Transverse control method, device and equipment of target vehicle, medium and product

Abstract

The invention relates to the technical field of automatic driving path control, and discloses a transverse control method and device for a target vehicle, equipment, a medium and a product, and the method comprises the steps: obtaining first coordinate information of the target vehicle at a planned position and second coordinate information of the target vehicle at an actual position; converting the first coordinate information into a target coordinate system to obtain third coordinate information, and converting the second coordinate information into the target coordinate system to obtain fourth coordinate information; error information is obtained based on the third coordinate information and the fourth coordinate information; constructing a target transverse error differential equation based on the error information and a vehicle kinetic equation; and obtaining a target error based on the target lateral error differential equation, and enabling the target vehicle to perform lateral control based on the target error. According to the invention, the coordinate information of the target vehicle at the planned position and the actual position is converted to the target coordinate system, and the target vehicle is transversely controlled based on the target error, so that the transverse control precision can be improved, and the transverse error is eliminated.

Description

Technical Field

[0001] The present disclosure relates to the technical field of autonomous driving path control, and particularly to a lateral control method, device, equipment, medium and product for a target vehicle. Background Art

[0002] The lateral control and longitudinal control of an autonomous driving vehicle complement each other. The longitudinal control adjusts the speed through braking and throttle, while the lateral control ensures that the vehicle can move forward stably in a complex environment. The lateral control technology is a key link to ensure driving safety and accuracy. Only with the guarantee of lateral control can an autonomous driving vehicle drive safely and accurately along a predetermined trajectory.

[0003] Existing lateral control technologies include proportional-integral-derivative control, model predictive control, linear quadratic regulator, and pure tracking algorithm, etc. However, these technologies still have some deficiencies: proportional-integral-derivative control adjusts the lateral error through proportional, integral, and derivative, but does not consider the vehicle dynamics characteristics, and has poor robustness in high-speed scenarios; model predictive control predicts the future state based on the vehicle dynamics model and optimizes the control quantity, but has high computational complexity and limited real-time performance; linear quadratic regulator combines feedforward compensation and is suitable for path-smoothing scenarios such as highways, but has a high dependence on model accuracy and is prone to failure under the non-linear characteristics of tires; pure tracking algorithm previews path points based on a geometric model, has good robustness but insufficient curve tracking accuracy.

[0004] Therefore, the existing technology has problems of insufficient accuracy and inability to eliminate lateral error when performing lateral control on a vehicle. Summary of the Invention

[0005] In view of this, the present disclosure provides a lateral control method, device, equipment, medium and product for a target vehicle to solve the problem of insufficient accuracy of lateral control.

[0006] In a first aspect, the present disclosure provides a lateral control method for a target vehicle, the method comprising:

[0007] Obtain first coordinate information of the target vehicle at a planned position and second coordinate information of the target vehicle at an actual position;

[0008] Convert the first coordinate information to a target coordinate system to obtain third coordinate information, and convert the second coordinate information to the target coordinate system to obtain fourth coordinate information;

[0009] Based on the third coordinate information and the fourth coordinate information, obtain error information;

[0010] Based on the error information and the vehicle dynamics equation, construct a target lateral error differential equation;

[0011] Based on the target lateral error differential equation, a target error is obtained, enabling the target vehicle to perform lateral control based on the target error, where the target error is used to characterize the error between the actual position and the planned position.

[0012] In an embodiment of the present disclosure, by obtaining the first coordinate information of the target vehicle at the planned position and the second coordinate information of the target vehicle at the actual position; converting the first coordinate information to the target coordinate system to obtain the third coordinate information, and converting the second coordinate information to the target coordinate system to obtain the fourth coordinate information; based on the third coordinate information and the fourth coordinate information, error information is obtained; based on the error information and the vehicle dynamics equation, a target lateral error differential equation is constructed; based on the target lateral error differential equation, a target error is obtained, enabling the target vehicle to perform lateral control based on the target error, where the target error is used to characterize the error between the actual position and the planned position. Since the embodiment of the present disclosure converts the coordinate information of the target vehicle at the planned position and the actual position to the target coordinate system and performs lateral control on the target vehicle based on the target error, the accuracy of lateral control can be improved and the lateral error can be eliminated.

[0013] In an alternative embodiment, converting the first coordinate information to the target coordinate system to obtain the third coordinate information, and converting the second coordinate information to the target coordinate system to obtain the fourth coordinate information includes:

[0014] Based on the first coordinate information, the fifth coordinate information of the first matching point on the reference line with the minimum distance from the target vehicle is obtained, and based on the second coordinate information, the sixth coordinate information of the second matching point on the reference line with the minimum distance from the target vehicle is obtained, where the reference line is used to represent the center line of the target coordinate system;

[0015] Based on the first coordinate information and the fifth coordinate information, the seventh coordinate information of the first projection point of the target vehicle on the reference line is obtained, and based on the second coordinate information and the sixth coordinate information, the eighth coordinate information of the second projection point of the target vehicle on the reference line is obtained;

[0016] Based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, the first coordinate information is converted to the target coordinate system to obtain the third coordinate information, and based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, the second coordinate information is converted to the target coordinate system to obtain the fourth coordinate information.

[0017] In an embodiment of the present disclosure, by converting the coordinate information of the target vehicle at the planned position and the actual position to the target coordinate system based on the matching points and projection points of the target vehicle on the reference line, the position information of the target vehicle in the target coordinate system can be accurately determined, realizing accurate positioning of the target vehicle.

[0018] In an alternative embodiment, based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, the first coordinate information is transformed into a target coordinate system to obtain the third coordinate information. Based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, the second coordinate information is transformed into the target coordinate system to obtain the fourth coordinate information, including:

[0019] Based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, the first abscissa of the target vehicle at the planned position is obtained. Based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, the second abscissa of the target vehicle at the actual position is obtained. Wherein, the first abscissa is the first distance from the target vehicle to the first projection point, and the second abscissa is the second distance from the target vehicle to the second projection point;

[0020] Based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, the first ordinate of the target vehicle at the planned position is obtained. Based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, the second ordinate of the target vehicle at the actual position is obtained. Wherein, the first ordinate is the third distance from the first projection point to the starting point of the reference line, and the second ordinate is the fourth distance from the second projection point to the starting point of the reference line;

[0021] The third coordinate information is obtained based on the first abscissa and the first ordinate, and the fourth coordinate information is obtained based on the second abscissa and the second ordinate.

[0022] In the embodiments of the present disclosure, by based on the coordinate information of the target vehicle in the original coordinate system, the coordinate information of the matching point of the target vehicle on the reference line, and the coordinate information of the projection point of the target vehicle on the reference line, the abscissa and ordinate of the planned position and the actual position of the target vehicle in the target coordinate system can be obtained, so as to accurately obtain the coordinate information of the planned position and the actual position of the target vehicle in the target coordinate system, and realize the accurate positioning of the target vehicle.

[0023] In an alternative embodiment, based on the error information and the vehicle dynamics equation, a target lateral error differential equation is constructed, including:

[0024] Based on the error information and the vehicle dynamics equation, an initial lateral error differential equation is constructed;

[0025] The third coordinate information and the fourth coordinate information are discretized to obtain the target lateral error differential equation after changing the initial lateral error differential equation.

[0026] In the embodiments of the present disclosure, by discretizing the third coordinate information and the fourth coordinate information, the target lateral error differential equation can be made more suitable for the server to process, reducing the computational complexity of the server and improving the processing efficiency of the server.

[0027] In an alternative embodiment, a vehicle dynamics equation is constructed, including:

[0028] Based on the front wheel side force of the vehicle, the rear wheel side force of the vehicle, and the front wheel steering angle, a force equation is constructed;

[0029] Based on the front wheel side force of the vehicle, the rear wheel side force of the vehicle, the front wheel steering angle, the fifth distance from the front wheel to the center of mass, and the sixth distance from the rear wheel to the center of mass, a moment equation is constructed;

[0030] Based on the force equation and the moment equation, the vehicle dynamics equation is obtained.

[0031] In the embodiments of the present disclosure, by constructing the force equation and the moment equation, and then obtaining the vehicle dynamics equation, the mechanical characteristics of the target vehicle during movement can be comprehensively and accurately described.

[0032] In an alternative embodiment, based on the target lateral error differential equation, a target error is obtained, including:

[0033] Based on the target lateral error differential equation, a feedback error is obtained;

[0034] Based on a preset feedforward error and the feedback error, the target error is obtained, where the feedforward error is used to eliminate the steady-state error of the target vehicle.

[0035] In the embodiments of the present disclosure, by introducing the feedforward error and combining the feedforward error and the feedback error to perform lateral control on the target vehicle, the steady-state error can be eliminated, and then the lateral error can be eliminated, improving the accuracy and reliability of the lateral control, and ensuring the safety and stability of the autonomous driving vehicle during driving.

[0036] In a second aspect, the present disclosure provides a lateral control device for a target vehicle, and the device includes:

[0037] An acquisition module, configured to acquire first coordinate information of the target vehicle at a planned position and second coordinate information of the target vehicle at an actual position;

[0038] A conversion module, configured to convert the first coordinate information into a target coordinate system to obtain third coordinate information, and convert the second coordinate information into the target coordinate system to obtain fourth coordinate information;

[0039] An obtaining module, configured to obtain error information based on the third coordinate information and the fourth coordinate information;

[0040] A construction module, configured to construct a target lateral error differential equation based on the error information and the vehicle dynamics equation;

[0041] A control module, configured to obtain a target error based on a target lateral error differential equation, such that a target vehicle performs lateral control based on the target error, where the target error is used to characterize the error between an actual position and a planned position.

[0042] In a third aspect, the present disclosure provides a computer device, including: a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to perform the lateral control method of the target vehicle according to the first aspect or any corresponding embodiment thereof.

[0043] In a fourth aspect, the present disclosure provides a computer-readable storage medium, on which computer instructions are stored. The computer instructions are used to cause a computer to perform the lateral control method of the target vehicle according to the first aspect or any corresponding embodiment thereof.

[0044] In a fifth aspect, the present disclosure provides a computer program product, including computer instructions, which are used to cause a computer to perform the lateral control method of the target vehicle according to the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the specific embodiments of the present disclosure or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0046] Figure 1 is a schematic flowchart of the lateral control method of the target vehicle according to an embodiment of the present disclosure;

[0047] Figure 2 is a schematic diagram of coordinate system conversion of the first coordinate information according to an embodiment of the present disclosure;

[0048] Figure 3 is a schematic diagram of lateral error according to an embodiment of the present disclosure;

[0049] Figure 4 is a schematic diagram of vehicle dynamics according to an embodiment of the present disclosure;

[0050] Figure 5 is a system diagram of feedforward error and feedback error according to an embodiment of the present disclosure;

[0051] Figure 6 is a structural block diagram of the lateral control device of the target vehicle according to an embodiment of the present disclosure;

[0052] Figure 7It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present disclosure. Detailed implementation manners

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Apparently, the described embodiments are some but not all of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0054] The lateral control and longitudinal control of an autonomous vehicle complement each other. The longitudinal control adjusts the speed through braking and acceleration, while the lateral control ensures that the vehicle can move forward stably in a complex environment. The lateral control technology is a key link to ensure driving safety and accuracy. Only with the guarantee of lateral control can the autonomous vehicle drive safely and accurately along the predetermined trajectory.

[0055] Existing lateral control technologies include proportional-integral-derivative control, model predictive control, linear quadratic regulator, and pure tracking algorithm, etc. However, these technologies still have some deficiencies: proportional-integral-derivative control adjusts the lateral error through proportional, integral, and derivative, but does not consider the vehicle dynamics characteristics, and has poor robustness in high-speed scenarios; model predictive control predicts the future state based on the vehicle dynamics model and optimizes the control quantity, but has a high computational complexity and limited real-time performance; linear quadratic regulator combines feedforward compensation and is suitable for path-smoothing scenarios such as highways, but has a high dependence on model accuracy and is prone to failure under the non-linear characteristics of tires; pure tracking algorithm previews path points based on a geometric model, has good robustness but insufficient corner tracking accuracy.

[0056] Therefore, the existing technologies have problems of insufficient accuracy and inability to eliminate lateral errors when performing lateral control on a vehicle.

[0057] To solve the above problems, according to an embodiment of the present disclosure, an embodiment of a lateral control method for a target vehicle is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0058] In this embodiment, a lateral control method for a target vehicle is provided, as Figure 1 shown Figure 1 is a flowchart of a lateral control method for a target vehicle according to an embodiment of the present disclosure. This process can be applied to a server and includes the following steps:

[0059] Step S101, obtain the first coordinate information of the target vehicle at the planned position and the second coordinate information of the target vehicle at the actual position.

[0060] Optionally, in the embodiments of the present disclosure, the original coordinate system where the target vehicle is located is a Cartesian coordinate system. The first coordinate information refers to the coordinate information of the planned position of the target vehicle in the Cartesian coordinate system, and the second coordinate information refers to the coordinate information of the actual position of the target vehicle in the Cartesian coordinate system.

[0061] Specifically, the server uses the planning module to generate a planned route of the target vehicle based on the high-precision map and the destination information, and uses the perception module to obtain the planned position of the target vehicle on the planned route in real time, so as to obtain the first coordinate information of the planned position of the target vehicle in the Cartesian coordinate system.

[0062] The server uses the positioning module to adopt positioning technology (such as the Global Navigation Satellite System) to obtain the actual position of the target vehicle on the movement trajectory in real time, so as to obtain the second coordinate information of the actual position of the target vehicle in the Cartesian coordinate system.

[0063] Step S102, convert the first coordinate information to the target coordinate system to obtain the third coordinate information, and convert the second coordinate information to the target coordinate system to obtain the fourth coordinate information.

[0064] Optionally, in the embodiments of the present disclosure, the target coordinate system is a Frenet coordinate system. The third coordinate information refers to the coordinate information of the planned position of the target vehicle in the Frenet coordinate system, and the fourth coordinate information refers to the coordinate information of the actual position of the target vehicle in the Frenet coordinate system.

[0065] It should be noted that the Frenet coordinate system is a way to describe the vehicle trajectory, which is used to decompose the movement of the vehicle on the road into two directions: longitudinal and lateral. It is a local coordinate system with the current position of the vehicle as the origin. The longitudinal direction represents the direction in which the vehicle travels along the road, and the lateral direction represents the lateral offset of the vehicle relative to the center line of the road. By decomposing the movement trajectory of the vehicle into longitudinal and lateral components in the Frenet coordinate system, it is easier to model and analyze the trajectory and perform path planning.

[0066] As Figure 2 shown, Figure 2 is a schematic diagram of the coordinate system conversion of the first coordinate information according to the embodiments of the present disclosure. Figure 2 The coordinate information of the trajectory of the target vehicle in it is the first coordinate information, and the reference line of the Frenet coordinate system is the center line of the road.

[0067] Specifically, taking the coordinate system conversion of the first coordinate information as an example, in the Cartesian coordinate system, the server traverses each discrete point on the reference line starting from the starting point on the road center line, and calculates the distance from each discrete point on the reference line to the actual position of the target vehicle. The Euclidean distance can be used to measure the distance from each discrete point to the actual position of the target vehicle. The calculation process is as follows:

[0068]

[0069] where dx is the horizontal distance between the abscissa x of the actual position of the target vehicle h and the abscissa x of the discrete point, and dy is the vertical distance between the ordinate y of the actual position of the target vehicle p and the ordinate y of the discrete point. distance is the straight-line distance from the actual position of the target vehicle to the discrete point on the reference line. h p

[0070] The server obtains the point with the minimum distance distance from the discrete points on the reference line to the actual position of the target vehicle, that is, the first matching point. After the server finds the first matching point in each traversal, the subsequent traversal can start from the first matching point at the previous moment.

[0071] Then, the server obtains the position vector from the coordinate origin to the first matching point the position vector from the first matching point to the actual position of the target vehicle and the direction vector at the first matching point to obtain the position vector of the first projection point of the actual position of the target vehicle on the reference line The calculation formula for the position vector of the first projection point is as follows:

[0072]

[0073] After that, the server obtains the curvature k m and the inclination angle θ m at the first matching point. θ m is the angle between the tangent direction at the first matching point and the x-axis. When the distance between discrete points on the reference line is small, it can be approximately considered that the curvature k r at the first projection point is equal to the curvature k m at the first matching point, and the calculation formula for the inclination angle θ r at the first projection point is as follows:

[0074]

[0075] The server obtains the position vector of the actual position of the target vehicle relative to the coordinate origin ​​Position vector of the first projection point Normal vector of the position vector of the first projection point on the road geometry Calculate the first abscissa l of the actual position of the target vehicle in the Frenet coordinate system. The calculation process of the first abscissa l is as follows:

[0076]

[0077] The server calculates the first ordinate s of the actual position of the target vehicle in the Frenet coordinate system according to the coordinate information x i of the first matching point, the position vector from the first matching point to the actual position of the target vehicle and the direction vector at the first matching point The calculation process of the first ordinate s is as follows:

[0078]

[0079] where s r is the distance from the first projection point of the actual position of the target vehicle on the reference line to the origin x0 of the Frenet coordinate system.

[0080] The state information of the actual position of the target vehicle in the Frenet coordinate system includes the first abscissa l, the first-order derivative l′ of the first abscissa l with respect to the arc length ds in the Frenet coordinate system, the second-order derivative l″ of the first abscissa l with respect to the arc length ds in the Frenet coordinate system, the first ordinate s, the first-order derivative of the first ordinate s with respect to time in the Frenet coordinate system and the second-order derivative

[0081]

[0082] The calculation formulas are as follows: is the velocity vector of the target vehicle in the Cartesian coordinate system, is the acceleration vector of the target vehicle in the Cartesian coordinate system, is the tangent vector of the position vector of the first projection point on the road geometry, is the first-order derivative of the first abscissa l with respect to time in the Frenet coordinate system, is the second-order derivative of the first abscissa l with respect to time in the Frenet coordinate system.

[0083] It should be noted that the coordinate system conversion method of the second coordinate information is the same as that of the first coordinate information, and will not be elaborated here.

[0084] Step S103: Obtain error information based on the third coordinate information and the fourth coordinate information.

[0085] Optionally, in the embodiments of the present disclosure, the error information refers to the lateral error between the planned position and the actual position of the target vehicle in the Frenet coordinate system.

[0086] As Figure 3 shown, Figure 3 is a schematic diagram of the lateral error according to the embodiments of the present disclosure. v represents the velocity vector of the target vehicle in the actual route, and v r represents the velocity vector of the target vehicle in the planned route. θ1 represents the angle between v and the horizontal direction in the Cartesian coordinate system, and θ2 represents v r in the Cartesian coordinate system and the horizontal direction. err represents the lateral error between the planned position and the actual position of the target vehicle, that is, the error information.

[0087] Specifically, the server calculates the difference between the abscissa of the third coordinate information and the abscissa of the fourth coordinate information to obtain the error information.

[0088] Step S104: Construct a target lateral error differential equation based on the error information and the vehicle dynamics equation.

[0089] Optionally, in the embodiments of the present disclosure, the server first calculates according to the error information and the vehicle dynamics equation where u = δ, is the lateral velocity, is the angular velocity, δ is the front wheel angle, A is the system matrix, B is the input matrix, and the differential equation about the error is calculated as:

[0090]

[0091] where is the first derivative of the error err with respect to time, is the system matrix.

[0092] Then, the server establishes a cost function J = min(err 2 ), which is equivalent to J = min(aerr 2 + bu 2 ) = err T Qerr + u T Ru is minimized under the constraint , where a and b are weight coefficients, and Q and R are weight matrices.

[0093] The server uses the Lagrange multiplier method to calculate the initial lateral error differential equation in the Frenet coordinate system:

[0094]

[0095] where e d 、 are the lateral error, the rate of change of the lateral error, the second derivative of the lateral error with respect to time, the yaw angle error, the rate of change of the yaw angle error, and the second derivative of the yaw angle error with respect to time respectively, m is the mass of the target vehicle, v x is the longitudinal speed of the target vehicle, a is the distance from the front wheel to the center of mass, b is the distance from the rear wheel to the center of mass, is the cornering stiffness of the vehicle's front wheels, is the cornering stiffness of the vehicle's rear wheels, δ is the front wheel steering angle, and I is the moment of inertia of the target vehicle.

[0096] The server simplifies this equation to obtain the simplified initial lateral error differential equation: where A, B, and C are weight matrices, is the rate of change of the inclination angle of the point on the reference line, and discretizes this simplified initial lateral error differential equation to obtain the target lateral error differential equation.

[0097] It should be noted that the cost function is a function used to measure the quality and utility of a path or decision. In path planning, the cost function is used to evaluate the advantages and disadvantages of different paths and select the path with the lowest cost as the optimal path. The cost function can consider various factors, such as the length, time, safety, smoothness, energy consumption, etc. of the path. By setting the weights of different factors, the cost function can be adjusted to meet specific requirements.

[0098] Step S105: Based on the target lateral error differential equation, obtain a target error, so that the target vehicle performs lateral control based on the target error, where the target error is used to characterize the error between the actual position and the planned position.

[0099] Optionally, in the embodiments of the present disclosure, the target error includes a feedback error and a feedforward error.

[0100] The server uses the Lagrange multiplier method, the forward Euler method, and the midpoint Euler method to obtain the cost function:

[0101]

[0102] where H k = x k T Qx k + u k T Ru k + λ k+1 T (Ax k + Bu k ), xk is the state vector of the target vehicle at time k, and u k is the input vector, Q and R are weight matrices, A is the system matrix, B is the input matrix, C is the weight matrix, and λ is the Lagrange coefficient.

[0103] The server solves the target lateral error differential equation under this cost function to obtain the feedback error u:

[0104] u = -(R + B T PB) -1 B T PAx k = -kx k

[0105] k = (R + B T PB) -1 B T PA

[0106] where k is the feedback gain matrix and P is the solution matrix of the Riccati equation.

[0107] After that, the server obtains the target error based on the preset feedforward error and feedback error, obtains the control command based on the target error, and transmits the control command to the execution module of the target vehicle. The steering wheel angle of the target vehicle is controlled through the execution module to achieve the lateral control of the target vehicle.

[0108] In the embodiments of the present disclosure, by obtaining the first coordinate information of the target vehicle at the planned position and the second coordinate information of the target vehicle at the actual position; converting the first coordinate information to the target coordinate system to obtain the third coordinate information, and converting the second coordinate information to the target coordinate system to obtain the fourth coordinate information; based on the third coordinate information and the fourth coordinate information, obtaining the error information; based on the error information and the vehicle dynamics equation, constructing the target lateral error differential equation; based on the target lateral error differential equation, obtaining the target error, so that the target vehicle performs lateral control based on the target error, where the target error is used to characterize the error between the actual position and the planned position. Since the embodiments of the present disclosure convert the coordinate information of the target vehicle at the planned position and the actual position to the target coordinate system and perform lateral control on the target vehicle based on the target error, the accuracy of lateral control can be improved and the lateral error can be eliminated.

[0109] In some alternative embodiments, converting the first coordinate information to the target coordinate system to obtain the third coordinate information, and converting the second coordinate information to the target coordinate system to obtain the fourth coordinate information includes:

[0110] Based on the first coordinate information, obtain the fifth coordinate information of the first matching point on the reference line with the minimum distance from the target vehicle. Based on the second coordinate information, obtain the sixth coordinate information of the second matching point on the reference line with the minimum distance from the target vehicle, where the reference line is used to represent the center line of the target coordinate system;

[0111] Based on the first coordinate information and the fifth coordinate information, obtain the seventh coordinate information of the first projection point of the target vehicle on the reference line. Based on the second coordinate information and the sixth coordinate information, obtain the eighth coordinate information of the second projection point of the target vehicle on the reference line;

[0112] Based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, convert the first coordinate information to the target coordinate system to obtain the third coordinate information. Based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, convert the second coordinate information to the target coordinate system to obtain the fourth coordinate information.

[0113] Optionally, in the embodiments of the present disclosure, the first matching point is the point on the discrete points on the reference line with the minimum distance from the actual position of the target vehicle, and the fifth coordinate information is the coordinate information of the first matching point. The second matching point is the point on the discrete points on the reference line with the minimum distance from the planned position of the target vehicle, and the sixth coordinate information is the coordinate information of the second matching point.

[0114] The first projection point is the projection point of the actual position of the target vehicle on the reference line, and the seventh coordinate information is the coordinate information of the first projection point. The second projection point is the projection point of the planned position of the target vehicle on the reference line, and the eighth coordinate information is the coordinate information of the second projection point.

[0115] In the embodiments of the present disclosure, by converting the coordinate information of the target vehicle at the planned position and the actual position to the target coordinate system based on the matching points and projection points of the target vehicle on the reference line, the position information of the target vehicle in the target coordinate system can be accurately determined, realizing accurate positioning of the target vehicle.

[0116] In some alternative embodiments, based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, converting the first coordinate information to the target coordinate system to obtain the third coordinate information, and based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, converting the second coordinate information to the target coordinate system to obtain the fourth coordinate information, includes:

[0117] Based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, obtain the first abscissa of the target vehicle at the planned position. Based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, obtain the second abscissa of the target vehicle at the actual position, where the first abscissa is the first distance from the target vehicle to the first projection point, and the second abscissa is the second distance from the target vehicle to the second projection point;

[0118] Based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, obtain the first ordinate of the target vehicle at the planned position. Based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, obtain the second ordinate of the target vehicle at the actual position, where the first ordinate is the third distance from the first projection point to the starting point of the reference line, and the second ordinate is the fourth distance from the second projection point to the starting point of the reference line;

[0119] Obtain the third coordinate information based on the first abscissa and the first ordinate, and obtain the fourth coordinate information based on the second abscissa and the second ordinate.

[0120] Optionally, in the embodiments of the present disclosure, the first abscissa is the abscissa of the actual position of the target vehicle in the Frenet coordinate system, and the second abscissa is the abscissa of the planned position of the target vehicle in the Frenet coordinate system. The first ordinate is the ordinate of the actual position of the target vehicle in the Frenet coordinate system, and the second ordinate is the ordinate of the planned position of the target vehicle in the Frenet coordinate system.

[0121] In the embodiments of the present disclosure, based on the coordinate information of the target vehicle in the original coordinate system, the coordinate information of the matching point of the target vehicle on the reference line, and the coordinate information of the projection point of the target vehicle on the reference line, the abscissa and ordinate of the planned position and the actual position of the target vehicle in the target coordinate system can be obtained, so as to accurately obtain the coordinate information of the planned position and the actual position of the target vehicle in the target coordinate system, and realize the accurate positioning of the target vehicle.

[0122] In some alternative embodiments, based on the error information and the vehicle dynamics equation, construct a target lateral error differential equation, including:

[0123] Based on the error information and the vehicle dynamics equation, construct an initial lateral error differential equation;

[0124] Discretize the third coordinate information and the fourth coordinate information to obtain the target lateral error differential equation after modifying the initial lateral error differential equation.

[0125] Optionally, in the embodiments of the present disclosure, after the server obtains the initial lateral error differential equation: After that, discretize the third coordinate information and the fourth coordinate information, that is Then the solution problem of the target lateral error differential equation is transformed into: finding the minimum value problem of the cost function of continuous points under the constraint, that is, the minimum value problem under the constraint under the constraint.

[0126] In the embodiments of the present disclosure, by discretizing the third coordinate information and the fourth coordinate information, the target lateral error differential equation can be made more suitable for processing by the server, reducing the computational complexity of the server and improving the processing efficiency of the server.

[0127] In some alternative embodiments, constructing a vehicle dynamics equation includes:

[0128] Constructing a force equation based on the front wheel side force of the vehicle, the rear wheel side force of the vehicle, and the front wheel steering angle;

[0129] Constructing a moment equation based on the front wheel side force of the vehicle, the rear wheel side force of the vehicle, the front wheel steering angle, the fifth distance from the front wheel to the center of mass, and the sixth distance from the rear wheel to the center of mass;

[0130] Obtaining a vehicle dynamics equation based on the force equation and the moment equation.

[0131] Optionally, in the embodiments of the present disclosure, as Figure 4 shown, Figure 4 is a schematic diagram of vehicle dynamics according to the embodiments of the present disclosure, Figure 4 where F yf is the front wheel side force of the vehicle, F yr is the rear wheel side force of the vehicle, v f is the front wheel speed vector, v r is the rear wheel speed vector, is the angle between the front wheel speed direction and the longitudinal axis of the vehicle, is the angle between the rear wheel speed direction and the longitudinal axis of the vehicle, a is the fifth distance from the front wheel to the center of mass, b is the sixth distance from the rear wheel to the center of mass, and δ is the front wheel steering angle.

[0132] The server first constructs a force equation based on the front wheel side force F yf , the rear wheel side force F yr , and the front wheel steering angle δ. The force equation is as follows:

[0133] ∑F y = ma y → ma y = F yf cosδ + F yr

[0134] where m is the mass of the target vehicle, F y is the resultant force of the tire side forces of the target vehicle, and a y is the lateral acceleration of the target vehicle.

[0135] Then, the server is based on the front wheel side force F yf , the rear wheel side force F yr, the front wheel angle δ, the fifth distance a from the front wheel to the center of mass, and the sixth distance b from the rear wheel to the center of mass are used to construct a moment equation, and the moment equation is as follows:

[0136]

[0137] Among them, M is the resultant moment acting on the target vehicle with the mass point as the center, and I is the moment of inertia of the target vehicle. is the yaw angular acceleration of the target vehicle. is the lateral acceleration of the target vehicle.

[0138] Since the body coordinate system is a non-inertial coordinate system, the inertial force needs to be added. After the server simplifies the force equation and the moment equation, the following can be obtained:

[0139]

[0140] Among them, a y is the lateral acceleration, is the front wheel cornering stiffness of the vehicle, is the rear wheel cornering stiffness of the vehicle.

[0141] After the server solves the force equation and the moment equation, the following can be obtained:

[0142]

[0143] Among them, is the angular velocity, is the angular acceleration.

[0144] The server simplifies this equation to obtain the vehicle dynamics equation:

[0145]

[0146] Among them u = δ, A is the system matrix, B is the input matrix, and the vehicle dynamics equation reflects that by controlling the front wheel angle δ, the lateral displacement y and the yaw angle can be controlled.

[0147] In the embodiments of the present disclosure, by constructing a force equation and a moment equation, and then obtaining a vehicle dynamics equation, the mechanical characteristics of the target vehicle during movement can be comprehensively and accurately described.

[0148] In an alternative embodiment, based on the target lateral error differential equation, the target error is obtained, including:

[0149] Based on the target lateral error differential equation, the feedback error is obtained;

[0150] Based on a preset feedforward error and feedback error, a target error is obtained, where the feedforward error is used to eliminate the steady-state error of the target vehicle.

[0151] Optionally, in the embodiments of the present disclosure, as Figure 5 shown, Figure 5 is a system diagram of the feedforward error and feedback error according to the embodiments of the present disclosure, Figure 5 where δ f is the feedforward error, u is the feedback error, A is the system matrix, B is the input matrix, k is the feedback gain matrix, S is the Laplace operator, represents the integral operation.

[0152] Specifically, since only performing feedback control will cause an algebraic loop problem, it is necessary to introduce feedforward control to eliminate the steady-state error. The server introduces the feedforward error δ f and then obtains the updated u and

[0153] u = -kx k + δ f

[0154]

[0155] where A is the system matrix, B is the input matrix, C is the weight matrix, is the rate of change of the tilt angle of the point on the reference line.

[0156] When the system is stable, that is, is as close to 0 as possible, and the feedforward error δ f is solved as:

[0157]

[0158] θ r = kv x

[0159] where k3 is a control parameter, C r is the front-wheel dynamic parameter, C f is the rear-wheel dynamic parameter.

[0160] The server combines the feedforward error and the feedback error to obtain the final target error: u = -kerr + δ f .

[0161] In the embodiments of the present disclosure, by introducing the feedforward error and combining the feedforward error and the feedback error to perform lateral control on the target vehicle, the steady-state error can be eliminated, and then the lateral error can be eliminated, improving the accuracy and reliability of the lateral control and ensuring the safety and stability of the driving of the autonomous vehicle.

[0162] In this embodiment, a lateral control device for a target vehicle is further provided. This device is used to implement the above-mentioned embodiments and preferred implementation manners, and those that have been described will not be elaborated again. As used hereinafter, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0163] This embodiment provides a lateral control device for a target vehicle, as Figure 6 shown, including:

[0164] An acquisition module 601, configured to acquire first coordinate information of the target vehicle at a planned position and second coordinate information of the target vehicle at an actual position;

[0165] A conversion module 602, configured to convert the first coordinate information into a target coordinate system to obtain third coordinate information, and convert the second coordinate information into the target coordinate system to obtain fourth coordinate information;

[0166] A obtaining module 603, configured to obtain error information based on the third coordinate information and the fourth coordinate information;

[0167] A construction module 604, configured to construct a target lateral error differential equation based on the error information and a vehicle dynamics equation;

[0168] A control module 605, configured to obtain a target error based on the target lateral error differential equation, so that the target vehicle performs lateral control based on the target error, where the target error is used to characterize the error between the actual position and the planned position.

[0169] In the embodiments of the present disclosure, by acquiring first coordinate information of the target vehicle at a planned position and second coordinate information of the target vehicle at an actual position; converting the first coordinate information into a target coordinate system to obtain third coordinate information, and converting the second coordinate information into the target coordinate system to obtain fourth coordinate information; obtaining error information based on the third coordinate information and the fourth coordinate information; constructing a target lateral error differential equation based on the error information and a vehicle dynamics equation; obtaining a target error based on the target lateral error differential equation, so that the target vehicle performs lateral control based on the target error, where the target error is used to characterize the error between the actual position and the planned position. Since the embodiments of the present disclosure convert the coordinate information of the target vehicle at the planned position and the actual position into the target coordinate system, and perform lateral control on the target vehicle based on the target error, the accuracy of lateral control can be improved and lateral errors can be eliminated.

[0170] In some alternative implementation manners, the conversion module 602 includes:

[0171] The first acquisition sub-module is used to obtain the fifth coordinate information of the first matching point with the minimum distance from the target vehicle on the reference line based on the first coordinate information, and obtain the sixth coordinate information of the second matching point with the minimum distance from the target vehicle on the reference line based on the second coordinate information, where the reference line is used to represent the center line of the target coordinate system;

[0172] The second acquisition sub-module is used to obtain the seventh coordinate information of the first projection point of the target vehicle on the reference line based on the first coordinate information and the fifth coordinate information, and obtain the eighth coordinate information of the second projection point of the target vehicle on the reference line based on the second coordinate information and the sixth coordinate information;

[0173] The conversion sub-module is used to convert the first coordinate information to the target coordinate system based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information to obtain the third coordinate information, and convert the second coordinate information to the target coordinate system based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information to obtain the fourth coordinate information.

[0174] In some alternative embodiments, the conversion sub-module includes:

[0175] The first obtaining unit is used to obtain the first abscissa of the target vehicle at the planned position based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, and obtain the second abscissa of the target vehicle at the actual position based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, where the first abscissa is the first distance from the target vehicle to the first projection point, and the second abscissa is the second distance from the target vehicle to the second projection point;

[0176] The second obtaining unit is used to obtain the first ordinate of the target vehicle at the planned position based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, and obtain the second ordinate of the target vehicle at the actual position based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, where the first ordinate is the third distance from the first projection point to the starting point of the reference line, and the second ordinate is the fourth distance from the second projection point to the starting point of the reference line;

[0177] The third obtaining unit is used to obtain the third coordinate information based on the first abscissa and the first ordinate, and obtain the fourth coordinate information based on the second abscissa and the second ordinate.

[0178] In some alternative embodiments, the construction module 604 includes:

[0179] The first construction sub-module is used to construct an initial lateral error differential equation based on the error information and the vehicle dynamics equation;

[0180] A discrete sub-module for discretizing the third coordinate information and the fourth coordinate information to obtain a target lateral error differential equation after modifying the initial lateral error differential equation.

[0181] In some alternative embodiments, the construction module 604 includes:

[0182] A second construction sub-module for constructing a force equation based on the lateral force of the vehicle's front wheels, the lateral force of the vehicle's rear wheels, and the front wheel steering angle;

[0183] A third construction sub-module for constructing a moment equation based on the lateral force of the vehicle's front wheels, the lateral force of the vehicle's rear wheels, the front wheel steering angle, the fifth distance from the front wheels to the center of mass, and the sixth distance from the rear wheels to the center of mass;

[0184] A first obtaining sub-module for obtaining a vehicle dynamics equation based on the force equation and the moment equation.

[0185] In some alternative embodiments, the control module 605 includes:

[0186] A second obtaining sub-module for obtaining a feedback error based on the target lateral error differential equation;

[0187] A third obtaining sub-module for obtaining a target error based on a preset feedforward error and the feedback error, where the feedforward error is used to eliminate the steady-state error of the target vehicle.

[0188] The further function descriptions of the above-mentioned various modules and units are the same as those in the corresponding embodiments above, and will not be elaborated here.

[0189] The lateral control device of the target vehicle in this embodiment is presented in the form of functional units. Here, the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and a memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0190] This disclosure embodiment also provides a computer device having the above Figure 6 shown lateral control device of the target vehicle.

[0191] Please refer to Figure 7 , Figure 7 which is a schematic structural diagram of a computer device provided by an alternative embodiment of this disclosure. As shown in Figure 7As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including a high-speed interface and a low-speed interface. Each component communicates with each other using different buses and can be installed on a common motherboard or installed in other ways as needed. The processor can process instructions executed within the computer device, including instructions stored in the memory or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some alternative embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a set of blade servers, or a multi-processor system). Figure 7 Taking one processor 10 as an example in

[0192] The processor 10 can be a central processing unit, a network processor, or a combination thereof. Among them, the processor 10 can further include a hardware chip. The above hardware chip can be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The above programmable logic device can be a complex programmable logic device, a field programmable gate array, a generic array logic, or any combination thereof.

[0193] Among them, the memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiments.

[0194] The memory 20 can include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the computer device. In addition, the memory 20 can include a high-speed random access memory, and can also include a non-transitory memory, such as at least one disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some alternative embodiments, the memory 20 can optionally include a memory remotely set relative to the processor 10, and these remote memories can be connected to the computer device through a network. Examples of the above network include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0195] The memory 20 can include a volatile memory, such as a random access memory; the memory can also include a non-volatile memory, such as a flash memory, a hard disk, or a solid-state drive; the memory 20 can also include a combination of the above types of memories.

[0196] The computer device further includes a communication interface 30 for the computer device to communicate with other devices or communication networks.

[0197] Embodiments of the present disclosure also provide a computer-readable storage medium. The methods according to the embodiments of the present disclosure can be implemented in hardware, firmware, or be implemented as computer code that can be recorded on a storage medium, or be implemented as computer code that is originally stored in a remote storage medium or a non-transitory machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the methods described herein can be processed by such software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid-state drive, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code, and when the software or computer code is accessed and executed by the computer, the processor, or the hardware, the methods shown in the above embodiments are implemented.

[0198] A part of the present disclosure can be applied as a computer program product, for example, computer program instructions, which when executed by a computer, can call or provide the methods and / or technical solutions according to the present disclosure through the operation of the computer. Those skilled in the art should be able to understand that the forms of computer program instructions existing in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways for computer program instructions to be executed by a computer include, but are not limited to: the computer directly executes the instructions, or the computer compiles the instructions and then executes the corresponding compiled program, or the computer reads and executes the instructions, or the computer reads and installs the instructions and then executes the corresponding installed program. Herein, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible by the computer.

[0199] Although the embodiments of the present disclosure are described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present disclosure, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A lateral control method for a target vehicle, characterized in that The method includes: Obtaining first coordinate information of the target vehicle at a planned position and second coordinate information of the target vehicle at an actual position; Converting the first coordinate information to a target coordinate system to obtain third coordinate information, and converting the second coordinate information to the target coordinate system to obtain fourth coordinate information; Based on the third coordinate information and the fourth coordinate information, obtaining error information; Based on the error information and a vehicle dynamics equation, constructing a target lateral error differential equation; Based on the target lateral error differential equation, obtaining a target error, such that the target vehicle performs lateral control based on the target error, where the target error is used to characterize the error between the actual position and the planned position.

2. The method according to claim 1, wherein The converting the first coordinate information to a target coordinate system to obtain third coordinate information, and converting the second coordinate information to the target coordinate system to obtain fourth coordinate information includes: Based on the first coordinate information, obtaining fifth coordinate information of a first matching point on a reference line that has the minimum distance from the target vehicle, and based on the second coordinate information, obtaining sixth coordinate information of a second matching point on the reference line that has the minimum distance from the target vehicle, where the reference line is used to represent the center line of the target coordinate system; Based on the first coordinate information and the fifth coordinate information, obtaining seventh coordinate information of a first projection point of the target vehicle on the reference line, and based on the second coordinate information and the sixth coordinate information, obtaining eighth coordinate information of a second projection point of the target vehicle on the reference line; Based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, converting the first coordinate information to the target coordinate system to obtain the third coordinate information, and based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, converting the second coordinate information to the target coordinate system to obtain the fourth coordinate information.

3. The method according to claim 2, wherein The based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, converting the first coordinate information to the target coordinate system to obtain the third coordinate information, and based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, converting the second coordinate information to the target coordinate system to obtain the fourth coordinate information includes: Based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, obtaining a first abscissa of the target vehicle at the planned position, and based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, obtaining a second abscissa of the target vehicle at the actual position, where the first abscissa is a first distance from the target vehicle to the first projection point, and the second abscissa is a second distance from the target vehicle to the second projection point; Based on the first coordinate information, the fifth coordinate information, and the seventh coordinate information, obtain the first ordinate of the target vehicle at the planned position. Based on the second coordinate information, the sixth coordinate information, and the eighth coordinate information, obtain the second ordinate of the target vehicle at the actual position, where the first ordinate is the third distance from the first projection point to the starting point of the reference line, and the second ordinate is the fourth distance from the second projection point to the starting point of the reference line; Obtain the third coordinate information based on the first abscissa and the first ordinate, and obtain the fourth coordinate information based on the second abscissa and the second ordinate.

4. The method according to claim 1, wherein Constructing a target lateral error differential equation based on the error information and the vehicle dynamics equation includes: Construct an initial lateral error differential equation based on the error information and the vehicle dynamics equation; Discretize the third coordinate information and the fourth coordinate information to obtain the target lateral error differential equation after modifying the initial lateral error differential equation.

5. The method according to claim 1, characterized in that Constructing the vehicle dynamics equation includes: Construct a force equation based on the vehicle front wheel side force, the vehicle rear wheel side force, and the front wheel steering angle; Construct a moment equation based on the vehicle front wheel side force, the vehicle rear wheel side force, the front wheel steering angle, the fifth distance from the front wheel to the center of mass, and the sixth distance from the rear wheel to the center of mass; Obtain the vehicle dynamics equation based on the force equation and the moment equation.

6. The method according to claim 1, wherein Obtaining a target error based on the target lateral error differential equation includes: Obtain a feedback error based on the target lateral error differential equation; Obtain a target error based on a preset feedforward error and the feedback error, where the feedforward error is used to eliminate the steady-state error of the target vehicle.

7. A lateral control device for a target vehicle, characterized in that, The device includes: An acquisition module for acquiring the first coordinate information of the target vehicle at the planned position and the second coordinate information of the target vehicle at the actual position; A conversion module for converting the first coordinate information to a target coordinate system to obtain third coordinate information, and converting the second coordinate information to the target coordinate system to obtain fourth coordinate information; An obtaining module for obtaining error information based on the third coordinate information and the fourth coordinate information; A construction module for constructing a target lateral error differential equation based on the error information and the vehicle dynamics equation; A control module for obtaining a target error based on the target lateral error differential equation, so that the target vehicle performs lateral control based on the target error, where the target error is used to characterize the error between the actual position and the planned position.

8. A computer device, characterized in that, Includes: A memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to execute the lateral control method of the target vehicle according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, Computer instructions are stored on the computer-readable storage medium, and the computer instructions are used to cause a computer to execute the lateral control method of the target vehicle according to any one of claims 1 to 6.

10. A computer program product, characterized in that, including computer instructions for causing a computer to execute the lateral control method of the target vehicle according to any one of claims 1 to 6.

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