Vehicle tire force determination method, device, equipment, medium, product and vehicle

Abstract

The present application discloses a vehicle tire force determination method, device, equipment, medium, product and vehicle, and relates to the field of vehicle technology. The vehicle tire force method comprises: obtaining a tire force distribution request, wherein the tire force distribution request includes a first parameter required to achieve the resultant force of the tire forces of the four tires of the vehicle and a second parameter required for tire force distribution; determining the first tire force of the front wheels and the rear wheels of the vehicle according to the first parameter, the second parameter and the constraints that the tire force needs to satisfy; constructing a tire force optimization problem corresponding to the constraints that the tire force needs to satisfy based on the first tire force; solving the tire force optimization problem to obtain the second tire force of the front wheels and the rear wheels of the vehicle. According to the scheme disclosed in the present application, the vehicle tire force can be reasonably determined so that the stability of the vehicle's yaw freedom can be guaranteed under extreme conditions, while the driving efficiency is optimized under normal conditions.

Description

Technical Field

[0001] The present application belongs to the field of vehicle technology, and in particular, relates to a method, device, equipment, medium, product and vehicle for determining vehicle tire force. Background Art

[0002] The Vehicle Motion Controller (VMC) is the core of high-performance vehicle path and speed tracking control technology. It requires the control algorithm to be able to accurately track any dynamically feasible reference trajectory so that the maneuverability of the intelligent vehicle reaches and exceeds the human driving level, making transportation more efficient and safer in emergency conditions.

[0003] In VMC, the target longitudinal force, target lateral force, and target yaw moment required by the vehicle are first determined. Then, the target tire force is obtained by allocating them, and the underlying controller controls the wheels to achieve the tire force to achieve the expected movement of the vehicle.

[0004] In the related art, when determining the vehicle tire force, VMC only determines it based on the target longitudinal resultant force and the target lateral resultant force, while ignoring the influence of the yaw moment on the vehicle tire force, resulting in inaccurate vehicle tire force. In addition, due to its inherent characteristics, the vehicle cannot achieve the target resultant yaw moment under normal working conditions, and a corresponding method needs to be designed to solve this problem. Summary of the invention

[0005] The embodiments of the present application provide a method, device, equipment, medium, product and vehicle for determining vehicle tire force, which can solve the problem of inaccurate determination of vehicle tire force.

[0006] In a first aspect, an embodiment of the present application provides a method for determining a vehicle tire force, comprising:

[0007] Obtaining a tire force distribution request, wherein the tire force distribution request includes a first parameter required to achieve a resultant force of tire forces of four tires of the vehicle and a second parameter required for tire force distribution, the first parameter includes a target resultant longitudinal force, a target resultant lateral force, and a target resultant yaw moment, and the second parameter includes a rear wheel adhesion coefficient, a rear wheel vertical load, a rear wheel sideslip angle, a rear wheel cornering stiffness, a first distance from the center of mass of the vehicle to the front axle, and a second distance from the center of mass of the vehicle to the rear axle;

[0008] Determine the first tire force of the front wheel and the rear wheel of the vehicle according to the first parameter, the second parameter and the constraint condition that the tire force needs to satisfy;

[0009] Based on the first tire force, constructing a tire force optimization problem corresponding to the constraint condition, wherein the tire force optimization problem includes a constraint between a rear wheel longitudinal force and a rear wheel lateral force of a quadratic type;

[0010] The tire force optimization problem is solved to obtain the second tire forces of the front wheels and the rear wheels of the vehicle.

[0011] In a second aspect, an embodiment of the present application provides a vehicle tire force determination device, comprising:

[0012] an acquisition module, configured to acquire a tire force distribution request, wherein the tire force distribution request includes a first parameter required to be achieved for the resultant force of the tire forces of the four tires of the vehicle and a second parameter required for tire force distribution, the first parameter includes a target resultant longitudinal force, a target resultant lateral force, and a target resultant yaw moment, and the second parameter includes a rear wheel adhesion coefficient, a rear wheel vertical load, a rear wheel sideslip angle, a rear wheel sideslip stiffness, a first distance from the vehicle center of mass to the front axle, and a second distance from the vehicle center of mass to the rear axle;

[0013] A determination module, used for determining first tire forces of the front wheels and the rear wheels of the vehicle according to the first parameter, the second parameter and the constraint conditions that the tire forces need to satisfy;

[0014] A construction module is used to construct a tire force optimization problem corresponding to the constraint condition based on the first tire force, wherein the tire force optimization problem includes a constraint between a rear wheel longitudinal force and a rear wheel lateral force of a quadratic form;

[0015] The solution module is used to solve the tire force optimization problem and obtain the second tire forces of the front wheels and the rear wheels of the vehicle.

[0016] In a third aspect, an embodiment of the present application provides an electronic device, comprising: a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, the steps of the vehicle tire force determination method provided in the embodiment of the present application are implemented.

[0017] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having computer program instructions stored thereon, and when the computer program instructions are executed by a processor, the steps of the vehicle tire force determination method provided in the embodiment of the present application are implemented.

[0018] In a fifth aspect, an embodiment of the present application provides a computer program product, which includes computer program instructions. When the computer program instructions are executed by a processor, the steps of the vehicle tire force determination method provided in the embodiment of the present application are implemented.

[0019] In a sixth aspect, an embodiment of the present application provides a vehicle, comprising at least one of the following:

[0020] The vehicle tire force determination device provided in the embodiment of the present application;

[0021] The electronic device provided by the embodiment of the present application;

[0022] The computer-readable storage medium provided by the embodiments of the present application.

[0023] In an embodiment of the present application, a tire force distribution request is obtained, wherein the tire force distribution request includes a first parameter required to achieve the resultant force of the tire forces of the four tires of the vehicle and a second parameter required for tire force distribution, the first parameter includes a target resultant longitudinal force, a target resultant lateral force and a target resultant yaw moment, and the second parameter includes a rear wheel adhesion coefficient, a rear wheel vertical load, a rear wheel sideslip angle, a rear wheel lateral stiffness, a first distance from the vehicle's center of mass to the front axle, and a second distance from the vehicle's center of mass to the rear axle; the first tire forces of the front wheels and the rear wheels of the vehicle are determined according to the first parameter, the second parameter and the constraints that the tire forces need to satisfy; based on the first tire force, a tire force optimization problem corresponding to the constraints is constructed, wherein the tire force optimization problem includes constraints between the rear wheel longitudinal force and the rear wheel lateral force of a quadratic form; the tire force optimization problem is solved to obtain the second tire forces of the front wheels and the rear wheels of the vehicle. In this way, when determining the vehicle tire force, the influence of the yaw moment on the vehicle tire force is not ignored, and it is achieved that according to the working conditions, the target combined yaw moment is adaptively considered when determining the tire force under extreme conditions, while the target combined yaw moment is not considered when determining the tire force under normal conditions, and a smooth transition between the two can be achieved, which can improve the accuracy and rationality of determining the vehicle's target tire force. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 is a flow chart of a method for determining vehicle tire force provided in an embodiment of the present application;

[0026] Figure 2 is a schematic diagram of a structure for distributing tire forces provided in an embodiment of the present application;

[0027] Figure 3 is a schematic diagram of a solution of rear wheel longitudinal force and rear wheel lateral force provided by an embodiment of the present application;

[0028] Figure 4 is a schematic diagram of a vehicle U-turn condition provided in an embodiment of the present application;

[0029] Figure 5 is a schematic diagram of tire forces provided by an embodiment of the present application;

[0030] Figure 6 is a schematic structural diagram of a vehicle tire force determination device provided in an embodiment of the present application;

[0031] Figure 7 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0033] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0034] In conjunction with the accompanying drawings, the vehicle tire force determination method, device, equipment, medium, product and vehicle provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0035] Figure 1 FIG. 1 is a flow chart of a method for determining vehicle tire force provided in an embodiment of the present application. Figure 1 As shown, the vehicle tire force determination method may include:

[0036] Step 101: Obtaining a tire force distribution request, wherein the tire force distribution request includes a first parameter required to achieve a resultant force of tire forces of four tires of the vehicle and a second parameter required for tire force distribution, the first parameter includes a target resultant longitudinal force, a target resultant lateral force, and a target resultant yaw moment, and the second parameter includes a rear wheel adhesion coefficient, a rear wheel vertical load, a rear wheel sideslip angle, a rear wheel cornering stiffness, a first distance from the center of mass of the vehicle to the front axle, and a second distance from the center of mass of the vehicle to the rear axle;

[0037] In some possible implementations of the embodiments of the present application, the VMC may include an upper motion control layer, a middle tire force distribution layer, and a lower actuator distribution layer.

[0038] The upper motion control layer calculates the required longitudinal force, lateral force and yaw moment of the vehicle based on the expected motion (expected path and expected speed) and the measured motion obtained by actual measurement, and calculates the rear wheel adhesion coefficient, rear wheel vertical load, rear wheel side slip angle, rear wheel side stiffness, the first distance from the vehicle's center of mass to the front axle and the second distance from the vehicle's center of mass to the rear axle through the vehicle motion state and parameter estimation module; the calculated data is transmitted to the middle tire force distribution layer; the middle tire force distribution layer calculates the tire forces of the front wheels and rear wheels of the vehicle based on the received data, and sends the calculated tire forces of the front wheels and rear wheels of the vehicle to the lower actuator distribution layer; the lower actuator distribution layer generates actuator (such as wheel angle, motor torque, etc.) instructions that can generate the received tire forces of the front wheels and rear wheels of the vehicle based on the received tire forces of the front wheels and rear wheels of the vehicle, and executes the actuator instructions to distribute the calculated tire forces of the front wheels and rear wheels of the vehicle. Figure 2 As shown, Figure 2 It is a schematic diagram of the architecture for distributing tire forces provided in an embodiment of the present application.

[0039] In some possible implementations of the embodiments of the present application, the tire force of the front wheels of the vehicle in the embodiments of the present application is represented by the component of the tire force of the front wheels of the vehicle on the vertical axis of the vehicle body coordinate system (referred to as the front wheel longitudinal force) and the component of the tire force of the front wheels of the vehicle on the horizontal axis of the vehicle body coordinate system (referred to as the front wheel lateral force); the tire force of the rear wheels of the vehicle in the embodiments of the present application is represented by the component of the tire force of the rear wheels of the vehicle on the vertical axis of the vehicle body coordinate system (referred to as the rear wheel longitudinal force) and the component of the tire force of the rear wheels of the vehicle on the horizontal axis of the vehicle body coordinate system (referred to as the rear wheel lateral force).

[0040] Step 102: Determine the first tire forces of the front wheels and the rear wheels of the vehicle according to the first parameter, the second parameter and the constraint conditions that the tire forces need to satisfy.

[0041] In some possible implementations of the embodiments of the present application, the constraints that the tire forces need to satisfy include: when the tire forces are synthesized, in the longitudinal direction, the resultant force of the tire forces of the vehicle's four tires is equal to the target resultant longitudinal force, that is, in the longitudinal direction, the resultant force of the front wheel longitudinal force and the rear wheel longitudinal force is equal to the target resultant longitudinal force; in the lateral direction, the resultant force of the tire forces of the vehicle's four tires is equal to the target resultant lateral force, that is, the resultant force of the front wheel lateral force and the rear wheel lateral force is equal to the target resultant lateral force; the resultant torque calculated based on the tire forces of the vehicle's four tires is equal to the target resultant yaw torque; and the physical constraints of the vehicle system.

[0042] For vehicles with front-wheel steering and independently controllable front and rear axle driving forces, the front wheels can steer and drive and brake at the same time, and the front wheel longitudinal force and front wheel lateral force can be controlled independently; while the rear wheels can only be driven and braked, and there is coupling between the rear wheel longitudinal force and the rear wheel lateral force, and the coupling relationship constraints must be satisfied between the rear wheel longitudinal force and the rear wheel lateral force.

[0043] In some possible implementations of the embodiments of the present application, the constraints that the tire force needs to satisfy are shown in the following formulas (1) and (2):

[0044]

[0045] In formulas (1) and (2), is the front wheel longitudinal force, is the lateral force of the front wheel, is the rear wheel longitudinal force, is the rear wheel lateral force, To achieve the goal of vertical force, is the target lateral force, is the target total yaw moment, is the distance from the vehicle's center of mass to the front axle, is the distance from the center of mass of the vehicle to the rear axle. Formula (2) represents the coupling constraint between the rear wheel longitudinal force and the rear wheel lateral force.

[0046] In some possible implementations of the present application, the coupling relationship constraint can be modeled by an existing tire model. Then the coupling relationship constraint between the rear wheel longitudinal force and the rear wheel lateral force is shown in the following formula (3):

[0047]

[0048] In formula (3), is the rear wheel adhesion coefficient, is the vertical load on the rear wheel, is the rear wheel lateral saturation rate. It can be calculated by the following formula (4):

[0049]

[0050] In formula (4), is the rear wheel slip angle, is the rear wheel cornering stiffness, As shown in the following formula (5):

[0051]

[0052] The equation group formed by formula (1) and (3) is solved to obtain the first tire force of the front wheel and the rear wheel of the vehicle, as shown in the following formula (6):

[0053]

[0054] In formula (6), is the front wheel longitudinal force, is the lateral force of the front wheel, is the rear wheel longitudinal force, is the rear wheel lateral force, is the distance from the vehicle's center of mass to the front axle, is the distance from the vehicle's center of mass to the rear axle, To achieve the goal of vertical force, is the target lateral force, is the target total yaw moment, is the rear wheel adhesion coefficient, is the vertical load on the rear wheel, is the rear wheel lateral saturation rate.

[0055] It can be understood that the first tire force of the front wheel of the vehicle includes the front wheel longitudinal force and the front wheel lateral force The first tire force of the rear wheel of the vehicle includes the rear wheel longitudinal force and rear wheel lateral force .

[0056] Step 103: Based on the first tire force, a tire force optimization problem corresponding to the constraint condition is constructed, wherein the tire force optimization problem includes constraints between the rear wheel longitudinal force and the rear wheel lateral force of the quadratic form.

[0057] In some possible implementations of the present application, the first tire force may not be able to meet the requirement of accurately controlling the vehicle motion in some cases. When it is 0 (for example, the vehicle is moving straight), the rear wheel lateral saturation rate is also 0, because Appearing in formula (6) and In the denominator of the deterministic formula, the problem is singular and it is impossible to determine and ; When the rear wheel slip angle is not 0 but very small (for example, less than the threshold), resulting in is also very small, calculated according to formula (6) and The physical meaning is that the front wheels and rear wheels are fully driven and fully braked respectively, which is inconsistent with the actual situation. =0 to solve the singular problem at this point, which will also cause the solution of the tire force at this point to be discontinuous, and further lead to frequent and large jumps in the tire force when the vehicle is traveling straight in actual use.

[0058] The reason for the above phenomenon is that although the front wheel steering and the front and rear axle driving forces can be independently controlled, the vehicle is a complete drive system in the motion control problem and can simultaneously achieve the upper target combined longitudinal force , target combined lateral force , and the target combined yaw moment However, in the straight-ahead condition and its vicinity, the range of the combined yaw moment that this vehicle configuration can generate is very limited, or in other words, its control authority for the combined yaw moment is very small. Therefore, in the straight-ahead condition and its vicinity, that is, in the condition where the above problem exists, the target combined yaw moment should not be considered in the process of determining the target tire force. Under such conditions, the ability to independently control the front and rear axle drive forces should be used to optimize power consumption (or other indicators for evaluating economy) or road adhesion utilization by distributing the front and rear axle drive forces, which is more in line with physical intuition.

[0059] In order to achieve the goal of ignoring the target yaw moment in and near the straight driving condition Request, and realize the smooth change of tire force when the working conditions change, design the following strategy: optimize the energy consumption or optimize the road adhesion utilization algorithm output as the driving force distribution ratio, and calculate the rear wheel target longitudinal force by optimizing energy consumption or optimizing road adhesion utilization. , the rear wheel target lateral force is calculated by the above formula (6): .

[0060] In some possible implementations of the embodiments of the present application, the tire force optimization problem corresponding to the constraint conditions constructed in the embodiments of the present application is shown in the following formula (7):

[0061]

[0062] In formula (7), and is the weight, which can be set according to actual needs. Optionally, The value can be 1, The value can be 10.

[0063] Formula (7) means: Under the constraint of the coupling relationship between the rear wheel longitudinal force and the rear wheel lateral force shown in the above formula (3), find the direction that can make the index Minimum rear wheel longitudinal force and rear wheel lateral force .

[0064] Step 104: Solve the tire force optimization problem to obtain the second tire forces of the front wheels and the rear wheels of the vehicle.

[0065] When the rear wheel longitudinal force is solved using formula (7): and rear wheel lateral force Then, combine the target with the vertical force Rear wheel longitudinal force The difference between the front wheel longitudinal force , the target lateral force Rear wheel lateral force The difference between the front wheel lateral force .

[0066] Below through Figure 3 The rear wheel longitudinal force and rear wheel lateral force are shown to explain how formula (7) can achieve smooth changes in tire forces in and near straight-ahead conditions.

[0067] Figure 3 It shows the rear wheel longitudinal force under given rear wheel slip angle (large rear wheel slip angle - extreme working condition, and small rear wheel slip angle - normal working condition). Rear wheel lateral force The value range of the combination is an ellipse (the gray curve in the figure only draws 1 / 4 of the ellipse). Figure 3 The longitudinal force of the rear wheel obtained by optimizing energy consumption or optimizing road adhesion is also plotted. , and the target yaw moment Calculated rear wheel target lateral force It can be seen that the rear wheels are under-driven because they can only drive and brake but cannot steer. and Cannot be obtained at the same time. Figure 3 The concentric ellipses in are the optimized cost functions. The contour lines of and The setting method makes the major axis of these ellipses significantly larger than the minor axis, and the direction of the major axis is the direction of the rear wheel longitudinal force. Rear wheel lateral force The tangent point when the ellipses in the combined value range are tangent is the solution of formula (7), such as Figure 3 as shown in .

[0068] Due to the combined slip characteristics of the tires, when the rear wheel slip angle is small ( Figure 3The upper part of the figure shows that the eccentricity of the ellipse representing the value range is less than the eccentricity of the ellipse representing the indicator. In this case, the value calculated by optimizing energy consumption or optimizing road adhesion utilization is Determine the vehicle tire force; when the rear wheel slip angle is large, the eccentricity of the ellipse representing the value range is greater than the eccentricity of the ellipse representing the indicator. At this time, according to the target combined yaw moment Determine vehicle tire forces.

[0069] In some possible implementations of the present application, formula (7) has no analytical solution. In order to reduce the computing resources consumed by calculating the tire force, the constraint between the quadratic rear wheel longitudinal force and the rear wheel lateral force can be converted into a linear constraint. Based on this, solving the tire force optimization problem to obtain the second tire force of the front wheel and the rear wheel of the vehicle may include: converting the constraint between the quadratic rear wheel longitudinal force and the rear wheel lateral force into a linear constraint; solving the second tire force of the front wheel and the rear wheel of the vehicle based on the linear constraint.

[0070] Since the solution of formula (7) must fall within Figure 3 Therefore, a straight line passing through the endpoints of the black curve segment is used to approximate the elliptical curve segment. At this time, the quadratic constraint between the rear wheel longitudinal force and the rear wheel lateral force shown in formula (7) is transformed into a linear constraint as shown in formula (8):

[0071]

[0072] Among them, the parameters in formula (8) are shown in formula (9):

[0073]

[0074] In formula (9), and are the rear wheel longitudinal force and rear wheel lateral force that satisfy the linearized tire joint slip constraint, and are the residuals of the longitudinal force and lateral force introduced to construct the optimization problem, respectively. and As shown in the following formula (10):

[0075]

[0076] The optimal solution of formula (8) As shown in formula (11):

[0077]

[0078] The optimal solution in formula (11) The first and second elements of are the rear wheel longitudinal forces that satisfy the linearized tire joint slip constraint. Rear wheel lateral force .

[0079] The obtained Determined as the final rear wheel longitudinal force , the final rear wheel lateral force is calculated according to the fourth equation in formula (6): , as shown in the following formula (12):

[0080]

[0081] When the final rear wheel longitudinal force is calculated and the resulting rear wheel lateral force Then, combine the target with the vertical force and The difference is determined as the final front wheel longitudinal force , the target lateral force and The difference is determined as the final front wheel lateral force , as shown in the following formula (13):

[0082]

[0083] The front wheel longitudinal force, front wheel lateral force, rear wheel longitudinal force and rear wheel lateral force in the second tire force finally determined are , , and .

[0084] In an embodiment of the present application, a tire force distribution request is obtained, wherein the tire force distribution request includes a first parameter required to achieve the resultant force of the tire forces of the four tires of the vehicle and a second parameter required for tire force distribution, the first parameter includes a target resultant longitudinal force, a target resultant lateral force and a target resultant yaw moment, and the second parameter includes a rear wheel adhesion coefficient, a rear wheel vertical load, a rear wheel sideslip angle, a rear wheel lateral stiffness, a first distance from the vehicle's center of mass to the front axle, and a second distance from the vehicle's center of mass to the rear axle; the first tire forces of the front wheels and the rear wheels of the vehicle are determined according to the first parameter, the second parameter and the constraints that the tire forces need to satisfy; based on the first tire force, a tire force optimization problem corresponding to the constraints is constructed, wherein the tire force optimization problem includes constraints between the rear wheel longitudinal force and the rear wheel lateral force of a quadratic form; the tire force optimization problem is solved to obtain the second tire forces of the front wheels and the rear wheels of the vehicle. In this way, when determining the vehicle tire force, the influence of the yaw moment on the vehicle tire force is not ignored, and it is achieved that according to the working conditions, the target combined yaw moment is adaptively considered when determining the tire force under extreme conditions, while the target combined yaw moment is not considered when determining the tire force under normal conditions, and a smooth transition between the two can be achieved, which can improve the accuracy and rationality of determining the vehicle's target tire force and reduce the computing resources consumed in calculating the tire force.

[0085] The vehicle tire force determination method provided in the embodiment of the present application is described below with reference to specific examples.

[0086] Figure 4 It is a schematic diagram of a vehicle U-turn condition provided in an embodiment of the present application. Figure 4 The reference path and attitude required by the vehicle are shown in Figure 4 The vehicle is traveling at a constant speed of 10 km / h. Figure 5 Schematic diagram of tire force provided by the embodiment of the present application. When the vehicle is traveling in a straight line (before 4.8 seconds and after 8 seconds), the front wheel longitudinal force and the rear wheel longitudinal force can be reasonably determined. The front wheel longitudinal force and the rear wheel longitudinal force are small in magnitude and in the same direction to overcome the driving resistance. Between 4.8 seconds and 8 seconds, the vehicle body side slip angle is large (such as Figure 4 ), the yaw motion is unstable, at this time the front wheel longitudinal force and the rear wheel longitudinal force are in opposite directions, so as to achieve the target combined longitudinal force while satisfying the target combined yaw moment for stability control.

[0087] The present application also provides a vehicle tire force determination device, such as Figure 6 shown. Figure 6 is a schematic diagram of the structure of a vehicle tire force determination device provided in an embodiment of the present application. The vehicle tire force determination device 600 may include:

[0088] An acquisition module 601 is used to acquire a tire force distribution request, wherein the tire force distribution request includes a first parameter required to achieve the resultant force of the tire forces of the four tires of the vehicle and a second parameter required for tire force distribution, the first parameter includes a target resultant longitudinal force, a target resultant lateral force, and a target resultant yaw moment, and the second parameter includes a rear wheel adhesion coefficient, a rear wheel vertical load, a rear wheel sideslip angle, a rear wheel cornering stiffness, a first distance from the vehicle center of mass to the front axle, and a second distance from the vehicle center of mass to the rear axle;

[0089] A determination module 602, configured to determine first tire forces of the front wheels and the rear wheels of the vehicle according to the first parameter, the second parameter and the constraint condition that the tire force needs to satisfy;

[0090] A construction module 603 is used to construct a tire force optimization problem corresponding to the constraint condition based on the first tire force, wherein the tire force optimization problem includes a constraint between a rear wheel longitudinal force and a rear wheel lateral force of a quadratic form;

[0091] The solving module 604 is used to solve the tire force optimization problem and obtain the second tire forces of the front wheels and the rear wheels of the vehicle.

[0092] In an embodiment of the present application, a tire force distribution request is obtained, wherein the tire force distribution request includes a first parameter required to achieve the resultant force of the tire forces of the four tires of the vehicle and a second parameter required for tire force distribution, the first parameter includes a target resultant longitudinal force, a target resultant lateral force and a target resultant yaw moment, and the second parameter includes a rear wheel adhesion coefficient, a rear wheel vertical load, a rear wheel sideslip angle, a rear wheel lateral stiffness, a first distance from the vehicle's center of mass to the front axle, and a second distance from the vehicle's center of mass to the rear axle; the first tire forces of the front wheels and the rear wheels of the vehicle are determined according to the first parameter, the second parameter and the constraints that the tire forces need to satisfy; based on the first tire force, a tire force optimization problem corresponding to the constraints is constructed, wherein the tire force optimization problem includes constraints between the rear wheel longitudinal force and the rear wheel lateral force of a quadratic form; the tire force optimization problem is solved to obtain the second tire forces of the front wheels and the rear wheels of the vehicle. In this way, when determining the vehicle tire force, the influence of the yaw moment on the vehicle tire force is not ignored, and it is achieved that according to the working conditions, the target combined yaw moment is adaptively considered when determining the tire force under extreme conditions, while the target combined yaw moment is not considered when determining the tire force under normal conditions, and a smooth transition between the two can be achieved, which can improve the accuracy and rationality of determining the vehicle's target tire force.

[0093] In some possible implementations of the embodiment of the present application, the solution module 604 is specifically used to:

[0094] Convert the constraints between the quadratic rear wheel longitudinal force and the rear wheel lateral force into linear constraints;

[0095] Solve for the tire forces on the front and rear wheels of the vehicle based on linear constraints.

[0096] In the embodiment of the present application, the computing resources consumed in calculating tire forces can be reduced.

[0097] In some possible implementations of the embodiments of the present application, the constraints include:

[0098] In the longitudinal direction, the resultant force of the tire forces of the vehicle's four tires is equal to the target resultant longitudinal force;

[0099] In the lateral direction, the resultant force of the tire forces of the vehicle's four tires is equal to the target resultant lateral force;

[0100] The resultant moment calculated based on the tire forces of the four tires of the vehicle is equal to the target resultant yaw moment;

[0101] Physical constraints of vehicle systems.

[0102] Figure 7 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0103] The electronic device may include a processor 701 and a memory 702 storing computer program instructions.

[0104] Specifically, the processor 701 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0105] The memory 702 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 702 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. Where appropriate, the memory 702 may include a removable or non-removable (or fixed) medium. Where appropriate, the memory 702 may be inside or outside the electronic device. In some specific embodiments, the memory 702 is a non-volatile solid-state memory.

[0106] In some specific embodiments, the memory may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Therefore, generally, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the vehicle tire force determination method according to the present application.

[0107] The processor 701 implements the steps of the vehicle tire force determination method provided in the embodiment of the present application by reading and executing the computer program instructions stored in the memory 702 .

[0108] In one example, the electronic device may further include a communication interface 703 and a bus 710. Figure 7 As shown, the processor 701, the memory 702, and the communication interface 703 are connected via a bus 710 and communicate with each other.

[0109] The communication interface 703 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0110] The bus 710 includes hardware, software or both, coupling the components of the electronic device to each other. For example, but not limitation, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnection, an Industry Standard Architecture (ISA) bus, an InfiniBand interconnection, a Low Pin Count (LPC) bus, a memory bus, a Micro channel architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local Bus (VLB) bus or other suitable buses or a combination of two or more of these. Where appropriate, the bus 710 may include one or more buses. Although embodiments of the present application describe and illustrate a particular bus, the present application contemplates any suitable bus or interconnect.

[0111] The electronic device can execute the vehicle tire force determination method provided in the embodiment of the present application, thereby achieving the corresponding technical effects of the vehicle tire force determination method provided in the embodiment of the present application.

[0112] In addition, in combination with the vehicle tire force determination method in the above embodiment, the embodiment of the present application also provides a computer-readable storage medium for implementation. The computer-readable storage medium stores computer program instructions; when the computer program instructions are executed by the processor, the steps of the vehicle tire force determination method provided in the embodiment of the present application are implemented. Examples of computer-readable storage media include non-transitory computer-readable media, such as ROM, RAM, magnetic disk or optical disk, etc.

[0113] An embodiment of the present application provides a computer program product, which includes: computer program instructions; when the computer program instructions are executed by a processor, the steps of the vehicle tire force determination method provided in the embodiment of the present application are implemented, and the same technical effect can be achieved. To avoid repetition, they will not be repeated here.

[0114] The present application also provides a vehicle, comprising at least one of the following:

[0115] The vehicle tire force determination device provided in the embodiment of the present application;

[0116] The electronic device provided by the embodiment of the present application;

[0117] The computer-readable storage medium provided by the embodiments of the present application.

[0118] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0119] The functional blocks shown in the structural block diagram described above can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), appropriate firmware, plug-in, function card, etc. When implemented in software, the elements of the present application are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or communication link through a data signal carried in a carrier. "Machine-readable medium" may include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable read-only memory (Erasable Read Only Memory, EROM), floppy disks, compact disc read-only memory (Compact Disc Read-Only Memory, CD-ROM), optical discs, hard disks, optical fiber media, radio frequency (Radio Frequency, RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0120] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0121] Aspects of the present disclosure are described above with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the functions / actions specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0122] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A method for determining vehicle tire force, characterized in that: The method comprises: Obtaining a tire force distribution request, wherein the tire force distribution request includes a first parameter required to achieve a resultant force of tire forces of four tires of the vehicle and a second parameter required for tire force distribution, the first parameter includes a target resultant longitudinal force, a target resultant lateral force, and a target resultant yaw moment, and the second parameter includes a rear wheel adhesion coefficient, a rear wheel vertical load, a rear wheel sideslip angle, a rear wheel cornering stiffness, a first distance from the center of mass of the vehicle to the front axle, and a second distance from the center of mass of the vehicle to the rear axle; Determine first tire forces of the front wheels and the rear wheels of the vehicle according to the first parameter, the second parameter and the constraint conditions that the tire forces need to satisfy; Based on the first tire force, constructing a tire force optimization problem corresponding to the constraint condition, wherein the tire force optimization problem includes a constraint between a rear wheel longitudinal force and a rear wheel lateral force of a quadratic type; Solving the tire force optimization problem to obtain second tire forces of the front wheels and the rear wheels of the vehicle; The step of solving the tire force optimization problem to obtain the second tire forces of the front wheels and the rear wheels of the vehicle includes: Converting the quadratic constraint between the rear wheel longitudinal force and the rear wheel lateral force into a linear constraint; Based on the linear constraint, solving the second tire forces of the front wheels of the vehicle and the rear wheels of the vehicle; The linear constraints include: in, and are the rear wheel longitudinal force and rear wheel lateral force that satisfy the linearized tire joint slip constraint, and are the residuals of the longitudinal force and lateral force introduced to construct the optimization problem, and is the weight, This is to ignore the target combined yaw moment request in straight-ahead conditions and achieve smooth changes in tire force when conditions change. The output of the energy-optimizing algorithm is the driving force distribution ratio. The target longitudinal force of the rear wheel is calculated by optimizing energy consumption. is based on The calculated rear wheel target lateral force is is the rear wheel lateral force, is the distance from the vehicle's center of mass to the front axle, is the distance from the vehicle's center of mass to the rear axle, is the target lateral force, is the target total yaw moment, and To satisfy Under the coupling relationship constraint between the rear wheel longitudinal force and the rear wheel lateral force, Minimum rear wheel longitudinal force and rear wheel lateral force; is the rear wheel adhesion coefficient, is the vertical load on the rear wheel, is the rear wheel lateral saturation rate.

2. The method according to claim 1, characterized in that The constraints include: In the longitudinal direction, the resultant force of the tire forces of the four tires of the vehicle is equal to the target resultant longitudinal force; In the lateral direction, the resultant force of the tire forces of the four tires of the vehicle is equal to the target resultant lateral force; The resultant moment calculated based on the tire forces of the four tires of the vehicle is equal to the target resultant yaw moment; Physical constraints of vehicle systems.

3. A vehicle tire force determination device, characterized in that: The device comprises: an acquisition module, configured to acquire a tire force distribution request, wherein the tire force distribution request includes a first parameter required to be achieved for the resultant force of the tire forces of the four tires of the vehicle and a second parameter required for tire force distribution, the first parameter includes a target resultant longitudinal force, a target resultant lateral force, and a target resultant yaw moment, and the second parameter includes a rear wheel adhesion coefficient, a rear wheel vertical load, a rear wheel sideslip angle, a rear wheel cornering stiffness, a first distance from the vehicle center of mass to the front axle, and a second distance from the vehicle center of mass to the rear axle; A determination module, configured to determine first tire forces of the front wheels and the rear wheels of the vehicle according to the first parameter, the second parameter and constraints that the tire forces need to satisfy; A construction module, configured to construct a tire force optimization problem corresponding to the constraint condition based on the first tire force, wherein the tire force optimization problem includes a constraint between a rear wheel longitudinal force and a rear wheel lateral force of a quadratic form; A solution module, used for solving the tire force optimization problem to obtain second tire forces of the front wheels and the rear wheels of the vehicle; The solution module is specifically used for: Converting the quadratic constraint between the rear wheel longitudinal force and the rear wheel lateral force into a linear constraint; Based on the linear constraint, solving the second tire forces of the front wheels of the vehicle and the rear wheels of the vehicle; The linear constraints include: in, and are the rear wheel longitudinal force and rear wheel lateral force that satisfy the linearized tire joint slip constraint, and are the residuals of the longitudinal force and lateral force introduced to construct the optimization problem, and is the weight, This is to ignore the target combined yaw moment request in straight-ahead conditions and achieve smooth changes in tire force when conditions change. The output of the energy-optimizing algorithm is the driving force distribution ratio. The target longitudinal force of the rear wheel is calculated by optimizing energy consumption. is based on The calculated rear wheel target lateral force is is the rear wheel lateral force, is the distance from the vehicle's center of mass to the front axle, is the distance from the vehicle's center of mass to the rear axle, is the target lateral force, is the target total yaw moment, and To satisfy Under the coupling relationship constraint between the rear wheel longitudinal force and the rear wheel lateral force, Minimum rear wheel longitudinal force and rear wheel lateral force; is the rear wheel adhesion coefficient, is the vertical load on the rear wheel, is the rear wheel lateral saturation rate.

4. The device according to claim 3, characterized in that The constraints include: In the longitudinal direction, the resultant force of the tire forces of the four tires of the vehicle is equal to the target resultant longitudinal force; In the lateral direction, the resultant force of the tire forces of the four tires of the vehicle is equal to the target resultant lateral force; The resultant moment calculated based on the tire forces of the four tires of the vehicle is equal to the target resultant yaw moment; Physical constraints of vehicle systems.

5. An electronic device, characterized in that: The electronic device comprises: a processor and a memory storing computer program instructions; The processor reads and executes the computer program instructions to implement the steps of the vehicle tire force determination method according to claim 1 or 2.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions, which, when executed by a processor, implement the steps of the vehicle tire force determination method according to claim 1 or 2.

7. A computer program product, characterized in that The computer program product comprises computer program instructions stored on a computer-readable storage medium, and when the computer program instructions are executed by a processor, the steps of the vehicle tire force determination method according to claim 1 or 2 are implemented.

8. A vehicle, characterized in that: The vehicle comprises at least one of the following: The vehicle tire force determination device according to claim 3 or 4; The electronic device according to claim 5; The computer readable storage medium of claim 6.

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