A method and system for automatically distributing tire forces of a chassis vehicle

Abstract

The application discloses a kind of automatic wheel intelligent chassis vehicle tire force distribution control method and system, the method includes the following steps: the generalized force tracking error index of vehicle and comprehensive tire utilization rate index are calculated;Adopt competitive cooperation game strategy, build competition function and cooperation function;Hybrid objective function is obtained by fusing competition function and cooperation function, and conflict degree dynamic adjustment is introduced;The minimum value of hybrid objective function is solved to obtain the expected longitudinal force and expected lateral force of each wheel of vehicle, and the expected longitudinal force and expected lateral force of each wheel are mapped and issued to the angle module actuator of each wheel of vehicle to carry out collaborative control.The application solves the problem that the existing fixed weight distribution strategy cannot dynamically coordinate tire adhesion utilization rate and tire force tracking accuracy when the vehicle is in extreme or severe working conditions, limiting the full play of the high degree of freedom control potential of automatic wheel intelligent chassis.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, specifically to a method and system for controlling tire force distribution in an automatic wheel intelligent chassis vehicle. Background Technology

[0002] With the rapid development of four-wheel independent drive and independent steering technologies, especially the maturity and application of corner module chassis architecture, vehicle dynamics control has entered a new stage. Based on this architecture, advanced algorithms such as vehicle stability control and integrated chassis control can calculate the desired longitudinal force, desired lateral force, and desired yaw moment at the vehicle level. Then, through tire force distribution strategies, these vehicle targets are rationally decomposed to the four wheels, generating the target longitudinal and lateral forces for each wheel, and finally distributed to the hub motors, brake actuators, and steering actuators located in the four corner modules to achieve precise torque and steering control. The automatic wheel intelligent driving chassis technology applied to electric vehicles highly integrates the traditionally dispersed steering, braking, drive, and suspension systems into the wheel modules, greatly simplifying the chassis mechanical structure and achieving 100% modular chassis configuration. Under this technological framework, each of the four wheels becomes an independently controllable actuator, capable of independent drive, independent braking, and independent steering, thus providing the vehicle with unprecedented handling freedom and dynamic adjustment potential.

[0003] However, in existing control schemes, the optimization objective of tire force distribution is usually quite singular, often employing a single indicator such as optimal tire utilization, or simply combining a few indicators such as tire utilization and tire force error in a simple linear weighted combination, with the weights of each indicator often preset as fixed parameters. This fixed-weight allocation strategy is applicable under normal stable driving conditions, but when the vehicle is under aggressive driving, experiencing severe load transfer, or transitioning from the stable zone to the extreme zone, for advanced architectures like vehicles with automatic wheel intelligent driving chassis that possess high degrees of freedom in four-wheel independent drive and independent steering, fixed weights are insufficient to dynamically coordinate the balance between tire adhesion utilization and tire force tracking accuracy. Overemphasizing minimizing utilization may sacrifice control response speed, while unilaterally pursuing tracking accuracy may prematurely deplete tire adhesion reserves, resulting in the inability to fully release control potential under critical conditions, and even affecting the overall vehicle stability boundary. Therefore, there is an urgent need to provide a tire force distribution method suitable for intelligent autonomous vehicle chassis. Based on a thorough consideration of tire nonlinear adhesion characteristics and the physical constraints of corner module actuators, this method can achieve a dynamic balance between vehicle performance and stability, thereby promoting the development of high-degree-of-freedom chassis control technology towards a more intelligent, safer, and more efficient direction. Summary of the Invention

[0004] The purpose of this invention is to provide a tire force distribution control method and system for intelligent automatic wheel chassis vehicles, in order to solve the problem that existing fixed-weight distribution strategies cannot dynamically coordinate tire adhesion utilization and tire force tracking accuracy when the vehicle is under extreme or drastically changing operating conditions, thus limiting the full realization of the high degree of freedom control potential of intelligent automatic wheel chassis vehicles.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for controlling tire force distribution in an autonomous intelligent chassis vehicle includes the following steps:

[0007] S1: Calculate the generalized force tracking error index and comprehensive tire utilization index of the vehicle based on the vehicle's expected longitudinal force, expected lateral force and expected yaw moment issued by the vehicle controller.

[0008] S2: A competitive-cooperative game strategy is adopted. The competition function and the cooperation function are constructed through the generalized force tracking error index and the comprehensive tire utilization rate index. The competition function and the cooperation function are fused to obtain a hybrid objective function. The conflict degree is introduced to adjust the competition and cooperation weight coefficients online to achieve adaptive adjustment of the hybrid objective function.

[0009] S3: Optimize and solve the hybrid objective function to obtain the desired longitudinal force and desired lateral force of each wheel of the vehicle in the vehicle body coordinate system. Map the desired longitudinal force and desired lateral force of each wheel and send them to the corner module actuators of each wheel of the vehicle for coordinated control.

[0010] To optimize the above technical solution, the specific limitations also include:

[0011] The formula for calculating the generalized force tracking error index is as follows:

[0012] ;

[0013] in, For generalized force tracking error index, For generalized longitudinal force error, For the desired longitudinal force of the whole vehicle, For the generalized longitudinal force of the vehicle; For generalized lateral force error, The desired lateral force for the entire vehicle. For generalized lateral forces on a vehicle; For generalized yaw moment error, For the desired yaw moment of the whole vehicle, The generalized yaw moment of a vehicle.

[0014] Preferably, the formula for calculating the comprehensive tire utilization rate index is as follows:

[0015] ;

[0016] in, To comprehensively measure tire utilization rate, This is the weighting coefficient for the maximum utilization rate of a single round. This is the weighting coefficient for the overall tire utilization rate of the vehicle, with a value range of [0,1]. The overall tire utilization rate is a weighting factor. To maximize the utilization rate of a single wheel, For the utilization rate of a single wheel tire, These represent the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively. This refers to the overall tire utilization rate of the vehicle.

[0017] Preferably, in step S2, a competitive-cooperative game strategy is adopted to construct a competition function and a cooperation function based on the generalized force tracking error index and the comprehensive tire utilization rate index, wherein the competition function is:

[0018] ;

[0019] in, For competition functions, To comprehensively measure tire utilization rate, This refers to the generalized force tracking error index.

[0020] The cooperation function is:

[0021] ;

[0022] in, For cooperative functions, The overall tire utilization rate is weighted by a coefficient. This is the weighting coefficient for the generalized force tracking error.

[0023] Further, in step S2, the fusion of the competition function and the cooperation function yields a hybrid objective function, wherein the formula for the hybrid objective function is:

[0024] ;

[0025] in, For a mixed objective function, This represents the competition / cooperation weighting coefficient.

[0026] Furthermore, in step S2, the dynamic adjustment of the hybrid objective function is achieved by introducing a conflict degree. Specifically, the conflict degree is used to characterize the degree of conflict between each indicator, and the competition and cooperation weight coefficients are updated online accordingly, thereby achieving adaptive adjustment of the hybrid objective function. The calculation formula is as follows:

[0027] ;

[0028] in, For the degree of conflict, For dispersion, The average of the combined tire utilization rate index and the generalized force tracking error index is used. For numerically stable terms, This refers to the sensitivity parameter.

[0029] Preferably, in step S3, the step of minimizing the mixed objective function to obtain the desired longitudinal force and desired lateral force of each wheel of the vehicle is specifically performed using a constrained nonlinear programming method, under the conditions of satisfying the friction circle constraint and the tire force balance relationship; the friction circle constraint is that the longitudinal force and lateral force of each tire satisfy the inequality constraint:

[0030] ;

[0031] in, The road surface adhesion coefficient, The vertical load for a single tire. This represents the longitudinal force of a single tire in the vehicle body coordinate system. This represents the lateral force of a single tire in the vehicle's coordinate system. These represent the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively.

[0032] Furthermore, in step S3, the actuator control parameters include the target torque at the wheel end and the wheel steering angle.

[0033] Furthermore, the formula for calculating the wheel steering angle is:

[0034] ;

[0035] in, For the wheel steering angle, It is the angle between the actual direction of travel of the wheels and the longitudinal direction of the vehicle body. This refers to the tire slip angle. These represent the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively.

[0036] The formula for calculating the target torque at the wheel end is:

[0037] ;

[0038] in, The target torque at the wheel end, For the desired wheel angular velocity, For the moment of inertia of the wheel, This represents the longitudinal force of the wheel in the tire coordinate system. The tire's rolling radius, The rolling resistance coefficient, This refers to the vertical load on a single tire.

[0039] This invention also proposes an automatic wheel intelligent chassis vehicle tire force distribution control system, comprising:

[0040] The index calculation module is used to calculate the generalized force tracking error index and the comprehensive tire utilization index of the vehicle based on the vehicle's expected longitudinal force, expected lateral force and expected yaw moment issued by the vehicle controller.

[0041] The competition-cooperation game module is used to construct competition and cooperation functions based on the generalized force tracking error index and the comprehensive tire utilization rate index using a competition-cooperation game strategy; the competition and cooperation functions are fused to obtain a hybrid objective function, and the competition and cooperation weight coefficients are adjusted online by introducing the conflict degree to achieve adaptive adjustment of the hybrid objective function;

[0042] The solution control module is used to optimize the solution of the hybrid objective function, thereby obtaining the expected longitudinal force and expected lateral force of each wheel of the vehicle in the vehicle body coordinate system. The expected longitudinal force and expected lateral force of each wheel are mapped into actuator control parameters and sent to the actuators in the wheel corner modules of the vehicle for coordinated control.

[0043] The corner module actuator, including the hub motor, brake actuator and steering actuator, is used to receive the target torque at the wheel end and the wheel steering angle issued by the system, and to perform corresponding coordinated control.

[0044] Compared with the prior art, the beneficial effects of the present invention are:

[0045] This invention provides a tire force distribution control method for vehicles with an automated wheel intelligent chassis. By considering the vehicle's generalized force tracking error index and comprehensive tire utilization rate index, it prevents excessive tire utilization of individual wheels while reasonably constraining the overall vehicle adhesion utilization level. A competitive-cooperative game theory control algorithm is employed to comprehensively consider tire utilization rate and tire force error, preventing either from becoming excessive and achieving a dynamic balance between vehicle dynamic performance and safety. Furthermore, a conflict degree adjustment hybrid objective function is introduced when using the competitive-cooperative game strategy, enabling dynamic adjustment of tire force distribution between competition and cooperation. This balances the control needs of each wheel. When both tire utilization rate and tire force error are small and not significantly different, cooperation takes precedence, comprehensively weighing both indicators. When one indicator is significantly greater than the other, competition takes precedence, prioritizing the suppression of the larger indicator, thus achieving a dynamic equilibrium between vehicle dynamic performance and driving stability.

[0046] This invention introduces a conflict degree mechanism to perceive the conflict state between tire force error and utilization rate in real time. The system prioritizes suppressing error surges or utilization rate saturation to prevent the vehicle from entering the instability zone. At the same time, it combines a hybrid objective function based on dynamic adjustment of conflict degree with nonlinear programming for solution. Under the premise of satisfying friction circle constraints and force balance relationship, the algorithm's computational complexity is reduced by conflict degree, ensuring the real-time performance of the algorithm in the vehicle embedded system. It is suitable for high-frequency chassis control loops.

[0047] This invention relies on the integrated execution characteristics of the vehicle corner modules of the automatic wheel intelligent driving chassis to map the desired longitudinal force and desired lateral force into actuator control parameters and send them to the hub motor, brake actuator and steering actuator in each corner module for coordinated control. This achieves accurate tracking of the actual longitudinal force and actual lateral force to the desired value, ensuring the vehicle's driving stability under complex working conditions. Attached Figure Description

[0048] Figure 1 : A flowchart illustrating a method for controlling tire force distribution in an automatic wheel intelligent chassis vehicle according to the present invention. Detailed Implementation

[0049] The present invention will be further described in detail below through specific embodiments, but it should not be construed as limiting the scope of the subject matter of the present invention to the following embodiments. All technologies implemented based on the above content of the present invention fall within the scope of the present invention.

[0050] The technical solution of the present invention will be further described in detail below with reference to specific embodiments:

[0051] The automatic wheel intelligent chassis vehicle includes four corner modules, which are located at the four corners of the vehicle. Each corner module is a wheel-end modular unit, which uses a hub motor as the drive source. It integrates the drive unit, brake actuator, steering actuator and suspension load-bearing structure at the wheel end, so that the vehicle forms an independently controllable actuator at each wheel, realizing independent driving, braking and independent steering of each wheel.

[0052] This invention proposes a tire force distribution control method for vehicles with an automated wheel intelligent chassis. It comprehensively considers tire utilization rate and tire force error, taking into account both the individual tire utilization rate of a single wheel and the overall tire utilization rate of the entire vehicle. While minimizing the overall tire utilization rate, it avoids saturation of individual wheel tire utilization. The tire force distribution control method employs a competitive-cooperative game strategy, incorporating the aforementioned core indicators into a unified optimization framework. Through a game mechanism, it balances the control needs of each wheel. When both tire utilization rate and tire force error are small and not significantly different, cooperation takes precedence, comprehensively weighing the two indicators. When one indicator is significantly greater than the other, competition takes precedence, prioritizing the suppression of the larger indicator. Furthermore, relying on the integrated execution characteristics of the corner modules, the desired longitudinal force and desired lateral force are mapped to the target torque at the wheel end and the wheel steering angle, and then distributed to the hub motors, brake actuators, and steering actuators within each corner module for coordinated control. This achieves accurate tracking of the actual longitudinal and lateral forces to the desired values, ensuring vehicle stability under complex operating conditions.

[0053] The flowchart of this method is as follows: Figure 1 As shown, the entire method includes the following steps:

[0054] S1: Calculate the generalized force tracking error index and comprehensive tire utilization index of the vehicle based on the vehicle's expected longitudinal force, expected lateral force and expected yaw moment issued by the vehicle controller.

[0055] S2: A competitive-cooperative game strategy is adopted. Based on the generalized force tracking error index and the comprehensive tire utilization rate index, a competitive function and a cooperative function are constructed. The competitive function and the cooperative function are merged to obtain a hybrid objective function. The conflict degree is introduced to adjust the competitive and cooperative weight coefficients online, so as to realize the adaptive adjustment of the hybrid objective function.

[0056] S3: Optimize the mixed objective function to obtain the desired longitudinal force and desired lateral force of each wheel in the vehicle body coordinate system. Map the desired longitudinal force and desired lateral force of each wheel into actuator control parameters and send them to the corner module actuators of each wheel for coordinated control.

[0057] In step S1, the upper-level controller sends the desired longitudinal force for the entire vehicle. Desired lateral force of the whole vehicle And the expected yaw moment of the whole vehicle And obtain the vehicle's generalized longitudinal force through allocation. Generalized lateral force of vehicles and vehicle generalized yaw moment :

[0058] (1);

[0059] in, The track width between the front and rear wheels. , These are the distances from the center of mass to the front axle and from the center of mass to the rear axle, respectively. This represents the longitudinal force of a single tire in the vehicle body coordinate system. This represents the lateral force of a single tire in the vehicle's coordinate system. These correspond to the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively.

[0060] Define the generalized longitudinal force error, the generalized lateral force error, and the generalized yaw moment error:

[0061] (2);

[0062] in, For generalized longitudinal force error, For generalized lateral force error, This refers to the generalized yaw moment error.

[0063] During the distribution process, due to limitations imposed by road surface adhesion conditions, the longitudinal and lateral forces of the tires must satisfy the friction circle constraint:

[0064] (3);

[0065] in, The road surface adhesion coefficient, The vertical load for a single tire. This represents the longitudinal force of a single tire in the vehicle body coordinate system. This represents the lateral force of a single tire in the vehicle's coordinate system. .

[0066] To prevent large errors in the generalized longitudinal force, generalized lateral force, and generalized yaw moment from reducing tracking accuracy, an error penalty function is constructed:

[0067] (4);

[0068] in, The sum of the squares of the generalized longitudinal force error, the generalized lateral force error, and the generalized yaw moment error is used as the error penalty function.

[0069] Therefore, the formula for calculating the generalized force tracking error index is defined as follows:

[0070] (5);

[0071] in, It is a generalized force tracking error index.

[0072] For a single wheel, calculate its tire utilization rate:

[0073] (6);

[0074] in, For the utilization rate of a single wheel tire, The road surface adhesion coefficient, The vertical load for a single tire. This represents the longitudinal force of a single tire in the vehicle body coordinate system. This represents the lateral force of a single tire in the vehicle's coordinate system. .

[0075] Maximum tire utilization rate of a single wheel:

[0076] (7);

[0077] in, To maximize the utilization rate of a single wheel, These represent the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively.

[0078] Therefore, the comprehensive tire utilization rate index is constructed as follows:

[0079] (8);

[0080] in, This is the weighting coefficient for the maximum utilization rate of a single round. This is the weighting coefficient for the overall tire utilization rate of the vehicle, with a value range of [0,1]. The overall tire utilization rate is a weighting factor. This refers to the overall tire utilization rate of the vehicle.

[0081] In step S2, a competitive-cooperative game strategy is adopted. A competition function and a cooperation function are constructed based on the generalized force tracking error index and the comprehensive tire utilization rate index. The competition function is as follows:

[0082] (9);

[0083] in, For competition functions, To comprehensively measure tire utilization rate, This refers to the generalized force tracking error index.

[0084] The cooperation function is:

[0085] (10);

[0086] in, For cooperative functions, The overall tire utilization rate is weighted by a coefficient. This is the weighting coefficient for the generalized force tracking error.

[0087] To achieve a continuous transition between competition and cooperation, a hybrid objective function is obtained by integrating the competition function and the cooperation function. The formula for the hybrid objective function is as follows:

[0088] (11);

[0089] in, For a mixed objective function, This represents the competition / cooperation weighting coefficient.

[0090] To ensure a smooth transition of the mixed objective function with changing operating conditions, a conflict degree is constructed and used to adaptively adjust the cooperation-competition weight coefficients, thereby dynamically adjusting the mixed objective function. The calculation formula is as follows:

[0091] (12);

[0092] in, For the degree of conflict, For dispersion, The average of the combined tire utilization rate index and the generalized force tracking error index is used. For numerically stable terms, For sensitivity parameters, To comprehensively measure tire utilization rate, It is a generalized force tracking error index.

[0093] In step S3, the minimum value of the mixed objective function is solved to obtain the desired longitudinal force and desired lateral force of each wheel of the vehicle, and a set of longitudinal forces and lateral forces of each tire contact point along the vehicle body direction are obtained. The desired longitudinal force and desired lateral force of each wheel are then mapped to the target torque at the wheel end and the wheel steering angle of each corner module of the vehicle, and then sent to the hub motor, brake actuator and steering actuator of the corner module actuator.

[0094] The relationship between the longitudinal and lateral forces of a single wheel in the tire coordinate system and in the vehicle body coordinate system is as follows:

[0095] (13);

[0096] in, For a single wheel, the longitudinal force in the vehicle body coordinate system, Lateral force of a single wheel in the vehicle body coordinate system. For a single wheel, the longitudinal force in the tire coordinate system, This represents the lateral force of a single wheel in the tire coordinate system. For the wheel steering angle, These represent the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively.

[0097] The Dugoff tire inverse model is used to convert the longitudinal and lateral forces of the wheels in the tire coordinate system into target torques and steering angles at the wheel ends, thereby achieving unified control of torque and steering of all four wheels.

[0098] The Dugoff tire model is as follows:

[0099] (14);

[0100] in, For a single wheel, the longitudinal force in the tire coordinate system, This represents the lateral force of a single wheel in the tire coordinate system. For tire lateral stiffness, For tire longitudinal stiffness. For tire slip ratio, The tire slip angle, These represent the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively.

[0101] The scaling function is calculated using the following formula:

[0102] (15);

[0103] in, For scaling functions, Indicates the area where the tire is located. This indicates that the tire is in a non-linear region. This indicates that the tire is in the linear region. The vertical load for a single tire. For tire slip ratio, This refers to the tire slip angle. The road surface adhesion coefficient, For tire lateral stiffness, For tire longitudinal stiffness. These represent the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively.

[0104] By combining the Dugoff tire model, the area where the tire is located can be determined. for:

[0105] (16);

[0106] in, The vertical load for a single tire. The road surface adhesion coefficient, These represent the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively.

[0107] Combining equations (15) and (16), the scaling function can be obtained as follows:

[0108] (17);

[0109] Based on the Dugoff tire model and scaling function, the tire slip angle is:

[0110] (18);

[0111] in, This refers to the tire slip angle. The road surface adhesion coefficient, For tire lateral stiffness, For tire longitudinal stiffness. This represents the longitudinal force of the wheel in the tire coordinate system. This represents the lateral force of the wheel in the tire coordinate system. The vertical load for a single tire. These represent the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively.

[0112] The formula for calculating wheel slip ratio is:

[0113] (19);

[0114] in, For tire slip ratio, The road surface adhesion coefficient, For a single wheel, the longitudinal force in the tire coordinate system, This represents the lateral force of a single wheel in the tire coordinate system. The vertical load for a single tire. These represent the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively.

[0115] The wheel steering angle is:

[0116] (20);

[0117] in, For the wheel steering angle, It is the angle between the actual direction of travel of the wheels and the longitudinal direction of the vehicle body. This refers to the tire slip angle. These represent the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively.

[0118] Based on the calculated wheel slip ratio, the desired wheel angular velocity can be obtained:

[0119] (twenty one);

[0120] in, For the desired wheel angular velocity, For tire slip ratio, Let be the longitudinal velocity of the wheel in the tire coordinate system. This is the tire's rolling radius.

[0121] Based on the desired wheel angular velocity, the target torque at the wheel ends of all four wheels can be obtained:

[0122] (twenty two);

[0123] in, The target torque at the wheel end, For the desired wheel angular velocity, For the moment of inertia of the wheel, This represents the longitudinal force of the wheel in the tire coordinate system. The tire's rolling radius, The rolling resistance coefficient, This refers to the vertical load on a single tire.

[0124] This invention also proposes an automatic wheel intelligent chassis vehicle tire force distribution control system, comprising:

[0125] The index calculation module is used to calculate the generalized force tracking error index and the comprehensive tire utilization index of the vehicle based on the vehicle's expected longitudinal force, expected lateral force and expected yaw moment issued by the vehicle controller.

[0126] The competition-cooperation game module is used to construct competition and cooperation functions based on the generalized force tracking error index and the comprehensive tire utilization rate index using a competition-cooperation game strategy. The competition and cooperation functions are then fused to obtain a hybrid objective function, and the competition and cooperation weight coefficients are adjusted online by introducing the conflict degree to achieve adaptive adjustment of the hybrid objective function.

[0127] The solution control module is used to optimize the solution of the hybrid objective function, thereby obtaining the expected longitudinal force and expected lateral force of each wheel of the vehicle in the vehicle body coordinate system. The expected longitudinal force and expected lateral force of each wheel are mapped into actuator control parameters and sent to the actuators in the wheel corner modules of the vehicle for coordinated control.

[0128] The corner module actuator, including the hub motor, brake actuator and steering actuator, is used to receive the target torque at the wheel end and the wheel steering angle issued by the system, and to perform corresponding coordinated control.

[0129] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent substitutions, and improvements made by those skilled in the art to the above embodiments without departing from the scope of the technical solution of the present invention, based on the technical essence of the present invention, shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for controlling tire force distribution in an automatic wheel intelligent chassis vehicle, characterized in that, Includes the following steps: S1: Calculate the generalized force tracking error index and comprehensive tire utilization index of the vehicle based on the vehicle's expected longitudinal force, expected lateral force and expected yaw moment issued by the vehicle controller. The formula for calculating the generalized force tracking error index is as follows: ； in, For generalized force tracking error index, For generalized longitudinal force error, For the desired longitudinal force of the whole vehicle, For the generalized longitudinal force of the vehicle; For generalized lateral force error, The desired lateral force for the entire vehicle. For generalized lateral forces on a vehicle; For generalized yaw moment error, For the desired yaw moment of the whole vehicle, For the generalized yaw moment of the vehicle; The formula for calculating the comprehensive tire utilization rate index is as follows: ； in, To comprehensively measure tire utilization rate, This is the weighting coefficient for the maximum utilization rate of a single round. This is the weighting coefficient for the overall tire utilization rate of the vehicle, with a value range of [0,1]. The overall tire utilization rate index is a weighting factor. To maximize the utilization rate of a single wheel, For the utilization rate of a single wheel tire, These correspond to the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively. For the overall tire utilization rate of the vehicle; S2: Employing a competitive-cooperative game strategy, a competition function and a cooperation function are constructed based on the generalized force tracking error index and the comprehensive tire utilization rate index; The competition function is: ； in, For competition functions; The cooperation function is: ； in, For cooperative functions, The overall tire utilization rate is weighted by a coefficient. The weighting coefficient for the generalized force tracking error; By combining the competition function and the cooperation function, a mixed objective function is obtained. The formula for the mixed objective function is: ； in, For a mixed objective function, For competition and cooperation weighting coefficients; By introducing conflict level to adjust the competition and cooperation weight coefficients online, the adaptive adjustment of the mixed objective function is achieved. The calculation formula is as follows: ； in, For the degree of conflict, For dispersion, The average of the combined tire utilization rate index and the generalized force tracking error index is used. For numerically stable terms, For sensitivity parameters; S3: Optimize the hybrid objective function to obtain the desired longitudinal force and desired lateral force of each wheel in the vehicle's coordinate system. Specifically, this is achieved by using a constrained nonlinear programming method, under the conditions of satisfying the friction circle constraint and the tire force balance relationship; the friction circle constraint is that the longitudinal force and lateral force of each tire satisfy the inequality constraint: ； in, The road surface adhesion coefficient, The vertical load for a single tire. This represents the longitudinal force of a single tire in the vehicle body coordinate system. The lateral force of a single tire in the vehicle body coordinate system; The desired longitudinal force and desired lateral force of each wheel are mapped into actuator control parameters and sent to the actuators in the wheel corner modules of the vehicle for coordinated control.

2. The method for controlling tire force distribution in an automatic wheel intelligent chassis vehicle according to claim 1, characterized in that: In step S3, the actuator control parameters include the target torque at the wheel end and the wheel steering angle.

3. The method for controlling tire force distribution in an automatic wheel intelligent chassis vehicle according to claim 2, characterized in that: The formula for calculating the wheel steering angle is: ； in, For the wheel steering angle, It is the angle between the actual direction of travel of the wheels and the longitudinal direction of the vehicle body. This refers to the tire slip angle. These represent the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively. The formula for calculating the target torque at the wheel end is: ； in, The target torque at the wheel end, For the desired wheel angular velocity, For the moment of inertia of the wheel, This represents the longitudinal force of the wheel in the tire coordinate system. The tire's rolling radius, The rolling resistance coefficient, This refers to the vertical load on a single tire.

4. A tire force distribution control system for an automatic wheel intelligent chassis vehicle, characterized in that, include: The index calculation module is used to calculate the generalized force tracking error index and the comprehensive tire utilization index of the vehicle based on the vehicle's expected longitudinal force, expected lateral force and expected yaw moment issued by the vehicle controller. The competition-cooperation game module is used to construct competition and cooperation functions based on the generalized force tracking error index and the comprehensive tire utilization rate index using a competition-cooperation game strategy; the competition and cooperation functions are fused to obtain a hybrid objective function, and the competition and cooperation weight coefficients are adjusted online by introducing the conflict degree to achieve adaptive adjustment of the hybrid objective function; The solution control module is used to optimize the solution of the hybrid objective function, thereby obtaining the expected longitudinal force and expected lateral force of each wheel of the vehicle in the vehicle body coordinate system. The expected longitudinal force and expected lateral force of each wheel are mapped into actuator control parameters and sent to the actuators in the wheel corner modules of the vehicle for coordinated control. The corner module actuator, including the hub motor, brake actuator and steering actuator, is used to receive the target torque at the wheel end and the wheel steering angle issued by the system, and to perform corresponding coordinated control.

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