Vehicle control method, system, and vehicle

Abstract

The application provides a vehicle control method, system and vehicle, wherein the method comprises: acquiring driving information of the vehicle, the driving information comprising load information, braking information and speed information; distributing total braking force to each wheel according to the load and braking state of each wheel to obtain target braking force of each wheel; determining left and right side braking force difference of the vehicle according to the target braking force of each wheel, and determining the front wheel turning angle of the vehicle according to the left and right side braking force difference and the speed information; and performing braking and steering control of the vehicle according to the target braking force of each wheel and the front wheel turning angle. In the braking failure working condition, the braking force demand of the failed wheel can be transferred to the remaining normal wheels, the braking efficiency and braking effect are ensured, the active steering compensation mechanism is combined to prevent the vehicle from running off and losing stability during braking, and the driving safety and stability of the vehicle are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle control, and in particular to a vehicle control method and system and vehicle. BACKGROUND

[0002] With the rapid development of intelligent networked technology of automobiles, there is a higher requirement for the drive-by-wire of various functions of vehicles. The traditional hydraulic braking system has been difficult to meet the needs of intelligent automobiles due to its complex structure, cumbersome maintenance and slow response speed. The traditional hydraulic braking system usually sets two sets of braking systems based on diagonal wheels, that is, the braking system is divided into two sets of independent hydraulic circuits, and each set of circuit is responsible for controlling one front wheel and one diagonal rear wheel. When one set of braking system fails, the other set can still provide braking force for the other two wheels, but when one set of braking system fails, both diagonal wheels lose braking force, the braking effect is poor, and the risk of accidents is greatly increased.

[0003] In related technologies, EMB (Electro-Mechanical Braking, electronic mechanical braking system) emerges as the times require as an innovative braking solution, which not only simplifies the complex structure of the traditional hydraulic braking system and improves the braking efficiency and response speed, but also, compared with the traditional hydraulic braking system, does not use the arrangement of sharing one set of braking system for diagonal wheels, but each braking actuator of each wheel is independent and redundant, when a certain actuator fails, only the braking ability of the corresponding wheel is affected, and the remaining three wheels can still provide braking force, avoiding the serious consequences that one set of braking system failure in the traditional hydraulic system leads to the simultaneous braking failure of two diagonal wheels. However, although the EMB system has certain advantages in redundancy design, the whole vehicle control scheme after the braking failure of a single or multiple wheels is not perfect, which not only reduces the total amount of vehicle braking force, but also causes the vehicle to lose control due to uneven distribution of braking force, affecting the driving safety and stability of the vehicle. SUMMARY

[0004] The present application discloses a vehicle control method, system and vehicle, which solves the technical problem of vehicle losing control after braking failure.

[0005] The application provides a vehicle control method, which comprises the following steps: acquiring driving information of a vehicle, wherein the driving information comprises load information, braking information and speed information, the load information comprises loads of wheels, and the braking information comprises total braking force and braking states of the wheels; distributing the total braking force to the wheels according to the loads and the braking states of the wheels, so as to obtain target braking forces of the wheels; determining a left-right braking force difference of the vehicle according to the target braking forces of the wheels, and determining a front wheel steering angle of the vehicle according to the left-right braking force difference and the speed information, wherein the front wheel steering angle is used to generate a reverse yaw moment to inhibit a yaw moment caused by the left-right braking force difference; and performing braking and steering control of the vehicle according to the target braking forces of the wheels and the front wheel steering angle.

[0006] In an embodiment of the application, the step of determining the front wheel steering angle of the vehicle according to the left-right braking force difference and the speed information comprises the following steps: constructing a first calculation equation of a front wheel lateral force according to the speed information and the front wheel steering angle based on a vehicle yaw motion model, wherein the front wheel steering angle is a variable; constructing a second calculation equation of the front wheel lateral force according to the left-right braking force difference and the front wheel steering angle based on a moment balance principle, wherein the front wheel steering angle is a variable; and solving the front wheel steering angle according to the first calculation equation and the second calculation equation.

[0007] In an embodiment of the application, after the front wheel steering angle of the vehicle is determined, the method further comprises the following steps: acquiring physical parameter information and road information of the vehicle, wherein the physical parameter information comprises center of mass position information; constructing a state space of the vehicle according to the speed information, the target braking forces of the wheels, the front wheel steering angle, the braking states of the wheels, the center of mass position information and the road information; inputting the state space into a steering angle correction model to obtain a corrected front wheel steering angle, so as to perform steering control of the vehicle according to the corrected front wheel steering angle, wherein the steering angle correction model is obtained by training a state space sample based on the center of mass position information, the road information, the load information, the braking information and the speed information.

[0008] In an embodiment of the application, the training method of the steering angle correction model comprises the following steps: constructing a reinforcement learning model and a reward function of the reinforcement learning model, wherein the reward function comprises a yaw angular velocity deviation term, a center of mass side slip angle deviation term and a penalty term, and the penalty term is used to constrain excessive correction of the front wheel steering angle; iteratively training the reinforcement learning model according to the state space sample, and obtaining the steering angle correction model when a preset convergence condition is reached.

[0009] In an embodiment of the present application, the determination of the load of each wheel comprises: if the lateral acceleration of the vehicle is less than a preset first speed threshold, the front axle load and the rear axle load of the vehicle are respectively evenly distributed between the left and right wheels of the corresponding axle to obtain the load of each wheel; if the lateral acceleration is greater than or equal to the first speed threshold and less than a preset second speed threshold, the front axle load and the rear axle load are respectively weighted and distributed between the left and right wheels of the corresponding axle according to the proportion of the left side load and the right side load of the vehicle to obtain the load of each wheel; if the lateral acceleration is greater than or equal to the second speed threshold, the left side load and the right side load are respectively weighted and distributed between the front and rear wheels of the corresponding side according to the proportion of the front axle load and the rear axle load to obtain the load of each wheel; wherein the speed information comprises the lateral acceleration, and the load information further comprises the front axle load, the rear axle load, the left side load and the right side load.

[0010] In an embodiment of the present application, the determination of the front axle load, the rear axle load, the left side load and the right side load comprises: obtaining physical parameter information and road information of the vehicle, wherein the physical parameter information comprises mass information, center of mass position information and wheel position information; determining the front axle load and the rear axle load according to the mass information, the center of mass position information, the wheel position information, the road information and the longitudinal acceleration, wherein the speed information further comprises the longitudinal acceleration; determining the left side load and the right side load according to the mass information, the center of mass position information, the wheel position information, the road information and the lateral acceleration.

[0011] In an embodiment of the present application, the distribution of the total braking force to each wheel according to the load of each wheel and the braking state to obtain the target braking force of each wheel comprises: determining the braking force distribution proportion of each wheel according to the load of each wheel and the braking state, wherein if the braking state of a target wheel is a failure state, the braking force distribution proportion of the target wheel is zero; calculating the proportion of each wheel and the total braking force respectively to obtain the target braking force of each wheel.

[0012] The application further provides a vehicle control system, comprising: an acquisition module, configured to acquire driving information of a vehicle, wherein the driving information comprises load information, braking information and speed information, the load information comprises load of each wheel, and the braking information comprises total braking force and braking state of each wheel; a distribution module, configured to distribute the total braking force to each wheel according to the load and the braking state of each wheel, and obtain target braking force of each wheel; a determination module, configured to determine left-right side braking force difference of the vehicle according to the target braking force of each wheel, and determine front wheel steering angle of the vehicle according to the left-right side braking force difference and the speed information, wherein the front wheel steering angle is used to generate reverse yaw moment to inhibit yaw moment caused by the left-right side braking force difference; and a control module, configured to perform braking and steering control of the vehicle according to the target braking force of each wheel and the front wheel steering angle.

[0013] The application further provides a vehicle control system, comprising: a controller, configured to determine target braking force of each wheel and front wheel steering angle of the vehicle by using the vehicle control method described above; a plurality of brakes, respectively connected to the controller and respectively acting on each wheel of the vehicle, and configured to perform braking operation of the vehicle in response to braking instruction issued by the controller, wherein the target braking force of each wheel is carried in the braking instruction; and a steering device, connected to the controller through a steering motor, and configured to perform steering operation of the vehicle in response to steering instruction issued by the controller, wherein the front wheel steering angle is carried in the steering instruction.

[0014] The application further provides a vehicle, comprising a processor and a storage device, wherein the storage device is configured to store a program, and when the program is executed by the processor, the vehicle is caused to perform the vehicle control method described above, or the vehicle control system described above.

[0015] The beneficial effects of the present application: the vehicle control method, system and vehicle provided by the present application first acquire the driving information of the vehicle, the driving information includes load information, braking information and speed information, the load information includes the load of each wheel, the braking information includes the total braking force and the braking state of each wheel, then the total braking force is distributed to each wheel according to the load and braking state of each wheel, the target braking force of each wheel is obtained, then the left and right side braking force difference of the vehicle is determined according to the target braking force of each wheel, and the front wheel steering angle of the vehicle is determined according to the left and right side braking force difference and the speed information, the front wheel steering angle is used to generate a reverse yaw moment to suppress the yaw moment caused by the left and right side braking force difference, finally, the braking and steering control of the vehicle is performed according to the target braking force of each wheel and the front wheel steering angle, based on the braking state of each wheel and the load transfer principle, the total braking force is intelligently redistributed to timely and effectively transfer the braking force demand of the failed wheel to the remaining normal wheels in the braking failure working condition, ensure the braking efficiency and braking effect, and when the left and right side braking force imbalance is detected, the active steering compensation mechanism is fused to cooperatively control the braking and steering of the vehicle, prevent the vehicle from running off and instability phenomenon caused by the uneven left and right braking force, and significantly improve the driving safety and stability of the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0016] The drawings incorporated into the specification and forming a part thereof, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application. It is to be expressly understood that the drawings are only some embodiments of the present application, and other drawings can be obtained from these drawings without creative labor for those of ordinary skill in the art.

[0017] In the drawings:

[0018] Figure 1 is a schematic diagram of an implementation environment of a vehicle control system according to an example embodiment of the present application;

[0019] Figure 2 is a flowchart of a vehicle control method according to an example embodiment of the present application;

[0020] Figure 3 is a block diagram of a vehicle control system according to an example embodiment of the present application;

[0021] Figure 4 is a schematic diagram of a vehicle control system according to an example embodiment of the present application;

[0022] Figure 5 is a schematic diagram of an electronic device according to an example embodiment of the present application. DETAILED DESCRIPTION

[0023] Following, the advantages and effects of the present application can be easily understood by those skilled in the art from the present description. The present application can also be implemented or applied by other different specific embodiments, and the details in the present description can be modified or changed based on different views and applications without departing from the spirit of the present application. The following embodiments and features in the embodiments can be combined with each other without conflict.

[0024] It should be noted that the diagrams provided in the following embodiments only schematically illustrate the basic concepts of the present application, and the drawings only show the components related to the present application, not the number, shape and size of the components when actually implemented. The shapes, numbers and proportions of the components when actually implemented can be arbitrarily changed, and the layout form of the components can also be more complex.

[0025] In the following description, a large number of details are discussed to provide a more thorough explanation of the embodiments of the present application, however, it is obvious to those skilled in the art that the embodiments of the present application can be implemented without these specific details, and in other embodiments, the known structures and devices are shown in the form of block diagrams rather than in the form of details to avoid making the embodiments of the present application difficult to understand.

[0026] As an innovative braking system, the EMB system not only simplifies the complex structure of the traditional hydraulic braking system and improves the braking efficiency and response speed, but also, compared with the traditional hydraulic braking system, does not use the arrangement mode of sharing a set of braking system for diagonal wheels, but each braking actuator of each wheel is independent and redundant. When a certain actuator fails, it only affects the braking ability of the corresponding wheel, and the remaining three wheels can still provide normal braking force, avoiding the serious consequences that the failure of a set of braking system in the traditional hydraulic system leads to the simultaneous braking failure of the diagonal two wheels. However, the inventors of the present application found that although the EMB system has certain advantages in redundancy design, the whole vehicle control scheme after the braking failure of a single or multiple wheels is not perfect, and the load transfer under the failure condition is less considered. Not only does it make the total amount of vehicle braking force decrease, but also it makes the vehicle out of control due to uneven distribution of braking force, affecting the driving safety and stability of the vehicle.

[0027] Therefore, please refer to Figure 1 , Figure 1 is a schematic diagram of an implementation environment of a vehicle control system according to an exemplary embodiment of the present application. As Figure 1As shown, the implementation environment may include a vehicle 110 and a vehicle control system 120. The vehicle control system 120 is embedded in the vehicle 110 and is used to control the vehicle 110. The vehicle control system 120 includes, but is not limited to, vehicle infotainment systems and on-board computers. Based on the braking status of each wheel and the principle of load transfer, it intelligently redistributes the total braking force so that in the event of brake failure, it can transfer the braking force demand of the failed wheel to the other normal wheels in a timely and effective manner, ensuring braking efficiency and braking effect. When an imbalance of braking force between the left and right sides is detected, it integrates an active steering compensation mechanism to coordinate the control of the vehicle's braking and steering, preventing the vehicle from deviating and becoming unstable due to uneven braking force between the left and right sides, thus significantly improving the vehicle's driving safety and stability.

[0028] Please see Figure 2 , Figure 2 This is a flowchart illustrating a vehicle control method as shown in an exemplary embodiment of this application. This method can be applied to... Figure 1 The implementation environment shown is specifically executed by the vehicle control system 120 within that implementation environment. It should be understood that this method can also be applied to other exemplary implementation environments and executed by devices in other implementation environments; this embodiment does not limit the implementation environment to which the method is applicable.

[0029] like Figure 2 As shown, in an exemplary embodiment, the vehicle control method includes at least steps S210 to S240, which are described in detail below:

[0030] Step S210: Obtain vehicle driving information, including load information, braking information and speed information. Load information includes the load on each wheel, and braking information includes the total braking force and the braking status of each wheel.

[0031] Step S220: Based on the load and braking status of each wheel, the total braking force is distributed to each wheel to obtain the target braking force for each wheel;

[0032] Step S230: Determine the difference in braking force between the left and right sides of the vehicle based on the target braking force of each wheel, and determine the front wheel steering angle of the vehicle based on the difference in braking force between the left and right sides and the speed information. The front wheel steering angle is used to generate a reverse yaw moment to suppress the yaw moment caused by the difference in braking force between the left and right sides.

[0033] Step S240: Based on the target braking force of each wheel and the front wheel turning angle, perform vehicle braking and steering control.

[0034] The load of each wheel includes the vertical load of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel, which can be estimated by a dynamic model or directly measured by a sensor; the total braking force refers to the braking force demand of the whole vehicle requested by the driver or planned by the automatic driving system, which can be determined according to the input of the driver's brake pedal (such as pedal stroke or pressure), and dynamically calculated in combination with the mass of the vehicle, the current speed and the required deceleration; the braking state of each wheel includes the failure state and the normal state, which can be determined by real-time acquisition of the running state information of the EMB through sensors installed at each part of the EMB and the wheels.

[0035] In step S210, real-time driving information of the vehicle is acquired, wherein the driving information includes real-time speed information of the vehicle, real-time load of each wheel, current total braking force and real-time braking state of each wheel, which provides real-time and accurate vehicle state input for subsequent intelligent distribution of braking force and determination of front wheel steering angle.

[0036] In step S220, the braking force is coordinately distributed according to the load and braking state of each wheel, that is, the target braking force of the failed wheel is configured to zero, the wheel with greater load is allocated with greater braking force, and the braking force originally borne by the failed wheel is also redistributed to the remaining normal wheels, so as to ensure the braking efficiency.

[0037] In step S230, when a slight left-right side braking force difference (the left-right side braking force difference is less than or equal to a preset difference value) is detected, the front wheel steering angle generated by the front wheel steering angle generation mechanism is zero, that is, no steering compensation is performed; when a significant left-right side braking force difference (the left-right side braking force difference is greater than the preset difference value) is detected, a front wheel steering angle with a specific angle value is generated by the front wheel steering angle generation mechanism, which makes the front wheel generate a lateral force to form an opposite yaw moment to the yaw moment caused by the left-right side braking force difference, that is, a reverse yaw moment, so as to offset or inhibit the unintended deviation and instability of the vehicle.

[0038] In step S240, the braking control of the vehicle is performed according to the target braking force of each wheel, that is, the braking instruction is generated according to the target braking force of each wheel and sent to the braking system, and each wheel brake applies the corresponding braking force according to the instruction to realize the braking of the vehicle, wherein the target braking force of the wheel in the failure state is zero, and the target braking force of the wheel in the normal state is completed based on the applied target braking force to complete the braking of the vehicle, and the steering control of the vehicle is performed according to the front wheel steering angle, that is, the steering instruction is generated according to the front wheel steering angle and sent to the steering system, and the steering system adjusts the direction of the front wheel according to the instruction to realize the steering of the vehicle.

[0039] In this embodiment, based on the braking state of each wheel and the load transfer principle, the total braking force is intelligently redistributed to timely and effectively transfer the braking force demand of the failed wheel to the remaining normal wheels in the brake failure condition, ensuring braking efficiency and braking effect, and when detecting that the left and right side braking forces are unbalanced, the active steering compensation mechanism is combined to prevent the vehicle from running off and losing stability due to unbalanced left and right braking forces, significantly improving the driving safety and stability of the vehicle.

[0040] Exemplarily, the braking state of each wheel can be determined by real-time acquisition of the running state information of the EMB through sensors installed at each part of the EMB and its wheels, i.e., real-time diagnosis of the working state of the EMB through the running state information of the EMB, wherein the running state information includes the caliper clamping force, motor current, motor voltage, motor temperature, wheel speed and caliper displacement; when detecting that the braking signal of a wheel or multiple wheels is abnormal, the braking pressure cannot reach the set value, and the braking response time is too long, etc., it is determined that the corresponding wheel is brake failure. In addition, when it is determined that a wheel or multiple wheels are brake failure, the vehicle control method is called for execution.

[0041] Exemplarily, the calculation formula of the left and right side braking force difference is:

[0042] Formula (1)

[0043] wherein, represents the left and right side braking force difference; represents the target braking force of the left front wheel; represents the target braking force of the right front wheel; represents the target braking force of the left rear wheel; represents the target braking force of the right rear wheel.

[0044] In this exemplary embodiment, the left and right side braking force difference is the difference between the total braking force of the left side of the vehicle and the total braking force of the right side, wherein the total braking force of the left side is the sum of the target braking force of the left front wheel and the target braking force of the left rear wheel, and the total braking force of the right side is the sum of the target braking force of the right front wheel and the target braking force of the right rear wheel, i.e., the left and right side braking force difference is the total braking force of all wheels on the left side of the vehicle minus the total braking force of all wheels on the right side. In addition, in the judgment of whether the left and right side braking force difference is less than or equal to a preset difference value or greater than a preset difference value, the difference between the braking forces of all wheels on the left and right sides is considered, rather than judging the left and right wheels of the front axle or the left and right wheels of the rear axle separately.

[0045] In one embodiment, determining the front wheel steering angle of the vehicle according to the difference between the left and right braking forces and the speed information comprises: constructing a first calculation equation of the front wheel lateral force according to the speed information and the front wheel steering angle based on a vehicle yaw motion model, wherein the front wheel steering angle is a variable; constructing a second calculation equation of the front wheel lateral force according to the difference between the left and right braking forces and the front wheel steering angle based on a moment balance principle, wherein the front wheel steering angle is a variable; and solving the front wheel steering angle according to the first calculation equation and the second calculation equation.

[0046] In this embodiment, considering that the braking force calculated based on the braking force redistribution strategy will cause the braking forces on the two sides to be different, which will cause serious braking deviation in an emergency, when the difference between the left and right braking forces is large, a front wheel steering angle is calculated according to the difference and in combination with the speed information of the vehicle, so as to suppress the occurrence of the braking deviation phenomenon.

[0047] In this embodiment, considering that the speed information of the vehicle and the front wheel steering angle will affect the front wheel lateral force, a first calculation equation of the front wheel lateral force generated by the front wheel steering angle can be constructed based on a vehicle yaw motion model, and the front wheel steering angle is used to suppress the braking deviation and instability phenomena caused by the difference between the left and right braking forces, so a second calculation equation of the front wheel lateral force generated by the front wheel steering angle can be constructed based on a moment balance principle.

[0048] In this way, by combining the vehicle yaw motion model and the moment balance principle, the difference between the left and right braking forces and the speed information, a solving equation for estimating the front wheel steering angle of the vehicle is constructed to back-calculate the front wheel steering angle, which significantly improves the estimation accuracy of the front wheel steering angle.

[0049] In addition, since other physical parameter information of the vehicle is also involved in the vehicle yaw motion model, exemplarily, the first calculation equation of the front wheel lateral force according to the speed information and the front wheel steering angle based on the vehicle yaw motion model comprises: constructing the first calculation equation of the front wheel lateral force according to the front wheel cornering stiffness, the first distance from the front axle to the center of mass, the speed information and the front wheel steering angle based on the vehicle yaw motion model, wherein the front wheel cornering stiffness and the first distance from the front axle to the center of mass are the physical parameter information of the vehicle obtained, and the speed information includes the longitudinal speed, the lateral speed and the yaw angular speed.

[0050] Since other physical parameter information of the vehicle is also involved in the moment balance principle, exemplarily, the second calculation equation of the front wheel lateral force according to the difference between the left and right braking forces and the front wheel steering angle based on the moment balance principle comprises: constructing the second calculation equation of the front wheel lateral force according to the difference between the left and right braking forces, the width of the vehicle, the first distance from the front axle to the center of mass and the front wheel steering angle based on the moment balance principle, wherein the physical parameter information also includes the width of the vehicle.

[0051] wherein, the front wheel side stiffness and the vehicle width are inherent physical parameters of the vehicle; the first distance from the front axle to the center of mass can be determined based on the vehicle load distribution after determining the center of mass position; the longitudinal velocity and the lateral velocity can be estimated by a vehicle state observer, and the yaw angular velocity can be measured by an IMU (Inertial Measurement Unit).

[0052] Specifically, when the vehicle brakes, due to the existence of the left and right side braking force difference, the vehicle will be subjected to a yaw moment around the center of mass, and the yaw moment is determined according to the left and right side braking force difference and the vehicle width, and the yaw moment will cause the vehicle to deflect to the side with smaller braking force. The front wheel lateral force can be generated by adjusting the front wheel steering angle in the opposite direction to realize vehicle stability control. In order to ensure the best stable state of the vehicle, according to the moment balance principle, the opposite yaw moment generated by the front wheel lateral force needs to be equal to the yaw moment. Therefore, by using the moment balance principle, a reverse front wheel lateral force is determined. In addition, the front wheel lateral force can also be determined based on a linear two-degree-of-freedom vehicle yaw motion model. Both of the two determination methods involve the front wheel steering angle, so the front wheel steering angle can be taken as a variable to solve the specific angle value of the front wheel steering angle by combining the two front wheel lateral force calculation equations.

[0053] In this way, by combining the vehicle dynamics model and the moment balance equation, the front wheel steering angle is inversely calculated by using the real-time left and right side braking force difference and the motion state of the vehicle, which significantly improves the estimation accuracy of the front wheel steering angle and effectively ensures the safety and stability of the vehicle braking.

[0054] Exemplarily, based on the linear two-degree-of-freedom vehicle yaw motion model, the first calculation equation of the front wheel lateral force is:

[0055] Formula (2)

[0056] wherein, represents the front wheel lateral force; represents the front wheel side stiffness; represents the front wheel steering angle; represents the lateral velocity; represents the longitudinal velocity; represents the yaw angular velocity; represents the first distance from the front axle to the center of mass;

[0057] Exemplarily, the calculation formula of the yaw moment is:

[0058] Formula (3)

[0059] wherein, represents the yaw moment; represents the left and right side braking force difference; represents the vehicle width;

[0060] The formula for calculating the reverse yaw moment is:

[0061] Equation (4)

[0062] wherein, represents the reverse yaw moment; represents the front wheel lateral force; represents the first distance from the front axle to the center of mass; represents the front wheel steering angle;

[0063] Based on the torque balance principle, , the second calculation equation for the front wheel lateral force is obtained, which is:

[0064] Equation (5)

[0065] wherein, represents the front wheel lateral force; represents the difference between the left and right side braking forces; represents the vehicle width; represents the first distance from the front axle to the center of mass; represents the front wheel steering angle;

[0066] Therefore, according to the first calculation equation and the second calculation equation, the solving equation for the front wheel steering angle can be obtained, so as to obtain the front wheel steering angle, and the solving equation for the front wheel steering angle is:

[0067] Equation (6)

[0068] wherein, represents the difference between the left and right side braking forces; represents the vehicle width; represents the first distance from the front axle to the center of mass; represents the front wheel steering angle; represents the front wheel cornering stiffness; represents the lateral velocity; represents the longitudinal velocity; represents the yaw angular velocity.

[0069] The above equation (6) can be simplified as:

[0070] Equation (7)

[0071] Therefore, the solving equation for the front wheel steering angle is a transcendental equation (a mixed equation of trigonometric function and polynomial), since the trigonometric function is nonlinearly coupled with the first order function , the equation does not have an analytical solution expressed by elementary functions, and needs to be approximately solved by numerical methods.

[0072] In a possible embodiment, the front wheel steering angle is solved based on a dichotomy method, as follows: an initial interval of the front wheel steering angle is obtained, and a front wheel steering angle function is set based on a solving equation of the front wheel steering angle; a first intermediate value of the initial interval is taken, and a left interval value and a right interval value of the initial interval and the first intermediate value are substituted into the front wheel steering angle function for calculation; if a front wheel steering angle function value at the first intermediate value is zero, the first intermediate value is taken as the front wheel steering angle; if the front wheel steering angle function value at the first intermediate value is not zero, a new interval is determined based on the left interval value and the first intermediate value on a condition that a product of the front wheel steering angle function value at the left interval value and the front wheel steering angle function value at the first intermediate value is less than zero, and the new interval is determined based on the first intermediate value and the right interval value on a condition that a product of the front wheel steering angle function value at the first intermediate value and the front wheel steering angle function value at the right interval value is less than zero; a second intermediate value of the new interval is taken, and iteration is repeated until an interval length is less than a preset length threshold, to obtain a target interval; and a third intermediate value of the target interval is taken as the front wheel steering angle.

[0073] As a possible embodiment, the front wheel steering angle function is as follows:

[0074] Formula (8)

[0075] wherein, represents the front wheel steering angle function; represents a left-right brake force difference; represents a vehicle width; represents a first distance from a front axle to a center of mass; represents a front wheel steering angle; represents a front wheel cornering stiffness; represents a lateral velocity; represents a longitudinal velocity; represents a yaw angular velocity.

[0076] For example, the initial interval is , the first intermediate value is , and , , are calculated, if , the solution is , that is, the angle value of the front wheel steering angle; if , the new interval is , and the solution is in , if , the new interval is , and the solution is in ; continue to take an intermediate value in the new interval, and repeat iteration until the interval length is less than a preset length threshold , such as If the target interval is obtained, the middle value of the target interval is taken as the solution.

[0077] For example, the initial interval is the inherent parameter of the vehicle, which is determined based on the specific vehicle, such as .

[0078] In an embodiment, after determining the front wheel steering angle of the vehicle, the method further comprises: obtaining physical parameter information of the vehicle and road information, wherein the physical parameter information comprises center of mass position information; constructing a state space of the vehicle according to the speed information, the target braking force of each wheel, the front wheel steering angle, the braking state of each wheel, the center of mass position information and the road information; inputting the state space into a steering angle correction model to obtain a corrected front wheel steering angle, so as to perform steering control of the vehicle according to the corrected front wheel steering angle, wherein the steering angle correction model is obtained by training a state space sample based on the center of mass position information, the road information, the load information, the braking information and the speed information.

[0079] The center of mass position information comprises a center of mass side slip angle; the road information comprises a road adhesion coefficient; the speed information comprises a yaw rate and a longitudinal speed; and the target braking force of each wheel is used to reflect a front axle braking force difference and a rear axle braking force difference of the vehicle.

[0080] Therefore, the state space of the vehicle is constructed according to the speed information, the target braking force of each wheel, the front wheel steering angle, the braking state of each wheel, the center of mass position information and the road information, specifically: the state space of the vehicle is constructed according to the yaw rate, the longitudinal speed, the front axle braking force difference, the rear axle braking force difference, the front wheel steering angle, the road adhesion coefficient, the braking state of each wheel and the center of mass side slip angle.

[0081] For example, the calculation formula of the front axle braking force difference is:

[0082] Formula (9)

[0083] wherein, represents the front axle braking force difference; represents the target braking force of the left front wheel; represents the target braking force of the right front wheel;

[0084] The calculation formula of the rear axle braking force difference is:

[0085] Formula (10)

[0086] wherein, represents the rear axle braking force difference; represents the target braking force of the left rear wheel; represents the target braking force of the right rear wheel.

[0087] For example, the state space is:

[0088]

[0089] wherein, denotes the yaw rate; denotes the center of mass side slip angle; denotes the longitudinal velocity; denotes the front axle braking force difference; denotes the rear axle braking force difference; denotes the front wheel steering angle; denotes the road adhesion coefficient; respectively correspond to the braking states of the four wheels (1 represents the failure state, and 0 represents the normal state).

[0090] In this embodiment, considering the problem of insufficient accuracy of the estimated front wheel steering angle based on only the physical characteristics under complex working conditions, in order to further ensure the driving safety and stability of the vehicle under brake failure, a steering angle correction model suitable for complex working conditions is established based on the physical algorithm, to optimize and correct the calculated front wheel steering angle, and the braking conditions of the four wheels are introduced into the steering angle correction model, so that the agent can perceive the specific position and state of brake failure, and the decision robustness of the model under the brake failure scene is strengthened, thereby improving the accuracy of the yaw moment offset.

[0091] In addition, after the state space input is input into the steering angle correction model, the output action space A can be the correction amount of the front wheel steering angle, or can be the corrected front wheel steering angle directly. If the action space is defined as the correction amount of the front wheel steering angle, that is, the value range is determined by the physical constraints of the vehicle, if the boundary interval of the front wheel steering angle is , then the interval of is also , and the corrected front wheel steering angle is .

[0092] In an embodiment, the training method of the steering angle correction model comprises: constructing a reinforcement learning model and a reward function of the reinforcement learning model, wherein the reward function comprises a yaw rate deviation term, a center of mass side slip angle deviation term and a penalty term, and the penalty term is used to constrain the excessive correction of the front wheel steering angle; iteratively training the reinforcement learning model according to the state space sample, and obtaining the steering angle correction model when the preset convergence condition is reached.

[0093] wherein the yaw rate deviation refers to a deviation between a yaw rate generated based on the front wheel steering angle expectation and an actual yaw rate, and the mass center side slip angle deviation refers to a deviation between a mass center side slip angle generated based on the front wheel steering angle expectation and an actual mass center side slip angle; in addition, the preset convergence condition includes but is not limited to a change amount of the reward function value being less than a set threshold, a training number reaching a set threshold, and a change amount of a performance index (such as an accuracy, a mean square error, etc.) of the reinforcement learning model being less than a set threshold.

[0094] In this embodiment, in order to guarantee the correction effect of the front wheel steering angle, a reward function including the yaw rate deviation, the mass center side slip angle deviation and the front wheel steering angle correction constraint is constructed, so as to guide the reinforcement learning model to learn how to accurately correct the front wheel steering angle in the iterative training, so that the steering angle correction model has good dynamic adaptability and control robustness.

[0095] Exemplarily, the reward function is:

[0096] Formula (11)

[0097] wherein, represents the reward function value; represents a weight coefficient of the yaw rate deviation; represents the yaw rate deviation; represents the yaw rate deviation term; represents a weight coefficient of the mass center side slip angle deviation; represents the mass center side slip angle deviation; represents the mass center side slip angle deviation term; represents a weight coefficient of the penalty factor; represents the penalty factor; represents the penalty term.

[0098] In this exemplary embodiment, , , may be adjusted according to the control priority, for example = 0.4, = 0.4, = 0.2, of course, , , may be set according to specific circumstances and requirements, and the specific values of , , are not limited in the embodiments of the present application.

[0099] Exemplarily, the penalty factor is set according to the size relationship between the absolute value of the correction amount of the front wheel steering angle and the maximum allowed correction amount, and the expression of the penalty factor is:

[0100] Equation (12)

[0101] wherein, represents a penalty factor, represents a correction amount of the front wheel steering angle; represents a maximum correction amount allowed; represents a penalty coefficient.

[0102] In a possible embodiment, the state space samples include state space samples under various centroid position information collected, various road information, various load information, various braking information, various speed information, and state space samples generated by using a vehicle dynamics simulation model. In this way, both the actual driving characteristics are reflected by using real data, and the deficiencies of extreme or rare working conditions are made up by using simulation data.

[0103] In a possible embodiment, after each item of data in the state space samples is normalized, the data is input into the reinforcement learning model for model training. In this way, the stability and efficiency of model training are improved.

[0104] In a possible embodiment, during the operation of the vehicle, new state space samples are continuously collected to update the steering angle correction model online. In this way, the steering angle correction model can adapt to changes in vehicle parameters and various new working conditions in a timely manner, and the correction effect of the front wheel steering angle under various complex working conditions is ensured.

[0105] In an embodiment, the determination manner of the load of each wheel includes: if the lateral acceleration of the vehicle is less than a preset first speed threshold, the front axle load and the rear axle load of the vehicle are respectively evenly distributed between the left and right wheels of the corresponding axle to obtain the load of each wheel; if the lateral acceleration is greater than or equal to the first speed threshold and less than a preset second speed threshold, the front axle load and the rear axle load are respectively weightedly distributed between the left and right wheels of the corresponding axle according to the proportion of the left side load and the right side load to obtain the load of each wheel; if the lateral acceleration is greater than or equal to the second speed threshold, the left side load and the right side load are respectively weightedly distributed between the front and rear wheels of the corresponding side according to the proportion of the front axle load and the rear axle load to obtain the load of each wheel; wherein the speed information includes the lateral acceleration, and the load information further includes the front axle load, the rear axle load, the left side load and the right side load.

[0106] wherein the front axle load and the rear axle load include the total load of the front axle wheels and the total load of the rear axle wheels of the vehicle, and the left side load and the right side load include the total load of the left side wheels and the total load of the right side wheels of the vehicle; the first speed threshold and the second speed threshold are both lateral acceleration thresholds, which can be set according to specific requirements or conditions.

[0107] In this embodiment, considering that the lateral acceleration is small, the left and right loads can be regarded as uniformly distributed, and when the lateral acceleration gradually increases, the left and right load transfer begins to gradually occur, when the lateral acceleration has not reached a large degree, the vehicle has a certain roll, but the front and rear suspension systems respond relatively independently and are not fully linked, and when the lateral acceleration reaches a large degree, the vehicle body significantly inclines, the left and right sides form obvious high and low sides, the linkage effect of the suspension system is enhanced, and the load transfer presents a cross-axle coupling characteristic. Therefore, the first speed threshold and the second speed threshold are set to, at a low lateral acceleration, evenly distribute the front axle load and the rear axle load among the left and right wheels of the corresponding axle respectively; at a medium lateral acceleration, the left and right load transfer of the vehicle mainly reflects the independent response of each axle, and therefore it is more reasonable to distribute the front axle load and the rear axle load according to the left and right side ratio; and at a high lateral acceleration, the vehicle body significantly inclines, the left and right sides form obvious high and low sides, at this time, the left side and the right side should be regarded as two vertical bearing surfaces, and then the total load of each side is distributed to the front and rear axles according to the bearing ratio, so as to more truly reflect the actual load distribution.

[0108] In addition, the front axle load and the rear axle load of the vehicle are evenly distributed among the left and right wheels of the corresponding axle to obtain the load of each wheel, that is, the total front axle load is evenly distributed to the left front wheel and the right front wheel, and the total rear axle load is evenly distributed to the left rear wheel and the right rear wheel; the front axle load and the rear axle load are weightedly distributed among the left and right wheels of the corresponding axle according to the ratio of the left side load to the right side load, that is, the total front axle load is distributed to the left front wheel and the right front wheel according to the ratio of the left side load to the right side load, and the total rear axle load is distributed to the left rear wheel and the right rear wheel according to the ratio of the left side load to the right side load; the left side load and the right side load are weightedly distributed among the front and rear wheels of the corresponding side according to the ratio of the front axle load to the rear axle load to obtain the load of each wheel, that is, the total left side load is distributed to the left front wheel and the left rear wheel according to the ratio of the front axle load to the rear axle load, and the total right side load is distributed to the right front wheel and the right rear wheel according to the ratio of the front axle load to the rear axle load.

[0109] In this way, the load of each wheel is distributed by segment modeling according to the size of the lateral acceleration in combination with the left and right and front and rear load transfer characteristics of the vehicle, and the accuracy of the load estimation of each wheel under different working conditions is effectively improved.

[0110] For example, if the calculation formula of the load of each wheel is:

[0111] Formula (13)

[0112] Formula (14)

[0113] If the calculation formula of the load of each wheel is:

[0114] Equation (15)

[0115] Equation (16)

[0116] Equation (17)

[0117] Equation (18)

[0118] If , the calculation formula of the load of each wheel is:

[0119] Equation (19)

[0120] Equation (20)

[0121] Equation (21)

[0122] Equation (22)

[0123] wherein, represents the lateral acceleration; represents the first speed threshold; represents the second speed threshold; represents the load of the left front wheel; represents the load of the right front wheel; represents the load of the left rear wheel; represents the load of the right rear wheel; represents the total load of the front axle wheels; represents the total load of the rear axle wheels; represents the total load of the left side wheels; represents the total load of the right side wheels.

[0124] In an embodiment, the determination of the front axle load, the rear axle load, the left side load and the right side load comprises: obtaining physical parameter information and road information of the vehicle, wherein the physical parameter information comprises mass information, center of mass position information and wheel position information; determining the front axle load and the rear axle load according to the mass information, the center of mass position information, the wheel position information, the road information and the longitudinal acceleration, wherein the speed information further comprises the longitudinal acceleration; determining the left side load and the right side load according to the mass information, the center of mass position information, the wheel position information, the road information and the lateral acceleration.

[0125] wherein the mass information comprises the mass of the vehicle; the center of mass position information comprises the center of mass height, the first distance from the center of mass to the front axle and the second distance from the center of mass to the rear axle; the wheel position information comprises the wheel track and the wheel track of the vehicle; and the road information comprises the longitudinal slope.

[0126] Therefore, according to the mass information, the center of mass position information, the wheel position information, the road information and the longitudinal acceleration, the front axle load and the rear axle load are determined, specifically, the wheel track, the mass, the center of mass height, the gravitational acceleration, the lateral acceleration and the longitudinal slope of the vehicle are calculated to obtain the left side load and the right side load.

[0127] In the embodiment, considering that when the vehicle is braking or accelerating, the axle load of the front axle increases and the axle load of the rear axle decreases due to the effect of acceleration and deceleration, when the vehicle is turning, the load on the outer side increases and the load on the inner side decreases due to the effect of centrifugal force, therefore, when the vehicle is accelerating, decelerating and turning, the vehicle will have a load transfer phenomenon, and the load transfer is affected by multiple factors in the driving process. Therefore, the mass information, the center of mass position information, the wheel position information and the road information of the vehicle are combined, specifically, the longitudinal slope of the road, the mass, the wheel track, the center of mass height and the distance between the front axle and the rear axle and the center of mass of the vehicle are combined, and the longitudinal acceleration and the lateral acceleration of the vehicle are comprehensively considered, and the front axle load, the rear axle load, the left side load and the right side load are dynamically calculated, so that the actual load distribution of the vehicle under various complex driving conditions can be more accurately reflected, and the estimation accuracy of the front axle load, the rear axle load, the left side load and the right side load is improved.

[0128] Exemplarily, in the acceleration and deceleration case, the calculation formula of the total load of the front axle wheel is:

[0129] Formula (23)

[0130] The calculation formula of the total load of the rear axle wheel is:

[0131] Formula (24)

[0132] wherein, represents the total load of the front axle wheel; represents the total load of the rear axle wheel; represents the wheel track; represents the first distance from the center of mass to the front axle; represents the second distance from the center of mass to the rear axle; represents the mass; represents the center of mass height; represents the longitudinal acceleration; represents the longitudinal slope; represents the gravitational acceleration.

[0133] In the case of steering intervention, the calculation formula of the total load of the left wheel is:

[0134] Equation (25)

[0135] The calculation formula of the total load of the right wheel is:

[0136] Equation (26)

[0137] wherein, represents the total load of the left wheel; represents the total load of the right wheel; represents the wheel track; represents the mass; represents the height of the center of mass; represents the lateral acceleration; represents the longitudinal slope; represents the acceleration of gravity.

[0138] In an embodiment, the total braking force is distributed to each wheel according to the load and braking state of each wheel to obtain the target braking force of each wheel, including: determining the braking force distribution ratio of each wheel according to the load and braking state of each wheel, wherein if the target wheel is in a failure state, the braking force distribution ratio of the target wheel is zero; and calculating the braking force distribution ratio of each wheel with the total braking force to obtain the target braking force of each wheel.

[0139] In this embodiment, if the braking state of a wheel is in a failure state, the load of the wheel is configured to be zero, that is, the braking force distribution ratio of the wheel is also zero, so the target braking force allocated to the wheel is zero, and the total braking force is distributed to the normal wheels based on the braking force distribution ratio of the remaining normal wheels.

[0140] In this embodiment, the effective load proportion of each wheel is dynamically determined in combination with the load of each wheel and the number and position of the failure wheels, so that the braking force of the normal wheels is accurately redistributed, and the failure wheels do not participate in the distribution of the braking force.

[0141] Exemplarily, the calculation formula of the target braking force of each wheel is:

[0142] Equation (27)

[0143] Equation (28)

[0144] Equation (29)

[0145] Equation (30)

[0146] wherein, represents a target braking force of the left front wheel; represents a target braking force of the right front wheel; represents a target braking force of the left rear wheel; represents a target braking force of the right rear wheel; represents a load of the left front wheel; represents a load of the right front wheel; represents a load of the left rear wheel; represents a load of the right rear wheel; represents a total braking force.

[0147] The vehicle control method described above, first acquires driving information of the vehicle, the driving information including load information, braking information and speed information, the load information including loads of wheels, the braking information including a total braking force and braking states of the wheels, then distributes the total braking force to the wheels according to the loads and the braking states of the wheels to obtain target braking forces of the wheels, then determines a left-right side braking force difference of the vehicle according to the target braking forces of the wheels, and determines a front wheel steering angle of the vehicle according to the left-right side braking force difference and the speed information, the front wheel steering angle being used to generate a reverse yaw moment to suppress a yaw moment caused by the left-right side braking force difference, and finally performs braking and steering control of the vehicle according to the target braking forces of the wheels and the front wheel steering angle. Based on the braking states of the wheels and the load transfer principle, the total braking force is intelligently redistributed to timely and effectively transfer the braking force demand of a failed wheel to the remaining normal wheels in a braking failure condition, to ensure braking efficiency and braking effect, and when the left-right side braking force imbalance is detected, an active steering compensation mechanism is fused to cooperatively control the braking and steering of the vehicle, to prevent the vehicle from running off course and losing stability due to the left-right braking force imbalance, thereby significantly improving the driving safety and stability of the vehicle.

[0148] See Figure 3 , Figure 3 is a block diagram of a vehicle control system according to an example embodiment of the present application. The system can be applied to Figure 1 the implementation environment shown in the figure, it should be understood that the system can also be applied to other example implementation environments, and the present embodiment does not limit the implementation environment to which the system is applied.

[0149] As Figure 3 shown, in an example embodiment, the vehicle control system 300 at least includes an acquisition module 310, a distribution module 320, a determination module 330 and a control module 340, which are described in detail as follows:

[0150] The acquisition module 310 is configured to acquire driving information of the vehicle, wherein the driving information includes load information, braking information and speed information, the load information includes loads of wheels, and the braking information includes a total braking force and braking states of the wheels;

[0151] The distribution module 320 is configured to distribute the total braking force to each wheel according to the load and braking state of each wheel, and obtain a target braking force of each wheel;

[0152] The determination module 330 is configured to determine a left-right side braking force difference of the vehicle according to the target braking force of each wheel, and determine a front wheel steering angle of the vehicle according to the left-right side braking force difference and speed information, wherein the front wheel steering angle is used to generate a reverse yaw moment to suppress a yaw moment caused by the left-right side braking force difference;

[0153] The control module 340 is configured to perform braking and steering control of the vehicle according to the target braking force of each wheel and the front wheel steering angle.

[0154] It should be noted that the vehicle control system provided by the above embodiment and the vehicle control method provided by the above embodiment belong to the same concept, wherein the content of the operation of each module has been described in detail in the method embodiment, which will not be described here.

[0155] The application also provides a vehicle control system, comprising: a controller, which uses the vehicle control method as described above to determine the target braking force of each wheel of the vehicle and the front wheel steering angle; a plurality of brakes, which are respectively connected to the controller and respectively act on each wheel of the vehicle, and are used to perform braking operation of the vehicle in response to the braking instruction issued by the controller, wherein the target braking force of each wheel is carried in the braking instruction; a steering device, which is connected to the controller through a steering motor, and is used to perform steering operation of the vehicle in response to the steering instruction issued by the controller, wherein the front wheel steering angle is carried in the steering instruction.

[0156] Please see Figure 4 , Figure 4 is a structural schematic diagram of a vehicle control system according to an example embodiment of the application. As Figure 4As shown, the vehicle control system includes a vehicle controller (i.e., the controller described above), a steering device, a steering motor, and left front EMB, right front EMB, left rear EMB, and right rear EMB (i.e., the plurality of brakes described above) for braking the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel. The vehicle controller, as the core control unit, communicates with the EMB systems of the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel through a private CAN (Controller Area Network) bus, i.e., CAN1, and each wheel EMB receives the braking instruction issued by the vehicle controller and applies braking force to each wheel based on the physical contact connection with each wheel, thereby realizing the braking operation of the vehicle. Meanwhile, the vehicle controller is connected to the steering motor through a private CAN2, the steering motor is connected to the steering device through a physical contact connection, and the steering device is connected to the left front wheel and the right front wheel through a physical contact connection, so that the vehicle controller can issue a steering instruction to the steering motor, and the steering motor drives the steering device to realize the steering of the left front wheel and the right front wheel, thereby realizing the steering control of the vehicle. In addition, the vehicle control system also includes a vehicle inertia sensor, and the vehicle controller is connected to the vehicle inertia sensor through a public CAN bus to receive the dynamic information of the vehicle collected by the vehicle inertia sensor in real time, thereby assisting in the calculation of the braking force distribution and the front wheel steering angle.

[0157] In this way, the existing sensor and actuator resources are fully utilized to realize vehicle stability control without the need for additional hardware devices, thereby reducing the manufacturing cost of the vehicle and improving the reliability and maintainability of the system due to the absence of complex hardware redundancy design.

[0158] The application also provides a vehicle including a processor and a storage device, the storage device being configured to store a program, and the program, when executed by the processor, causing the vehicle to perform the vehicle control method described above, or the vehicle control system described above.

[0159] Please refer to Figure 5 , Figure 5 is a structural schematic diagram of an electronic device provided by an embodiment of the application. Figure 5 A structural schematic diagram of a computer system of an electronic device suitable for implementing the embodiments of the application is shown. It should be noted that Figure 5 The computer system 500 of the electronic device shown is only an example and should not impose any limitation on the functions and use range of the embodiments of the application.

[0160] As Figure 5As shown, the computer system 500 includes a central processing unit (CPU) 501 which can perform various appropriate actions and processes in accordance with a program stored in a read-only memory (ROM) 502 or a program loaded from a storage section 508 into a random access memory (RAM) 503, such as executing the method in the above-described embodiments. In the RAM 503, various programs and data required for the operation of the system are also stored. The CPU 501, the ROM 502, and the RAM 503 are connected to each other through a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0161] Connected to the I / O interface 505 are an input section 506 including a keyboard, a mouse, etc.; an output section 507 including a display such as a Cathode Ray Tube (CRT), a Liquid Crystal Display (LCD), etc., and a speaker, etc.; a storage section 508 including a hard disk, etc.; and a communication section 509 including a network interface card such as a LAN (Local Area Network) card, a modem, etc. The communication section 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to the I / O interface 505 as necessary. A removable recording medium 511 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc. is attached to the drive 510 as necessary, so that a computer program read therefrom is installed into the storage section 508 as necessary.

[0162] In particular, according to the embodiments of the present application, the processes described above with reference to the flowcharts can be implemented as a computer software program. For example, the embodiments of the present application include a computer program product including a computer program carried on a computer-readable medium, the computer program containing a computer program for executing the method shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network by the communication section 509, and / or installed from the removable recording medium 511. When the computer program is executed by the central processing unit (CPU) 501, various functions defined in the system of the present application are executed.

[0163] The present application also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor of a computer, causes the computer to perform the vehicle control method as described above. The computer-readable storage medium can be included in the electronic device described in the above-described embodiments, or can exist separately from the electronic device without being deployed in the electronic device.

[0164] Note that the computer readable medium shown in the embodiments of the present application can be a computer readable signal medium or a computer readable storage medium or any combination of the two. The computer readable storage medium may, for example, be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, or any combination of the above. More specific examples of the computer readable storage medium can include, but are not limited to, an electrical connection having 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), a 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 above. In this application, the computer readable signal medium can include a data signal propagated in or on a baseband medium or a propagated as a carrier wave in a propagated medium, in which computer readable computer program is embodied. Such propagated data signal can take a variety of forms, including but not limited to, an electromagnetic signal, an optical signal, or any suitable combination of the above. The computer readable signal medium can also be any computer readable medium other than the computer readable storage medium, which can send, propagate, or transmit the program for use by or in connection with the instruction execution system, apparatus, or device. The computer program embodied on the computer readable medium can be transmitted by any suitable medium, including but not limited to wireless, wired, or the like, or any suitable combination of the above.

[0165] The above embodiments are merely illustrative of the principles of the present application and the effects thereof, and are not intended to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas of the present application shall be covered by the claims of the present application.

Claims

1. A vehicle control method characterized by, The method comprises: obtaining driving information of the vehicle, the driving information comprising load information, braking information and speed information, the load information comprising load of each wheel, the braking information comprising total braking force and braking state of each wheel; allocating the total braking force to each wheel according to the load and the braking state of each wheel to obtain target braking force of each wheel; determining left-right braking force difference of the vehicle according to the target braking force of each wheel, and determining front wheel steering angle of the vehicle according to the left-right braking force difference and the speed information, wherein the front wheel steering angle is used to generate reverse yaw moment to suppress yaw moment caused by the left-right braking force difference; performing braking and steering control of the vehicle according to the target braking force of each wheel and the front wheel steering angle; determining the front wheel steering angle of the vehicle according to the left-right braking force difference and the speed information comprises: constructing a first calculation equation of front wheel lateral force according to the speed information and the front wheel steering angle based on a vehicle yaw motion model, wherein the front wheel steering angle is a variable; constructing a second calculation equation of front wheel lateral force according to the left-right braking force difference and the front wheel steering angle based on a moment balance principle, wherein the front wheel steering angle is a variable; and solving the front wheel steering angle according to the first calculation equation and the second calculation equation.

2. The vehicle control method according to claim 1, characterized by, After determining the front wheel steering angle of the vehicle, further comprising: obtaining physical parameter information and road information of the vehicle, wherein the physical parameter information comprises center of mass position information; constructing a state space of the vehicle according to the speed information, the target braking force of each wheel, the front wheel steering angle, the braking state of each wheel, the center of mass position information and the road information; inputting the state space into a steering angle correction model to obtain a corrected front wheel steering angle, so as to perform steering control of the vehicle according to the corrected front wheel steering angle, wherein the steering angle correction model is obtained by training a pre-constructed reinforcement learning model based on a state space sample constructed based on center of mass position information, road information, load information, braking information and speed information.

3. The vehicle control method according to claim 2, characterized by, The training method of the steering angle correction model comprises: constructing a reinforcement learning model and a reward function of the reinforcement learning model, wherein the reward function comprises yaw angular velocity deviation term, center of mass side slip angle deviation term and penalty term, and the penalty term is used to constrain excessive correction of the front wheel steering angle; iteratively training the reinforcement learning model according to the state space sample, and obtaining the steering angle correction model when a preset convergence condition is reached.

4. The vehicle control method according to claim 1, characterized by The determination method of the load of each wheel comprises: if lateral acceleration of the vehicle is less than a preset first acceleration threshold, then the front axle load and the rear axle load of the vehicle are respectively evenly distributed among the left and right wheels of the corresponding axle to obtain the load of each wheel; if the lateral acceleration is greater than or equal to the first acceleration threshold and less than a preset second acceleration threshold, then the front axle load and the rear axle load are respectively weightedly distributed among the left and right wheels of the corresponding axle according to the proportion of left and right loads of the vehicle to obtain the load of each wheel; If the lateral acceleration is greater than or equal to the second acceleration threshold, the front axle load and the rear axle load are weighted and distributed among the front and rear wheels on the corresponding side according to the proportion of the front axle load and the rear axle load, and the load of each wheel is obtained; The speed information includes the lateral acceleration, and the load information further includes the front axle load, the rear axle load, the left side load and the right side load.

5. The vehicle control method according to claim 4, characterized by The determination of the front axle load, the rear axle load, the left side load and the right side load comprises: Obtaining physical parameter information and road information of the vehicle, wherein the physical parameter information includes mass information, center of mass position information and wheel position information; Determining the front axle load and the rear axle load according to the mass information, the center of mass position information, the wheel position information, the road information and the longitudinal acceleration, wherein the speed information further includes the longitudinal acceleration; Determining the left side load and the right side load according to the mass information, the center of mass position information, the wheel position information, the road information and the lateral acceleration.

6. The vehicle control method according to any one of claims 1 to 5, characterized by, The distribution of the total braking force to each wheel according to the load of each wheel and the braking state to obtain the target braking force of each wheel comprises: Determining the braking force distribution proportion of each wheel according to the load of each wheel and the braking state, wherein if the target wheel is in the failure state, the braking force distribution proportion of the target wheel is zero; Calculating the braking force distribution proportion of each wheel and the total braking force to obtain the target braking force of each wheel.

7. A vehicle control system characterized by comprising: The system comprises: An acquisition module for acquiring driving information of the vehicle, wherein the driving information includes load information, braking information and speed information, the load information includes the load of each wheel, and the braking information includes a total braking force and a braking state of each wheel; A distribution module for distributing the total braking force to each wheel according to the load of each wheel and the braking state to obtain a target braking force of each wheel; A determination module for determining a left-right side braking force difference of the vehicle according to the target braking force of each wheel, and determining a front wheel steering angle of the vehicle according to the left-right side braking force difference and the speed information, wherein the front wheel steering angle is used to generate a reverse yaw moment to suppress a yaw moment caused by the left-right side braking force difference; A control module for controlling braking and steering of the vehicle according to the target braking force of each wheel and the front wheel steering angle. The determination module is specifically configured to construct a first calculation equation of the front wheel lateral force based on a vehicle yaw motion model according to the speed information and the front wheel steering angle, wherein the front wheel steering angle is a variable; construct a second calculation equation of the front wheel lateral force based on a moment balance principle according to the left-right side braking force difference and the front wheel steering angle, wherein the front wheel steering angle is a variable; and solve the front wheel steering angle according to the first calculation equation and the second calculation equation.

8. A vehicle control system characterized by comprising: The system comprises: A controller for determining the target braking force of each wheel of the vehicle and the front wheel steering angle by using the vehicle control method according to any one of claims 1 to 6. a plurality of brakes, respectively connected to the controller and respectively acting on each wheel of the vehicle, for performing braking operation of the vehicle in response to a braking instruction issued by the controller, wherein the braking instruction carries a target braking force for each wheel; a steering device connected to the controller through a steering motor, for performing steering operation of the vehicle in response to a steering instruction issued by the controller, wherein the steering instruction carries a front wheel steering angle.

9. A vehicle characterized by comprising: a processor and a storage device for storing a program, which when executed by the processor, causes the vehicle to perform the vehicle control method according to any one of claims 1 to 6, or the vehicle control system according to claim 7 or 8.

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