CN114572231A

CN114572231A - Centroid slip angle planning method and device for vehicle drifting movement under emergency obstacle avoidance working condition, vehicle and computer readable storage medium

Info

Publication number: CN114572231A
Application number: CN202210244964.5A
Authority: CN
Inventors: 刘洋; 尚秉旭; 陈志新; 王洪峰; 许朝文; 张勇; 何柳; 张中举; 金百鑫
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Priority date: 2022-03-14
Filing date: 2022-03-14
Publication date: 2022-06-03

Abstract

The invention discloses a method and a device for planning a centroid slip angle of vehicle drifting movement under an emergency obstacle avoidance working condition, a vehicle and a computer readable storage medium. The method for determining the mass center slip angle of the vehicle drifting movement under the emergency obstacle avoidance working condition comprises the following steps: establishing a mathematical representation of a first safe distance between the vehicle and the obstacle, the first safe distance being a function of the centroid slip angle; establishing a mathematical expression of a second safe distance between the vehicle and the road boundary, and constraints of the vehicle state and the control quantity; determining an optimal centroid slip angle based on the mathematical representation of the first safe distance, the mathematical representation of the second safe distance, and the constraints of the vehicle state and the controlled variable. According to the method, the reasonable centroid slip angle is planned, so that the vehicle can avoid a short-distance obstacle through drifting, the defects of the traditional obstacle avoidance method are overcome, and the accidents are reduced.

Description

Centroid slip angle planning method and device for vehicle drifting movement under emergency obstacle avoidance working condition, vehicle and computer readable storage medium

Technical Field

The invention relates to the technical field of vehicles, in particular to a method and a device for planning a mass center slip angle of vehicle drifting movement under an emergency obstacle avoidance working condition, a vehicle and a computer readable storage medium.

Background

When the vehicle meets an emergency condition in the driving process, certain action needs to be taken to avoid the obstacle. The existing emergency obstacle avoidance scheme generally adopts emergency braking or emergency steering, and when the existing emergency obstacle avoidance scheme faces an obstacle suddenly appearing in a short distance, the method cannot ensure that a vehicle safely avoids the obstacle. Therefore, a drifting method can be adopted to avoid the obstacles.

The expected centroid slip angle in the existing drift motion control is given as a fixed value obtained according to experience, and the requirement for the safe distance between a vehicle and an obstacle under an emergency obstacle avoidance working condition is difficult to guarantee.

Disclosure of Invention

The invention provides a centroid slip angle planning method for vehicle drifting movement under an emergency obstacle avoidance working condition, which is used for realizing that a vehicle can safely avoid obstacles in a drifting manner when facing the obstacles suddenly appearing in a short distance, and reducing accidents.

In order to realize the technical problem, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a method for determining a centroid slip angle of a vehicle drifting movement under an emergency obstacle avoidance condition, including:

establishing a mathematical representation of a first safe distance between the vehicle and the obstacle, the first safe distance being a function of the centroid slip angle;

establishing a mathematical expression of a second safety distance between the vehicle and the road boundary, and constraints of the vehicle state and the control quantity;

determining an optimal centroid slip angle based on the mathematical representation of the first safe distance, the mathematical representation of the second safe distance, and the constraints of the vehicle state and the controlled variable.

Optionally, establishing a mathematical representation of a first safe distance between the vehicle and the obstacle comprises:

the vehicle is equivalent to a rectangle, wherein the included angle between the speed of the vehicle and the longitudinal plane of the vehicle is the centroid slip angle;

taking the circumscribed circle of the obstacle as a mathematical expression of the obstacle;

and obtaining the first safety distance according to the parameters of the rectangle and the parameters of the circumscribed circle of the obstacle.

Optionally, establishing a mathematical representation of a second safe distance between the vehicle and the road boundary comprises:

and determining the second safety distance according to the parameters of the rectangle based on the fact that the vehicle avoids collision with the road edge when the vehicle performs drift motion according to the centroid slip angle, wherein the second safety distance is a nonlinear function of the centroid slip angle of the vehicle.

Optionally, establishing constraints on vehicle states and control quantities comprises:

determining a vehicle model and a tire model, and solving a vehicle state and a vehicle control input under a given (kappa, beta) combination according to the vehicle model and the tire model; wherein, k is the curvature of the obstacle avoidance track, and β is the centroid slip angle;

constraints are established regarding vehicle states and control inputs.

Optionally, establishing constraints of the vehicle state and the control quantity further comprises:

and limiting the centroid slip angle within a certain range so that the vehicle tracks the obstacle avoidance track in a drifting motion mode.

Optionally, after determining the optimal centroid slip angle, the method further includes:

given the curvature k of the obstacle avoidance trajectory, according to (k, β)^*) Determining a desired vehicle state, where β^*Is the optimal centroid slip angle.

In a second aspect, the present invention provides a device for determining a centroid slip angle of a vehicle drifting under an emergency obstacle avoidance condition, including:

a first safe distance determination module for establishing a mathematical representation of a first safe distance between the vehicle and the obstacle, the first safe distance being a function of the centroid slip angle;

the second safe distance determination module is used for establishing mathematical expression of a second safe distance between the vehicle and the road boundary and constraints of the vehicle state and the control quantity;

and the centroid slip angle determination module is used for determining an optimal centroid slip angle based on the mathematical expression of the first safety distance, the mathematical expression of the second safety distance and the constraints of the vehicle state and the control quantity.

Optionally, the first safe distance determining module is specifically configured to:

In a third aspect, the invention provides a vehicle comprising a control module, the desired vehicle condition of the first aspect being a reference input to the control module.

In a fourth aspect, the present invention provides a computer-readable storage medium,

the computer readable storage medium stores computer instructions for causing a processor to implement the method for determining the centroid slip angle of vehicle drifting under an emergency obstacle avoidance condition according to the first aspect when executed.

The method for planning the centroid slip angle of the vehicle drifting movement under the emergency obstacle avoidance working condition comprises the following steps: establishing a mathematical representation of a first safe distance between the vehicle and the obstacle, the first safe distance being a function of the centroid slip angle; establishing a mathematical expression of a second safe distance between the vehicle and the road boundary, and constraints of the vehicle state and the control quantity; determining an optimal centroid slip angle based on the mathematical representation of the first safe distance, the mathematical representation of the second safe distance, and the constraints of the vehicle state and the controlled variable. Through the technical scheme of the embodiment of the invention, the reasonable centroid slip angle can be planned, so that the vehicle can avoid a short-distance obstacle through drifting, the defects of the traditional obstacle avoiding method are overcome, and the occurrence of accidents is reduced.

It should be understood that the statements in this section do not necessarily identify key or critical features of the embodiments of the present invention, nor do they necessarily limit the scope of the invention. Other features of the present invention will become apparent from the following description.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic flow chart of a method for planning a centroid slip angle of a vehicle drifting movement under an emergency obstacle avoidance condition according to an embodiment of the present invention;

fig. 2 is a schematic flow chart of a method for determining a centroid slip angle of vehicle drifting movement under an emergency obstacle avoidance condition according to a second embodiment of the present invention;

FIG. 3 is a schematic diagram of a mathematical representation for establishing a safe distance between a vehicle and an obstacle provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of a mathematical representation for establishing a safe distance between a vehicle and a road boundary provided by an embodiment of the present invention;

FIG. 5 is a schematic diagram of a three-degree-of-freedom single-track model used for building a vehicle model according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a centroid slip angle determining device for vehicle drifting movement under an emergency obstacle avoidance condition according to a third embodiment of the present invention;

fig. 7 is a schematic structural diagram of an electronic device for implementing the centroid slip angle planning method for vehicle drifting movement under an emergency obstacle avoidance condition according to the embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Example one

The embodiment of the invention provides a method for determining a centroid slip angle of vehicle drifting movement under an emergency obstacle avoidance condition, and fig. 1 is a flow schematic diagram of the method for determining the centroid slip angle of vehicle drifting movement under the emergency obstacle avoidance condition, which is applicable to the emergency obstacle avoidance condition. As shown in fig. 1, the method includes:

s1, establishing a mathematical expression of a first safe distance between the vehicle and the obstacle, wherein the first safe distance is a function of the centroid slip angle.

Vehicle drift has the following characteristics: large centroid slip angles, reverse steering and rear wheel tire force saturation. The mass center slip angle directly influences the drifting motion, and a large mass center slip angle indicates that the rear wheel has sideslip, namely, the tire force of the rear wheel is saturated; to ensure that the vehicle maintains a large centroid roll angle movement, the vehicle front wheel steering angle needs to be kept opposite to the vehicle yaw rate direction, the so-called reverse steering. Furthermore, a large centroid slip angle means that the vehicle longitudinal plane is deflected by a large angle relative to the vehicle speed direction at the vehicle centroid, which directly affects the safe distance between the vehicle and the obstacles and road boundaries.

Therefore, in order to ensure that the vehicle can safely avoid the close-distance obstacles in a drifting manner, a reasonable centroid slip angle needs to be planned. On the premise of giving an obstacle avoidance track, establishing a mathematical expression of a safe distance between a vehicle and an obstacle, wherein the safe distance is a function of a centroid slip angle, and is used as an objective function of a planning problem, and the safe distance is required to be as large as possible. The centroid slip angle is an included angle between the speed of the vehicle and a longitudinal plane of the vehicle, and a mathematical expression of a first safety distance between the speed of the vehicle and the longitudinal plane of the vehicle can be determined according to model parameters of the vehicle and model parameters of the obstacle.

S2, establishing a mathematical expression of a second safety distance between the vehicle and the road boundary, and constraints of the vehicle state and the control quantity.

When the vehicle drifts to avoid the obstacle, the vehicle body deflects greatly, in order to ensure the safety of the drifting process, the mathematical expression of the second safety distance between the vehicle and the road boundary is established, and the mathematical expression is used as the constraint in the optimization process of the objective function, and the safety distance is required to be larger than zero at any time. In addition, to keep the vehicle tracking the obstacle avoidance track in a drifting motion mode, the mass center slip angle needs to be limited within a certain range; to avoid actuator saturation, constraints on the controlled variable need to be added in the centroid slip angle planning. A mathematical representation of the second safe distance between the vehicle and the road boundary may be established from the model parameters of the vehicle. Constraints on the vehicle state and the control quantity are determined based on the vehicle-related parameters.

And S3, determining the optimal centroid slip angle based on the mathematical expression of the first safety distance, the mathematical expression of the second safety distance and the constraints of the vehicle state and the control quantity.

And after the mathematical expression of the safe distance, the mathematical expression of the second safe distance and the constraints of the vehicle state and the control quantity are obtained, namely, a centroid slip angle planning problem of vehicle drifting movement under emergency obstacle avoidance is established, and an objective function and related constraints of the problem are given. And solving to obtain the optimal centroid slip angle.

The technical scheme that this embodiment provided has guaranteed that the safe distance between vehicle and the barrier is as big as possible, has still guaranteed that the vehicle does not collide with the curb when carrying out the drift motion to plan out reasonable barycenter sideslip angle, solved the risk that is difficult to avoid the barrier, reached the security that improves the vehicle and travel, reduced the effect that the accident took place.

Example two

Fig. 2 is a schematic flow chart of a method for determining a centroid slip angle of vehicle drifting movement under an emergency obstacle avoidance condition according to a second embodiment of the present invention, where the method is optimized based on the second embodiment, and includes:

s11, the vehicle is equivalent to a rectangle, wherein the included angle between the speed of the vehicle and the longitudinal plane of the vehicle is the centroid slip angle; taking the circumcircle of the obstacle as the mathematical expression of the obstacle; and obtaining the first safety distance according to the parameters of the rectangle and the parameters of the circumscribed circle of the obstacle.

Illustratively, fig. 3 is a schematic diagram of a mathematical expression for establishing a safe distance between a vehicle and an obstacle according to an embodiment of the present invention. In order to solve the safety distance mathematical expression conveniently, the vehicle is equivalent to a rectangle ABCD, the center of the rectangle is the center of mass of the vehicle and is recorded as O₂. The length h and width w of the rectangle are determined by vehicle parameters. The included angle between the speed V of the vehicle and the longitudinal plane of the vehicle is a centroid slip angle beta, and the method is a research object of the method provided by the invention.

In order to ensure that the vehicle keeps enough distance from the obstacle in drifting running, the circumcircle of the obstacle is used as the mathematical expression of the obstacle, the radius of the circumcircle is R, and the center of the circle is O₁. The safety distance between the obstacle and the vehicle is L_obIs an objective function of the centroid slip angle planning problem, requiring L_obAs large as possible. The safe distance between the vehicle and the road boundary is L_roadIs the constraint of the centroid slip angle planning problem, requires L_roadGreater than zero.

Assuming that the obstacle avoidance track is known, the black curve in the figure is the obstacle avoidance track, that is, at any point on the obstacle avoidance track, the curvature k of the track, the included angle γ between the tangent line of the point and the road, and the vertical distance l between the tangent line of the point and the road₂Are known.

Assuming that the obstacle information is known, i.e. the distance l of the obstacle relative to any point on the obstacle avoidance track₁Knowing a relative angle alpha between the obstacle and any point on the obstacle avoidance track; it is assumed that various parameters of the vehicle are known.

The specific derivation method of the mathematical expression of the safe distance between the vehicle and the obstacle is as follows:

1) solving for parameter theta

The parameter θ is uniquely determined by the vehicle parameter at Δ MO₂In C, there are

2) Solving for a safe distance L between a vehicle and an obstacle_ob

At Δ CO₂O₁In

∠CO₂O₁＝α-β-θ (3)

According to the cosine theorem

Considering that the radius of the circumscribed circle of the obstacle is R, a safe distance L between the obstacle and the vehicle is obtained_obIs composed of

L_ob＝d₁-R (5)

Obviously, L_obIs a nonlinear function of the vehicle's centroid slip angle beta, recorded as

L_ob＝f_ob(β) (6)

(6) The formula is a mathematical expression of the safe distance between the vehicle and the obstacle.

And S12, based on the fact that the vehicle avoids collision with the road edge when the vehicle performs drift motion according to the centroid slip angle, determining the second safety distance according to the parameters of the rectangle, wherein the second safety distance is a nonlinear function of the centroid slip angle of the vehicle.

Illustratively, fig. 4 is a schematic diagram of a mathematical expression for establishing a safe distance between a vehicle and a road boundary provided by an embodiment of the present invention. The specific derivation method of the mathematical expression of the safe distance between the vehicle and the road boundary is as follows:

1) solving | JH |

In Δ AFH

∠FAH＝β-γ (7)

Thus, in the rectangular ABCD, one can obtain

At Δ O₂In EK

∠O₂EK＝β-γ (11)

Then the

|EH|＝|O₂E|-|O₂H| (13)

In Δ HEJ

|HJ|＝|EH|sin∠HEJ (14)

Thus, a safe distance L of the vehicle from the road boundary is obtained_roadIs composed of

L_road＝|HJ|-|HA| (15)

Obviously, L_roadIs a nonlinear function of the vehicle's centroid slip angle beta, recorded as

L_road＝f_road(β) (16)

S13, determining a vehicle model and a tire model, and obtaining a vehicle state and a vehicle control input under a given (kappa, beta) combination according to the vehicle model and the tire model; wherein, k is the curvature of the obstacle avoidance track, and β is the centroid slip angle.

Fig. 5 is a schematic diagram of a three-degree-of-freedom single-track model used for building a vehicle model according to an embodiment of the present invention. The mathematical expression of the vehicle state under the (k, β) combination is specifically deduced as follows:

1.1) vehicle model

The vehicle model adopts a three-degree-of-freedom single-rail model with front wheel steering and rear wheel driving, and as shown in figure 3, the mathematical expression of the vehicle model is as follows

In formulae (17) to (19), v_x，v_yThe components of vehicle speed on the vehicle x-axis and y-axis, respectively; r is the yaw angular velocity of the vehicle; delta is the corner of the front wheel of the vehicle; f_xrIs a vehicle rear wheel longitudinal force; f_yf，F_yrThe lateral forces of the front wheel and the rear wheel of the vehicle are respectively; a and b are respectively the distance between the center of mass of the vehicle and a front axle and the distance between the center of mass of the vehicle and a rear axle; m is the mass of the whole vehicle; i is_zIs the moment of inertia in the vertical direction of the vehicle coordinate system.

1.2) tire model

Selecting the brush model to calculate the front and rear wheel tire force F_yWhich is expressed mathematically as follows

In the above formula, C_αIs the cornering stiffness of the tyre; α is a tire slip angle, and is determined by the formulae (21) to (22); alpha (alpha) ("alpha")_slThe minimum slip angle corresponding to the tire lateral force reaching the friction limit; mu is the road surface adhesion coefficient; f_zIs the tire vertical load; the peak discount coefficient ξ is determined by equation (23).

Front wheel side slip angle alpha_FAnd rear wheel side slip angle alpha_RIs composed of

A peak discount coefficient of

1.3) solving for vehicle states

Under a given combination of (kappa, beta), there are

By simultaneously solving equations (17) to (25), the vehicle state X ═ v [ v ] can be obtained in a given combination (κ, β)_x，v_y，r]And vehicle control input U ═ delta, F_xr]。

For convenience of representation, the solution process for the vehicle state is represented as (k, β) in a given (k, β) combination

Wherein f is_vehiAre uniquely defined by the formulae (17) to (25).

S14, establishing constraints on the vehicle state and the control input.

Illustratively, fig. 5 is a schematic diagram of a three-degree-of-freedom single-track model used for building a vehicle model according to an embodiment of the present invention. Considering that actuator saturation should be avoided, constraint on control quantity needs to be added in centroid slip angle planning

δ_lb≤δ≤δ_ub (27)

|F_xr|≤μF_zr (28)

In the formula (27), δ_lb，δ_ubThe upper and lower boundaries of the front wheel corner are respectively; f_zrIs the vertical force applied to the rear wheel of the vehicle.

And S15, limiting the centroid slip angle to a certain range, so that the vehicle can track the obstacle avoidance track in a drifting motion mode.

Illustratively, fig. 5 is a schematic diagram of a three-degree-of-freedom single-track model used for building a vehicle model according to an embodiment of the present invention.

β_min≤|β|≤β_max (29)

In the formula (29), beta_max，β_minThe maximum and minimum values of the centroid slip angle are respectively.

S16, under the curvature k of the given obstacle avoidance track, according to (k, beta)^*) Determining a desired vehicle state, wherein^*Is the optimal centroid slip angle.

Establishing the planning problem of the mass center slip angle of the vehicle drifting movement under the emergency obstacle avoidance working condition

s.t.L_road＞0

δ_lb≤δ≤δ_ub

|F_xr|≤μF_zr

β_min≤|β|≤β_max (30)

Solving the planning problem (30) to obtain an optimal centroid slip angle beta^*Then, at a given curvature k,according to (kappa, beta)^*) And equation (26) can determine the desired vehicle state, i.e.

According to the technical scheme provided by the embodiment, the drift is considered to be a limit motion of the vehicle, so that the state and the control input of the vehicle are limited to a certain extent, the saturation of the actuator is avoided, the risk that the performance of the vehicle is reduced or even unstable due to the saturation of the actuator is solved, the running safety of the vehicle is improved, and the accident is reduced.

EXAMPLE III

The third embodiment of the invention provides a centroid slip angle determining device for vehicle drifting movement under an emergency obstacle avoidance working condition, and the device enables a vehicle to avoid a short-distance obstacle through drifting by planning out a reasonable centroid slip angle, so that accidents are reduced. Fig. 6 is a schematic structural diagram of a centroid slip angle determination apparatus for vehicle drifting movement under an emergency obstacle avoidance condition according to a sixth embodiment of the present invention, and referring to fig. 6, the apparatus includes:

a first safe distance determination module 1 for establishing a mathematical representation of a first safe distance between the vehicle and the obstacle, said first safe distance being a function of the centroid slip angle. Specifically, the vehicle is equivalent to a rectangle, wherein the included angle between the speed of the vehicle and the longitudinal plane of the vehicle is the centroid slip angle; taking the circumcircle of the obstacle as the mathematical expression of the obstacle; and obtaining the first safety distance according to the parameters of the rectangle and the parameters of the circumscribed circle of the obstacle.

And the second safe distance determination module 2 is used for establishing a mathematical expression of a second safe distance between the vehicle and the road boundary and constraints of the vehicle state and the control quantity.

And the centroid slip angle determination module 3 is used for determining an optimal centroid slip angle based on the mathematical expression of the first safety distance, the mathematical expression of the second safety distance and the constraints of the vehicle state and the control quantity.

The device for determining the centroid slip angle of the vehicle drifting movement under the emergency obstacle avoidance condition, provided by the embodiment of the invention, can execute the method for determining the centroid slip angle of the vehicle drifting movement under the emergency obstacle avoidance condition, provided by any embodiment of the invention, and has corresponding functional modules and beneficial effects of the execution method.

Example four

An embodiment of the present invention provides a vehicle, including:

a control module 4;

the desired vehicle state in embodiment two is used as a reference input for the control module.

EXAMPLE five

The fifth embodiment of the present invention provides an electronic device 10, where the electronic device 10 is configured to handle the problem of planning the centroid slip angle.

As shown in fig. 7, the electronic device 10 includes at least one processor 11, and a memory communicatively connected to the at least one processor 11, such as a Read Only Memory (ROM)12, a Random Access Memory (RAM)13, and the like, wherein the memory stores a computer program executable by the at least one processor, and the processor 11 can perform various suitable actions and processes according to the computer program stored in the Read Only Memory (ROM)12 or the computer program loaded from a storage unit 18 into the Random Access Memory (RAM) 13. In the RAM 13, various programs and data necessary for the operation of the electronic apparatus 10 can also be stored. The processor 11, the ROM12, and the RAM 13 are connected to each other via a bus 14. An input/output (I/O) interface 15 is also connected to bus 14.

A number of components in the electronic device 10 are connected to the I/O interface 15, including: an input unit 16 such as a keyboard, a mouse, or the like; an output unit 17 such as various types of displays, speakers, and the like; a storage unit 18 such as a magnetic disk, an optical disk, or the like; and a communication unit 19 such as a network card, modem, wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information/data with other devices via a computer network, such as the internet, and/or various telecommunication networks.

The processor 11 may be a variety of general and/or special purpose processing components having 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 specialized Artificial Intelligence (AI) computing chips, various processors running machine learning model algorithms, a Digital Signal Processor (DSP), and any suitable processor, controller, microcontroller, or the like. The processor 11 performs the various methods and processes described above, such as a method of centroid slip angle planning for vehicle drift motion in emergency obstacle avoidance conditions.

In some embodiments, the method for centroid slip angle planning for vehicle drift motion under emergency obstacle avoidance conditions may be implemented as a computer program tangibly embodied on 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 onto electronic device 10 via ROM12 and/or communications unit 19. When loaded into RAM 13 and executed by processor 11, the computer program may perform one or more of the steps of the method for centroid slip angle planning for vehicle drift motion in emergency obstacle avoidance operation described above. Alternatively, in other embodiments, the processor 11 may be configured by any other suitable means (e.g., by means of firmware) to execute a centroid slip angle planning method for vehicle drift motion under emergency obstacle avoidance conditions.

Various implementations of the systems and techniques described here above may be implemented in digital electronic circuitry, integrated circuitry, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Application Specific Standard Products (ASSPs), system on a chip (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and/or combinations thereof. These various embodiments may include: implemented in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which may be special or general purpose, receiving data and instructions from, and transmitting data and instructions to, a storage system, at least one input device, and at least one output device.

A computer program for implementing 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, special purpose computer, or other programmable data processing apparatus, such that the computer programs, when executed by the processor, cause the functions/acts specified in the flowchart and/or block diagram block or blocks to be performed. A computer program can execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present invention, a computer-readable storage medium may be a tangible medium that can contain, or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. A computer readable storage medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Alternatively, the computer readable storage medium may be a machine readable signal medium. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

To provide for interaction with a user, the systems and techniques described here can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to a user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which a user can provide input to the electronic device. Other kinds of devices may also be used to provide for interaction with a 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 may be received in any form, including acoustic, speech, or tactile input.

The systems and techniques described here can be implemented in a computing system that includes a back-end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front-end component (e.g., a user computer having a graphical user interface or a web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: local Area Networks (LANs), Wide Area Networks (WANs), blockchain networks, and the internet.

The computing system may include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. The server can be a cloud server, also called a cloud computing server or a cloud host, and is a host product in a cloud computing service system, so that the defects of high management difficulty and weak service expansibility in the traditional physical host and VPS service are overcome.

It should be understood that various forms of the flows shown above may be used, with steps reordered, added, or deleted. For example, the steps described in the present invention may be executed in parallel, sequentially, or in different orders, and are not limited herein as long as the desired results of the technical solution of the present invention can be achieved.

The above-described embodiments should not be construed as limiting the scope of the invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made in accordance with design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining a centroid slip angle of vehicle drifting movement under an emergency obstacle avoidance working condition is characterized by comprising the following steps:

establishing a mathematical expression of a second safe distance between the vehicle and the road boundary, and constraints of the vehicle state and the control quantity;

2. The method of claim 1, wherein establishing a mathematical representation of a first safe distance between the vehicle and the obstacle comprises:

taking the circumcircle of the obstacle as the mathematical expression of the obstacle;

3. The method of claim 1, wherein establishing a mathematical representation of a second safe distance between the vehicle and the roadway boundary comprises:

and based on the fact that the vehicle avoids collision with the road edge when the vehicle performs drifting motion according to the centroid slip angle, determining the second safety distance according to the parameters of the rectangle, wherein the second safety distance is a nonlinear function of the centroid slip angle of the vehicle.

4. The method according to any one of claims 1-3, wherein establishing constraints on vehicle states and control quantities comprises:

constraints are established regarding vehicle states and control inputs.

5. The method of claim 4, wherein establishing constraints on vehicle states and control quantities further comprises:

6. The method of claim 1, wherein after determining the optimal centroid slip angle, further comprising:

given the curvature k of the obstacle avoidance trajectory, according to (k, β)^*) Determining a desired vehicle state, wherein^*Is the optimal centroid slip angle.

7. The utility model provides a device is confirmed to barycenter slip angle of vehicle drift motion under urgent obstacle avoidance operating mode which characterized in that includes:

8. The apparatus of claim 7, wherein the first safe distance determining module is specifically configured to:

9. A vehicle comprising a control module, the desired vehicle state of claim 6 being a reference input to the control module.

10. A computer readable storage medium storing computer instructions for causing a processor to implement the method for determining the centroid slip angle of vehicle drift motion under an emergency obstacle avoidance condition according to any one of claims 1 to 6.