A vehicle lane-changing trajectory planning method, device, equipment and medium

Abstract

Embodiments of the present application disclose a vehicle lane-changing trajectory planning method, device, equipment and medium. The method comprises: obtaining a reference lane-changing trajectory equation of a target vehicle; determining a first constraint condition of the reference lane-changing trajectory equation, and performing parameter solving on the reference lane-changing trajectory equation according to the first constraint condition to obtain a candidate lane-changing trajectory equation of the target vehicle; wherein the first constraint condition is a boundary constraint condition of the target vehicle at a starting and ending position of lane changing; determining a second constraint condition of the candidate lane-changing trajectory equation, and performing parameter solving on the candidate lane-changing trajectory equation according to the second constraint condition to obtain a target lane-changing trajectory equation of the target vehicle; wherein the second constraint condition is a lateral stability constraint condition of the target vehicle in the lane-changing process. The technical solution can realize vehicle lane-changing trajectory planning based on the boundary constraint condition and the lateral stability constraint condition, thereby ensuring the accuracy of vehicle lane changing and improving the safety of vehicle lane changing.

Description

Technical Field

[0001] This invention relates to the field of vehicle driving technology, and in particular to a method, apparatus, device and medium for planning vehicle lane-changing trajectories. Background Technology

[0002] With the development of autonomous driving technology, vehicle trajectory planning has become a crucial component. Currently, the most mainstream trajectory planning algorithms include graph methods, artificial potential field methods, neural network algorithms, genetic algorithms, particle swarm optimization, and polynomial curve fitting algorithms. Among these, the polynomial curve fitting algorithm offers strong real-time performance, requires less computing power from the controller chip, and can solve trajectory planning problems under different lane-changing requirements by applying constraints, thus making it widely used.

[0003] However, existing research on trajectory planning algorithms based on polynomial curves does not take into account the lateral stability requirements of vehicles during lane changes at the trajectory planning level of autonomous driving technology. This may lead to yaw instability of vehicles during lane changes, thereby causing safety issues. Summary of the Invention

[0004] This invention provides a vehicle lane-changing trajectory planning method, apparatus, equipment, and medium, which can realize vehicle lane-changing trajectory planning based on boundary constraints and lateral stability constraints, thereby improving the safety of vehicle lane changing while ensuring the accuracy of vehicle lane changing.

[0005] According to one aspect of the present invention, a vehicle lane-changing trajectory planning method is provided, the method comprising:

[0006] Obtain the reference lane-changing trajectory equation of the target vehicle; wherein, the reference lane-changing trajectory equation is used to characterize the functional relationship between the lateral displacement and the longitudinal displacement of the target vehicle;

[0007] A first constraint condition is determined for the reference lane-changing trajectory equation, and the candidate lane-changing trajectory equation for the target vehicle is obtained by parametric solution based on the first constraint condition; wherein, the first constraint condition is the boundary constraint condition of the target vehicle at the start and end positions of the lane change.

[0008] A second constraint condition is determined for the candidate lane-changing trajectory equation, and the target lane-changing trajectory equation of the target vehicle is obtained by parametric solution of the candidate lane-changing trajectory equation according to the second constraint condition; wherein, the second constraint condition is the lateral stability constraint condition of the target vehicle during the lane-changing process.

[0009] According to another aspect of the present invention, a vehicle lane-changing trajectory planning device is provided, comprising:

[0010] A reference lane-changing trajectory equation acquisition module is used to acquire the reference lane-changing trajectory equation of the target vehicle; wherein, the reference lane-changing trajectory equation is used to characterize the functional relationship between the lateral displacement and the longitudinal displacement of the target vehicle;

[0011] The candidate lane-changing trajectory equation determination module is used to determine the first constraint condition of the reference lane-changing trajectory equation, and to obtain the candidate lane-changing trajectory equation of the target vehicle by solving the parameters of the reference lane-changing trajectory equation according to the first constraint condition; wherein, the first constraint condition is the boundary constraint condition of the target vehicle at the start and end positions of the lane change.

[0012] The target lane-changing trajectory equation determination module is used to determine the second constraint condition of the candidate lane-changing trajectory equation, and to obtain the target lane-changing trajectory equation of the target vehicle by solving the parameters of the candidate lane-changing trajectory equation according to the second constraint condition; wherein, the second constraint condition is the lateral stability constraint condition of the target vehicle during the lane-changing process.

[0013] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0014] At least one processor; and

[0015] A memory communicatively connected to the at least one processor; wherein,

[0016] The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the vehicle lane-changing trajectory planning method according to any embodiment of the present invention.

[0017] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions for causing a processor to execute and implement the vehicle lane-changing trajectory planning method according to any embodiment of the present invention.

[0018] The technical solution of this invention involves obtaining a reference lane-changing trajectory equation for a target vehicle. This reference trajectory equation characterizes the functional relationship between the lateral and longitudinal displacements of the target vehicle. A first constraint condition is determined for the reference trajectory equation, and a candidate lane-changing trajectory equation for the target vehicle is obtained by parametric solution based on the first constraint condition. The first constraint condition is a boundary constraint condition for the target vehicle at the start and end positions of the lane change. A second constraint condition is determined for the candidate lane-changing trajectory equation, and a target lane-changing trajectory equation for the target vehicle is obtained by parametric solution based on the second constraint condition. The second constraint condition is a lateral stability constraint condition for the target vehicle during the lane-changing process. This technical solution enables vehicle lane-changing trajectory planning based on boundary and lateral stability constraints, improving the safety of lane changes while ensuring accuracy.

[0019] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a vehicle lane-changing trajectory planning method provided in Embodiment 1 of the present invention;

[0022] Figure 2A This is a schematic diagram of a target lane-changing trajectory equation provided in Embodiment 1 of the present invention;

[0023] Figure 2B This is a schematic diagram of another target lane-changing trajectory equation provided in Embodiment 1 of the present invention;

[0024] Figure 2C This is a schematic diagram of another target lane-changing trajectory equation provided in Embodiment 1 of the present invention;

[0025] Figure 3 This is a flowchart of a vehicle lane-changing trajectory planning method provided in Embodiment 2 of the present invention;

[0026] Figure 4 This is a schematic diagram of the structure of a vehicle lane-changing trajectory planning device according to Embodiment 3 of the present invention;

[0027] Figure 5 This is a schematic diagram of the structure of an electronic device that implements a vehicle lane-changing trajectory planning method according to an embodiment of the present invention. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first," "second," "target," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders 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 apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0030] Example 1

[0031] Figure 1 This is a flowchart of a vehicle lane-changing trajectory planning method provided in Embodiment 1 of the present invention. This embodiment is applicable to situations requiring safe and accurate planning of vehicle lane-changing trajectories. The method can be executed by a vehicle lane-changing trajectory planning device, which can be implemented in hardware and / or software. This device can be configured in an electronic device with data processing capabilities. Figure 1 As shown, the method includes:

[0032] S110, Obtain the reference lane-changing trajectory equation of the target vehicle; wherein, the reference lane-changing trajectory equation is used to characterize the functional relationship between the lateral displacement and the longitudinal displacement of the target vehicle.

[0033] In this embodiment, the reference lane-changing trajectory equation of the target vehicle needs to be obtained first. For example, the reference lane-changing trajectory equation can be expressed in polynomial form (such as a fifth-degree polynomial). For instance, the reference lane-changing trajectory equation can be represented as y(x) = a0 + a1x + a2x 2 +a3x 3 +a4x 4+a5x 5 Where y is the lateral displacement of the target vehicle, x is the longitudinal displacement of the target vehicle, and a i (i = 0, 1, 2, 3, 4, 5) are undetermined coefficients (unknown, to be solved).

[0034] The key to determining the reference lane-changing trajectory equation is solving for the undetermined coefficient 'a'. i The undetermined coefficient a i The solution can be obtained by imposing constraints on the reference lane-changing trajectory equations. When planning lane-changing trajectories for autonomous vehicles, it is necessary to consider the smoothness of the lane-changing trajectory and the lateral dynamics constraints of the vehicle during the lane-changing process. Therefore, constraints can be set from these two aspects.

[0035] S120, determine the first constraint condition of the reference lane-changing trajectory equation, and solve the parameter of the reference lane-changing trajectory equation according to the first constraint condition to obtain the candidate lane-changing trajectory equation of the target vehicle; wherein, the first constraint condition is the boundary constraint condition of the target vehicle at the start and end positions of the lane change.

[0036] In this embodiment, after obtaining the reference lane-changing trajectory equation of the target vehicle, it is necessary to determine the first constraint condition of the reference lane-changing trajectory equation, and then solve the parameter of the reference lane-changing trajectory equation according to the first constraint condition to obtain the candidate lane-changing trajectory equation of the target vehicle. The first constraint condition is the boundary constraint condition of the target vehicle at the start and end positions of the lane change. Optionally, the first constraint condition includes a displacement constraint condition, a heading angle constraint condition, and a first lateral acceleration constraint condition, which can be used to constrain the displacement, heading angle, and lateral acceleration of the target vehicle at the start and end positions of the lane change, respectively.

[0037] In this embodiment, optionally, determining the first constraint condition of the reference lane-changing trajectory equation includes: determining a displacement constraint condition based on the reference lane-changing trajectory equation and the longitudinal and lateral displacements of the target vehicle at the lane-changing start and end positions; determining a heading angle constraint condition based on the first derivative of the reference lane-changing trajectory equation and the longitudinal displacement and heading angle of the target vehicle at the lane-changing start and end positions; and determining a first lateral acceleration constraint condition based on the second derivative of the reference lane-changing trajectory equation and the longitudinal displacement and lateral acceleration of the target vehicle at the lane-changing start and end positions.

[0038] In this embodiment, the reference lane-changing trajectory equation is y(x)=a0+a1x+a2x 2 +a3x 3 +a4x 4 +a5x 5 The first and second derivatives are obtained as follows:

[0039]

[0040] in, Let y be the first derivative. Let y be the second derivative of y.

[0041] Assume that the longitudinal and lateral displacements of the target vehicle at the starting position of the lane change are both 0, and the longitudinal and lateral displacements of the target vehicle at the ending position of the lane change are x. f and y f Therefore, the displacement constraint condition can be obtained as follows:

[0042] Since the target vehicle is traveling in a straight line along the x-axis of the vehicle coordinate system both before and after the lane change, meaning the heading angle at the start and end points of the lane change trajectory is 0, its expression is: in, and Let represent the vehicle's heading angles at the start and end positions of the lane change, respectively. The x-axis of the vehicle coordinate system represents the direction the vehicle is traveling (i.e., the direction the front of the vehicle is facing). Therefore, the heading angle constraint condition can be obtained as follows:

[0043] To prevent abrupt changes in the lateral acceleration of the target vehicle at the start and end of a lane change, and to improve lateral stability during the lane change process, the lateral acceleration of the vehicle at the start and end positions of the lane change trajectory should be zero. Therefore, the first lateral acceleration constraint condition can be obtained as follows:

[0044] After determining the displacement constraint, heading angle constraint, and first lateral acceleration constraint, these three constraints can be substituted into y(x) = a0 + a1x + a2x. 2 +a3x 3 +a4x 4 +a5x 5 , and From this, we can derive: in, a 3，4，5 =[a3 a4 a5] T b = [y f 0 0] T Further solutions can be obtained. Will Substituting into y(x) = a0 + a1x + a2x 2 +a3x 3 +a4x 4 +a5x 5 From this, the candidate lane-changing trajectory equations for the target vehicle can be obtained as follows:

[0045] This scheme, through such a setting, can solve the parameters of the reference lane-changing trajectory equation based on displacement constraints, heading angle constraints, and the first lateral acceleration constraints, thereby achieving boundary constraints on the target vehicle at the start and end positions of the lane change.

[0046] S130, determine the second constraint condition of the candidate lane-changing trajectory equation, and solve the parameter of the candidate lane-changing trajectory equation according to the second constraint condition to obtain the target lane-changing trajectory equation of the target vehicle; wherein, the second constraint condition is the lateral stability constraint condition of the target vehicle during the lane-changing process.

[0047] In this embodiment, after obtaining the candidate lane-changing trajectory equations of the target vehicle, it is necessary to further determine the second constraint conditions of the candidate lane-changing trajectory equations, and then solve the parameters of the candidate lane-changing trajectory equations according to the second constraint conditions to obtain the target lane-changing trajectory equation of the target vehicle. The second constraint condition is the lateral stability constraint condition of the target vehicle during the lane-changing process. Optionally, the second constraint condition includes a centroid sideslip angle constraint condition, which can be used to constrain the centroid sideslip angle of the target vehicle during the lane-changing process.

[0048] In this embodiment, optionally, determining the second constraint condition of the candidate lane-changing trajectory equation includes: determining the transformed lane-changing trajectory equation based on the candidate lane-changing trajectory equation; wherein the transformed lane-changing trajectory equation is used to characterize the functional relationship between the lateral displacement of the target vehicle and the lane-changing time; determining the maximum lateral speed of the target vehicle during the lane-changing process based on the first derivative of the transformed lane-changing trajectory equation; determining the first maximum centroid sideslip angle of the target vehicle during the lane-changing process based on the maximum lateral speed and longitudinal speed of the target vehicle during the lane-changing process; wherein the longitudinal speed remains unchanged during the lane-changing process; determining the correspondence between the maximum centroid sideslip angle and the road surface adhesion coefficient based on the vehicle attribute information of the target vehicle, and determining the second maximum centroid sideslip angle of the target vehicle during the lane-changing process based on the correspondence; and determining the centroid sideslip angle constraint condition based on the first maximum centroid sideslip angle and the second maximum centroid sideslip angle.

[0049] In this embodiment, when determining the centroid sideslip angle constraint condition of the candidate lane-changing trajectory equation, the candidate lane-changing trajectory equation is first rewritten into a transformed lane-changing trajectory equation. The transformed lane-changing trajectory equation can be used to characterize the functional relationship between the lateral displacement of the target vehicle and the lane-changing time. Specifically, assuming that the longitudinal speed of the target vehicle remains constant during the lane-changing process, x and x' can be represented as... f Expressed as a function with independent variable t: Among them, v x Let t be the longitudinal speed of the vehicle, and t be the lane-changing time (independent variable). f The time required for the target vehicle to complete the lane change. Substitute into the candidate lane-changing trajectory equation From this, we can obtain the equation for the transformed lane-changing trajectory as follows: As can be seen from the transformed lane-changing trajectory equation, the vehicle's lane-changing trajectory is determined solely by y f and t f Two parameters determine this. One is the lateral displacement y of the target vehicle at the lane change termination position. f It can be set according to actual needs, for example, y can be... f The standard lane width is set at 3.5m. The time t required for the target vehicle to complete the lane change is... f Further determination is needed based on the second constraint.

[0050] Specifically, the sideslip angle of the target vehicle during lane changing is expressed as: Among them, v x Let v be the longitudinal speed of the vehicle, which is assumed to remain constant during lane changing; y (t) represents the lateral speed of the target vehicle during the lane-changing process. Taking the first derivative, the lateral speed of the target vehicle during the lane-changing process can be obtained as follows: Taking the first derivative, we get: make The extreme points can be solved as follows: Will Substitute into From this, we can obtain the maximum lateral speed of the target vehicle during the lane-changing process as: As can be seen from the above formula, the sideslip angle β(t) of the target vehicle during lane changing changes with the lateral speed v y The angle increases with the increase of (t). Therefore, the first maximum sideslip angle of the target vehicle during lane changing can be expressed as follows:

[0051] It should be noted that the maximum sideslip angle of a vehicle is related to the road adhesion coefficient, and the maximum sideslip angle under different road adhesion conditions can be obtained through simulation or experimentation. After determining the first maximum sideslip angle, the correspondence between the maximum sideslip angle and the road adhesion coefficient can be determined based on the vehicle attribute information of the target vehicle. Then, the second maximum sideslip angle of the target vehicle during lane changing can be determined based on the correspondence. The vehicle attribute information may include vehicle size information and model information, etc. For example, taking a domestically produced luxury full-size SUV as an example, the relationship between its maximum sideslip angle and the road adhesion coefficient is shown in Table 1 below:

[0052] Table 1. Relationship between maximum centroid sideslip angle and road adhesion coefficient

[0053] Maximum centroid sideslip angle 1.21° 2.06° 2.96° 3.95°

[0054] By performing cubic polynomial curve fitting on the data in Table 1, the second maximum centroid sideslip angle of the target vehicle during lane changing can be determined as: β max (μ)=0.8333μ 3 -0.625μ 2 +4.342μ-0.05875. Where β max (μ) is the second maximum centroid sideslip angle, and μ is the road surface adhesion coefficient.

[0055] Therefore, the centroid sideslip angle constraint condition can be determined based on the first and second maximum centroid sideslip angles. Specifically, the centroid sideslip angle constraint condition can be expressed as: β(t) max ≤β max (μ). β(t) max and β max Substituting the expression for (μ) into β(t) max ≤β max From (μ), the expression for the centroid sideslip angle constraint condition can be obtained as follows: Among them, t fβ This represents the time required for a vehicle to complete a lane change under the constraint of the center of gravity sideslip angle.

[0056] In this embodiment, optionally, the second constraint condition further includes a second lateral acceleration constraint condition; correspondingly, the second constraint condition for determining the candidate lane-changing trajectory equation further includes: determining the first maximum lateral acceleration of the target vehicle during the lane-changing process based on the second derivative of the transformed lane-changing trajectory equation; determining the second maximum lateral acceleration of the target vehicle during the lane-changing process based on the target lane-changing urgency and the target road surface adhesion coefficient; and determining the second lateral acceleration constraint condition based on the first maximum lateral acceleration and the second maximum lateral acceleration.

[0057] The second lateral acceleration constraint can be used to constrain the lateral acceleration of the target vehicle during lane changing. The target lane change urgency level can be used to characterize the urgency of the target vehicle's lane change. The target lane change urgency level ε ranges from 0.1 to 0.5; a larger ε indicates a more urgent lane change, and a smaller ε indicates a smoother lane change. The target road surface adhesion coefficient can refer to the road surface adhesion coefficient where the target vehicle is located.

[0058] In this embodiment, when determining the second lateral acceleration constraint condition of the candidate lane-changing trajectory equation, the lateral acceleration of the target vehicle during the lane-changing process can be expressed as follows, based on the second derivative of the transformed lane-changing trajectory equation (i.e., the first derivative of the lateral velocity of the target vehicle during the lane-changing process): Taking the first reciprocal of this expression, we get: make The extreme points can be solved as follows: Will Substitute into From this, we can obtain the first maximum lateral acceleration of the target vehicle during the lane-changing process as: On a road surface with good adhesion (μ = 0.8), the maximum lateral acceleration of a vehicle during a lane change should not exceed 0.4g; otherwise, a dangerous situation may easily occur. This invention considers the urgency of the lane change process and can express the second maximum lateral acceleration of the target vehicle during the lane change process as: a ymax =εμg. Furthermore, the second lateral acceleration constraint can be expressed as: |a y (t) max |≤a ymax . a y (t) max and a ymax Substituting the expression into |a y (t) max |≤a ymax From this, we can obtain the expression for the second lateral acceleration constraint condition as follows: in, This represents the time required for the target vehicle to complete a lane change under lateral acceleration constraints.

[0059] This scheme, through such a setting, based on the centroid sideslip angle constraint and the second lateral acceleration constraint, can quickly determine the second constraint condition of the candidate lane-changing trajectory equation, so as to facilitate the subsequent parameter solution of the candidate lane-changing trajectory equation according to the second constraint condition.

[0060] In this embodiment, after determining the second constraint condition of the candidate lane-changing trajectory equation, the candidate lane-changing trajectory equation can be parametrically solved according to the second constraint condition to obtain the target lane-changing trajectory equation of the target vehicle. Optionally, obtaining the target lane-changing trajectory equation of the target vehicle by parametrically solving the candidate lane-changing trajectory equation according to the second constraint condition includes: determining the target lane-changing time of the target vehicle according to the centroid sideslip angle constraint condition and the second lateral acceleration constraint condition; and parametrically solving the converted lane-changing trajectory equation according to the target lane-changing time to obtain the target lane-changing trajectory equation of the target vehicle.

[0061] In this embodiment, the target lane-changing time of the target vehicle is determined as... Therefore, given the sideslip angle constraint and the second lateral acceleration constraint, the target lane-changing time can be obtained. Then, the target lane-changing time is substituted into... From this, the target lane-changing trajectory equation of the target vehicle can be obtained. It should be noted that the target lane-changing trajectory equation obtained in the above manner can characterize the functional relationship between the lateral displacement of the target vehicle and the lane-changing time. Furthermore, the target lane-changing trajectory equation can be transformed into a functional relationship between the lateral displacement of the target vehicle and the longitudinal distance; both functional relationships can be used to describe the target lane-changing trajectory equation.

[0062] Figure 2A This is a schematic diagram of a target lane-changing trajectory equation provided in Embodiment 1 of the present invention. The urgency level of the target lane change is ε = 0.3, the target road surface adhesion coefficient is μ = 0.8, and the longitudinal speed of the target vehicle is v. x =30km / h, v x =60km / h and v x = 90km / h. Figure 2B This is a schematic diagram of another target lane-changing trajectory equation provided in Embodiment 1 of the present invention. The urgency of the target lane change is ε = 0.3, and the longitudinal speed of the target vehicle is v. x =60km / h, and the target road surface adhesion coefficients are μ=0.4, μ=0.6 and μ=0.8 respectively. Figure 2C This is a schematic diagram of another target lane-changing trajectory equation provided in Embodiment 1 of the present invention. The target road surface adhesion coefficient is μ = 0.8, and the longitudinal speed of the target vehicle is v. x =60km / h, the emergency levels of the target lane change are ε=0.1, ε=0.3 and ε=0.5 respectively.

[0063] The technical solution of this invention involves obtaining a reference lane-changing trajectory equation for a target vehicle. This reference trajectory equation characterizes the functional relationship between the lateral and longitudinal displacements of the target vehicle. A first constraint condition is determined for the reference trajectory equation, and a candidate lane-changing trajectory equation for the target vehicle is obtained by parametric solution based on the first constraint condition. The first constraint condition is a boundary constraint condition for the target vehicle at the start and end positions of the lane change. A second constraint condition is determined for the candidate lane-changing trajectory equation, and a target lane-changing trajectory equation for the target vehicle is obtained by parametric solution based on the second constraint condition. The second constraint condition is a lateral stability constraint condition for the target vehicle during the lane-changing process. This technical solution enables vehicle lane-changing trajectory planning based on boundary and lateral stability constraints, improving the safety of lane changes while ensuring accuracy.

[0064] Example 2

[0065] Figure 3 This is a flowchart of a vehicle lane-changing trajectory planning method provided in Embodiment 2 of the present invention. This embodiment is an optimization based on the above embodiment.

[0066] like Figure 3 As shown, the method in this embodiment specifically includes the following steps:

[0067] S210, Obtain the reference lane-changing trajectory equation of the target vehicle; wherein, the reference lane-changing trajectory equation is used to characterize the functional relationship between the lateral displacement and the longitudinal displacement of the target vehicle.

[0068] S220, determine the first constraint condition of the reference lane change trajectory equation; wherein, the first constraint condition includes the displacement constraint condition, heading angle constraint condition and first lateral acceleration constraint condition of the target vehicle at the start and end positions of the lane change.

[0069] S230, the candidate lane-changing trajectory equation of the target vehicle is obtained by solving the parameters of the reference lane-changing trajectory equation according to the first constraint condition.

[0070] S240, determine the transformed lane-changing trajectory equation based on the candidate lane-changing trajectory equation; wherein, the transformed lane-changing trajectory equation is used to characterize the functional relationship between the lateral displacement of the target vehicle and the lane-changing time.

[0071] S250, determine the second constraint condition for the candidate lane-changing trajectory equation; wherein, the second constraint condition includes the target vehicle's center of gravity sideslip angle constraint condition and the second lateral acceleration constraint condition during the lane-changing process.

[0072] S260, the target lane-changing trajectory equation of the target vehicle is obtained by parametrically solving the candidate lane-changing trajectory equation according to the second constraint condition.

[0073] In this embodiment, vehicle lane-changing trajectory planning can be achieved based on boundary constraints and lateral stability constraints, which improves the safety of vehicle lane changing while ensuring the accuracy of vehicle lane changing.

[0074] Example 3

[0075] Figure 4 This is a schematic diagram of a vehicle lane-changing trajectory planning device provided in Embodiment 3 of the present invention. This device can execute the vehicle lane-changing trajectory planning method provided in any embodiment of the present invention, and possesses the corresponding functional modules and beneficial effects of the method. For example... Figure 4 As shown, the device includes:

[0076] The reference lane-changing trajectory equation acquisition module 310 is used to acquire the reference lane-changing trajectory equation of the target vehicle; wherein, the reference lane-changing trajectory equation is used to characterize the functional relationship between the lateral displacement and the longitudinal displacement of the target vehicle.

[0077] The candidate lane-changing trajectory equation determination module 320 is used to determine the first constraint condition of the reference lane-changing trajectory equation, and to obtain the candidate lane-changing trajectory equation of the target vehicle by solving the parameters of the reference lane-changing trajectory equation according to the first constraint condition; wherein, the first constraint condition is the boundary constraint condition of the target vehicle at the start and end positions of the lane change.

[0078] The target lane-changing trajectory equation determination module 330 is used to determine the second constraint condition of the candidate lane-changing trajectory equation, and to obtain the target lane-changing trajectory equation of the target vehicle by solving the parameters of the candidate lane-changing trajectory equation according to the second constraint condition; wherein, the second constraint condition is the lateral stability constraint condition of the target vehicle during the lane-changing process.

[0079] Optionally, the first constraint condition includes a displacement constraint condition, a heading angle constraint condition, and a first lateral acceleration constraint condition;

[0080] Accordingly, the candidate lane-changing trajectory equation determination module 320 is used for:

[0081] The displacement constraint conditions are determined based on the reference lane-changing trajectory equation and the longitudinal and lateral displacements of the target vehicle at the lane-changing start and end positions.

[0082] The heading angle constraint is determined based on the first derivative of the reference lane-changing trajectory equation and the longitudinal displacement and heading angle of the target vehicle at the lane-changing start and end positions.

[0083] The first lateral acceleration constraint condition is determined based on the second derivative of the reference lane-changing trajectory equation and the longitudinal displacement and lateral acceleration of the target vehicle at the lane-changing start and end positions.

[0084] Optionally, the second constraint includes a centroid sideslip angle constraint.

[0085] Accordingly, the target lane change trajectory equation determination module 330 is used for:

[0086] The conversion lane-changing trajectory equation is determined based on the candidate lane-changing trajectory equation; wherein, the conversion lane-changing trajectory equation is used to characterize the functional relationship between the lateral displacement of the target vehicle and the lane-changing time;

[0087] The maximum lateral speed of the target vehicle during the lane-changing process is determined based on the first derivative of the transformed lane-changing trajectory equation.

[0088] Based on the target vehicle's maximum lateral speed and longitudinal speed during the lane-changing process, the first maximum centroid sideslip angle of the target vehicle during the lane-changing process is determined; wherein, the longitudinal speed remains constant during the lane-changing process.

[0089] The correspondence between the maximum centroid sideslip angle and the road surface adhesion coefficient is determined based on the vehicle attribute information of the target vehicle, and the second maximum centroid sideslip angle of the target vehicle during the lane-changing process is determined based on the correspondence.

[0090] The centroid sideslip angle constraint condition is determined based on the first maximum centroid sideslip angle and the second maximum centroid sideslip angle.

[0091] Optionally, the second constraint condition may further include a second lateral acceleration constraint condition;

[0092] Accordingly, the target lane-changing trajectory equation determination module 330 is also used for:

[0093] The first maximum lateral acceleration of the target vehicle during the lane-changing process is determined based on the second derivative of the lane-changing trajectory equation.

[0094] Based on the target lane change urgency and the target road surface adhesion coefficient, determine the second maximum lateral acceleration of the target vehicle during the lane change process;

[0095] The second lateral acceleration constraint condition is determined based on the first maximum lateral acceleration and the second maximum lateral acceleration.

[0096] Optionally, the target lane-changing trajectory equation determination module 330 is further configured to:

[0097] The target lane-changing time of the target vehicle is determined based on the centroid sideslip angle constraint and the second lateral acceleration constraint.

[0098] The target lane-changing trajectory equation of the target vehicle is obtained by solving the parameters of the lane-changing trajectory equation based on the target lane-changing time.

[0099] The vehicle lane-changing trajectory planning device provided in this embodiment of the invention can execute the vehicle lane-changing trajectory planning method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0100] Example 4

[0101] Figure 5A schematic diagram of an electronic device 10 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0102] like Figure 5 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0103] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0104] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as vehicle lane-changing trajectory planning methods.

[0105] In some embodiments, the vehicle lane-change trajectory planning method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the vehicle lane-change trajectory planning method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to execute the vehicle lane-change trajectory planning method by any other suitable means (e.g., by means of firmware).

[0106] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0107] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0108] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0109] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0110] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0111] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0112] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0113] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for planning vehicle lane-changing trajectories, characterized in that, The method includes: Obtain the reference lane-changing trajectory equation of the target vehicle; wherein, the reference lane-changing trajectory equation is used to characterize the functional relationship between the lateral displacement and the longitudinal displacement of the target vehicle; A first constraint condition is determined for the reference lane-changing trajectory equation, and the candidate lane-changing trajectory equation for the target vehicle is obtained by parametric solution based on the first constraint condition; wherein, the first constraint condition is the boundary constraint condition of the target vehicle at the start and end positions of the lane change. A second constraint condition is determined for the candidate lane-changing trajectory equation, and the target lane-changing trajectory equation of the target vehicle is obtained by parametric solution of the candidate lane-changing trajectory equation according to the second constraint condition; wherein, the second constraint condition is the lateral stability constraint condition of the target vehicle during the lane-changing process. The second constraint includes a centroid sideslip angle constraint; correspondingly, the second constraint for determining the candidate lane-changing trajectory equation includes: The conversion lane-changing trajectory equation is determined based on the candidate lane-changing trajectory equation; wherein, the conversion lane-changing trajectory equation is used to characterize the functional relationship between the lateral displacement of the target vehicle and the lane-changing time; The maximum lateral speed of the target vehicle during the lane-changing process is determined based on the first derivative of the transformed lane-changing trajectory equation. Based on the target vehicle's maximum lateral speed and longitudinal speed during the lane-changing process, the first maximum centroid sideslip angle of the target vehicle during the lane-changing process is determined; wherein, the longitudinal speed remains constant during the lane-changing process. The correspondence between the maximum centroid sideslip angle and the road surface adhesion coefficient is determined based on the vehicle attribute information of the target vehicle, and the second maximum centroid sideslip angle of the target vehicle during the lane-changing process is determined based on the correspondence. The centroid sideslip angle constraint condition is determined based on the first maximum centroid sideslip angle and the second maximum centroid sideslip angle.

2. The method according to claim 1, characterized in that, The first constraint condition includes displacement constraint condition, heading angle constraint condition and first lateral acceleration constraint condition; Accordingly, the first constraint condition for determining the reference lane-changing trajectory equation includes: The displacement constraint conditions are determined based on the reference lane-changing trajectory equation and the longitudinal and lateral displacements of the target vehicle at the lane-changing start and end positions. The heading angle constraint is determined based on the first derivative of the reference lane-changing trajectory equation and the longitudinal displacement and heading angle of the target vehicle at the lane-changing start and end positions. The first lateral acceleration constraint condition is determined based on the second derivative of the reference lane-changing trajectory equation and the longitudinal displacement and lateral acceleration of the target vehicle at the lane-changing start and end positions.

3. The method according to claim 1, characterized in that, The second constraint also includes a second lateral acceleration constraint. Accordingly, the second constraint condition for determining the candidate lane-changing trajectory equation also includes: The first maximum lateral acceleration of the target vehicle during the lane-changing process is determined based on the second derivative of the lane-changing trajectory equation. Based on the target lane change urgency and the target road surface adhesion coefficient, determine the second maximum lateral acceleration of the target vehicle during the lane change process; The second lateral acceleration constraint condition is determined based on the first maximum lateral acceleration and the second maximum lateral acceleration.

4. The method according to claim 3, characterized in that, The target lane-changing trajectory equation of the target vehicle is obtained by parametrically solving the candidate lane-changing trajectory equation according to the second constraint condition, including: The target lane-changing time of the target vehicle is determined based on the centroid sideslip angle constraint and the second lateral acceleration constraint. The target lane-changing trajectory equation of the target vehicle is obtained by solving the parameters of the lane-changing trajectory equation based on the target lane-changing time.

5. A vehicle lane-changing trajectory planning device, characterized in that, The device includes: A reference lane-changing trajectory equation acquisition module is used to acquire the reference lane-changing trajectory equation of the target vehicle; wherein, the reference lane-changing trajectory equation is used to characterize the functional relationship between the lateral displacement and the longitudinal displacement of the target vehicle; The candidate lane-changing trajectory equation determination module is used to determine the first constraint condition of the reference lane-changing trajectory equation, and to obtain the candidate lane-changing trajectory equation of the target vehicle by solving the parameters of the reference lane-changing trajectory equation according to the first constraint condition; wherein, the first constraint condition is the boundary constraint condition of the target vehicle at the start and end positions of the lane change. The target lane-changing trajectory equation determination module is used to determine the second constraint condition of the candidate lane-changing trajectory equation, and to obtain the target lane-changing trajectory equation of the target vehicle by solving the parameters of the candidate lane-changing trajectory equation according to the second constraint condition; wherein, the second constraint condition is the lateral stability constraint condition of the target vehicle during the lane-changing process. The second constraint condition includes a centroid sideslip angle constraint condition; correspondingly, the target lane change trajectory equation determination module is used for: The conversion lane-changing trajectory equation is determined based on the candidate lane-changing trajectory equation; wherein, the conversion lane-changing trajectory equation is used to characterize the functional relationship between the lateral displacement of the target vehicle and the lane-changing time; The maximum lateral speed of the target vehicle during the lane-changing process is determined based on the first derivative of the transformed lane-changing trajectory equation. Based on the target vehicle's maximum lateral speed and longitudinal speed during the lane-changing process, the first maximum centroid sideslip angle of the target vehicle during the lane-changing process is determined; wherein, the longitudinal speed remains constant during the lane-changing process. The correspondence between the maximum centroid sideslip angle and the road surface adhesion coefficient is determined based on the vehicle attribute information of the target vehicle, and the second maximum centroid sideslip angle of the target vehicle during the lane-changing process is determined based on the correspondence. The centroid sideslip angle constraint condition is determined based on the first maximum centroid sideslip angle and the second maximum centroid sideslip angle.

6. The apparatus according to claim 5, characterized in that, The first constraint condition includes displacement constraint condition, heading angle constraint condition and first lateral acceleration constraint condition; Accordingly, the candidate lane-changing trajectory equation determination module is used for: The displacement constraint conditions are determined based on the reference lane-changing trajectory equation and the longitudinal and lateral displacements of the target vehicle at the lane-changing start and end positions. The heading angle constraint is determined based on the first derivative of the reference lane-changing trajectory equation and the longitudinal displacement and heading angle of the target vehicle at the lane-changing start and end positions. The first lateral acceleration constraint condition is determined based on the second derivative of the reference lane-changing trajectory equation and the longitudinal displacement and lateral acceleration of the target vehicle at the lane-changing start and end positions.

7. The apparatus according to claim 5, characterized in that, The second constraint also includes a second lateral acceleration constraint. Accordingly, the target lane-changing trajectory equation determination module is also used for: The first maximum lateral acceleration of the target vehicle during the lane-changing process is determined based on the second derivative of the lane-changing trajectory equation. Based on the target lane change urgency and the target road surface adhesion coefficient, determine the second maximum lateral acceleration of the target vehicle during the lane change process; The second lateral acceleration constraint condition is determined based on the first maximum lateral acceleration and the second maximum lateral acceleration.

8. The apparatus according to claim 7, characterized in that, The target lane-changing trajectory equation determination module is also used for: The target lane-changing time of the target vehicle is determined based on the centroid sideslip angle constraint and the second lateral acceleration constraint. The target lane-changing trajectory equation of the target vehicle is obtained by solving the parameters of the lane-changing trajectory equation based on the target lane-changing time.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the vehicle lane-changing trajectory planning method according to any one of claims 1-4.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the vehicle lane-changing trajectory planning method according to any one of claims 1-4.

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