initial position along the second target trajectory into the first target trajectory;

[0007] After generating the second target trajectory, updating the second target trajectory according to the vehicle initial position information and the vehicle traveling speed and the first target trajectory obtained in real time.

[0008] Further, the generating a second target trajectory based on the vehicle initial position information, the vehicle traveling speed and the first target trajectory includes:

[0009] 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 far from the vehicle initial position, and the position information of the target point includes the coordinates of the target point and the heading angle of the target point;

[0010] Determine the final curvature based on the initial vehicle position and the vehicle driving speed;

[0011] Calculate the minimum turning radius based on the vehicle driving speed and the final curvature;

[0012] Construct a curve with the minimum turning radius as the radius, passing through the initial vehicle position and tangent to the vehicle driving direction and the auxiliary line respectively, to obtain the second target trajectory.

[0013] Further, the extracting the target point position information at the end of the first target trajectory includes:

[0014] Extract the position information of several points at the end of the first target trajectory;

[0015] Obtain the target point position information based on the position information of the several points.

[0016] Further, the determining the final curvature according to the initial vehicle position and the vehicle driving speed includes:

[0017] Obtain the first curvature corresponding to the initial vehicle position; wherein, the first curvature is the lane curvature;

[0018] Query the allowable lateral acceleration corresponding to the vehicle driving speed;

[0019] Calculate the second curvature according to the vehicle driving speed and the allowable lateral acceleration;

[0020] Obtain the final curvature based on the first curvature and the second curvature.

[0021] Further, the constructing a curve with the minimum turning radius as the radius, passing through the initial vehicle position and tangent to the vehicle driving direction and the auxiliary line respectively, to obtain the second target trajectory includes:

[0022] Construct an auxiliary coordinate system with the initial vehicle position as the origin; wherein, the x-axis direction of the auxiliary coordinate system is determined according to the vehicle driving direction or the heading angle of the target point, and the y-axis of the auxiliary coordinate system is perpendicular to the x-axis;

[0023] Determine a first center on the y-axis of the auxiliary coordinate system according to the initial vehicle position and the minimum turning radius; wherein, the first center is the center of the first auxiliary circle, and the first center is located between the initial vehicle position and the auxiliary line;

[0024] Construct the first auxiliary circle based on the first center and the minimum turning radius;

[0025] Determine a second center based on the auxiliary line and the first auxiliary circle; wherein, the second center is the center of the second auxiliary circle;

[0026] Construct the second auxiliary circle based on the second center and the minimum turning radius;

[0027] Take the shortest S-shaped curve connecting the vehicle's initial position, intermediate point position, and end point position on the first auxiliary circle and the second auxiliary circle as the second target trajectory, wherein the intermediate 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.

[0028] Further, constructing a curve with the minimum turning radius as the radius passing through the vehicle's initial position and tangent to the vehicle's driving direction and the auxiliary line respectively to obtain the second target trajectory includes:

[0029] Determine the center of the third auxiliary circle based on the vehicle's initial position, the vehicle's driving direction, the minimum turning radius, and the auxiliary line; wherein, the third auxiliary circle is tangent to the vehicle's driving direction at the vehicle's 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;

[0030] Construct the third auxiliary circle with the minimum turning radius as the radius based on the determined center;

[0031] Take the shortest circular curve connecting the vehicle's initial position and end point position on the third auxiliary circle as the second target trajectory; wherein, the end point position is the tangent point of the third auxiliary circle and the auxiliary line.

[0032] Further, after generating the second target trajectory based on the vehicle's initial position information, the vehicle's driving speed, and the first target trajectory, it further includes:

[0033] Take a number of auxiliary points at preset time intervals on both sides of the positions of the points already calculated on the second target trajectory; wherein, the auxiliary points are on the second target trajectory; the points already calculated include the vehicle's initial position, and the intermediate point or end point of the second target trajectory;

[0034] Smooth the second target trajectory according to the positions of the points already calculated and the number of auxiliary points to obtain the smoothed second target trajectory.

[0035] A second aspect of the present invention proposes an initial trajectory planning device, including:

[0036] An acquisition module, configured to acquire the initial vehicle position information, the vehicle traveling speed, and the first target trajectory of the host vehicle in response to a target control instruction for causing the host vehicle to travel along a first target trajectory within a target lane; wherein, the initial vehicle position information includes the initial vehicle position and the vehicle traveling direction; the first target trajectory is obtained based on the lane lines of the target lane and the trajectory detection result of a target vehicle, and the target vehicle travels within the target lane.

[0037] A trajectory generation module, configured to generate a second target trajectory based on the initial vehicle position information, the vehicle traveling speed, and the first target trajectory, so that the host vehicle merges into the first target trajectory from the initial vehicle position along the second target trajectory.

[0038] A trajectory update module, configured to update the second target trajectory according to the initial vehicle position information and the vehicle traveling speed and the first target trajectory obtained in real time after generating the second target trajectory.

[0039] A third aspect of the present invention provides an electronic device, which includes a processor and a memory. At least one instruction or at least one segment of program is stored in the memory, and the at least one instruction or the at least one segment of program is loaded and executed by the processor to implement the initial trajectory planning method proposed in the first aspect of the present invention.

[0040] A fourth aspect of the present invention provides a computer-readable storage medium, in which at least one instruction or at least one segment of program is stored, and the at least one instruction or the at least one segment of program is loaded and executed by a processor to implement the initial trajectory planning method proposed in the first aspect of the present invention.

[0041] Implementing the present invention has the following beneficial effects:

[0042] 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 within the lane, and move quickly and smoothly along the planned second target trajectory directly to the first target trajectory without generating redundant actions.

[0043] The additional aspects and advantages of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0045] Figure 1 is a flowchart of an initial trajectory planning method provided by an embodiment of the present invention;

[0046] Figure 2 is a schematic diagram of a second target trajectory at a certain moment provided by an embodiment of the present invention;

[0047] Figure 3 is a schematic diagram of a second target trajectory at another moment provided by an embodiment of the present invention;

[0048] Figure 4 is a planning effect diagram of a second target trajectory provided by an embodiment of the present invention;

[0049] Figure 5 is a flowchart of updating the second target trajectory provided by an embodiment of the present invention;

[0050] Figure 6 is a schematic diagram of planning a second target trajectory provided by an embodiment of the present invention;

[0051] Figure 7 is another schematic diagram of planning a second target trajectory provided by an embodiment of the present invention;

[0052] Figure 8 is a structural block diagram of an initial trajectory planning device provided by an embodiment of the present invention. Detailed implementation manners

[0053] To make the objectives, 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. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout.

[0054] It should be noted that the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of this application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of this application described here can be implemented in an order other than those illustrated or described here. In addition, 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 does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0055] In the lane centering control function in the intelligent driving industry, the target trajectory is calculated based on the lane line and the detected result of the leading vehicle's trajectory and the target trajectory is updated in real time. Finally, the vehicle needs to drive along the target trajectory. For the situation where the lateral position of the vehicle's current position from the target trajectory line may be relatively far at the initial moment when such a function is activated, the embodiment of the present invention plans an additional initial trajectory path between the vehicle's current position and the target trajectory line, so that the vehicle smoothly merges into the target trajectory along the initial trajectory.

[0056] It should be noted that the initial trajectory planning method provided by the embodiment of the present invention can be used in path planning of various scenarios, including but not limited to similar scenarios such as lane centering hold, high-level autonomous driving lane change, and merging of two paths.

[0057] Embodiment

[0058] Figure 1 is a flowchart of an initial trajectory planning method provided by an embodiment of the present invention. This specification provides the method operation steps as described in the embodiment or flowchart, but based on routine or non-creative labor, it may include more or fewer operation steps. The step sequence listed in the embodiment is only one way among the execution sequences of numerous steps and does not represent the only execution sequence. When the actual system or server product executes, it can be executed in the order of the method shown in the embodiment or the drawings or executed in parallel (for example, in an environment of parallel processors or multi-threaded processing). Specifically, as Figure 1 shown, the method may include:

[0059] S101: In response to a target control instruction for causing the host vehicle to travel along a first target trajectory in a target lane, obtain the initial position information of the vehicle, the vehicle traveling speed, and the first target trajectory of the host vehicle;

[0060] Among them, the vehicle initial position information includes the vehicle initial position and the vehicle driving direction; the first target trajectory is obtained based on the lane lines of the target lane and the trajectory detection result of the target vehicle, and the target vehicle travels within the target lane.

[0061] 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 article.

[0062] Specifically, in the vehicle lane change scenario, the target lane can be other lanes except the vehicle's own lane, such as adjacent lanes; in the lane keeping scenario, the target lane can be the vehicle's own lane.

[0063] S102: Generate a second target trajectory based on the vehicle initial position information, the vehicle driving speed, and the first target trajectory, so that the vehicle merges into the first target trajectory along the second target trajectory from the vehicle initial position.

[0064] Among them, the second target trajectory is a line segment starting from the vehicle's current position and finally merging into the first target trajectory. The line type of the second target trajectory includes but is not limited to straight lines, broken lines, curves, etc.

[0065] S103: After generating the second target trajectory, update the second target trajectory according to the vehicle initial position information and the vehicle driving speed and the first target trajectory obtained in real time.

[0066] That is to say, after generating the second target trajectory, keep the vehicle initial position information unchanged, and update the second target trajectory according to the vehicle initial position information and the vehicle driving direction and the first target trajectory obtained in real time.

[0067] Figure 2 is a schematic diagram of the second target trajectory at a certain moment provided by an embodiment of the present invention. Figure 3 is a schematic diagram of the second target trajectory at another moment provided by an embodiment of the present invention. Please refer to Figure 2 and Figure 3 , after generating the second target trajectory line, the auxiliary line will be updated in real time along with the first target path. At subsequent moments, keep the vehicle initial position S2 and the vehicle driving direction unchanged, and only switch to the real-time vehicle coordinate system, and calculate and update M1, M2, M3, E1, E2, E3 in real time. As Figure 2 and Figure 3 shown, the vehicle initial position at one moment is the same as that at another moment, and the position, heading angle, and auxiliary line at the end of the first target trajectory at one moment are different from the vehicle position, the position, heading angle, and auxiliary line at the end of the first target trajectory at another moment.

[0068] Figure 4This is the planning effect diagram of a second target trajectory provided by an embodiment of the present invention. Among them, the dashed line is the first target trajectory, the solid lines on both sides of the dashed line are lane lines, the lower left corner is the initial vehicle position Num2 (i.e., S2) and the auxiliary points Num1 (i.e., S1) and Num3 (i.e., S3) on its front and rear sides, and the upper right corner are the points Num7 (i.e., P3), Num8 (i.e., P2), and Num9 (i.e., P1) on the first target trajectory near the end. This end is far from the initial vehicle position Num2. There are also intermediate points Num4 (i.e., M3) and its auxiliary points Num5 (i.e., M2) and Num6 (i.e., M1) between the starting point and the ending point. The rectangular frame is the real-time vehicle position. After generating the second target trajectory line, points Num7, Num8, Num9 and the auxiliary lines determined according to points Num7, Num8, Num9 will be updated in real time along with the first target path. At subsequent moments, keeping the initial vehicle position Num2 and the initial vehicle driving direction unchanged, M1, M2, M3, E1, E2, and E3 are calculated and updated in real time according to the initial vehicle position Num2, the initial vehicle driving direction, the real-time obtained vehicle driving speed, and the auxiliary lines.

[0069] Compared with the existing method without an initial trajectory, the method provided by the embodiment of the present invention is not restricted by the vehicle's initial state conditions and can smoothly merge into the target trajectory after being activated at any position in the lane.

[0070] Figure 5 This is the flowchart for updating the second target trajectory provided by an embodiment of the present invention. Specifically, as Figure 5 shown, based on the initial vehicle position information, the vehicle driving speed, and the first target trajectory, a second target trajectory is generated, including the following steps:

[0071] S201: Extract the position information of the target points at the end of the first target trajectory, and construct auxiliary lines according to the position information of the target points;

[0072] Among them, the end is the end of the first target trajectory far from the initial vehicle position. The position information of the target points includes the coordinates of the target points and the heading angles of the target points. Here, the extraction position of the position information of the target points is set at the end of the first target trajectory to avoid too long a path for the vehicle to merge into the first target trajectory from the initial vehicle position, enabling the vehicle to quickly transition to the first target trajectory line.

[0073] In some embodiments, extracting the position information of the target points at the end of the first target trajectory includes:

[0074] 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;

[0075] After obtaining the position information of several points, the target point position information is obtained based on the position information of the several points. Specifically, it can be to calculate the coordinate average value and the heading angle average value of the above-mentioned several points according to the position information of the several points, use the coordinate average value of the several points as the coordinates of the target point, and use the heading angle average value of the several points as the heading angle of the target point.

[0076] In one example, P1, P2,..., Pn are the points on the first target trajectory planned. Please continue to refer to Figure 2 and Figure 3 , take the last three points P1, P2, and P3 to calculate the average heading angle α; α = (α1 + α2 + α3) / 3, where the heading angle of P1 is α1, the heading angle of P2 is α2, and the heading angle of P3 is α3.

[0077] An auxiliary line is constructed according to the position information of the target point. It can be that after obtaining the coordinate average value and the average heading angle α, a straight line is calculated as the auxiliary line by using the least squares method with tan(α) as the slope, and it is represented by A*x + B*y + C = 0.

[0078] S202: Determine the final curvature according to the initial position of the vehicle and the vehicle driving speed;

[0079] In some embodiments, determining the final curvature according to the initial position of the vehicle and the vehicle driving speed includes:

[0080] Obtain the first curvature corresponding to the initial position of the vehicle; where the first curvature is the lane curvature;

[0081] Query the allowable lateral acceleration corresponding to the vehicle driving speed;

[0082] Calculate the second curvature according to the vehicle driving 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 driving speed.

[0083] Obtain the final curvature according to the first curvature and the second curvature.

[0084] It should be noted that the minimum turning radius is calculated according to the second curvature, so that the method is applicable to both straight roads and curved roads. And calculating the minimum turning radius only according to the road curvature is not applicable to the case where the road is a straight road, because the curvature of the straight road is infinitely small, and the minimum turning radius calculated directly by the road curvature tends to be infinitely large, making the planned second target trajectory too large to meet the vehicle's need to quickly merge into the target line. Adding the road curvature (i.e., the first curvature) to the second curvature here is because compared with a straight road, a curved road requires a more urgent circular auxiliary line to quickly transition to the auxiliary line.

[0085] In the embodiment of the present invention, instead of calculating using vehicle attitude signals such as yaw rate and steering angle, the final curvature is adjusted by the allowed lateral acceleration obtained through querying to limit the real-time lateral acceleration, so as to adjust the second target trajectory and make the whole merging process stable.

[0086] S203: Calculate the minimum turning radius according to the vehicle driving speed and the final curvature;

[0087] The maximum lateral acceleration a can be deduced based on the final curvature and the vehicle driving speed max ; that is, the maximum lateral acceleration a max = final curvature * v^2, and then the minimum turning radius R = V^2 / a can be calculated according to the vehicle driving speed and the maximum lateral acceleration max .

[0088] In some embodiments, step S202 and step S203 can be replaced with the following steps:

[0089] Query the allowed lateral acceleration a corresponding to the vehicle driving speed 允许 ;

[0090] Calculate the minimum turning radius R = V^2 / a according to the vehicle driving speed and the allowed lateral acceleration a 允许 允许 .

[0091] S204: Construct a curve with the minimum turning radius as the radius passing through the initial position of the vehicle and tangent to the vehicle driving direction and the auxiliary line respectively to obtain the second target trajectory.

[0092] In the embodiment of the present invention, the points of the final merging target trajectory are not limited, but the tangent points of the second target trajectory and the auxiliary line determined according to the target point position information are solved dynamically in real time, so as to quickly merge into the target line under the condition of ensuring stability.

[0093] In some embodiments, constructing a curve with the minimum turning radius as the radius passing through the initial position of the vehicle and tangent to the vehicle driving direction and the auxiliary line respectively to obtain the second target trajectory includes:

[0094] Construct an auxiliary coordinate system with the initial position of the vehicle as the origin;

[0095] Figure 6 is a schematic diagram for planning the second target trajectory provided by the embodiment of the present invention. Please refer to Figure 6 , the x-axis direction of the auxiliary coordinate system is determined according to the vehicle driving direction, and the y-axis of the auxiliary coordinate system is perpendicular to the x-axis;

[0096] Determine the first center on the y-axis of the auxiliary coordinate system according to the initial position of the vehicle and the minimum turning radius; asFigure 6 As shown, the first center of the circle is the center of the first auxiliary circle, and the first center of the circle 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 center of the circle are (0, -R);

[0097] Construct the first auxiliary circle based on the first center of the circle and the minimum turning radius;

[0098] Determine the second center of the circle based on the auxiliary line and the first auxiliary circle; among them, the second center of the circle is the center of the second auxiliary circle; among them, the coordinates of the second center of the circle are (a, b);

[0099] Construct the second auxiliary circle based on the second center of the circle and the minimum turning radius;

[0100] Take the shortest S-shaped curve connecting the initial position, the intermediate point position and the end point position on the first auxiliary circle and the second auxiliary circle as the second target trajectory, and the obtained S-shaped second target trajectory conforms to the driving habit of the driver turning the steering wheel.

[0101] Among them, the intermediate point position is the tangent point of the first auxiliary circle and the second auxiliary circle, and its coordinates are (M x , M y ) = (a - R * cosβ, b + R * sinβ); the end point position is the tangent point of the second auxiliary circle and the auxiliary line, and 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, and α is a negative value with direction.

[0102] 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, the first auxiliary circle is tangent to the driving direction of the vehicle at the initial position of the vehicle (i.e., point S2), the second auxiliary circle is tangent to the auxiliary line at point E2, and the first auxiliary circle is externally tangent to the second auxiliary circle at M2. The second target trajectory is the S-shaped curve passing through S3, S2, S1, M3, M2, M1, E3, E2, E1 as shown in the figure.

[0103] As the auxiliary line is updated in real time at each moment, the points S3, S2, S1, M3, M2, M1, E3, E2, E1 are also updated in real time, and the S-shaped curve determined by these points is also updated in real time.

[0104] Substitute the coordinates (E x , E y ) = (a + R * sinα, b + R * cosα) of the trajectory end point into the auxiliary line expression to obtain:

[0105] sinα · E x - cosα · E y + C0 = 0 (Equation 1)

[0106] Equation 2 can be obtained according to Equation 1

[0107] sinα·(a + R*sinα) - cosα·(b + R*cosα) + C0 = 0 (Equation 2)

[0108] Convert Equation 2 into Equation 3, and Equation 3 is an expression of b in terms of a

[0109] b = tanα·(a + R*sinα) - R·cosα + C0 / cosα (Equation 3)

[0110] According to the geometric relationship between the first center and the second center, Equation 4 is obtained

[0111] a 2 +(R + b) 2 =(2R) 2 (Equation 4)

[0112] Substitute Equation 3 into Equation 4 to obtain Equation 5, and Equation 5 is a quadratic equation in a

[0113] (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(Equation 5)

[0114] Use C1, C2, and C3 to represent the coefficients of each term of the quadratic equation and simplify to obtain Equation 6

[0115] C1·a 2 +C2·a + C3 = 0 (Equation 6)

[0116] Solve Equation 7 in a general way, and Equation 7 is an expression of a

[0117]

[0118] Substitute Equation 7 back into Equation 3 to find b, and obtain the coordinates (a, b)

[0119] Then substitute the solved coordinates (a, b) back into 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 )

[0120] Construct the expressions of β: sinβ = (R + b) / 2R, cosβ = a / 2R,

[0121] Substitute the expressions of β back into the coordinate expressions of the midpoint M x == a - R*cosβ, M y = b + R*sinβ, and find (M x , M y ).

[0122] Figure 7 This is another schematic diagram for planning the second target trajectory provided by the embodiments of the present invention. Please refer to Figure 7 , in some embodiments, construct a curve with the minimum turning radius as the radius that passes through the initial position of the vehicle and is tangent to the vehicle's driving direction and the auxiliary line respectively to obtain the second target trajectory, including:

[0123] Take the initial position of the vehicle as the origin (S x , S y ) to construct an auxiliary coordinate system; wherein, the direction of the x'-axis 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;

[0124] Determine the first center 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 center is the center of the first auxiliary circle, and its coordinates are (0, -R), and the first center is located between the initial position of the vehicle and the auxiliary line; the expression of the auxiliary line is sinα·x - cosα·y + C0 = 0, and the auxiliary line is parallel to the x'-axis.

[0125] Construct the first auxiliary circle based on the first center and the minimum turning radius;

[0126] Determine the second center based on the auxiliary line and the first auxiliary circle; wherein, the second center is the center of the second auxiliary circle;

[0127] Construct the second auxiliary circle based on the second center and the minimum turning radius;

[0128] Take the shortest S-shaped curve connecting the initial position of the vehicle, the midpoint position (M x , M y ) and the end point position (E x , E y ) on the first auxiliary circle and the second auxiliary circle as the second target trajectory, wherein, the midpoint 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.

[0129] The lateral distance from the origin along the normal direction of the auxiliary line to the auxiliary line is

[0130] L 横向 = sinα·Sx -cosα·S y +C0 (Equation 8)

[0131] The longitudinal distance translated from the origin along the auxiliary line to the auxiliary line is

[0132] Drawing a perpendicular line from the origin to an auxiliary line can be expressed as

[0133] -cosα·x - sinα·y + C1 = 0

[0134] Calculating M by the translation method x 、M y 、E x and E y

[0135] M x = S x -cosα*L 纵向 / 2 - sinα*L 横向 / 2

[0136] M y = S y -sinα*L 纵向 / 2 + cosα*L 横向 / 2

[0137] E x = S x -cosα*L 纵向 -sinα*L 横向

[0138] E y = S y -sinα*L 纵向 +cosα*L 横向

[0139] Compared with Figure 6 the calculation method shown, Figure 7 the calculation method shown can simplify the solution process, and the finally obtained trajectory line is also relatively close, and can achieve an approximate effect.

[0140] What is disclosed in the above embodiments is a method for obtaining the second target trajectory using two auxiliary circles. In addition, a method for obtaining the second target trajectory using one auxiliary circle is also feasible.

[0141] For example, in some embodiments, constructing a curve with the minimum turning radius as the radius that passes through the initial position of the vehicle and is tangent to the vehicle's driving direction and the auxiliary line respectively to obtain the second target trajectory, including:

[0142] Determine the center of the third auxiliary circle based on the initial vehicle position, the vehicle driving direction, the minimum turning radius, and the auxiliary line; wherein, the third auxiliary circle is tangent to the vehicle driving direction at the initial vehicle position, the radius of the third auxiliary circle is the minimum turning radius, and the third auxiliary circle is tangent to the auxiliary line;

[0143] Construct the third auxiliary circle with the determined center and the minimum turning radius as the radius;

[0144] Take the shortest circular curve on the third auxiliary circle connecting the initial vehicle position and the end point position as the second target trajectory; wherein, the end point position is the tangent point of the third auxiliary circle and the auxiliary line.

[0145] In some alternative embodiments, the second target trajectory can be a straight line from the initial vehicle position to the end point. Compared with the above example of the S-shaped curve, the straight-line second target trajectory can shorten the line segment length of the second target trajectory, enabling the vehicle to transition from the current vehicle position to the first target trajectory line more quickly. However, the straight-line second target trajectory is not smooth enough, reducing the comfort of the passengers and drivers, resulting in a poor user experience and not conforming to the driving habit of turning the steering wheel.

[0146] It should be noted that the embodiments of the present invention preferably adopt the above-mentioned scheme of obtaining the second target trajectory using the auxiliary circle, rather than other shaped auxiliary graphics such as ellipses, because the circular curve can smoothly transition to the target trajectory line, and the circular curve is easier to calculate compared with other shapes (such as ellipses, etc.). In addition to the above-listed preferred embodiments, the second target trajectory in the embodiments of the present invention can also be of other shapes and adopt other planning methods, and this embodiment is not limited thereto.

[0147] In some alternative embodiments, the end point position can be a fixed position on the first target trajectory. Compared with the above scheme where the end point position is updated in real time, the second target trajectory planned by this scheme has a longer path and cannot transition to the first target trajectory quickly or smoothly.

[0148] Please continue to refer to Figure 2 and Figure 3 , in some embodiments, after generating the second target trajectory based on the initial vehicle position information, the vehicle driving speed, and the first target trajectory, it further includes:

[0149] On both sides of the positions of the calculated points on the second target trajectory, a number of auxiliary points are respectively taken at a preset time interval; among them, the auxiliary points are on the second target trajectory; the calculated points include the vehicle initial position, as well as the intermediate point or the end point of the second target trajectory; for example, one point S3 and one point S1 are taken 1 s before and 1 s after the current vehicle position S2 respectively, one point M3 and one point M1 are taken 1 s before and 1 s after the intermediate point position M2 respectively, and one point E3 and one point E1 are taken 1 s before and 1 s after the end point position E2 respectively. It should be noted that according to actual needs, the preset time interval can also be other values, and the number of auxiliary points can also be other values, such as taking 2 auxiliary points before and after respectively, etc. This embodiment is not limited thereto.

[0150] Perform smoothing processing on the second target trajectory according to the positions of the calculated points and a number of auxiliary points to obtain the smoothed second target trajectory.

[0151] The embodiment of the present invention is not limited by the vehicle initial state conditions, can activate the initial trajectory planning function at any position in the lane, and directly move quickly and smoothly along the planned second target trajectory to the first target trajectory, and the actual vehicle performance effect is good.

[0152] It should be noted that the present invention is not limited by the described action sequence, because according to the present invention, some steps can be performed in other sequences or simultaneously.

[0153] Figure 8 is a structural block diagram of an initial trajectory planning device provided by an embodiment of the present invention, specifically as Figure 8 shown, the device includes:

[0154] An acquisition module 301, configured to acquire the vehicle initial position information, the vehicle driving speed, and the first target trajectory of the host vehicle in response to a target control instruction for causing the host vehicle to travel along the first target trajectory in the target lane; wherein, the vehicle initial position information includes the vehicle initial position and the vehicle driving direction; the first target trajectory is obtained according to the lane lines of the target lane and the trajectory detection result of the target vehicle, and the target vehicle travels in the target lane;

[0155] A trajectory generation module 302, configured to generate a second target trajectory based on the vehicle initial position information, the vehicle driving speed, and the first target trajectory, so that the host vehicle merges into the first target trajectory from the vehicle initial position along the second target trajectory;

[0156] A trajectory update module 303, configured to update the second target trajectory according to the vehicle initial position information and the vehicle driving speed and the first target trajectory obtained in real time after generating the second target trajectory.

[0157] Embodiments of the present invention further provide a vehicle, which has the initial trajectory planning device provided in the above device embodiments. It should be noted that without departing from the scope of the present disclosure, the vehicle of the present invention can be a truck, a sport utility vehicle, a van, a recreational vehicle, or any other type of vehicle.

[0158] Embodiments of the present invention further provide an electronic device, which includes a processor and a memory. At least one instruction, at least one program segment, a code set, or an instruction set is stored in the memory, and the at least one instruction, the at least one program segment, the code set, or the instruction set is loaded and executed by the processor to implement the initial trajectory planning method as in the method embodiments.

[0159] Embodiments of the present invention further provide a storage medium, which can be disposed in a server to store at least one instruction, at least one program segment, a code set, or an instruction set related to implementing the initial trajectory planning method in the method embodiments. The at least one instruction, the at least one program segment, the code set, or the instruction set is loaded and executed by the processor to implement the initial trajectory planning method provided in the above method embodiments.

[0160] Optionally, in this embodiment, the above storage medium can be located in at least one of multiple network servers in a computer network. Optionally, in this embodiment, the above storage medium may include, but is not limited to: various media that can store program codes such as a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk, or an optical disc.

[0161] It can be seen from the embodiments of the initial trajectory planning method, device, electronic device, or storage medium provided by the present invention described above that the embodiments of the present invention are not restricted by the initial state conditions of the vehicle, can activate the initial trajectory planning function at any position within the lane, and move quickly and smoothly along the planned second target trajectory directly to the first target trajectory without generating redundant actions.

[0162] It should be noted that: the above order of the embodiments of the present invention is only for description and does not represent the superiority or inferiority of the embodiments. And the above specific embodiments of this specification have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be executed in a different order than in the embodiments and still achieve the desired results. Additionally, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0163] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made 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 reference can be made to the corresponding parts of the method embodiments for the relevant content.

[0164] Those of ordinary skill in the art can understand that all or part of the steps to implement the above embodiments can be completed by hardware, or can be completed by instructing relevant hardware through a program. The program can be stored in a computer-readable storage medium. The above-mentioned storage medium can be a read-only memory, a disk, an optical disc, or the like.

[0165] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An initial trajectory planning method, characterized in that, Including: In response to a target control instruction for making the host vehicle travel along a first target trajectory within a target lane, obtaining the initial vehicle position information, the vehicle traveling speed, and the first target trajectory of the host vehicle; wherein, the initial vehicle position information includes the initial vehicle position and the vehicle traveling direction; the first target trajectory is obtained based on the lane lines of the target lane and the trajectory detection result of a target vehicle traveling within the target lane; Generating a second target trajectory based on the initial vehicle position information, the vehicle traveling speed, and the first target trajectory, so that the host vehicle merges into the first target trajectory from the initial vehicle position along the second target trajectory; After generating the second target trajectory, updating the second target trajectory according to the initial vehicle position information and the vehicle traveling speed and the first target trajectory obtained in real time; The generating the second target trajectory based on the initial vehicle position information, the vehicle traveling speed, and the first target trajectory includes: 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 far from the initial vehicle position, and 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 vehicle position and the vehicle traveling speed; Calculating a minimum turning radius according to the vehicle traveling speed and the final curvature; Constructing a curve with the minimum turning radius as the radius that passes through the initial vehicle position and is tangent to the vehicle traveling direction and the auxiliary line respectively, to obtain the second target trajectory.

2. The method according to claim 1, wherein The extracting the target point position information at the end of the first target trajectory includes: Extracting the position information of several points at the end of the first target trajectory; Obtaining the target point position information according to the position information of the several points.

3. The method according to claim 1, characterized in that The determining the final curvature according to the initial vehicle position and the vehicle traveling speed includes: Obtaining a first curvature corresponding to the initial vehicle position; wherein, the first curvature is the lane curvature; Querying the allowable lateral acceleration corresponding to the vehicle traveling speed; Calculating a second curvature according to the vehicle traveling speed and the allowable lateral acceleration; Obtaining the final curvature according to the first curvature and the second curvature.

4. The method according to claim 1, wherein The constructing a curve with the minimum turning radius as the radius that passes through the initial vehicle position and is tangent to the vehicle traveling direction and the auxiliary line respectively, to obtain the second target trajectory, includes: Constructing an auxiliary coordinate system with the initial vehicle position as the origin; wherein, the x-axis direction of the auxiliary coordinate system is determined according to the vehicle traveling direction or the heading angle of the target point, and the y-axis of the auxiliary coordinate system is perpendicular to the x-axis; Determining a first center on the y-axis of the auxiliary coordinate system according to the initial vehicle position and the minimum turning radius; wherein, the first center is the center of a first auxiliary circle, and the first center is located between the initial vehicle position and the auxiliary line; Constructing the first auxiliary circle based on the first center and the minimum turning radius; Determine a second center of a circle based on the auxiliary line and the first auxiliary circle; wherein, the second center of the circle is the center of the second auxiliary circle; Construct the second auxiliary circle based on the second center of the circle and the minimum turning radius; Take the shortest S-shaped curve connecting the initial position of the vehicle, the intermediate point position, and the end point position on the first auxiliary circle and the second auxiliary circle as the second target trajectory, wherein the intermediate 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.

5. The method according to claim 1, characterized in that, Constructing the second target trajectory by constructing a curve with the minimum turning radius as the radius passing through the initial position of the vehicle and tangent to the vehicle driving direction and the auxiliary line respectively includes: Determine the center of the third auxiliary circle based on the initial position of the vehicle, the vehicle driving direction, the minimum turning radius, and the auxiliary line; wherein, the third auxiliary circle is tangent to the vehicle driving direction at 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; Construct the third auxiliary circle with the minimum turning radius as the radius based on the determined center of the circle; Take the shortest circular curve connecting the initial position of the vehicle and the end point position on the third auxiliary circle as the second target trajectory; wherein, the end point position is the tangent point of the third auxiliary circle and the auxiliary line.

6. The method according to claim 1, wherein After generating the second target trajectory based on the vehicle initial position information, the vehicle driving speed, and the first target trajectory, it further includes: Take a number of auxiliary points at both sides of the position of the points already calculated on the second target trajectory at a preset time interval; wherein, the auxiliary points are on the second target trajectory; the points already calculated include the initial position of the vehicle, and the intermediate point or the end point of the second target trajectory; Smooth the second target trajectory according to the positions of the points already calculated and the number of auxiliary points to obtain the smoothed second target trajectory.

7. An initial trajectory planning device, characterized in that, It includes: An acquisition module, configured to respond to a target control instruction for enabling the host vehicle to travel along a first target trajectory in a target lane, and acquire the vehicle initial position information, the vehicle driving speed, and the first target trajectory of the host vehicle; wherein, the vehicle initial position information includes the vehicle initial position and the vehicle driving direction; the first target trajectory is obtained according to the lane lines of the target lane and the trajectory detection result of the target vehicle, and the target vehicle travels in the target lane; A trajectory generation module, configured to generate a second target trajectory based on the vehicle initial position information, the vehicle traveling speed, and the first target trajectory, so that the host vehicle merges into the first target trajectory along the second target trajectory from the vehicle initial position; and is further configured to extract 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 far from the vehicle initial position, and the position information of the target point includes the coordinates of the target point and the heading angle of the target point; determine the final curvature according to the vehicle initial position and the vehicle traveling speed; calculate the minimum turning radius according to the vehicle traveling speed and the final curvature; construct a curve with the minimum turning radius as the radius passing through the vehicle initial position and tangent to the vehicle traveling direction and the auxiliary line respectively, to obtain the second target trajectory; A trajectory update module, configured to update the second target trajectory according to the vehicle initial position information, the vehicle traveling speed obtained in real time, and the first target trajectory after the second target trajectory is generated.

8. An electronic device, characterized in that, The electronic device includes a processor and a memory, and at least one instruction or at least one program segment is stored in the memory, and the at least one instruction or the at least one program segment is loaded and executed by the processor to implement the initial trajectory planning method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, At least one instruction or at least one program segment is stored in the storage medium, and the at least one instruction or the at least one program segment is loaded and executed by a processor to implement the initial trajectory planning method according to any one of claims 1 to 6.

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