CN115675635B

CN115675635B - Front and rear wheel control method, system, electronic device, storage medium and vehicle

Info

Publication number: CN115675635B
Application number: CN202211436861.5A
Authority: CN
Inventors: 刘福星; 宋丹丹
Original assignee: Great Wall Motor Co Ltd
Current assignee: Great Wall Motor Co Ltd
Priority date: 2022-11-16
Filing date: 2022-11-16
Publication date: 2025-02-25
Anticipated expiration: 2042-11-16
Also published as: CN115675635A

Abstract

The present disclosure provides a control method, system, electronic device, storage medium and vehicle for front and rear wheels. The method comprises: obtaining vehicle information; wherein the vehicle information comprises an actual deflection angle of the front wheel; processing the actual deflection angle of the front wheel to obtain an expected deflection angle of the front wheel; judging the deflection direction of the rear wheel of the vehicle according to the vehicle information to obtain the deflection direction of the rear wheel; determining a first rear wheel deflection angle based on the vehicle's center of mass side slip angle using the expected deflection angle of the front wheel; determining a second rear wheel deflection angle based on the expected deflection angle of the front wheel and the vehicle's yaw rate; performing weighted calculation on the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle; controlling the front wheel of the vehicle according to the expected deflection angle of the front wheel, and controlling the rear wheel of the vehicle according to the rear wheel deflection direction and the rear wheel deflection angle.

Description

Front and rear wheel control method and system, electronic device, storage medium and vehicle

Technical Field

The disclosure relates to the technical field of vehicle control, and in particular relates to a front and rear wheel control method, a system, electronic equipment, a storage medium and a vehicle.

Background

In the running process of the vehicle, particularly in the running process of a curve, the wheels slip due to the factors such as overhigh speed or change of the adhesive force of the tires, the problem of understeer or oversteer of the vehicle is easy to occur, the vehicle is out of control, and the safety accident is caused.

In view of this, how to avoid the problem of understeer or oversteer of the vehicle and to improve the driving stability and safety has become an important research problem.

Disclosure of Invention

In view of the above, an object of the present disclosure is to provide a method, a system, an electronic device, a storage medium and a vehicle for controlling front and rear wheels, so as to solve the problem of understeer or oversteer occurring when the vehicle is running in the prior art.

Based on the above object, a first aspect of the present disclosure proposes a control method of front and rear wheels, including:

Acquiring vehicle information, wherein the vehicle information comprises the actual deflection angle of the front wheels;

Processing the actual deflection angle of the front wheel to obtain an expected deflection angle of the front wheel;

judging the deflection direction of the rear wheels of the vehicle according to the vehicle information to obtain the deflection direction of the rear wheels;

determining a first rear wheel yaw angle based on a vehicle centroid slip angle using the front wheel desired yaw angle;

determining a second rear wheel yaw angle based on the front wheel desired yaw angle and a vehicle yaw rate;

weighting and calculating the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle;

And controlling front wheels of the vehicle according to the expected deflection angle of the front wheels, and controlling rear wheels of the vehicle according to the deflection direction of the rear wheels and the deflection angle of the rear wheels.

Based on the same inventive concept, a second aspect of the present disclosure proposes a control system of front and rear wheels, comprising:

the vehicle information acquisition module is configured to acquire vehicle information, wherein the vehicle information comprises the actual deflection angle of the front wheels;

The front wheel expected deflection angle acquisition module is configured to process the actual deflection angle of the front wheel to obtain the expected deflection angle of the front wheel;

the rear wheel deflection direction acquisition module is configured to judge the vehicle rear wheel deflection direction according to the vehicle information to obtain the rear wheel deflection direction;

A first rear wheel yaw angle acquisition module configured to determine a first rear wheel yaw angle based on a vehicle centroid slip angle using the front wheel desired yaw angle;

A second rear wheel yaw angle acquisition module configured to determine a second rear wheel yaw angle based on the front wheel desired yaw angle and a vehicle yaw angle speed;

the rear wheel deflection angle acquisition module is configured to perform weighted calculation on the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle;

and a vehicle control module configured to control front wheels of the vehicle according to the desired yaw angle of the front wheels and to control rear wheels of the vehicle according to the yaw direction of the rear wheels and the yaw angle of the rear wheels.

Based on the same inventive concept, a third aspect of the present disclosure proposes an electronic device comprising a memory, a processor and a computer program stored on the memory and executable by the processor, the processor implementing the method as described above when executing the computer program.

Based on the same inventive concept, a fourth aspect of the present disclosure proposes a non-transitory computer-readable storage medium storing computer instructions for causing a computer to perform the method as described above.

Based on the same inventive concept, a fifth aspect of the present disclosure proposes a vehicle including the control system of the front and rear wheels of the second aspect or the electronic device of the third aspect or the storage medium of the fourth aspect.

From the above, the control method, the system, the electronic device, the storage medium and the vehicle for the front and rear wheels provided by the present disclosure process the actual deflection angle of the front wheel to obtain the desired deflection angle of the front wheel, control the front wheel of the vehicle according to the desired deflection angle of the front wheel, and perform weighted calculation on the first rear wheel deflection angle and the second rear wheel deflection angle to obtain the rear wheel deflection angle, so as to improve the accuracy of the rear wheel deflection angle, realize the accurate control of the rear wheel deflection angle, control the rear wheel of the vehicle according to the rear wheel deflection direction and the rear wheel deflection angle, and further improve the stability of the vehicle during steering. Under the condition that the front wheels are under-turned or oversteered, through the scheme, when the vehicle turns, the deflection angles of the front wheels and the rear wheels are controlled and adjusted together, so that the vehicle turns more stably than the vehicle turns only when the rear wheels are controlled, and the driving safety is improved.

Drawings

In order to more clearly illustrate the technical solutions of the present disclosure or related art, the drawings required for the embodiments or related art description will be briefly described below, and it is apparent that the drawings in the following description are only embodiments of the present disclosure, and other drawings may be obtained according to these drawings without inventive effort to those of ordinary skill in the art.

FIG. 1 is a flow chart of a method of controlling front and rear wheels in accordance with an embodiment of the present disclosure;

FIG. 2 is a first partial flow chart of an embodiment in another application scenario of the present disclosure;

FIG. 3 is a second partial flow chart of an embodiment in another application scenario of the present disclosure;

FIG. 4 is a schematic structural view of a control system for front and rear wheels according to an embodiment of the present disclosure;

Fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the disclosure.

Detailed Description

For the purposes of promoting an understanding of the principles and advantages of the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same.

It should be noted that unless otherwise defined, technical or scientific terms used in the embodiments of the present disclosure should be given the ordinary meaning as understood by one of ordinary skill in the art to which the present disclosure pertains. The terms "first," "second," and the like, as used in embodiments of the present disclosure, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.

As described above, there is a problem in that the vehicle is under-steered or over-steered due to wheel slip caused by factors such as an excessive vehicle speed or a change in tire adhesion during running of the vehicle, particularly during running on a curve.

Based on the above description, as shown in fig. 1, the method for controlling front and rear wheels according to the present embodiment includes:

And 101, acquiring vehicle information, wherein the vehicle information comprises the actual deflection angle of the front wheels.

In specific implementation, the vehicle information comprises vehicle self information and vehicle running information. Wherein the vehicle self information includes vehicle mass or vehicle tire information, and the vehicle operation information includes at least one of vehicle steering information, vehicle operation information, and vehicle shift position information. There are various ways to obtain vehicle information, for example, corresponding vehicle operation information may be collected by corresponding sensors.

In the scheme, the vehicle information is acquired in a plurality of modes, the speed and the accuracy of acquiring the vehicle information are improved, the vehicle is controlled according to the acquired vehicle information, and the efficiency and the accuracy of controlling the vehicle are improved.

And 102, processing the actual deflection angle of the front wheel to obtain the expected deflection angle of the front wheel.

In the specific implementation, the acquired vehicle information comprises the actual deflection angle of the front wheels, the front wheel steering angle control coefficient is acquired, and the front wheel expected deflection angle is obtained by processing the actual deflection angle of the front wheels and the front wheel steering angle control coefficient. The front wheel steering angle control coefficient is a coefficient reflecting the relation between the actual steering angle of the front wheel and the expected steering angle of the front wheel, can be obtained through table lookup and is related to the vehicle speed and the average rolling rate of the front wheel or the average rolling rate of the front wheel, and the expected steering angle of the front wheel is the steering angle required by the front wheel when the front wheel is controlled in order to ensure the stability of the vehicle during steering of the vehicle.

In the scheme, the expected deflection angle of the front wheel is obtained by calculating according to the actual deflection angle of the front wheel and the control coefficient of the front wheel steering angle. And the front wheels of the vehicle are controlled according to the calculated expected deflection angles of the front wheels, so that the control method is more accurate than the control of the front wheels of the vehicle by directly using a steering wheel in the related art.

And step 103, judging the deflection direction of the rear wheels of the vehicle according to the vehicle information to obtain the deflection direction of the rear wheels.

In specific implementation, the vehicle information comprises vehicle gear information and acceleration information, and the vehicle state is judged according to the gear information and the acceleration information to determine whether the vehicle is in a driving state or a braking state.

The vehicle state is determined according to the vehicle acceleration information and the gear information, wherein the vehicle state refers to a state of the vehicle under different accelerations and different gears and comprises one of a forward driving state, a forward braking state, a reverse braking state or a reverse driving state.

The vehicle acceleration is positive in the direction of the vehicle head and negative in the direction of the vehicle tail. The method comprises the steps of determining that a vehicle state is a forward driving state by responding to gear information which is a forward gear and acceleration information which is a positive value, determining that the vehicle state is a forward braking state by responding to the gear information which is a forward gear and acceleration information which is a negative value, determining that the vehicle state is a reverse braking state by responding to the gear information which is a reverse gear and determining that the vehicle state is a reverse driving state by responding to the gear information which is a reverse gear and acceleration information which is a negative value.

When the vehicle is in a driving state, calculating the slip ratio of the vehicle tyre, wherein the slip ratio of the vehicle tyre comprises a front wheel slip ratio and a rear wheel slip ratio. And determining the deflection direction of the rear wheels according to the slip ratio of the vehicle tyre.

The calculation process of the slip ratio of the vehicle tire comprises the steps of obtaining the wheel speed of the vehicle tire, the rolling radius of the vehicle tire and the longitudinal speed of the vehicle, and carrying out calculation processing on the wheel speed of the vehicle tire, the rolling radius of the vehicle tire and the longitudinal speed of the vehicle to obtain the slip ratio of the vehicle tire, wherein S= (omega. R-u)/(omega. R). Where S is the slip ratio of the vehicle tire, ω is the wheel speed of the vehicle tire, R is the rolling radius of the vehicle tire, and u is the longitudinal speed of the vehicle.

The process of determining the deflection direction of the rear wheels according to the slip ratio of the vehicle tires is that when the vehicle is in a driving state, at least one front wheel slip ratio meets a first front wheel slip ratio condition, and at least one rear wheel slip ratio meets a first rear wheel slip ratio condition, the vehicle is in an understeer state, and the deflection direction of the rear wheels of the vehicle is reversed to the front wheels. For example, when the slip ratio of at least one front wheel is calculated to be equal to or less than-10% and then the slip ratio of at least one rear wheel is calculated to be equal to or less than-10%, the rear wheel of the vehicle is deflected in the opposite direction to the front wheel. When the at least one front wheel slip ratio meets the front wheel second slip ratio condition and the at least one rear wheel slip ratio meets the rear wheel second slip ratio condition, the vehicle is in an oversteered state, and the rear wheel deflection direction of the vehicle is in the same direction as the front wheel deflection. For example, when the slip ratio of at least one rear wheel is calculated to be equal to or less than-10% and then the slip ratio of at least one front wheel is calculated to be equal to or less than-10%, the yaw direction of the rear wheel of the vehicle is the same direction as the yaw direction of the front wheel.

When the vehicle is in a braking state, calculating the slip rate of the vehicle tyre, wherein the slip rate of the vehicle tyre comprises a front wheel slip rate and a rear wheel slip rate. And determining the deflection direction of the rear wheels according to the slip rate of the vehicle tires.

The calculation process of the slip rate of the vehicle tire comprises the steps of obtaining the wheel speed of the vehicle tire, the rolling radius of the vehicle tire and the longitudinal speed of the vehicle, and carrying out calculation processing on the wheel speed of the vehicle tire, the rolling radius of the vehicle tire and the longitudinal speed of the vehicle to obtain the slip rate K= (u-omega-R)/u of the vehicle tire. Where K is the slip ratio of the vehicle tire, ω is the wheel speed of the vehicle tire, R is the rolling radius of the vehicle tire, and u is the longitudinal speed of the vehicle.

The process of determining the deflection direction of the rear wheels according to the slip ratio of the vehicle tires is that when the vehicle is in a braking state, at least one front wheel slip ratio meets a first front wheel slip ratio condition, and at least one rear wheel slip ratio meets a first rear wheel slip ratio condition, the vehicle is in an understeer state, and the deflection direction of the rear wheels of the vehicle is reversed to the front wheels. For example, when the slip ratio of at least one front wheel is 10% or more and the slip ratio of the rear wheel is 10% or more, the vehicle is deflected in the direction opposite to the front wheel. When the at least one front wheel slip ratio meets the first wheel second slip ratio condition and the at least one rear wheel slip ratio meets the second rear wheel slip ratio condition, the vehicle is in an oversteered state, and the rear wheel deflection direction of the vehicle is in the same direction as the front wheel deflection. For example, at least one rear wheel slip ratio is 10% or more, and the front wheel slip ratio is 10% or more, the rear wheel of the vehicle is deflected in the same direction as the front wheel.

In the scheme, the vehicle state is determined according to the vehicle gear and the acceleration information, so that the determined vehicle state is more accurate. And respectively judging the deflection direction of the rear wheels of the vehicle according to the vehicle state through the slip ratio or the slip ratio of the tires of the vehicle. The vehicle rear wheel deflection direction judgment is more in line with the actual requirement of vehicle control.

Step 104, determining a first rear wheel yaw angle based on the vehicle center of mass yaw angle using the front wheel desired yaw angle.

When the vehicle is in steering running, the influence of centripetal force causes the additional cornering force of the tires of the vehicle, so that the cornering angle of the tires is generated, the cornering angle of the center of mass of the whole vehicle is further influenced, and the smaller the cornering angle of the center of mass is, the smaller the tendency of the tire to sideslip is, and the better the steering stability is. The vehicle running information comprises a vehicle longitudinal speed, a lateral speed, a vehicle yaw rate, a vehicle mass center slip angle and the like, and a vehicle mass center slip angle function is obtained based on a vehicle two-degree-of-freedom model algorithm according to the vehicle running information. The vehicle centroid slip angle function at least comprises the following parameter information of a vehicle centroid slip angle, a vehicle centroid slip angle speed, a vehicle lateral speed and a vehicle acceleration.

In the scheme, the vehicle mass center slip angle function is obtained through calculation, and the first rear wheel deflection angle is obtained through calculation according to the function, so that the control of the vehicle is realized, the trend of tire sideslip is weakened, and the driving smoothness is improved.

Step 105, determining a second rear wheel yaw angle based on the desired front wheel yaw angle and the vehicle yaw rate.

In specific implementation, when the vehicle is in steering running, the influence of centripetal force causes additional cornering force to the tires of the vehicle, so that the cornering angle of the tires is generated, and the yaw rate of the whole vehicle is influenced, so that the smaller the yaw rate is, the smaller the tendency of the tire sideslip is, and the better the steering stability is. The vehicle running information comprises a vehicle longitudinal speed, a lateral speed, a vehicle yaw rate, a vehicle mass center side deflection angle and the like, and a vehicle yaw rate function is obtained based on a vehicle two-degree-of-freedom model algorithm according to the vehicle running information. The vehicle yaw rate function at least comprises the following parameter information of a vehicle yaw rate change rate, a vehicle acceleration and a rear wheel deflection angle.

In the scheme, the yaw rate function of the vehicle is obtained through calculation, and the second rear wheel deflection angle is obtained through calculation according to the function, so that the control of the vehicle is realized, the trend of tire sideslip is weakened, and the driving smoothness is improved.

And 106, carrying out weighted calculation on the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle.

In the specific implementation, corresponding weights are obtained according to the importance degree of the first rear wheel deflection angle and the second rear wheel deflection angle on the control of the rear wheel deflection angle, and the rear wheel deflection angle is calculated according to the first rear wheel deflection angle, the second rear wheel deflection angle and the corresponding weights.

In the scheme, the rear wheel deflection angle can be calculated according to the importance degrees of the first rear wheel deflection angle and the second rear wheel deflection angle and the weight, so that the obtained rear wheel deflection angle is more accurate.

And 107, controlling the front wheels of the vehicle according to the expected deflection angle of the front wheels, and controlling the rear wheels of the vehicle according to the deflection direction of the rear wheels and the deflection angle of the rear wheels.

In specific implementation, the expected deflection angle of the front wheel is sent to the controller to control the front wheel, and the deflection direction of the rear wheel and the deflection angle of the rear wheel are sent to the controller to control the rear wheel.

In the scheme, the front wheels of the vehicle are controlled according to the expected deflection angle of the front wheels, the rear wheels of the vehicle are controlled according to the deflection direction of the rear wheels and the deflection angle of the rear wheels, and the cooperative control of the front wheels and the rear wheels of the vehicle is realized.

In the embodiment, the actual deflection angle of the front wheel is processed to obtain the expected deflection angle of the front wheel, the front wheel of the vehicle is controlled according to the expected deflection angle of the front wheel, the first rear wheel deflection angle and the second rear wheel deflection angle are weighted and calculated to obtain the rear wheel deflection angle, the accuracy of the rear wheel deflection angle can be improved, the accurate control of the rear wheel deflection angle is realized, the rear wheel of the vehicle is controlled according to the rear wheel deflection direction and the rear wheel deflection angle, and the stability of the vehicle in steering is further improved. Under the condition that the front wheels are under-turned or oversteered, through the scheme, when the vehicle turns, the deflection angles of the front wheels and the rear wheels are controlled and adjusted together, so that the vehicle turns more stably than the vehicle turns only when the rear wheels are controlled, and the driving safety is improved.

In some embodiments, the vehicle information includes vehicle speed, front wheel average slip rate, and front wheel average slip rate;

step 102 comprises:

And 1021, obtaining a front wheel steering angle control coefficient by inquiring a relation table of the vehicle speed, the average front wheel slip rate and the front wheel steering angle control coefficient, or obtaining the front wheel steering angle control coefficient by inquiring a relation table of the vehicle speed, the average front wheel slip rate and the front wheel steering angle control coefficient.

Step 1022, performing operation processing according to the front wheel steering angle control coefficient and the front wheel actual deflection angle to obtain a front wheel expected deflection angle:

δ₁=d*δ

Wherein delta ₁ is the expected deflection angle of the front wheel, d is the control coefficient of the front wheel steering angle, and delta is the actual deflection angle of the front wheel.

When the vehicle is in a driving state, the acquired vehicle information comprises the average front wheel slip rate, and the front wheel steering angle control coefficient can be determined according to the vehicle speed and the average front wheel slip rate by inquiring a relation table of the vehicle speed, the average front wheel slip rate and the front wheel steering angle control coefficient. For example, when the vehicle speed is zero and the average slip ratio of the front wheels is-0.2%, the front wheel steering angle control coefficient is 0.8.

When the vehicle is in a braking state, the acquired vehicle information comprises a front wheel average slip rate, and the front wheel angle control coefficient can be determined according to the vehicle speed and the front wheel average slip rate by inquiring a relation table of the vehicle speed, the front wheel average slip rate and the front wheel angle control coefficient. For example, when the vehicle speed is zero and the average slip ratio of the front wheels is 0.2%, the front wheel steering angle control coefficient is 0.8.

According to the front wheel steering angle control coefficient and the actual front wheel deflection angle, carrying out operation processing to obtain the expected front wheel deflection angle:

δ₁=d*δ

The front wheel actual deflection angle is the deflection angle of the current front wheel of the vehicle, which is obtained through a steering wheel, the front wheel steering angle control coefficient is a coefficient reflecting the relation between the front wheel actual deflection angle and the front wheel expected deflection angle, which can be obtained through a table lookup and is related to the vehicle speed and the average front wheel slip rate or the average front wheel slip rate, and the front wheel expected deflection angle is the deflection angle required by the front wheel when the front wheel is controlled in order to ensure the stability of the vehicle when the vehicle turns.

In some embodiments, step 104 comprises:

And 104A, processing the expected deflection angle of the front wheel based on a rear wheel rotation angle relation function determined by the vehicle centroid side deflection angle to obtain a first rear wheel deflection angle, wherein the rear wheel rotation angle relation function is obtained according to a vehicle two-degree-of-freedom model algorithm.

And when the method is implemented, obtaining a rear wheel steering angle relation function according to a two-degree-of-freedom model algorithm of the vehicle, substituting the expected deflection angle of the front wheel into the rear wheel steering angle relation function, and obtaining a first rear wheel deflection angle.

In some embodiments, prior to step 104, further comprising:

step 1041, obtaining a vehicle centroid slip angle function based on a vehicle two-degree-of-freedom model algorithm, wherein the vehicle centroid slip angle function comprises a plurality of parameter information, and the vehicle centroid slip angle is one of the plurality of parameter information.

Step 1042, determining that the plurality of parameter information satisfies a preset condition, and obtaining a rear wheel steering angle relation function according to the vehicle centroid slip angle function and the front wheel expected slip angle.

When the vehicle is in steering running, the influence of centripetal force causes the additional cornering force of the tires of the vehicle, so that the cornering angle of the tires is generated, the cornering angle of the center of mass of the whole vehicle is further influenced, and the smaller the cornering angle of the center of mass is, the smaller the tendency of the tire to sideslip is, and the better the steering stability is. And obtaining a vehicle mass center slip angle function based on a vehicle two-degree-of-freedom model algorithm. Wherein the vehicle centroid slip angle is one of the plurality of parameter information. And obtaining a rear wheel steering angle relation function according to the obtained vehicle mass center slip angle function when the parameter information meets the preset condition.

In the scheme, the vehicle mass center slip angle function is obtained through calculation, and the rear wheel deflection angle is obtained through calculation according to the function, so that the control of the vehicle is realized, the trend of tire sideslip is weakened, and the driving smoothness is improved. And calculating a rear wheel steering angle relation function by using a vehicle centroid side deflection angle function, wherein in the execution process of the follow-up step, the rear wheel steering angle is calculated based on the rear wheel steering angle relation formula function, and the rear wheel steering angle is more accurate.

In some embodiments, step 1041 comprises:

Step 1041A, obtaining a vehicle centroid slip angle function based on a vehicle two-degree-of-freedom model algorithm:

Wherein m is the mass of the whole vehicle, a is the distance from the mass center to the front axle, b is the distance from the mass center to the rear axle, k ₁ is the cornering stiffness of the front axle, k ₂ is the cornering stiffness of the rear axle, u is the longitudinal vehicle speed, Is the vehicle acceleration, beta is the vehicle centroid slip angle, omega _r is the vehicle yaw rate,The yaw rate change rate of the vehicle is represented by delta ₁, the yaw angle of the front wheels, delta ₂, the yaw angle of the rear wheels and I _Z, which are the moment of inertia of the whole vehicle.

When the method is implemented, the vehicle running information comprises vehicle longitudinal speed, lateral speed, vehicle yaw rate, vehicle centroid side deflection angle and the like, and a vehicle centroid side deflection angle function is obtained based on a vehicle two-degree-of-freedom model algorithm according to the vehicle running information.

In the scheme, the vehicle mass center slip angle function is obtained through calculation, and the rear wheel deflection angle is obtained through calculation according to the function, so that the control of the vehicle is realized, the trend of tire sideslip is weakened, and the driving smoothness is improved.

In some embodiments, step 1042 comprises:

step 1042A, the plurality of parameter information satisfying a preset condition includes that the centroid slip angle is zero, the vehicle acceleration is zero, and the rear wheel steering angle relation function is determined according to the vehicle centroid slip angle function:

wherein δ ₂|_β＝0 is the first rear wheel yaw angle.

In specific implementation, the centroid side deflection angle beta is zero and the vehicle accelerationSubstituting zero into the vehicle centroid side deflection angle function, obtaining a vehicle corner relation function through operation processing, and determining the relation between the vehicle rear wheel deflection angle and the front wheel deflection angle according to the vehicle corner relation function to obtain a first vehicle rear wheel deflection angle.

In the scheme, when the centroid side deflection angle beta is zero, the centroid side deflection angle can be controlled in a stable working interval, so that the first rear wheel deflection angle of the vehicle is ensured, and the running smoothness of the vehicle is ensured.

In some embodiments, step 1042 comprises:

Step 1042B, the plurality of parameter information meeting preset conditions includes that the centroid slip angle is zero, the vehicle yaw rate change rate is zero, the vehicle acceleration is zero, and the rear wheel steering angle relation function is determined according to the vehicle centroid slip angle function:

Wherein delta ₂|_β＝0 is the deflection angle of the first rear wheel, K' is the deflection angle coefficient,

In specific implementation, the centroid side deflection angle beta is zero and the change rate of the yaw rate of the vehicleZero vehicle accelerationSubstituting zero into the vehicle centroid side deflection angle function, obtaining a vehicle corner relation function through operation processing, and determining the relation between the vehicle rear wheel deflection angle and the front wheel deflection angle according to the vehicle corner relation function to obtain a first vehicle rear wheel deflection angle.

In the scheme, when the centroid side deflection angle beta is zero, the centroid side deflection angle can be controlled in a stable working interval, so that the first rear wheel deflection angle of the vehicle is ensured, and the running smoothness of the vehicle is ensured. On the basis of zero centroid slip angle beta, the change rate of the yaw rate of the vehicleAnd the stability of the vehicle during steering can be further improved due to zero.

In some embodiments, step 105 comprises:

Step 1051, determining a vehicle yaw rate function based on the vehicle centroid slip angle function, wherein the magnitude of the centroid slip angle is the ratio of the lateral speed to the longitudinal speed, and the vehicle yaw rate change is zero, the vehicle acceleration is zero, and the rear wheel slip angle is zero:

where v is the vehicle speed.

Step 1052, obtaining an ideal yaw rate by processing the vehicle yaw rate function:

wherein, K is a stabilizing factor, For the ideal yaw rate, L is the front-rear wheelbase of the vehicle, l=a+b.

And 1053, processing the deflection angle of the rear wheels of the vehicle according to the ideal yaw rate to obtain a second deflection angle of the rear wheels.

In specific implementation, the change rate of the yaw rate of the vehicleZero vehicle accelerationAnd substituting zero into the vehicle centroid side deviation angle function to obtain the vehicle yaw rate function when the rear wheel deflection angle delta ₂ is zero. And carrying out operation processing on the yaw rate function to obtain an ideal yaw rate of the vehicle, and calculating a second rear wheel deflection angle according to the yaw rate of the vehicle.

In the above-described aspect, the calculated ideal yaw rate is the yaw rate operation section in which the stability of the vehicle is maintained. The yaw rate of the vehicle is calculated according to the ideal yaw rate, and the yaw rate is calculated according to the ideal yaw rate, so that the yaw rate is calculated according to the ideal yaw rate, and the yaw rate is calculated according to the ideal yaw rate.

In some embodiments, step 1053 includes:

step 1053A, processing the vehicle yaw rate and the expected yaw rate to obtain a second rear wheel yaw angle:

wherein δ ₂ |ω is the second rear wheel yaw angle, K _ω is a yaw-rate control coefficient set in advance, For the desired yaw rate.

In particular, omega _r is the vehicle yaw rate,And calculating a second rear wheel deflection angle according to the vehicle yaw rate and the expected yaw rate to obtain the expected yaw rate.

In the scheme, the yaw rate function of the vehicle is obtained through calculation, the deflection angle of the rear wheels is obtained through calculation according to the function, the control of the vehicle is realized, the trend of sideslip of tires is weakened, and the driving smoothness is improved.

In some embodiments, step 106 comprises:

Step 1061, weighting the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle:

Wherein δ ₂ is the total rear wheel deflection angle, δ ₂|_β＝0 is the first rear wheel deflection angle, δ ₂ |ω is the second rear wheel deflection angle, ζ ₁ is the weight of the first rear wheel deflection angle, and ζ ₂ is the weight of the second rear wheel deflection angle.

In specific implementation, the first rear wheel deflection angle and the second rear wheel deflection angle are respectively weighted, and the rear wheel deflection angle is obtained by weighting operation according to the corresponding weights. The weight may reflect the degree of influence of the first rear wheel yaw angle and the second rear wheel yaw angle on the rear wheel yaw angle calculation. Wherein the sum of the weight of the first rear wheel deflection angle and the weight of the second rear wheel deflection angle is 1.

In the scheme, the first rear wheel deflection angle and the second rear wheel deflection angle are subjected to weighted calculation to obtain the rear wheel deflection angle, so that the vehicle mass center side deflection angle and the yaw rate are controlled in a stable working interval, and the obtained rear wheel deflection angle is more accurate.

During the running of the vehicle, the front wheel state preferably comprises a runaway state or a non-runaway state when the vehicle runs on a curve.

And when the stress of the tire does not break through the friction circle, determining that the front wheel of the vehicle is in a non-uncontrolled state, executing the steps of the embodiment, and adjusting the deflection of the vehicle by adjusting the front wheel and the rear wheel of the vehicle.

And (3) obtaining the stress information of the vehicle tyre, determining that the front wheel of the vehicle is in a runaway state when the tyre stress breaks through a friction circle, executing the processes of the step 103-the step 106 in the embodiment, and adjusting the deflection of the vehicle by adjusting the deflection direction and the deflection angle of the rear wheel of the vehicle.

It should be noted that the embodiments of the present disclosure may be further described in the following manner:

Based on the same inventive concept, another embodiment of the present disclosure in an application scenario in response to a vehicle being in a driving state is shown in fig. 2, including:

In step 201, vehicle information is acquired.

In specific implementation, vehicle information is monitored and acquired through an ECU (Electronic Control Unit electronic controller unit), the vehicle information comprises vehicle basic information, vehicle running information, vehicle front wheel rotation angle information and the like, wherein the vehicle basic information comprises vehicle quality, vehicle tire information and the like, the vehicle running information comprises vehicle rotation angle information, vehicle running speed, vehicle gear information and the like, and the vehicle front wheel rotation angle information is acquired through a steering wheel. According to the scheme, based on the acquired vehicle information, the subsequent steps are used for judging the deflection direction of the rear wheel, so that the accuracy of judgment is improved.

Step 202, determining vehicle gear information.

In specific implementation, vehicle gear information is acquired through a vehicle internal sensor, wherein the gear information comprises a forward gear (D gear) and a reverse gear (R gear), and the basis is that the deflection direction of the rear wheels of the vehicle is judged subsequently.

And 203, judging the running state of the vehicle according to the longitudinal acceleration information of the vehicle.

When the vehicle is in specific implementation, the vehicle comprises a vehicle speed sensor, the vehicle longitudinal speed is acquired through the vehicle speed sensor, the vehicle longitudinal acceleration is calculated according to the acquired vehicle longitudinal speed, the vehicle running state is judged according to the vehicle longitudinal acceleration information, and the vehicle running state comprises a driving state and a braking state. According to the scheme, the vehicle running state is judged according to the vehicle longitudinal acceleration information, in the follow-up step, the slip rate of the vehicle wheels is calculated in response to the vehicle running state being a driving state, and the slip rate of the vehicle wheels is calculated in response to the vehicle running state being a braking state so as to be used for judging the deflection direction of the rear wheels of the vehicle subsequently.

Step 204, calculating slip ratio of the vehicle wheel.

In specific implementation, vehicle information is acquired through a sensor, wherein the vehicle information comprises wheel speed, rolling radius of a tire, longitudinal vehicle speed, gear information, vehicle acceleration information and the like. The vehicle comprises a wheel speed sensor and a vehicle speed sensor, the wheel speed sensor is used for collecting the wheel speed of the wheel, the vehicle speed sensor is used for collecting the longitudinal vehicle speed of the vehicle, a tire rolling radius map is obtained according to a rotary drum experiment, and the tire rolling radius is determined according to the tire pressure and the vehicle speed information of the vehicle. And calculating the slip rate or slip rate of the wheels of the vehicle according to the vehicle information, and judging the deflection direction of the rear wheels according to the slip rate obtained by calculation. The slip ratio of the vehicle wheel is calculated by the following formula:

S=(ω·R-u)/(ω·R)

where S is the slip ratio of the vehicle tire, ω is the wheel speed of the vehicle tire, R is the rolling radius of the vehicle tire, and u is the longitudinal speed of the vehicle.

Step 205, determining the deflection direction of the rear wheel according to the slip ratio of the vehicle wheel.

In specific implementation, the vehicle state is judged according to the calculated slip rate of the vehicle wheels, and the vehicle state refers to the running state of the vehicle in the current state, and comprises an understeer state and an oversteer state. According to the scheme, the slip rate obtained through calculation is used for judging the deflection direction of the rear wheels, the control of the rear wheels of the vehicle is achieved together with the deflection angle of the rear wheels obtained in the following steps, the judgment result is more accurate, and the driving safety is improved.

In some embodiments, step 205 specifically includes:

Step 2051, in response to calculating the slip ratio of the front wheels of the at least one vehicle to be less than or equal to-10% and then calculating the slip ratio of the rear wheels of the at least one vehicle to be less than or equal to-10%, determining that the vehicle is in an understeer condition and that the direction of deflection of the rear wheels is reversed with respect to the front wheels.

When the method is implemented, the slip rate of the wheels of the vehicle is judged to be met, the slip rate of at least one front wheel of the vehicle is calculated to be less than or equal to-10%, the slip rate of at least one rear wheel of the vehicle is calculated to be less than or equal to-10%, the vehicle is determined to be in an understeer state, the deflection direction of the rear wheel is determined to be deflected reversely to the front wheel, the deflection angle of the rear wheel is calculated in the follow-up step process, the rear wheel is controlled to be adjusted according to the deflection direction reversely deflected to the front wheel and the deflection angle of the rear wheel, the situation that the front wheel of the vehicle slides out in the tangential direction of an arc line is avoided, and the potential safety hazard is reduced.

Step 2052, in response to calculating the slip ratio of the rear wheels of the at least one vehicle to be less than or equal to-10% and then calculating the slip ratio of the front wheels of the at least one vehicle to be less than or equal to-10%, determining that the vehicle is in an oversteered state and that the yaw direction of the rear wheels is the same direction as the yaw direction of the front wheels.

When the method is specifically implemented, the slip rate of the wheels of the vehicle is judged to be met, the slip rate of at least one rear wheel of the vehicle is calculated to be less than or equal to-10%, the slip rate of at least one front wheel of the vehicle is calculated to be less than or equal to-10%, the vehicle is determined to be in an oversteered state, the deflection direction of the rear wheel is determined to deflect in the same direction as the front wheel, the deflection angle of the rear wheel is calculated in the subsequent step, the rear wheel is controlled to be adjusted according to the deflection direction deflected in the same direction as the front wheel and the deflection angle of the rear wheel, the situation that the rear wheel slides out in the tangential direction of a vehicle tail extension arc line is avoided, and the potential safety hazard is reduced.

Step 2053, determining a rear wheel yaw direction based on the slip ratio of the vehicle wheel.

In specific implementation, the deflection direction of the rear wheels of the vehicle is judged through the calculated slip rate of the wheels of the vehicle, wherein the deflection direction comprises deflection opposite to the front wheels and deflection in the same direction as the front wheels. The method comprises the steps of determining that a vehicle is in an understeer state according to the slip ratio of the vehicle wheels, determining that the deflection direction of the rear wheels is reversely deflected with the front wheels, and determining that the deflection direction of the rear wheels is deflected in the same direction as the front wheels according to the slip ratio of the vehicle wheels, wherein the determination result is more accurate.

Step 206, obtaining the actual deflection angle of the front wheel.

In specific implementation, the actual deflection angle of the front wheels of the vehicle is obtained through the steering wheel of the vehicle.

Step 207, calculating the expected front wheel yaw angle based on the actual front wheel yaw angle.

In specific implementation, according to the front wheel steering angle control coefficient and the actual front wheel deflection angle, operation processing is performed to obtain the expected front wheel deflection angle:

δ₁=d*δ

And obtaining the front wheel steering angle control coefficient by inquiring a relation table of the vehicle speed, the average slip rate of the front wheels and the front wheel steering angle control coefficient.

When the vehicle is in a driving state, the acquired vehicle information comprises the average slip rate of the front wheels, and the front wheel steering angle control coefficient can be determined according to the vehicle speed and the average slip rate of the front wheels by inquiring a relation table of the vehicle speed, the average slip rate of the front wheels and the front wheel steering angle control coefficient. For example, when the vehicle speed is zero and the average slip ratio of the front wheels is-0.2%, the front wheel steering angle control coefficient is 0.8.

In some embodiments, step 207 specifically comprises:

Step 2071 obtains a first rear wheel yaw angle based on the ideal centroid yaw angle.

In the specific implementation, a vehicle mass center side deflection angle function is calculated based on a vehicle two-degree-of-freedom model algorithm, a rear wheel deflection angle is calculated according to the vehicle front wheel deflection angle and the vehicle mass center side deflection angle function, and a first rear wheel deflection angle is obtained. According to the scheme, the vehicle mass center side deflection angle function is calculated according to the vehicle two-degree-of-freedom model algorithm, the first vehicle rear wheel deflection angle is calculated based on the obtained front wheel deflection angle and the calculated vehicle mass center side deflection angle function, the calculation result is more accurate, the control of the vehicle rear wheels is achieved together with the rear wheel deflection direction obtained in the steps, and the driving safety is improved.

Step 2072 obtains a second rear wheel yaw angle based on the desired yaw rate.

And in the specific implementation, calculating and obtaining a vehicle yaw rate function based on a vehicle two-degree-of-freedom model algorithm. And calculating a rear wheel deflection angle according to the front wheel deflection angle of the vehicle and the yaw rate function of the vehicle to obtain a second rear wheel deflection angle. According to the scheme, the vehicle yaw rate function is calculated according to the two-degree-of-freedom model algorithm of the vehicle, the second rear wheel yaw angle is calculated based on the obtained front wheel yaw angle and the calculated vehicle yaw rate function, and the calculation result is more accurate.

Step 2073, controlling the front wheels of the vehicle according to the desired yaw angle of the front wheels.

In specific implementation, the expected deflection angle of the front wheels is sent to the controller, and the controller controls the front wheels of the vehicle based on control information, so that the driving smoothness is improved, and the safety risk in driving is reduced.

And step 208, performing weighted calculation on the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle.

In specific implementation, when the vehicle runs, preferably when the vehicle runs in a steering way, the tire of the vehicle is additionally subjected to lateral deflection force due to the influence of centripetal force, so that the tire lateral deflection angle is generated, the yaw rate and the mass center lateral deflection angle of the whole vehicle are further influenced, a first rear wheel deflection angle and a second rear wheel deflection angle are obtained through the mass center lateral deflection angle function of the vehicle and the yaw rate function of the vehicle, and the first rear wheel deflection angle and the second rear wheel deflection angle are subjected to weighted calculation, so that the rear wheel deflection angle is obtained. Through the scheme, the calculation process of the rear wheel deflection angle considers two important parameters of the vehicle mass center side deflection angle and the vehicle yaw rate, controls the vehicle mass center side deflection angle and the vehicle yaw rate to be in a stable working interval, and jointly controls the rear wheels of the vehicle with the rear wheel deflection direction obtained by the steps, so that the running stability is improved, and the safety risk is reduced.

And step 209, controlling the rear wheels of the vehicle according to the rear wheel deflection direction and the rear wheel deflection angle.

In specific implementation, the rear wheel deflection direction and the rear wheel deflection angle are sent to the controller, and the controller controls the rear wheels of the vehicle based on control information, wherein the control information comprises the rear wheel deflection direction and the rear wheel deflection angle, so that the driving smoothness is improved, and the safety risk in driving is reduced.

Based on the same inventive concept, another embodiment of the present disclosure in an application scenario in response to a vehicle being in a braked state is shown in fig. 3, comprising:

In step 301, vehicle information is acquired.

Step 302, determining vehicle gear information.

Step 303, judging the running state of the vehicle according to the vehicle longitudinal acceleration information.

Step 304, calculating a slip ratio of the vehicle wheel.

In specific implementation, vehicle information is acquired through a sensor, wherein the vehicle information comprises wheel speed, rolling radius of a tire, longitudinal vehicle speed, gear information, vehicle acceleration information and the like. The vehicle comprises a wheel speed sensor and a vehicle speed sensor, the wheel speed sensor is used for collecting the wheel speed of the wheel, the vehicle speed sensor is used for collecting the longitudinal vehicle speed of the vehicle, a tire rolling radius map is obtained according to a rotary drum experiment, and the tire rolling radius is determined according to the tire pressure and the vehicle speed information of the vehicle. And calculating the slip rate or slip rate of the wheels of the vehicle according to the vehicle information, and judging the deflection direction of the rear wheels according to the calculated slip rate. The slip ratio of the vehicle wheels is calculated by the following formula:

K=(u-ω·R)/u

where K is the slip ratio of the vehicle tire, ω is the wheel speed of the vehicle tire, R is the rolling radius of the vehicle tire, and u is the longitudinal speed of the vehicle.

And 305, judging the deflection direction of the rear wheels according to the slip rate of the wheels of the vehicle.

In specific implementation, the vehicle state is judged according to the calculated slip rate of the wheels of the vehicle, and the vehicle state refers to the running state of the vehicle in the current state, and comprises an understeer state and an oversteer state. According to the scheme, the slip rate obtained through calculation is used for judging the deflection direction of the rear wheels, the control of the rear wheels of the vehicle is achieved together with the deflection angle of the rear wheels obtained in the following steps, the judging result is more accurate, and the driving safety is improved.

In some embodiments, step 305 specifically includes:

Step 3051, in response to calculating that at least one of the front wheels of the vehicle has a slip ratio of 10% or greater and the rear wheels of the vehicle have a slip ratio of 10% or greater, determining that the vehicle is in an understeer condition and that the rear wheels are deflected in a direction opposite to the front wheels.

When the method is specifically implemented, the slip rate of the wheels of the vehicle is judged to be met, the slip rate of at least one front wheel of the vehicle is more than or equal to 10%, the slip rate of the rear wheels of the vehicle is equal to 10%, the vehicle is determined to be in an understeer state, the deflection direction of the rear wheels is determined to be reversely deflected with the front wheels, the deflection angle of the rear wheels is calculated in the follow-up step process, the rear wheels are controlled to be adjusted according to the deflection direction reversely deflected with the front wheels and the deflection angle of the rear wheels, the situation that the front wheels of the vehicle slip out in the tangential direction of a vehicle head extending arc line is avoided, and the potential safety hazard is reduced.

Step 3052, in response to calculating that the slip ratio of at least one rear wheel of the vehicle is greater than or equal to 10% and the slip ratio of the front wheels of the vehicle is equal to 10%, determining that the vehicle is in an oversteered state and that the rear wheel is deflected in the same direction as the front wheels.

When the method is specifically implemented, the slip ratio of the wheels of the vehicle is judged to be met, the slip ratio of at least one rear wheel of the vehicle is more than or equal to 10%, the slip ratio of the front wheel of the vehicle is equal to 10%, the vehicle is determined to be in an oversteering state, the deflection direction of the rear wheel is determined to deflect in the same direction as the front wheel, the deflection angle of the rear wheel is calculated in the subsequent step process, the rear wheel is controlled to be adjusted according to the deflection direction deflected in the same direction as the front wheel and the deflection angle of the rear wheel, the slipping out of the vehicle tail along the tangential direction of an arc line is avoided, and the potential safety hazard is reduced.

Step 3053, determining a rear wheel yaw direction according to the slip ratio of the vehicle wheel.

In specific implementation, the deflection direction of the rear wheels of the vehicle is judged through the calculated slip rate of the wheels of the vehicle, wherein the deflection direction comprises the deflection opposite to the front wheels and the deflection same as the front wheels. The method comprises the steps of determining that a vehicle is in an understeer state according to the slip rate of the vehicle wheels, determining that the deflection direction of the rear wheels is reversely deflected with the front wheels, and determining that the deflection direction of the rear wheels is deflected in the same direction with the front wheels according to the slip rate of the vehicle wheels, wherein the determination result is more accurate.

Step 306, the actual deflection angle of the front wheel is obtained.

Step 307 calculates the desired yaw angle of the front wheel based on the actual yaw angle of the front wheel.

δ₁=d*δ

In some embodiments, step 307 specifically comprises:

Step 3071, a first rear wheel yaw angle is obtained based on the ideal centroid yaw angle.

Step 3072, a second rear wheel yaw angle is obtained based on the desired yaw rate.

Step 3073, controlling the front wheels of the vehicle according to the desired yaw angle of the front wheels.

And 308, performing weighted calculation on the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle.

And 309, controlling the rear wheels of the vehicle according to the rear wheel deflection direction and the rear wheel deflection angle.

It should be noted that the method of the embodiments of the present disclosure may be performed by a single device, such as a computer or a server. The method of the embodiment can also be applied to a distributed scene, and is completed by mutually matching a plurality of devices. In the case of such a distributed scenario, one of the devices may perform only one or more steps of the methods of embodiments of the present disclosure, the devices interacting with each other to accomplish the methods.

It should be noted that the foregoing describes some embodiments of the present disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments described above and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Based on the same inventive concept, the present disclosure also provides a control system for front and rear wheels, corresponding to the method of any embodiment described above.

Referring to fig. 4, the control system of the front and rear wheels includes:

A vehicle information acquisition module 401 configured to acquire vehicle information, wherein the vehicle information includes an actual yaw angle of the front wheels;

A front wheel expected deflection angle acquisition module 402 configured to process the actual deflection angle of the front wheel to obtain an expected deflection angle of the front wheel;

a rear wheel yaw direction obtaining module 403 configured to determine a vehicle rear wheel yaw direction according to the vehicle information, to obtain a rear wheel yaw direction;

A first rear wheel yaw angle acquisition module 404 configured to determine a first rear wheel yaw angle based on a vehicle centroid slip angle using the front wheel desired yaw angle;

A second rear wheel yaw angle acquisition module 405 configured to determine a second rear wheel yaw angle based on the front wheel desired yaw angle and a vehicle yaw angle speed;

A rear wheel deflection angle acquisition module 406 configured to perform weighted calculation on the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle;

The vehicle control module 407 is configured to control the front wheels of the vehicle according to the desired yaw angle of the front wheels and to control the rear wheels of the vehicle according to the rear wheel yaw direction and the rear wheel yaw angle.

the front wheel desired yaw angle acquisition module 402 includes:

The front wheel steering angle control coefficient acquisition unit is configured to acquire a front wheel steering angle control coefficient by inquiring a relation table of the vehicle speed, the average slip rate of the front wheels and the front wheel steering angle control coefficient, or acquire the front wheel steering angle control coefficient by inquiring a relation table of the vehicle speed, the average slip rate of the front wheels and the front wheel steering angle control coefficient;

The front wheel expected deflection angle acquisition unit is configured to process according to the front wheel steering angle control coefficient and the front wheel actual deflection angle to obtain a front wheel expected deflection angle:

δ₁=d*δ

In some embodiments, the first rear wheel yaw angle acquisition module 404 includes:

the first rear wheel deflection angle acquisition unit is configured to process the front wheel expected deflection angle based on a rear wheel deflection angle relation function determined by the vehicle centroid side deflection angle to obtain a first rear wheel deflection angle, wherein the rear wheel deflection angle relation function is obtained according to a vehicle two-degree-of-freedom model algorithm.

In some embodiments, before the first rear wheel yaw angle acquisition module 404, further includes:

The system comprises a centroid side deflection angle function acquisition unit, a vehicle mass center side deflection angle calculation unit and a vehicle mass center side deflection angle calculation unit, wherein the centroid side deflection angle function acquisition unit is configured to obtain a vehicle centroid side deflection angle function based on a vehicle two-degree-of-freedom model algorithm, and the vehicle centroid side deflection angle function comprises a plurality of parameter information, wherein the vehicle centroid side deflection angle is one of the plurality of parameter information;

And the rear wheel steering angle relation function acquisition unit is configured to determine that the plurality of parameter information meets a preset condition, and obtain a rear wheel steering angle relation function according to the vehicle mass center side deflection angle function and the front wheel expected deflection angle.

In some embodiments, the centroid slip angle function acquisition unit comprises:

the centroid side deflection angle function obtaining subunit is configured to obtain a vehicle centroid side deflection angle function based on a vehicle two-degree-of-freedom model algorithm:

Wherein m is the mass of the whole vehicle, a is the distance from the mass center to the front axle, b is the distance from the mass center to the rear axle, k ₁ is the cornering stiffness of the front axle, k ₂ is the cornering stiffness of the rear axle, delta ₁ is the front wheel deflection angle, u is the longitudinal vehicle speed, Is the vehicle acceleration, beta is the vehicle centroid slip angle, omega _r is the vehicle yaw rate,For the yaw rate change rate of the vehicle, δ ₂ is the rear wheel yaw angle, and I _Z is the moment of inertia of the whole vehicle.

In some embodiments, the rear wheel steering angle relation function obtaining unit includes:

The rear wheel steering angle relation function obtaining subunit is configured to enable the plurality of parameter information to meet preset conditions, wherein the centroid slip angle is zero, the vehicle acceleration is zero, and the rear wheel steering angle relation function is determined according to the vehicle centroid slip angle function:

wherein δ ₂|_α＝0 is the first rear wheel yaw angle.

In some embodiments, the first vehicle corner relationship function acquisition unit includes:

The rear wheel steering angle relation function obtaining subunit is configured to enable the plurality of parameter information to meet preset conditions, wherein the parameter information comprises zero centroid slip angle, zero vehicle yaw rate change rate and zero vehicle acceleration, and the rear wheel steering angle relation function is determined according to the vehicle centroid slip angle function:

wherein δ ₂|_β＝0 is the first rear wheel yaw angle.

In some embodiments, the second rear wheel yaw angle acquisition module 405 includes:

A yaw-rate function obtaining unit configured to determine a vehicle yaw rate function based on the vehicle centroid slip angle function, the magnitude of the centroid slip angle being a ratio of the lateral velocity to the longitudinal velocity, and the vehicle yaw rate change rate being zero, the vehicle acceleration being zero, and the rear-wheel yaw angle being zero:

an ideal yaw rate calculation unit configured to obtain an ideal yaw rate by processing the vehicle yaw rate function:

wherein, K is a stabilizing factor, L is the front-rear wheelbase of the vehicle, l=a+b, which is the ideal yaw rate;

And the second rear wheel deflection angle acquisition unit is configured to process the vehicle rear wheel deflection angle according to the ideal yaw rate to obtain a second rear wheel deflection angle.

In some embodiments, the second rear wheel yaw angle acquisition unit includes:

A second rear wheel yaw angle calculation subunit configured to perform calculation processing on the vehicle yaw rate and the expected yaw rate to obtain a second rear wheel yaw angle:

In some embodiments, the rear wheel control module 406 includes:

The rear wheel deflection angle calculation unit is configured to process weights of the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle:

For convenience of description, the above devices are described as being functionally divided into various modules, respectively. Of course, the functions of the various modules may be implemented in the same one or more pieces of software and/or hardware when implementing the present disclosure.

The device of the foregoing embodiment is used to implement the corresponding front and rear wheel control method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiment, which is not described herein.

Based on the same inventive concept, the present disclosure also provides an electronic device corresponding to the method of any embodiment, including a memory, a processor, and a computer program stored on the memory and capable of running on the processor, where the processor implements the method of controlling the front and rear wheels according to any embodiment when executing the program.

Fig. 5 shows a more specific hardware architecture of an electronic device provided by the present embodiment, which may include a processor 1010, a memory 1020, an input/output interface 1030, a communication interface 1040, and a bus 1050. Wherein processor 1010, memory 1020, input/output interface 1030, and communication interface 1040 implement communication connections therebetween within the device via a bus 1050.

The processor 1010 may be implemented by a general-purpose CPU (Central Processing Unit ), a microprocessor, an application-specific integrated circuit (Appl ication SPECIFIC INTEGRATED CI rcuit, ASIC), or one or more integrated circuits, etc. for executing relevant programs to implement the technical solutions provided in the embodiments of the present disclosure.

The Memory 1020 may be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory ), static storage, dynamic storage, etc. Memory 1020 may store an operating system and other application programs, and when the embodiments of the present specification are implemented in software or firmware, the associated program code is stored in memory 1020 and executed by processor 1010.

The input/output interface 1030 is used to connect with an input/output module for inputting and outputting information. The input/output module may be configured as a component in a device (not shown) or may be external to the device to provide corresponding functionality. Wherein the input devices may include a keyboard, mouse, touch screen, microphone, various types of sensors, etc., and the output devices may include a display, speaker, vibrator, indicator lights, etc.

Communication interface 1040 is used to connect communication modules (not shown) to enable communication interactions of the present device with other devices. The communication module may implement communication through a wired manner (such as USB (Universal Serial Bus, universal serial bus), network cable, etc.), or may implement communication through a wireless manner (such as mobile network, WIFI (WIRELESS FIDELITY, wireless network communication technology), bluetooth, etc.).

Bus 1050 includes a path for transferring information between components of the device (e.g., processor 1010, memory 1020, input/output interface 1030, and communication interface 1040).

It should be noted that although the above-described device only shows processor 1010, memory 1020, input/output interface 1030, communication interface 1040, and bus 1050, in an implementation, the device may include other components necessary to achieve proper operation. Furthermore, it will be understood by those skilled in the art that the above-described apparatus may include only the components necessary to implement the embodiments of the present description, and not all the components shown in the drawings.

The electronic device of the foregoing embodiment is configured to implement the corresponding front and rear wheel control method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiment, which is not described herein.

Based on the same inventive concept, the present disclosure also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to perform the front-rear wheel control method according to any of the above embodiments, corresponding to any of the above embodiments.

The computer readable media of the present embodiments, including both permanent and non-permanent, removable and non-removable media, may be used to implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device.

The storage medium of the foregoing embodiments stores computer instructions for causing the computer to execute the method for controlling front and rear wheels according to any one of the foregoing embodiments, and has the advantages of the corresponding method embodiments, which are not described herein.

Based on the same inventive concept, the application also provides a vehicle, which comprises the control system of the front and rear wheels, or the electronic device or the storage medium in the embodiment, corresponding to the method in any embodiment, and the vehicle device realizes the control method of the front and rear wheels in any embodiment.

The vehicle of the foregoing embodiments is used to implement the front and rear wheel control method of any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which are not described herein.

It will be appreciated by persons skilled in the art that the foregoing discussion of any embodiment is merely exemplary and is not intended to imply that the scope of the disclosure, including the claims, is limited to these examples, that the steps may be implemented in any order and that many other variations of the different aspects of the disclosed embodiments described above are present, which are not provided in detail for the sake of brevity, and that the features of the above embodiments or of the different embodiments may also be combined within the spirit of the disclosure.

Additionally, well-known power/ground connections to Integrated Circuit (IC) chips and other components may or may not be shown within the provided figures, in order to simplify the illustration and discussion, and so as not to obscure the embodiments of the present disclosure. Furthermore, the devices may be shown in block diagram form in order to avoid obscuring the embodiments of the present disclosure, and this also accounts for the fact that specifics with respect to implementation of such block diagram devices are highly dependent upon the platform on which the embodiments of the present disclosure are to be implemented (i.e., such specifics should be well within purview of one skilled in the art). Where specific details (e.g., circuits) are set forth in order to describe example embodiments of the disclosure, it should be apparent to one skilled in the art that embodiments of the disclosure can be practiced without, or with variation of, these specific details. Accordingly, the description is to be regarded as illustrative in nature and not as restrictive.

While the present disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations of those embodiments will be apparent to those skilled in the art in light of the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.

The disclosed embodiments are intended to embrace all such alternatives, modifications and variances which fall within the broad scope of the appended claims. Accordingly, any omissions, modifications, equivalents, improvements, and the like, which are within the spirit and principles of the embodiments of the disclosure, are intended to be included within the scope of the disclosure.

Claims

1.A method of controlling front and rear wheels, the method comprising:

2. The method of claim 1, wherein the vehicle information includes vehicle speed, front wheel average slip rate, and front wheel average slip rate;

The step of processing the actual deflection angle of the front wheel to obtain the expected deflection angle of the front wheel comprises the following steps:

Obtaining a front wheel steering angle control coefficient by inquiring a relation table of the vehicle speed, the front wheel average slip rate and the front wheel steering angle control coefficient, or obtaining the front wheel steering angle control coefficient by inquiring a relation table of the vehicle speed, the front wheel average slip rate and the front wheel steering angle control coefficient;

processing according to the front wheel steering angle control coefficient and the actual front wheel deflection angle to obtain a front wheel expected deflection angle:

δ₁=d*δ

3. The method of claim 1, wherein the determining a first rear wheel yaw angle based on a vehicle center of mass yaw angle using the front wheel desired yaw angle comprises:

and processing the expected deflection angle of the front wheel based on a rear wheel rotation angle relation function determined by the vehicle centroid side deflection angle to obtain a first rear wheel deflection angle, wherein the rear wheel rotation angle relation function is obtained according to a vehicle two-degree-of-freedom model algorithm.

4. The method of claim 1, further comprising, prior to processing the front wheel desired yaw angle to obtain a first rear wheel yaw angle based on a rear wheel steering angle relationship function determined from a vehicle centroid yaw angle:

obtaining a vehicle centroid slip angle function based on a vehicle two-degree-of-freedom model algorithm, wherein the vehicle centroid slip angle function comprises a plurality of parameter information, and the vehicle centroid slip angle is one of the plurality of parameter information;

And determining that the plurality of parameter information meets preset conditions, and obtaining a rear wheel steering angle relation function according to the vehicle mass center side deflection angle function and the front wheel expected deflection angle.

5. The method of claim 4, wherein the deriving a vehicle centroid slip angle function based on a vehicle two-degree-of-freedom model algorithm comprises:

Based on a vehicle two-degree-of-freedom model algorithm, a vehicle centroid side deviation angle function is obtained:

6. The method of claim 5, wherein determining that the plurality of parameter information satisfies a preset condition, and obtaining a rear wheel steering angle relationship function from the vehicle centroid side angle function and the front wheel desired yaw angle, comprises:

the plurality of parameter information meeting preset conditions comprises that the centroid slip angle is zero, the vehicle acceleration is zero, and the rear wheel steering angle relation function is determined according to the vehicle centroid slip angle function:

wherein δ ₂|_β＝0 is the first rear wheel yaw angle.

7. The method of claim 5, wherein determining that the plurality of parameter information satisfies a preset condition, and obtaining a rear wheel steering angle relationship function from the vehicle centroid side angle function and the front wheel desired yaw angle, comprises:

The plurality of parameter information satisfies preset conditions including zero centroid slip angle, zero vehicle yaw rate change rate and zero vehicle acceleration, and the rear wheel steering angle relation function is determined according to the vehicle centroid slip angle function:

8. The method of claim 5, wherein the determining a second rear wheel yaw angle based on the front wheel desired yaw angle and a vehicle yaw rate comprises:

The magnitude of the centroid side deflection angle is the ratio of the lateral speed to the longitudinal speed, the change rate of the vehicle yaw angle speed is zero, the vehicle acceleration is zero and the rear wheel deflection angle is zero, and the vehicle yaw angle speed function is determined based on the vehicle centroid side deflection angle function:

Wherein v is the vehicle speed;

and obtaining an ideal yaw rate by processing the vehicle yaw rate function:

and processing the deflection angle of the rear wheels of the vehicle according to the ideal yaw rate to obtain a second deflection angle of the rear wheels.

9. The method of claim 8, wherein processing the vehicle rear wheel yaw angle according to the desired yaw rate to obtain a second rear wheel yaw angle comprises:

processing the yaw rate of the vehicle and the expected yaw rate to obtain a second rear wheel deflection angle:

10. The method of claim 1, wherein weighting the first rear wheel yaw angle and the second rear wheel yaw angle to obtain a rear wheel yaw angle comprises:

Weighting the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle:

Wherein δ _{2 Total (S)} is a rear wheel deflection angle, δ ₂|_β＝0 is a first rear wheel deflection angle, δ ₂ |ω is a second rear wheel deflection angle, ζ ₁ is a weight of the first rear wheel deflection angle, and ζ ₂ is a weight of the second rear wheel deflection angle.

11. A control system for front and rear wheels, comprising:

12. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the method of any one of claims 1 to 10 when the program is executed.

13. A non-transitory computer readable storage medium storing computer instructions for causing a computer to perform the method of any one of claims 1 to 10.

14. A vehicle characterized by comprising the control system of front and rear wheels of claim 11 or the electronic device of claim 12 or the storage medium of claim 13.