CN114852052B

CN114852052B - Method, device, equipment and storage medium for determining vehicle transverse stable area

Info

Publication number: CN114852052B
Application number: CN202210591869.2A
Authority: CN
Inventors: 白明慧; 蒋永峰; 郝文权; 李论
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Priority date: 2022-05-27
Filing date: 2022-05-27
Publication date: 2024-07-26
Anticipated expiration: 2042-05-27
Also published as: CN114852052A

Abstract

The application discloses a method, a device, equipment and a storage medium for determining a vehicle transverse stable region, wherein the method comprises the following steps: determining a stable yaw rate of the vehicle stability balance point based on the attribute parameters and the travel parameters of the vehicle; determining a yaw rate convergence interval of the stable balance point based on the error correction coefficient and the stable yaw rate; determining a solving area of the phase plane, and dividing the solving area into a plurality of subareas; and calculating a phase track corresponding to each sub-area in the plurality of sub-areas, and determining a transverse stable area of the vehicle based on the yaw rate convergence interval and the phase track corresponding to each sub-area. According to the technical scheme provided by the application, the accurate solution of the transverse stable region of the vehicle can be realized, two quantitative analysis indexes of the yaw rate convergence interval of the stable balance point and the number of the stable subareas in the transverse stable region are provided, and a more accurate and reliable theoretical guiding basis can be provided for the design of the stability controller.

Description

Method, device, equipment and storage medium for determining vehicle transverse stable area

Technical Field

The present application relates to the field of vehicle control technologies, and in particular, to a method, an apparatus, a device, and a storage medium for determining a lateral stability area of a vehicle.

Background

The actual running state of the vehicle deviates from the expected stable state due to the fact that the vehicle is inevitably disturbed from the external environment during running, so that a driver has to make proper adjustment to correct the lateral movement of the vehicle so as to keep stable running. However, in many cases, it is difficult to control the running state of the vehicle only by the operation of the driver, and the vehicle is kept stable by the intervention of the stability controller. Therefore, the deep analysis of the stability of the lateral movement of the vehicle is particularly important, particularly the solution of the lateral stability area can provide reliable theoretical basis for the design of the stability controller.

The most mature application in the prior art is the phase plane method and the Lyapunov function method, and the transverse stable region obtained by the two methods has become a main theoretical basis for the design of a vehicle stability controller. However, the above method still has the following disadvantages: 1. the obtained transverse stable region is a relatively conservative closed region, the division of the stable boundary is not accurate enough, and the stability judgment basis of the vehicle under the limit working condition cannot be accurately provided; 2. no quantitative analysis index can be provided for describing the change in the stable region. Therefore, the prior art cannot provide a more comprehensive theoretical guiding basis for the extended design application of the stability controller.

Disclosure of Invention

The application provides a method, a device, equipment and a storage medium for determining a transverse stable region of a vehicle, which can realize accurate solution of the transverse stable region of the vehicle, simultaneously provide two quantitative analysis indexes of a yaw rate convergence interval of a stable balance point and the number of stable subareas in the transverse stable region, and provide more accurate and reliable theoretical guidance basis for the design of a stability controller.

In a first aspect, the present application provides a method of determining a vehicle lateral stability region, the method comprising:

determining a stable yaw rate of the vehicle stability balance point based on the attribute parameters and the travel parameters of the vehicle;

Determining a yaw rate convergence interval of the stable equilibrium point based on an error correction coefficient and the stable yaw rate, wherein the error correction coefficient is determined in advance based on phase trajectory solving errors caused by multiple types of vehicle tire models;

determining a solving area of a phase plane, and dividing the solving area into a plurality of subareas;

And calculating a phase track corresponding to each sub-region in the plurality of sub-regions, and determining a transverse stable region of the vehicle based on the yaw rate convergence interval and the phase track corresponding to each sub-region.

In a second aspect, the present application provides a vehicle lateral stability region determination apparatus, comprising:

a first determination module for determining a steady yaw rate of the vehicle steady balance point based on the attribute parameters and the travel parameters of the vehicle;

A second determining module, configured to determine a yaw rate convergence interval of the stable balance point based on an error correction coefficient and the stable yaw rate, where the error correction coefficient is determined in advance based on phase trajectory solving errors caused by multiple types of vehicle tire models;

the subarea dividing module is used for determining a solving area of the phase plane and dividing the solving area into a plurality of subareas;

and the stability area determining module is used for calculating the phase track corresponding to each sub-area in the plurality of sub-areas and determining the transverse stability area of the vehicle based on the yaw rate convergence interval and the phase track corresponding to each sub-area.

In a third aspect, the present application provides an electronic device comprising:

At least one processor; and

A memory communicatively coupled to the at least one processor; wherein,

The memory stores a computer program executable by the at least one processor to enable the at least one processor to perform the method of determining a vehicle lateral stability region according to any of the embodiments of the present application.

In a fourth aspect, the present application provides a computer readable storage medium storing computer instructions for causing a processor to implement a method for determining a lateral stability region of a vehicle according to any embodiment of the present application when executed.

The embodiment of the application provides a method, a device, equipment and a storage medium for determining a vehicle transverse stable region, wherein the method comprises the following steps: determining a stable yaw rate of the vehicle stability balance point based on the attribute parameters and the travel parameters of the vehicle; determining a yaw rate convergence interval of a stable balance point based on an error correction coefficient and a stable yaw rate, wherein the error correction coefficient is determined in advance based on phase trajectory solving errors caused by various vehicle tire models; determining a solving area of the phase plane, and dividing the solving area into a plurality of subareas; and calculating a phase track corresponding to each sub-area in the plurality of sub-areas, and determining a transverse stable area of the vehicle based on the yaw rate convergence interval and the phase track corresponding to each sub-area. The application is based on the steady-state response characteristic of the vehicle, fully considers the phase track solving error caused by the difference of the used vehicle tire models, and uses the error correction coefficient to determine the yaw rate convergence interval of the stable balance point, thereby ensuring the accuracy of phase track convergence judgment. By solving the lateral stability region by using a finely divided sub-region, the lateral stability region boundary of the vehicle can be accurately found. The application provides two quantitative analysis indexes of the yaw rate convergence interval of the stable balance point and the number of the stable subareas in the transverse stable area while solving the transverse stable area, can quantitatively describe the change condition of the transverse stable area of the vehicle, and provides a more accurate and reliable theoretical guiding basis for the design of the stability controller.

It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the application or to delineate the scope of the application. Other features of the present application will become apparent from the description that follows.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic flow chart of a method for determining a lateral stability area of a vehicle according to an embodiment of the present application;

FIG. 2 is a second flow chart of a method for determining a lateral stability region of a vehicle according to an embodiment of the present application;

FIGS. 3A-3D are schematic illustrations of a lateral stability zone of a vehicle provided by an embodiment of the present application;

Fig. 4 is a schematic structural view of a device for determining a lateral stability region of a vehicle according to an embodiment of the present application;

fig. 5 is a block diagram of an electronic device for implementing a method of determining a vehicle lateral stability region according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, shall fall within the scope of the present application.

It should be noted that the terms "first," "second," "target," and "original," etc. in the description and claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be capable of executing sequences other than those illustrated or otherwise described. Furthermore, the terms "comprises," "comprising," 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 or inherent to such process, method, article, or apparatus.

Fig. 1 is a schematic flow chart of a method for determining a lateral stability area of a vehicle according to an embodiment of the present application, where the embodiment is applicable to a case of determining a lateral stability area of a vehicle phase plane. The method for determining the lateral stability area of the vehicle provided by the embodiment of the application can be implemented by the device for determining the lateral stability area of the vehicle provided by the embodiment of the application, and the device can be implemented in a software and/or hardware mode and is integrated in an electronic device for executing the method. The execution subject of the determination method of the vehicle lateral stability region of the application may be a microprocessor provided in the vehicle.

Referring to fig. 1, the method of the present embodiment includes, but is not limited to, the following steps:

s110, determining the stable yaw rate of the vehicle stability balance point based on the attribute parameters and the running parameters of the vehicle.

The attribute parameter refers to physical quantity information of the vehicle or parameters of each controller in the vehicle, and may include a mass of the vehicle, a moment of inertia of the vehicle, a distance between a center of mass of the vehicle and a front and rear axis, tire side force parameters of front and rear wheels, and the like. The driving parameters refer to working condition information acquired by a measuring instrument in the driving process of the vehicle, and can comprise road attachment coefficients, vehicle speed, front wheel rotation angles and the like.

Optionally, before determining the steady yaw rate of the vehicle steady balance point based on the attribute parameter and the driving parameter of the vehicle, the method further comprises: and acquiring attribute parameters and driving parameters of the vehicle.

In the embodiment of the application, a microprocessor CAN acquire attribute parameters of a vehicle from each controller through a controller area network (Controller Area Network, CAN) bus, and acquire running parameters of the vehicle when the vehicle runs; or each controller actively reports the attribute parameters of the controller to the microprocessor.

In the embodiment of the application, when the vehicle encounters interference of external environment (uneven road surface, windy weather, laterally inclined road surface or vehicle turning) during running, lateral deviation can occur, and the vehicle stability controller can enable the vehicle to be kept stable at a stable balance point. The steady yaw rate of the vehicle steady balance point is determined by the steady state response characteristic of the vehicle based on the attribute parameters and the travel parameters of the vehicle. Wherein the steady yaw rate of the steady balance point can be calculated by the following formula (1):

wherein ω _s is the steady yaw rate; v _x is the longitudinal speed, i.e. vehicle speed; l is the wheelbase of the vehicle; m is the mass of the vehicle; k _f is the front tire cornering stiffness; k _r is the rear tire cornering stiffness; l _f is the distance from the vehicle centroid to the front axle; l _r is the distance from the vehicle centroid to the rear axle; delta _f is the front wheel angle. The driving parameters k _f and k _r include road adhesion coefficients.

And S120, determining a yaw rate convergence interval of the stable balance point based on the error correction coefficient and the stable yaw rate.

Wherein the error correction coefficient is determined in advance based on phase trajectory solving errors caused by various types of vehicle tire models.

In the embodiments of the present application, there are many types of methods for constructing a tire model of a vehicle in the prior art, including, but not limited to, magic formulas, unityre models, du Gaofu models, fiala models, gim models. The numerical calculation methods of various vehicle tire models are different, or errors occur in phase trajectory solving. The solving of the phase trajectory will be described in detail in the following embodiments, where the present application fully considers the phase trajectory solving error due to the difference of the used vehicle tire models, sets an error correction coefficient, and determines the yaw rate convergence interval of the stable equilibrium point from the error correction coefficient and the stable yaw rate. The advantage of this arrangement is that the accuracy of convergence judgment of the phase track can be ensured when solving the phase track in the following embodiments, and the change condition of the convergence state of the phase track of the vehicle motion can be quantitatively represented.

Alternatively, the magnitude of the error correction coefficient may be determined to be a value between 0.05 or more and 0.1 or less.

Specifically, determining the yaw rate convergence interval of the stable equilibrium point based on the error correction coefficient and the stable yaw rate includes: determining the magnitude relation between the stable yaw rate and a preset value; if the magnitude relation is equal to the preset interval range, determining the yaw rate convergence interval as the preset interval range; if the magnitude relation is larger than the first error correction mode, determining a yaw rate convergence interval based on the error correction coefficient and the stable yaw rate; and if the magnitude relation is smaller than the first error correction mode, determining a yaw rate convergence interval according to a second error correction mode based on the error correction coefficient and the stable yaw rate.

In the embodiment of the present application, optionally, the preset value may be 0; the preset interval range may be [ -0.01,0.01]. Wherein the yaw-rate convergence interval can be determined by the following formula (2):

Wherein omega is a yaw rate convergence interval; e is an error correction coefficient; omega _s is the steady yaw rate.

S130, determining a solving area of the phase plane, and dividing the solving area into a plurality of subareas.

Wherein the phase plane refers to a graphical solution for solving the lateral stability region of the vehicle. The solution region refers to the region of the lateral velocity-yaw velocity phase diagram.

Specifically, determining a solution area of a phase plane, and dividing the solution area into a plurality of sub-areas, including: determining a state parameter of the vehicle, the state parameter including a lateral velocity and a yaw rate; determining a solving area of the phase plane according to the value range of the state parameter; dividing the solving area into a plurality of subareas according to the value interval of the state parameter.

In an embodiment of the present application, yaw rate is the angle at which the vehicle rotates about a Z axis perpendicular to the ground, the magnitude of which represents the degree of stability of the vehicle. If the yaw rate reaches a threshold value, dangerous working conditions such as slip measurement or tail flick of the automobile are indicated. Lateral speed refers to the speed of the vehicle in the vertical direction of motion, such as when the vehicle turns on a level road or when it is laterally offset due to external environmental disturbances.

For example, the range of values for the lateral velocity may be determined to be (-10 m/s,10 m/s), and the interval between values may be determined to be a value of 0.01m/s or more and 0.05m/s or less; the range of values of the yaw rate may be determined to be (-2 rad/s,2 rad/s), and the interval between values may be determined to be a value of 0.01rad/s or more and 0.05rad/s or less.

S140, calculating a phase track corresponding to each sub-area in the sub-areas, and determining a transverse stable area of the vehicle based on the yaw rate convergence interval and the phase track corresponding to each sub-area.

The lateral stability of a vehicle refers to the ability to resist lateral overturning or sliding when the vehicle encounters interference from the external environment (rough road, windy weather, laterally sloped road or vehicle cornering) during travel. The lateral stability region refers to a region constituted by a range of state parameters (i.e., lateral speed and yaw rate) that give the vehicle lateral stability. When the state parameter changes, the lateral stability of the vehicle will also change.

Specifically, calculating a phase trajectory corresponding to each sub-region in the plurality of sub-regions, and determining a lateral stability region of the vehicle based on the yaw rate convergence interval and the phase trajectory corresponding to each sub-region, including: determining a target subarea from the plurality of subareas, and calculating a phase track corresponding to the target subarea; determining whether the target subarea is a stable subarea or not based on the yaw rate convergence interval and the phase track corresponding to the target subarea, and if the target subarea is the stable subarea, storing the stable subarea into a stable subarea set; judging whether the next subarea of the target subarea is the last subarea in the plurality of subareas, if not, repeatedly executing the operations of determining the target subarea from the plurality of subareas and calculating the corresponding phase track of the target subarea; connecting the stability subregions in the stability subregion set results in a lateral stability region of the vehicle.

Specifically, determining whether the target sub-region is a stable sub-region based on the yaw rate convergence interval and the phase trajectory corresponding to the target sub-region includes: determining whether the phase track corresponding to the target sub-region is converged in a yaw rate convergence interval; and if the target subarea is converged, determining the target subarea as a stable subarea.

In the embodiment of the application, a nonlinear vehicle model can be constructed in advance. Starting from the first sub-area, generating a random point in the target sub-area, acquiring the lateral velocity and the yaw velocity of the random point, and then carrying the lateral velocity and the yaw velocity of the random point into a nonlinear vehicle model to obtain a corresponding phase track of the target sub-area. After calculating the phase track corresponding to the target sub-region, whether the phase track is converged to the yaw rate convergence interval or not is further required to be judged according to the convergence characteristics of the phase track. The phase trajectory convergence characteristic means that under a certain input condition, in a given phase plane (or phase space) solving area, a stable phase trajectory converges to a specific stable equilibrium point (or stable interval), while an unstable phase trajectory diverges and cannot converge to the stable equilibrium point (or stable interval). If the phase track of a certain subarea converges, representing that the subarea is stable, recording and storing the random points to a stable subarea set, wherein the phase track is a stable phase track; if the phase track of a certain sub-area diverges, which means that the sub-area is unstable, the phase track is a diverged phase track, and the random point is not recorded or stored. And connecting all the subareas corresponding to the stable phase tracks, namely the stable subareas, so as to obtain the transverse stable area of the vehicle.

Because the phase track solving mode of dividing the subareas is used in the step S130, the change condition of the size of the transverse stable area can be recorded while solving the phase track in each subarea, the boundary of the transverse stable area of the vehicle can be accurately obtained, and an effective quantitative analysis index can be provided for the design of the stability controller.

The number of the stabilizing subareas in the transverse stabilizing area can quantitatively represent the size of the transverse stabilizing area of the vehicle and can be used as an effective analysis index for describing the change of the transverse stabilizing area of the vehicle.

According to the technical scheme provided by the embodiment, the stable yaw rate of the stable balance point of the vehicle is determined based on the attribute parameters and the running parameters of the vehicle; determining a yaw rate convergence interval of the stable balance point based on the error correction coefficient and the stable yaw rate; determining a solving area of the phase plane, and dividing the solving area into a plurality of subareas; and calculating a phase track corresponding to each sub-area in the plurality of sub-areas, and determining a transverse stable area of the vehicle based on the yaw rate convergence interval and the phase track corresponding to each sub-area. The application is based on the steady-state response characteristic of the vehicle, fully considers the phase track solving error caused by the difference of the used vehicle tire models, and uses the error correction coefficient to determine the yaw rate convergence interval of the stable balance point, thereby ensuring the accuracy of phase track convergence judgment. By solving the lateral stability region by using a finely divided sub-region, the lateral stability region boundary of the vehicle can be accurately found. The application provides two quantitative analysis indexes of the yaw rate convergence interval of the stable balance point and the number of the stable subareas in the transverse stable area while solving the transverse stable area, can quantitatively describe the change condition of the transverse stable area of the vehicle, and provides a more accurate and reliable theoretical guiding basis for the design of the stability controller.

The method for determining a lateral stability area of a vehicle according to an embodiment of the present application is further described below, and fig. 2 is a second schematic flow chart of the method for determining a lateral stability area of a vehicle according to an embodiment of the present application. The embodiment of the application is optimized based on the embodiment, and is specifically optimized as follows: the present embodiment explains the process of calculating the phase trajectory corresponding to the sub-region in step S140 in the above embodiment in detail.

Referring to fig. 2, the method of the present embodiment includes, but is not limited to, the following steps:

s210, constructing a nonlinear vehicle model based on the attribute parameters and the driving parameters.

The nonlinear vehicle model may include a nonlinear dynamics model, a nonlinear tire model, and a tire slip angle model, among others.

In the embodiment of the application, the microprocessor CAN acquire the attribute parameters of the vehicle from each controller through the CAN bus, or each controller actively reports the attribute parameters to the microprocessor. The microprocessor may acquire the running parameters of the vehicle while the vehicle is running.

And constructing a nonlinear dynamics model for describing the lateral movement and the yaw movement of the vehicle according to the acquired attribute parameters and the acquired driving parameters. Wherein the nonlinear dynamics model can be represented by the following formula (3):

Wherein m is the mass of the vehicle; i _z is the moment of inertia of the vehicle about the Z axis perpendicular to the ground; l _f is the distance from the vehicle centroid to the front axle; l _r is the distance from the vehicle centroid to the rear axle; delta _f is the front wheel corner; v _x is the longitudinal speed, i.e. vehicle speed; v _y is the lateral velocity; omega is yaw rate; f _sf is the tire side force of the front wheel; f _sr is the tire side force of the rear wheel.

Wherein the tire side force F _sf of the front wheel and the tire side force F _sr of the rear wheel in the formula (3) can be determined by a nonlinear tire model. Specifically, a nonlinear tire model is constructed according to the acquired attribute parameters and the running parameters, and the nonlinear tire model comprises, but is not limited to, a magic formula, unityre model, du Gaofu model, fiala model and Gim model. Optionally, a magic formula is used to calculate the tire lateral force parameter, and the specific formula is as follows formula (4):

F＝Dsin(Carctan(Bα-E(Bα-arctanBα))) (4)

Wherein B is a rigidity factor; c is a form factor; d is a peak factor; e is a curvature factor; f is the tire lateral force; alpha is the tire slip angle. The driving parameter D includes a road adhesion coefficient.

Wherein the tire slip angle α in the formula (4) can be determined from a tire slip angle model. Specifically, a tire slip angle model is constructed according to the acquired attribute parameters and the acquired driving parameters. Wherein the tire slip angle model can be represented by the following formula (5):

Wherein alpha _f is the tire slip angle of the front wheel; alpha _r is the tire slip angle of the rear wheel; delta _f is the front wheel corner; v _x is the longitudinal speed, i.e. vehicle speed; v _y is the lateral velocity; omega is yaw rate; delta _f is the front wheel corner; l _f is the distance from the vehicle centroid to the front axle; and l _r is the distance from the vehicle center of mass to the rear axle.

S220, randomly generating representative points in the target subarea.

In the embodiment of the application, after the solving area of the phase plane is divided into a plurality of subareas, a representative point is randomly generated in each subarea, wherein the representative point refers to a point capable of representing the subarea, can be a center point of the area or a point which accords with a certain standard in the area, and the application is not limited.

S230, determining solving time and time step of the phase trajectory.

In the embodiment of the application, since the solution of the nonlinear dynamics equation represents the motion state of the representative point, such as the phase track of the vehicle within 10 seconds, the solution time (such as 10 seconds) of the phase track also needs to be determined, and in addition, a corresponding time step needs to be set for the solution time.

Alternatively, the solution time of the phase trajectory may be set to a value between 10 seconds and 20 seconds, and the solution step size may be set to a value between 0.001 seconds and 0.01 seconds.

S240, inputting the state parameters, the solving time and the time step of the representative point into the nonlinear vehicle model.

In the embodiment of the present application, since the solving area refers to an area of the lateral velocity-yaw velocity phase diagram, the state parameters of the representative point in each of the solving areas include the lateral velocity and the yaw velocity, and then the lateral velocity, the yaw velocity, the solving time, and the time step of the representative point of each of the sub-areas are input to the nonlinear vehicle model.

S250, determining the phase track of the representative point in solving time according to the output result of the nonlinear vehicle model.

In the embodiment of the application, the lateral speed, the yaw rate, the solving time and the time step of the representative point of each sub-area are input into the nonlinear vehicle model, and the phase track of the representative point in the solving time is determined according to the output result of the nonlinear vehicle model until all the sub-areas are traversed, so that the phase tracks corresponding to the sub-areas are obtained. Illustratively, the lateral velocity and yaw velocity of the representative point a in the sub-region a are input into the nonlinear vehicle model, resulting in a motion state within 10 seconds (i.e., solution time) with respect to the representative point a.

In a specific embodiment, in order to detect the change relationship between the running parameter and the lateral stability region of the vehicle, four specific application scenarios are set, and the running parameter of the running condition is set for the four application scenarios, as shown in table 1:

TABLE 1 Driving parameters for different Driving conditions

Application scenario	Running parameter (road adhesion coefficient mu, vehicle speed v _x, front wheel rotation angle delta _f)
		Running condition 1	μ＝0.8、v_x＝20ms、δ_f＝0
Running condition 2	μ＝0.8、v_x＝20ms、δ_f＝0.04rad
		Running condition 3	μ＝0.8、v_x＝30ms、δ_f＝0
Running condition 4	μ＝0.3、v_x＝20ms、δ_f＝0

By adopting the method for determining the transverse stable region of the vehicle provided by the embodiment, the stable yaw rate of the stable balance point, the yaw rate convergence interval of the stable balance point and the number of stable subareas under different working conditions are solved, and the solving result is shown in table 2:

TABLE 2 solution results for different Driving conditions

The vehicle lateral stability region corresponding to the running condition 1 is shown in fig. 3A, the vehicle lateral stability region corresponding to the running condition 2 is shown in fig. 3B, the vehicle lateral stability region corresponding to the running condition 3 is shown in fig. 3C, and the vehicle lateral stability region corresponding to the running condition 4 is shown in fig. 3D.

As can be seen in connection with fig. 3A-3D and table 2: the transverse stable region of the vehicle solved in the prior engineering technology is a conservative closed quadrilateral and triangular region, and the method provided by the invention can accurately solve the strip-shaped stable region expressed by the yaw rate-lateral speed, and can accurately solve the boundary of the transverse stable region of the vehicle. Quantitative conclusions can be obtained by comparing the solving results of different driving conditions: when the front wheel rotation angle is increased from 0 to 0.04rad, the vehicle lateral stability area is reduced by 5.26%, and meanwhile, the lateral stability area is not symmetrical about the origin due to the fact that the convergence interval of the yaw rate is changed from [ -0.01,0.01] to [0.2068,0.2528 ]; when the vehicle speed increases from 20m/s to 30m/s, the vehicle lateral stability region decreases by 28.71%; when the road adhesion coefficient was reduced from 0.8 to 0.3, the vehicle lateral stability region was reduced by 78.44%.

The technical scheme provided by the embodiment can solve the problems that the existing engineering technology solves the problem that a transverse stable region is inaccurate and lacks quantitative analysis indexes, can realize the accurate solution of the transverse stable region of the vehicle, provides two quantitative analysis indexes of a yaw rate convergence interval of a stable balance point and the number of stable subareas in the transverse stable region, can provide more accurate and reliable theoretical guidance basis for the design of a stability controller, and has the advantages of simple method and easy programming realization.

Fig. 4 is a schematic structural diagram of a device for determining a lateral stability area of a vehicle according to an embodiment of the present application, and as shown in fig. 4, the device 400 may include:

A first determining module 410 for determining a steady yaw rate of the vehicle stability balance point based on the attribute parameters and the travel parameters of the vehicle;

A second determining module 420, configured to determine a yaw rate convergence interval of the stable balance point based on an error correction coefficient and the stable yaw rate, where the error correction coefficient is determined in advance based on phase trajectory solving errors caused by multiple types of vehicle tire models;

A subregion division module 430, configured to determine a solution region of the planar surface, and divide the solution region into a plurality of subregions;

the stability region determining module 440 is configured to calculate a phase trajectory corresponding to each of the plurality of sub-regions, and determine a lateral stability region of the vehicle based on the yaw rate convergence interval and the phase trajectory corresponding to each of the sub-regions.

Further, the second determining module 420 may be specifically configured to: determining the magnitude relation between the stable yaw rate and a preset numerical value; if the magnitude relation is equal to the yaw rate convergence interval, determining that the yaw rate convergence interval is a preset interval range; if the magnitude relation is larger than the first threshold value, determining a yaw rate convergence interval according to a first error correction mode based on an error correction coefficient and the stable yaw rate; and if the magnitude relation is smaller than the first error correction mode, determining the yaw rate convergence section according to a second error correction mode based on the error correction coefficient and the stable yaw rate.

Further, the above-mentioned sub-region dividing module 430 may be specifically configured to: determining state parameters of the vehicle, the state parameters including lateral speed and yaw rate; determining a solving area of the phase plane according to the value range of the state parameter; and dividing the solving area into a plurality of subareas according to the value interval of the state parameter.

Further, the stability area determining module 440 may be specifically configured to: determining a target subarea from the plurality of subareas, and calculating a phase track corresponding to the target subarea; determining whether the target subarea is a stable subarea or not based on the yaw rate convergence interval and the phase track corresponding to the target subarea, and if so, storing the stable subarea into a stable subarea set; judging whether the next subarea of the target subarea is the last subarea in the plurality of subareas, if not, repeatedly executing the operation of determining the target subarea from the plurality of subareas and calculating the phase track corresponding to the target subarea; and connecting the stable subareas in the stable subarea set to obtain the transverse stable area of the vehicle.

Further, the stable region determining module 440 may include a phase trajectory calculating unit and a stable sub-region determining unit;

The phase trajectory calculation unit is specifically configured to: constructing a nonlinear vehicle model based on the attribute parameters and the driving parameters; randomly generating representative points in the target subregion; and calculating the phase track of the representative point in the target subarea based on the nonlinear vehicle model.

The stable subarea determining unit is specifically configured to: determining whether the phase track corresponding to the target sub-region is converged in the yaw rate convergence interval; and if so, determining the target subarea as the stable subarea.

The phase trajectory calculation unit may be further specifically configured to: determining solving time and time step of a phase track; inputting the state parameters of the representative points, the solving time and the time step into the nonlinear vehicle model; and determining the phase track of the representative point in the solving time according to the output result of the nonlinear vehicle model.

The device for determining the lateral stability area of the vehicle provided in the embodiment is applicable to the method for determining the lateral stability area of the vehicle provided in any of the above embodiments, and has corresponding functions and beneficial effects.

Fig. 5 is a block diagram of an electronic device for implementing a display method according to an embodiment of the present application. The electronic device 10 is intended to represent various forms of digital computers, such as laptops, desktops, workstations, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. Electronic equipment may also represent various forms of mobile devices, such as personal digital processing, cellular telephones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions, are meant to be exemplary only, and are not meant to limit implementations of the applications described and/or claimed herein.

As shown in fig. 5, the electronic device 10 includes at least one processor 11, and a memory, such as a Read Only Memory (ROM) 12, a Random Access Memory (RAM) 13, etc., communicatively connected to the at least one processor 11, in which the memory stores a computer program executable by the at least one processor, and the processor 11 may perform various appropriate actions and processes according to the computer program stored in the Read Only Memory (ROM) 12 or the computer program loaded from the storage unit 18 into the Random Access Memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 may also be stored. The processor 11, the ROM 12 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.

Various 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, etc.; 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, digital Signal Processors (DSPs), and any suitable processor, controller, microcontroller, etc. The processor 11 executes the respective methods and processes described above, such as a method of determining a vehicle lateral stability region.

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

Various implementations of the systems and techniques described here above may be implemented in digital electronic circuitry, integrated circuit systems, field Programmable Gate Arrays (FPGAs), application Specific Integrated Circuits (ASICs), application Specific Standard Products (ASSPs), systems On 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, the one or more computer programs may be executed and/or interpreted on a programmable system including at least one programmable processor, which may be a special purpose or general-purpose programmable processor, that may receive data and instructions from, and transmit data and instructions to, a storage system, at least one input device, and at least one output device.

A computer program for carrying out methods of the present application 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 implemented. The computer program may execute entirely on the 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 application, 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. The 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) through 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 may 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 input, speech input, or tactile input.

The systems and techniques described here can be implemented in a computing system that includes a background 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 background, 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. The client and server are typically 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 hosts and VPS service are overcome.

It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present application may be performed in parallel, sequentially, or in a different order, so long as the desired results of the technical solution of the present application are achieved, and the present application is not limited herein.

The above embodiments do not limit the scope of the present application. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of the present application.

Claims

1. A method of determining a lateral stability region of a vehicle, the method comprising:

determining a yaw rate convergence interval of the stable equilibrium point based on an error correction coefficient and the stable yaw rate, the error correction coefficient being determined in advance based on phase trajectory solving errors caused by a plurality of types of vehicle tire models, comprising: determining the magnitude relation between the stable yaw rate and a preset numerical value; if the magnitude relation is equal to the yaw rate convergence interval, determining that the yaw rate convergence interval is a preset interval range; if the magnitude relation is larger than the first threshold value, determining a yaw rate convergence interval according to a first error correction mode based on an error correction coefficient and the stable yaw rate; if the magnitude relation is smaller than the first error correction mode, determining a yaw rate convergence interval according to a second error correction mode based on an error correction coefficient and the stable yaw rate;

Determining a solution region of a planar surface and dividing the solution region into a plurality of sub-regions, comprising: determining state parameters of the vehicle, the state parameters including lateral speed and yaw rate; determining a solving area of the phase plane according to the value range of the state parameter; dividing the solving area into a plurality of subareas according to the value interval of the state parameter;

Calculating a phase trajectory corresponding to each sub-region of the plurality of sub-regions, and determining a lateral stability region of the vehicle based on the yaw rate convergence interval and the phase trajectory corresponding to each sub-region, including: determining a target subarea from the plurality of subareas, and calculating a phase track corresponding to the target subarea; determining whether the target subarea is a stable subarea or not based on the yaw rate convergence interval and the phase track corresponding to the target subarea, and if so, storing the stable subarea into a stable subarea set; judging whether the next subarea of the target subarea is the last subarea in the plurality of subareas, if not, repeatedly executing the operation of determining the target subarea from the plurality of subareas and calculating the phase track corresponding to the target subarea; and connecting the stable subareas in the stable subarea set to obtain the transverse stable area of the vehicle.

2. The method for determining a lateral stability area of a vehicle according to claim 1, wherein the calculating a phase trajectory corresponding to the target sub-area includes:

constructing a nonlinear vehicle model based on the attribute parameters and the driving parameters;

Randomly generating representative points in the target subregion;

And calculating the phase track of the representative point in the target subarea based on the nonlinear vehicle model.

3. The method for determining a vehicle lateral stability region according to claim 1, characterized in that the determining whether the target sub-region is a stability sub-region based on the yaw-rate convergence interval and a phase trajectory corresponding to the target sub-region includes:

determining whether the phase track corresponding to the target sub-region is converged in the yaw rate convergence interval;

and if so, determining the target subarea as the stable subarea.

4. The method of determining a vehicle lateral stability region according to claim 2, characterized in that the calculating a phase trajectory of the representative point in the target subregion based on the nonlinear vehicle model includes:

Determining solving time and time step of a phase track;

inputting the state parameters of the representative points, the solving time and the time step into the nonlinear vehicle model;

And determining the phase track of the representative point in the solving time according to the output result of the nonlinear vehicle model.

5. A vehicle lateral stability area determination apparatus for implementing the vehicle lateral stability area determination method according to any one of claims 1 to 4, the apparatus comprising:

6. An electronic device, the electronic device comprising:

At least one processor; and

A memory communicatively coupled to the at least one processor; wherein,

The memory stores a computer program executable by the at least one processor to enable the at least one processor to perform the method of determining a vehicle lateral stability region of any one of claims 1 to 4.

7. A computer readable storage medium storing computer instructions for causing a processor to perform the method of determining a vehicle lateral stability region of any one of claims 1 to 4.