Vehicle parameter calibration method, device, computer equipment and storage medium

Abstract

The present application relates to the field of autonomous driving technology, and to a vehicle parameter calibration method, device, computer equipment, computer-readable storage medium, and computer program product. The method comprises: obtaining the weight of the front and rear wheel axles, the lateral speed of the wheels, the yaw rate, and the wheelbase of the vehicle; obtaining the understeering coefficient of the vehicle according to the weight of the front and rear wheel axles, the lateral speed of the wheels, the yaw rate, and the wheelbase of the vehicle; determining the vehicle's cornering stiffness parameter calculation formula and steering transmission ratio parameter calculation formula according to the understeering coefficient; obtaining the vehicle's real-time driving data; and obtaining the vehicle's cornering stiffness parameter and steering transmission ratio parameter according to the real-time driving data using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula. The use of this method can more easily and accurately calibrate the parameters of cornering stiffness and steering transmission ratio, and is more in line with the use requirements of intelligent driving.

Description

Technical Field

[0001] The present application relates to the field of autonomous driving technology, and in particular to a vehicle parameter calibration method, apparatus, computer equipment, computer-readable storage medium, and computer program product. Background Art

[0002] In unmanned driving control systems, accurate vehicle parameters are crucial to achieve stable and reliable lateral control. Key parameters include vehicle mass, distance from center of mass to front and rear axles, cornering stiffness, and chassis steering ratio. These parameters affect the accuracy of the vehicle dynamics model, which in turn affects the performance of the control algorithm.

[0003] In traditional technology, images are collected while the vehicle is driving, and the position information of the calibration objects in the images is analyzed to calculate the center position of the vehicle's driving trajectory, and finally calibrate the steering gear ratio. By analyzing the vehicle's operating parameters and tire state parameters, the cornering force is estimated in combination with the brush tire model, and then the cornering stiffness is determined. However, traditional technology has some obvious limitations: it requires additional hardware and software equipment support, increases the complexity and cost of the system, and fails to fully consider the needs of intelligent driving.

[0004] Therefore, there is an urgent need for a vehicle parameter calibration method, device, computer equipment, computer-readable storage medium and computer program product that can more easily and accurately calibrate the parameters of the lateral stiffness and steering ratio, and better meet the use requirements of intelligent driving. Summary of the invention

[0005] Based on this, it is necessary to provide a vehicle parameter calibration method, device, computer equipment, computer-readable storage medium and computer program product that can more easily and accurately calibrate the parameters of the lateral stiffness and steering ratio and is more in line with the use requirements of intelligent driving in order to address the above-mentioned technical problems.

[0006] In a first aspect, the present application provides a vehicle parameter calibration method, comprising:

[0007] Obtain the vehicle's front and rear wheel axle weights, wheel lateral velocity, yaw rate and vehicle wheelbase;

[0008] Obtaining the understeering coefficient of the vehicle according to the front and rear wheel axle weights, wheel lateral speed, yaw angular velocity and vehicle wheelbase of the vehicle;

[0009] Determining a vehicle cornering stiffness parameter calculation formula and a steering transmission ratio parameter calculation formula according to the understeer coefficient;

[0010] Obtain real-time driving data of the vehicle;

[0011] According to the real-time driving data, the cornering stiffness parameter and the steering transmission ratio parameter of the vehicle are obtained by using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula.

[0012] In one embodiment, obtaining the understeer coefficient of the vehicle according to the front and rear wheel axle weights, wheel lateral velocity, yaw angular velocity and vehicle wheelbase of the vehicle includes:

[0013] Obtaining a calculation formula for tire force parameters of the front and rear wheels according to the front and rear wheel axle weights and wheel lateral speeds of the vehicle;

[0014] According to the tire force parameter calculation formula of the front and rear wheels, a first calculation formula for the sideslip angles of the front and rear wheels is obtained;

[0015] Obtaining a steady-state steering angle calculation formula according to the first calculation formula for the front and rear wheel sideslip angles and the vehicle wheelbase;

[0016] The understeering coefficient of the vehicle is obtained according to the yaw angular velocity and the steady-state steering angle calculation formula.

[0017] In one embodiment, the vehicle wheelbase includes a first distance between the center of mass of the vehicle and the front axle, and a second distance between the center of mass of the vehicle and the rear axle; the calculation formula for determining the cornering stiffness parameter of the vehicle according to the understeering coefficient includes:

[0018] Get the longitudinal velocity of the vehicle's center of mass;

[0019] Obtaining a front wheel longitudinal velocity calculation formula and a rear wheel longitudinal velocity calculation formula respectively according to the yaw angular velocity, the first distance, the second distance, and the longitudinal velocity of the vehicle center of mass;

[0020] Obtaining a second calculation formula for the front and rear wheel sideslip angles according to the front wheel longitudinal speed calculation formula and the rear wheel longitudinal speed calculation formula;

[0021] Obtaining a rear wheel cornering stiffness parameter calculation formula of the vehicle according to the first calculation formula and the second calculation formula of the front and rear wheel slip angles;

[0022] A calculation formula for the front wheel cornering stiffness parameter of the vehicle is determined based on the calculation formula for the rear wheel cornering stiffness parameter and the understeer coefficient.

[0023] In one embodiment, the calculation formula for determining the steering transmission ratio parameter of the vehicle according to the understeering coefficient includes:

[0024] Get the steering wheel angle;

[0025] A calculation formula for a steering transmission ratio parameter of the vehicle is determined according to the yaw angular velocity, the vehicle wheelbase, the wheel lateral velocity, the steering wheel angle and the understeering coefficient.

[0026] In one embodiment, the real-time driving data includes driving data of high-speed small-angle steering and driving data of low-speed large-angle steering; the method of obtaining the cornering stiffness parameter and the steering transmission ratio parameter of the vehicle according to the real-time driving data by using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula includes:

[0027] According to the driving data of the high-speed small-angle steering, the cornering stiffness parameter of the vehicle is obtained by using the cornering stiffness parameter calculation formula;

[0028] And, according to the driving data of the low-speed large-angle steering, the steering transmission ratio parameter calculation formula is used to obtain the steering transmission ratio parameter of the vehicle.

[0029] In one embodiment, the obtaining of the cornering stiffness parameter of the vehicle according to the driving data of the high-speed small-angle steering and using the cornering stiffness parameter calculation formula includes:

[0030] According to the driving data of the high-speed small-angle steering, the rear wheel cornering stiffness parameter of the vehicle is obtained by using the rear wheel cornering stiffness parameter calculation formula, and the front wheel cornering stiffness parameter of the vehicle is obtained by using the front wheel cornering stiffness parameter calculation formula;

[0031] A weighted average calculation is performed on the rear wheel cornering stiffness parameter and the front wheel cornering stiffness parameter to obtain a cornering stiffness parameter of the vehicle.

[0032] In a second aspect, the present application also provides a vehicle parameter calibration device, comprising:

[0033] An acquisition module, used to acquire the front and rear wheel axle weights, wheel lateral velocity, yaw angular velocity and vehicle wheelbase of the vehicle;

[0034] A calculation module, used for obtaining the understeering coefficient of the vehicle according to the front and rear wheel axle weights, the wheel lateral velocity, the yaw angular velocity and the vehicle wheelbase of the vehicle;

[0035] The calculation module is further used to determine a calculation formula for a cornering stiffness parameter and a calculation formula for a steering transmission ratio parameter of the vehicle according to the understeering coefficient;

[0036] The acquisition module is also used to acquire real-time driving data of the vehicle;

[0037] The calculation module is also used to obtain the vehicle's cornering stiffness parameter and steering transmission ratio parameter according to the real-time driving data using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula.

[0038] In a third aspect, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0039] Obtain the vehicle's front and rear wheel axle weights, wheel lateral velocity, yaw rate and vehicle wheelbase;

[0040] Obtaining the understeering coefficient of the vehicle according to the front and rear wheel axle weights, wheel lateral speed, yaw angular velocity and vehicle wheelbase of the vehicle;

[0041] Determining a vehicle cornering stiffness parameter calculation formula and a steering transmission ratio parameter calculation formula according to the understeer coefficient;

[0042] Obtain real-time driving data of the vehicle;

[0043] According to the real-time driving data, the cornering stiffness parameter and the steering transmission ratio parameter of the vehicle are obtained by using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula.

[0044] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0045] Obtain the vehicle's front and rear wheel axle weights, wheel lateral velocity, yaw rate and vehicle wheelbase;

[0046] Obtaining the understeering coefficient of the vehicle according to the front and rear wheel axle weights, wheel lateral speed, yaw angular velocity and vehicle wheelbase of the vehicle;

[0047] Determining a vehicle cornering stiffness parameter calculation formula and a steering transmission ratio parameter calculation formula according to the understeer coefficient;

[0048] Obtain real-time driving data of the vehicle;

[0049] According to the real-time driving data, the cornering stiffness parameter and the steering transmission ratio parameter of the vehicle are obtained by using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula.

[0050] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0051] Obtain the vehicle's front and rear wheel axle weights, wheel lateral velocity, yaw rate and vehicle wheelbase;

[0052] Obtaining the understeering coefficient of the vehicle according to the front and rear wheel axle weights, wheel lateral speed, yaw angular velocity and vehicle wheelbase of the vehicle;

[0053] Determining a vehicle cornering stiffness parameter calculation formula and a steering transmission ratio parameter calculation formula according to the understeer coefficient;

[0054] Obtain real-time driving data of the vehicle;

[0055] According to the real-time driving data, the cornering stiffness parameter and the steering transmission ratio parameter of the vehicle are obtained by using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula.

[0056] The above-mentioned vehicle parameter calibration method, device, computer equipment, computer-readable storage medium and computer program product can more accurately calculate the understeering coefficient of the vehicle by directly obtaining key parameters such as the front and rear wheel bearing weights, wheel lateral speed, yaw angular velocity and vehicle wheelbase, and thus more accurately determine the cornering stiffness and steering gear ratio. The method avoids the complexity of the traditional technology that requires additional hardware and software equipment support, and simplifies the calibration process by directly using the vehicle's own sensor data. Since the need for additional equipment is reduced, it helps to reduce the manufacturing and maintenance costs of the entire system. Taking into account the needs of intelligent driving, it can be better integrated with the unmanned driving control system to improve the lateral control performance of the intelligent driving vehicle. By acquiring and processing the driving data of the vehicle in real time, the method can quickly respond to changes in the vehicle state and realize dynamic vehicle parameter adjustment. By reducing the reliance on external image acquisition and analysis, the method reduces the uncertainty caused by environmental changes or image processing errors and improves the reliability of the system. The method can adapt to different vehicle conditions and tire conditions, and estimate the cornering force by combining the brush tire model, so as to more accurately determine the cornering stiffness. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0058] Figure 1 A diagram showing an application environment of a vehicle parameter calibration method in an embodiment;

[0059] Figure 2 A schematic diagram of a process flow of a vehicle parameter calibration method in one embodiment;

[0060] Figure 3 is a flow chart of a vehicle parameter calibration method in another embodiment;

[0061] Figure 4A schematic diagram of the steering angle of a vehicle turning under a high-speed and small-angle steering condition in one embodiment;

[0062] Figure 5 A schematic diagram of the steering angle of a vehicle turning under a low-speed and large-angle steering condition in one embodiment;

[0063] Figure 6 is a structural block diagram of a vehicle parameter calibration device in one embodiment;

[0064] Figure 7 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0066] The vehicle parameter calibration method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown, the terminal 102 communicates with the server 104 through a network. The data storage system can store data that the server 104 needs to process. The data storage system can be integrated on the server 104, or placed on the cloud or other network servers.

[0067] Server 104 obtains the front and rear wheel axle weights, wheel lateral speed, yaw angular velocity and vehicle wheelbase of the vehicle; obtains the understeer coefficient of the vehicle based on the front and rear wheel axle weights, wheel lateral speed, yaw angular velocity and vehicle wheelbase of the vehicle; determines the vehicle's lateral stiffness parameter calculation formula and steering transmission ratio parameter calculation formula based on the understeer coefficient; obtains the vehicle's real-time driving data; and obtains the vehicle's lateral stiffness parameters and steering transmission ratio parameters based on the real-time driving data using the lateral stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula.

[0068] The terminal 102 may be, but is not limited to, various personal computers, laptops, smart phones, tablet computers, IoT devices, and portable wearable devices. The IoT devices may be smart speakers, smart TVs, smart air conditioners, smart car devices, projection devices, etc. Portable wearable devices may be smart watches, smart bracelets, head-mounted devices, etc. Head-mounted devices may be virtual reality (VR) devices, augmented reality (AR) devices, smart glasses, etc. The server 104 may be an independent physical server, a server cluster or distributed system consisting of multiple physical servers, or a cloud server that provides cloud computing services.

[0069] In an exemplary embodiment, Figure 2 As shown, a vehicle parameter calibration method is provided, which is applied to Figure 1 The server in the example is used to illustrate, including the following steps S202 to S210. Among them:

[0070] Step S202, obtaining the front and rear wheel axle weights, wheel lateral velocity, yaw angular velocity and vehicle wheelbase.

[0071] Specifically, the front and rear wheel axles of the vehicle are weighted: the front and rear wheels of the vehicle are subjected to pressure exerted by the vehicle itself, which affects the stability and handling of the vehicle.

[0072] Wheel lateral speed: The speed at which the wheels turn affects the acceleration and deceleration performance of the vehicle.

[0073] Yaw rate: The lateral rotation speed of the vehicle on the horizontal plane, which affects the steering performance of the vehicle.

[0074] Vehicle wheelbase: The distance between the center of the front and rear wheels of a vehicle, which affects the stability and handling of the vehicle.

[0075] Step S204, obtaining the understeer coefficient of the vehicle according to the front and rear wheel axle weights, wheel lateral velocity, yaw angular velocity and vehicle wheelbase.

[0076] Specifically, the data collected in step S202 is used to calculate the understeer coefficient. The understeer coefficient is a parameter that describes the difference between the actual steering angle and the theoretical steering angle when the vehicle is turning. Understeer means that the actual steering angle of the vehicle is less than the expected one under a given steering input, which is usually related to the stability of the vehicle and is usually expressed as K. v It is represented as a vehicle-specific parameter.

[0077] Step S206: determining a calculation formula for the cornering stiffness parameter and a calculation formula for the steering transmission ratio parameter of the vehicle according to the understeering coefficient.

[0078] Specifically, lateral stiffness refers to the rigidity of a vehicle under lateral force, which affects the lateral stability and handling of the vehicle. Steering transmission ratio refers to the ratio of the steering system converting the driver's steering input into the actual steering angle of the wheel, which affects the steering sensitivity of the vehicle.

[0079] Step S208, obtaining real-time driving data of the vehicle.

[0080] Specifically, the real-time driving data of the vehicle is collected, including the real-time front and rear wheel bearing weights, wheel lateral speeds, yaw angular velocity and vehicle wheelbase of the vehicle. It should be noted that the front and rear wheel bearing weights, wheel lateral speeds, yaw angular velocity and vehicle wheelbase of the vehicle in step S202 refer to historical data.

[0081] Step S210, according to the real-time driving data, using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula, obtain the cornering stiffness parameter and the steering transmission ratio parameter of the vehicle.

[0082] Specifically, the vehicle's cornering stiffness parameter and steering ratio parameter are calculated using the real-time driving data collected in step S208 in combination with the calculation formula determined in step S206. These parameters are key values ​​used in the vehicle control system to adjust the vehicle's response and stability.

[0083] In the above vehicle parameter calibration method, by directly obtaining key parameters such as the front and rear wheel bearing weights, wheel lateral speed, yaw rate and vehicle wheelbase, the understeering coefficient of the vehicle can be calculated more accurately, and then the cornering stiffness and steering ratio can be determined more accurately. This method avoids the complexity of the traditional technology that requires additional hardware and software equipment support, and simplifies the calibration process by directly using the vehicle's own sensor data. Since the need for additional equipment is reduced, it helps to reduce the manufacturing and maintenance costs of the entire system. Taking into account the needs of intelligent driving, it can be better integrated with the unmanned driving control system to improve the lateral control performance of intelligent driving vehicles. By acquiring and processing the driving data of the vehicle in real time, the method can quickly respond to changes in the vehicle state and realize dynamic vehicle parameter adjustment. By reducing the reliance on external image acquisition and analysis, the method reduces the uncertainty caused by environmental changes or image processing errors and improves the reliability of the system. The method can adapt to different vehicle conditions and tire conditions, and estimate the cornering force by combining the brush tire model, so as to more accurately determine the cornering stiffness.

[0084] In an exemplary embodiment, Figure 3 As shown, the understeering coefficient of the vehicle is obtained according to the front and rear wheel axle weights, wheel lateral velocity, yaw angular velocity and vehicle wheelbase, including:

[0085] Step S302, obtaining a calculation formula for tire force parameters of the front and rear wheels according to the front and rear wheel axle weights and the lateral speed of the wheels;

[0086] Step S304, obtaining a first calculation formula for the sideslip angles of the front and rear wheels according to the calculation formula for the tire force parameters of the front and rear wheels;

[0087] Step S306, obtaining a calculation formula for a steady-state steering angle according to the first calculation formula for the front and rear wheel slip angles and the vehicle wheelbase;

[0088] Step S308, obtaining the understeering coefficient of the vehicle according to the yaw angular velocity and the steady-state steering angle calculation formula.

[0089] Specifically, Figure 4 As shown in the figure, the instantaneous turning center O of the vehicle is the intersection of the vertical lines of the two wheels' lateral speed directions. Assuming that the driving radius R is much larger than the vehicle's wheelbase L, that is, the curve length is approximately the arc length, the following calculation formula is used:

[0090] , ;

[0091] Solve and get the tire force parameter calculation formula of the front and rear wheels:

[0092] ;

[0093] A linear tire model is introduced, assuming that the sideslip angle is very small, that is, the tire force on each wheel is proportional to its sideslip angle, and its proportional coefficient is the sideslip stiffness. According to the tire force parameter calculation formula of the front and rear wheels, the first calculation formula for the sideslip angle of the front and rear wheels is obtained:

[0094] ;

[0095] According to the first calculation formula of the front and rear wheel slip angles and the vehicle wheelbase, the steady-state steering angle calculation formula is obtained (updated):

[0096] ;

[0097] According to the calculation formula of yaw rate and steady-state steering angle, the understeering coefficient of the vehicle is obtained:

[0098] ;

[0099] Since the driving radius R is unknown, use ω=v x / R, according to the above steady-state steering angle calculation formula, it can be concluded that:

[0100] ; At this time K v The parameters on the right side of the equation are all parameters in real-time driving data.

[0101] Among them, K v is the vehicle’s deficiency-specific coefficient, C f is the front wheel cornering stiffness parameter calculation formula, C r is the rear wheel cornering stiffness parameter calculation formula, δ is the steady-state steering angle, α f is the front wheel slip angle, α r is the rear wheel slip angle, F yf is the tire force parameter of the front wheel, F yris the tire force parameter of the rear wheel, L is the vehicle wheelbase, m is the vehicle weight, m f is the weight of the front wheel axle of the vehicle, m r is the weight of the rear wheel bearing of the vehicle, R is the driving radius, v x is the lateral speed of the wheel, l f is the first distance between the vehicle's center of mass and the front axle, l r is the second distance between the vehicle's center of mass and the rear axle; where L=l f + l r ,m=m f + m r .

[0102] In this embodiment, by accurately calculating the tire force parameters of the front and rear wheels, the grip and cornering force of the tire under different loads and speeds can be more accurately evaluated. The first calculation formula of the front and rear wheel slip angles provides a dynamic analysis of the tire side slip behavior when the vehicle is turning, which helps to understand the response of the vehicle under different turning conditions. The understeering coefficient of the vehicle can be accurately calculated through the yaw rate and steady-state steering angle calculation formula. Accurate acquisition of the understeering coefficient helps to optimize the vehicle dynamics model and improve the prediction ability of the model and the accuracy of the control algorithm.

[0103] In an exemplary embodiment, the real-time driving data includes driving data of high-speed small-angle steering and driving data of low-speed large-angle steering; according to the real-time driving data, the cornering stiffness parameter and the steering transmission ratio parameter are obtained by using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula, including:

[0104] According to the driving data of high-speed small-angle steering, the cornering stiffness parameters of the vehicle are obtained using the cornering stiffness parameter calculation formula;

[0105] And, according to the driving data of low-speed and large-angle steering, the steering transmission ratio parameter of the vehicle is obtained by using the steering transmission ratio parameter calculation formula.

[0106] Specifically, real-time driving data is divided into two types, namely, high-speed small-angle steering data and low-speed large-angle steering data. This classification helps to analyze the dynamic response of the vehicle for different driving conditions. Usually when driving on a highway, the driver may need to make a small-angle steering to keep the lane or make slight directional adjustments. When driving at a low speed, such as parking, turning or avoiding obstacles, the driver may need to make a larger angle steering. Using the driving data of high-speed small-angle steering, the cornering stiffness parameters of the vehicle are obtained through the cornering stiffness parameter calculation formula. Cornering stiffness describes the rigidity of the tire of the vehicle under the action of lateral force, which affects the lateral stability and handling of the vehicle. Using the driving data of low-speed large-angle steering, the steering transmission ratio parameters of the vehicle are obtained through the steering transmission ratio parameter calculation formula. The steering transmission ratio describes the ratio of the steering system converting the driver's steering input into the actual steering angle of the wheel, which affects the steering sensitivity and accuracy of the vehicle.

[0107] In the case of high-speed and small-angle steering, the vehicle's cornering stiffness is more important to maintaining vehicle stability, so special attention should be paid to the cornering stiffness parameter. In the case of low-speed and large-angle steering, the vehicle's steering gear ratio is more critical to improving steering accuracy and responsiveness, so attention should be paid to the steering gear ratio parameter.

[0108] Allows the vehicle control system to dynamically adjust parameters according to different driving conditions to achieve optimal vehicle performance and safety. For example, at high speeds, the system may increase cornering stiffness to improve stability; while at low speeds, the system may adjust the steering ratio to improve steering agility and precision.

[0109] In this embodiment, the real-time driving data includes driving data of high-speed small-angle steering and driving data of low-speed large-angle steering, which are respectively aimed at working conditions with greater influence on the cornering stiffness and the steering transmission ratio, and it is easier to calibrate more accurate parameter values; the cornering stiffness and steering transmission ratio parameters are calibrated by real-time driving data, so that the dynamic model can predict a motion trajectory that is highly consistent with the actual vehicle driving height in the real-time driving data, which is convenient for use by the model-based controller.

[0110] In an exemplary embodiment, the vehicle wheelbase includes a first distance between the center of mass of the vehicle and the front axle, and a second distance between the center of mass of the vehicle and the rear axle; and according to the understeer coefficient, a calculation formula for determining the cornering stiffness parameter of the vehicle includes:

[0111] Get the longitudinal velocity of the vehicle's center of mass;

[0112] According to the yaw angular velocity, the first distance, the second distance, and the longitudinal velocity of the center of mass of the vehicle, a front wheel longitudinal velocity calculation formula and a rear wheel longitudinal velocity calculation formula are respectively obtained;

[0113] According to the front wheel longitudinal speed calculation formula and the rear wheel longitudinal speed calculation formula, a second calculation formula for the front and rear wheel sideslip angles is obtained;

[0114] Obtaining a rear wheel cornering stiffness parameter calculation formula of the vehicle according to the first calculation formula and the second calculation formula of the front and rear wheel slip angles;

[0115] The calculation formula for the vehicle's front wheel cornering stiffness parameters is determined based on the rear wheel cornering stiffness parameter calculation formula and the understeer coefficient.

[0116] Specifically, according to the yaw angular velocity, the first distance, the second distance, and the longitudinal velocity of the vehicle center of mass, the front wheel longitudinal velocity calculation formula and the rear wheel longitudinal velocity calculation formula are obtained respectively:

[0117] ;

[0118] Assuming that the longitudinal velocity of the wheel is equal to the longitudinal velocity of the vehicle's center of mass and the sideslip angle is very small, ignoring the influence of tan, the second calculation formula for the front and rear wheel sideslip angle is obtained as follows:

[0119] ;

[0120] According to the first and second calculation formulas for the front and rear wheel slip angles, the calculation formula for the rear wheel cornering stiffness parameter of the vehicle is obtained:

[0121] ;

[0122] The rear wheel cornering stiffness parameter calculation formula is:

[0123] ; At this time, all the parameters on the right side of the equation are parameters in the real-time driving data;

[0124] According to the rear wheel cornering stiffness parameter calculation formula and understeering coefficient, the front wheel cornering stiffness parameter calculation formula of the vehicle is determined as follows:

[0125] ; At this time, all the parameters on the right side of the equation are parameters in the real-time driving data.

[0126] Among them, v yf is the front wheel longitudinal speed, v yr is the longitudinal speed of the rear wheel, v y is the longitudinal velocity of the vehicle's center of mass, l f is the first distance between the vehicle's center of mass and the front axle, l r is the second distance between the vehicle center of mass and the rear axle, ω is the yaw rate, K v is the vehicle's deficiency-specific coefficient, C f is the front wheel cornering stiffness parameter calculation formula, C r is the rear wheel cornering stiffness parameter calculation formula, δ is the steady-state steering angle, αf is the front wheel slip angle, α r is the rear wheel slip angle, v x is the lateral speed of the wheel, l f is the first distance between the vehicle's center of mass and the front axle, l r is the second distance between the vehicle's center of mass and the rear axle, m f is the weight of the front wheel axle of the vehicle, m r Weight the rear wheel axle of the vehicle.

[0127] In this embodiment, obtaining the longitudinal and lateral speeds of the center of mass of the vehicle is helpful for analyzing the dynamic behavior of the vehicle in different directions. By obtaining the calculation formulas for the longitudinal speeds of the front and rear wheels respectively, the dynamic response of the front and rear wheels can be analyzed independently, providing a basis for further analysis of the cornering stiffness. In combination with the yaw rate, the vehicle wheelbase and the center of mass speed, the dynamic factors of the vehicle during the steering process can be more comprehensively considered. The first and second calculation formulas for the front and rear wheel cornering angles can be used to more accurately evaluate the cornering behavior of the tire. The cornering stiffness of the vehicle can be more accurately determined by the calculation formula for the rear wheel cornering stiffness parameter. Determining the front wheel cornering stiffness parameter based on the rear wheel cornering stiffness parameter and the understeering coefficient helps to achieve a balance between the cornering stiffness of the front and rear wheels of the vehicle and optimize the steering performance of the vehicle.

[0128] In an exemplary embodiment, according to the driving data of high-speed small-angle steering, the cornering stiffness parameter of the vehicle is obtained by using the cornering stiffness parameter calculation formula, including:

[0129] According to the driving data of high-speed small-angle steering, the rear wheel cornering stiffness parameter of the vehicle is obtained by using the rear wheel cornering stiffness parameter calculation formula, and the front wheel cornering stiffness parameter of the vehicle is obtained by using the front wheel cornering stiffness parameter calculation formula;

[0130] The rear wheel cornering stiffness parameter and the front wheel cornering stiffness parameter are weighted averaged to obtain the vehicle cornering stiffness parameter.

[0131] Specifically, first, it is necessary to collect driving data of high-speed and small-angle steering. These data may include the vehicle's speed, steering angle, lateral force of the wheel, etc. The cornering stiffness parameter of the rear wheel of the vehicle is calculated based on the collected driving data using the rear wheel cornering stiffness parameter calculation formula. The cornering stiffness parameter is usually expressed as the lateral stiffness of the tire of the vehicle under the action of lateral force, which affects the stability and responsiveness of the vehicle when turning. Similarly, the cornering stiffness parameter of the front wheel of the vehicle is calculated using the front wheel cornering stiffness parameter calculation formula. Since the front and rear wheels of the vehicle may have different cornering stiffnesses and make different contributions to the overall handling and stability of the vehicle, it is necessary to perform a weighted average calculation on the cornering stiffness parameters of the rear and front wheels. The basis for weighting may be the actual impact of the front and rear wheels on the stability and handling of the vehicle, or the support ratio of the front and rear wheels to the weight of the vehicle. Through the weighted average calculation, the cornering stiffness parameter of the vehicle is finally obtained. This parameter reflects the overall lateral stiffness of the vehicle and is an important parameter in the vehicle dynamics model.

[0132] In this embodiment, by allowing the vehicle control system to dynamically adjust the control strategy according to real-time data to adapt to different driving conditions, the safety and controllability of the vehicle can be improved.

[0133] In an exemplary embodiment, a calculation formula for determining a steering transmission ratio parameter of a vehicle is determined according to the understeering coefficient, including:

[0134] Get the steering wheel angle;

[0135] The steering ratio parameter calculation formula of the vehicle is determined based on the yaw rate, vehicle wheelbase, wheel lateral velocity, steering wheel angle and understeering coefficient.

[0136] Specifically, considering the low-speed and large-angle steering conditions, the wheel slip angle is also close to 0, and the relationship between the vehicle's running radius and the steady-state steering angle of the front wheel is as follows: Figure 5 As shown, the steering center is on the extension line of the rear axle L / R=tan(δ). According to the calculation formula of the steady-state steering angle and the lateral speed of the wheel, the calculation formula of the yaw angular velocity is:

[0137] ;

[0138] In low-speed and large-angle steering conditions, tan should be restored. Combined with the definition of transmission ratio, the vehicle's steering transmission ratio parameter (ratio) is calculated as follows:

[0139] ; At this time, all the parameters on the right side of the equation are parameters in the real-time driving data.

[0140] Where ω is the yaw rate, K v is the vehicle's deficiency coefficient, δ is the steady-state steering angle, vx is the lateral speed of the wheel, L is the vehicle wheelbase, and steer is the steering wheel angle.

[0141] In this embodiment, under low-speed and large-angle steering conditions, the steering transmission ratio parameters of the vehicle can be determined more accurately through comprehensive analysis of the yaw angular velocity, vehicle wheelbase, wheel lateral speed, steering wheel angle and understeering coefficient, thereby optimizing the steering performance and handling of the vehicle.

[0142] In an exemplary embodiment, when there are difficult-to-obtain and very important parameters in the time-invariant mathematical model that need to be calibrated, for example, when the longitudinal control wants to use an MPC-like algorithm to control the vehicle speed and acceleration, it is necessary to obtain the longitudinal slip stiffness of the wheel. It is only necessary to derive the formula for calculating the longitudinal slip stiffness based on the driving data in combination with the longitudinal dynamics model, design the working conditions to collect the required data, and solve it.

[0143] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0144] Based on the same inventive concept, the embodiment of the present application also provides a vehicle parameter calibration device for implementing the vehicle parameter calibration method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations of one or more vehicle parameter calibration device embodiments provided below can refer to the limitations of the vehicle parameter calibration method above, and will not be repeated here.

[0145] In an exemplary embodiment, Figure 6 As shown, a vehicle parameter calibration device is provided, including: an acquisition module 602, for acquiring the front and rear wheel axle weights, wheel lateral velocity, yaw angular velocity and vehicle wheelbase of the vehicle;

[0146] A calculation module 604 is used to obtain the understeering coefficient of the vehicle according to the front and rear wheel axle weights, the wheel lateral velocity, the yaw angular velocity and the vehicle wheelbase;

[0147] The calculation module 604 is further used to determine a calculation formula for a cornering stiffness parameter and a calculation formula for a steering transmission ratio parameter of the vehicle according to the understeering coefficient;

[0148] The acquisition module 602 is also used to acquire real-time driving data of the vehicle;

[0149] The calculation module 604 is further used to obtain the vehicle's cornering stiffness parameter and steering transmission ratio parameter according to the real-time driving data using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula.

[0150] In an exemplary embodiment, the calculation module 604 is also used to obtain a calculation formula for the tire force parameters of the front and rear wheels based on the front and rear wheel axle weights and the lateral speed of the wheels of the vehicle; obtain a first calculation formula for the front and rear wheel sideslip angles based on the calculation formula for the front and rear wheel tire force parameters; obtain a calculation formula for the steady-state steering angle based on the first calculation formula for the front and rear wheel sideslip angles and the vehicle wheelbase; and obtain the understeer coefficient of the vehicle based on the yaw angular velocity and the steady-state steering angle calculation formula.

[0151] In an exemplary embodiment, the vehicle wheelbase includes a first distance between the center of mass of the vehicle and the front axle, and a second distance between the center of mass of the vehicle and the rear axle;

[0152] The acquisition module 602 is also used to obtain the longitudinal velocity of the center of mass of the vehicle;

[0153] The calculation module 604 is further used to obtain the front wheel longitudinal velocity calculation formula and the rear wheel longitudinal velocity calculation formula respectively according to the yaw angular velocity, the first distance, the second distance, and the longitudinal velocity of the center of mass of the vehicle; obtain the second calculation formula of the front and rear wheel sideslip angles according to the front wheel longitudinal vehicle speed calculation formula and the rear wheel longitudinal vehicle speed calculation formula; obtain the vehicle's rear wheel sideslip stiffness parameter calculation formula according to the first calculation formula and the second calculation formula of the front and rear wheel sideslip angles; determine the vehicle's front wheel sideslip stiffness parameter calculation formula according to the rear wheel sideslip stiffness parameter calculation formula and the understeer coefficient.

[0154] In an exemplary embodiment, the acquisition module 602 is further used to acquire a steering wheel angle;

[0155] The calculation module 604 is further used to determine a calculation formula for a steering transmission ratio parameter of the vehicle according to the yaw angular velocity, the vehicle wheelbase, the lateral velocity of the wheels, the steering wheel angle and the understeering coefficient.

[0156] In an exemplary embodiment, the real-time driving data includes high-speed small-angle steering driving data and low-speed large-angle steering driving data;

[0157] The calculation module 604 is also used to obtain the vehicle's cornering stiffness parameters based on the driving data of high-speed small-angle steering using the cornering stiffness parameter calculation formula; and to obtain the vehicle's steering transmission ratio parameters based on the driving data of low-speed large-angle steering using the steering transmission ratio parameter calculation formula.

[0158] In an exemplary embodiment, the calculation module 604 is also used to obtain the rear wheel cornering stiffness parameters of the vehicle using the rear wheel cornering stiffness parameter calculation formula based on the driving data of high-speed and small-angle steering, and to obtain the front wheel cornering stiffness parameters of the vehicle using the front wheel cornering stiffness parameter calculation formula; and to perform weighted average calculation on the rear wheel cornering stiffness parameters and the front wheel cornering stiffness parameters to obtain the cornering stiffness parameters of the vehicle.

[0159] Each module in the above vehicle parameter calibration device can be implemented in whole or in part by software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each module.

[0160] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Figure 7 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store vehicle front and rear wheel axle weights, wheel lateral speeds, yaw angular velocity and vehicle wheelbase data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a vehicle parameter calibration method is implemented.

[0161] Those skilled in the art will understand that Figure 7 The structure shown is merely a block diagram of a portion of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0162] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0163] Obtain the vehicle's front and rear wheel axle weights, wheel lateral velocity, yaw rate and vehicle wheelbase;

[0164] Obtain the understeering coefficient of the vehicle according to the front and rear wheel axle weights, wheel lateral velocity, yaw angular velocity and vehicle wheelbase;

[0165] According to the understeering coefficient, the calculation formula of the vehicle's cornering stiffness parameter and the calculation formula of the steering transmission ratio parameter are determined;

[0166] Obtain real-time driving data of the vehicle;

[0167] According to the real-time driving data, the cornering stiffness parameter and the steering transmission ratio parameter of the vehicle are obtained by using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula.

[0168] In one embodiment, when the processor executes the computer program, the following steps are also implemented:

[0169] According to the front and rear wheel axle weights and wheel lateral speeds of the vehicle, the tire force parameter calculation formula of the front and rear wheels is obtained;

[0170] According to the tire force parameter calculation formula of the front and rear wheels, a first calculation formula for the front and rear wheel sideslip angles is obtained;

[0171] According to the first calculation formula of the front and rear wheel slip angles and the vehicle wheelbase, a calculation formula of the steady-state steering angle is obtained;

[0172] The understeering coefficient of the vehicle is obtained according to the calculation formula of yaw angular velocity and steady-state steering angle.

[0173] In one embodiment, when the processor executes the computer program, the following steps are also implemented:

[0174] The vehicle wheelbase includes a first distance between the center of mass of the vehicle and the front axle, and a second distance between the center of mass of the vehicle and the rear axle;

[0175] Get the longitudinal velocity of the vehicle's center of mass;

[0176] According to the yaw angular velocity, the first distance, the second distance, and the longitudinal velocity of the center of mass of the vehicle, a front wheel longitudinal velocity calculation formula and a rear wheel longitudinal velocity calculation formula are respectively obtained;

[0177] According to the front wheel longitudinal speed calculation formula and the rear wheel longitudinal speed calculation formula, a second calculation formula for the front and rear wheel sideslip angles is obtained;

[0178] Obtaining a rear wheel cornering stiffness parameter calculation formula of the vehicle according to the first calculation formula and the second calculation formula of the front and rear wheel slip angles;

[0179] The calculation formula for the vehicle's front wheel cornering stiffness parameters is determined based on the rear wheel cornering stiffness parameter calculation formula and the understeer coefficient.

[0180] In one embodiment, when the processor executes the computer program, the following steps are also implemented:

[0181] Get the steering wheel angle;

[0182] The steering ratio parameter calculation formula of the vehicle is determined based on the yaw rate, vehicle wheelbase, wheel lateral velocity, steering wheel angle and understeering coefficient.

[0183] In one embodiment, when the processor executes the computer program, the following steps are also implemented:

[0184] Real-time driving data includes high-speed small-angle steering driving data and low-speed large-angle steering driving data;

[0185] According to the driving data of high-speed small-angle steering, the cornering stiffness parameters of the vehicle are obtained using the cornering stiffness parameter calculation formula;

[0186] And, according to the driving data of low-speed and large-angle steering, the steering transmission ratio parameter of the vehicle is obtained by using the steering transmission ratio parameter calculation formula.

[0187] In one embodiment, when the processor executes the computer program, the following steps are also implemented:

[0188] According to the driving data of high-speed small-angle steering, the rear wheel cornering stiffness parameter of the vehicle is obtained by using the rear wheel cornering stiffness parameter calculation formula, and the front wheel cornering stiffness parameter of the vehicle is obtained by using the front wheel cornering stiffness parameter calculation formula;

[0189] The rear wheel cornering stiffness parameter and the front wheel cornering stiffness parameter are weighted averaged to obtain the vehicle cornering stiffness parameter.

[0190] In one embodiment, a computer readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

[0191] Obtain the vehicle's front and rear wheel axle weights, wheel lateral velocity, yaw rate and vehicle wheelbase;

[0192] Obtain the understeering coefficient of the vehicle according to the front and rear wheel axle weights, wheel lateral velocity, yaw angular velocity and vehicle wheelbase;

[0193] According to the understeering coefficient, the calculation formula of the vehicle's cornering stiffness parameter and the calculation formula of the steering transmission ratio parameter are determined;

[0194] Obtain real-time driving data of the vehicle;

[0195] According to the real-time driving data, the cornering stiffness parameter and the steering transmission ratio parameter of the vehicle are obtained by using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula.

[0196] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0197] According to the front and rear wheel axle weights and wheel lateral speeds of the vehicle, the tire force parameter calculation formula of the front and rear wheels is obtained;

[0198] According to the tire force parameter calculation formula of the front and rear wheels, a first calculation formula for the front and rear wheel sideslip angles is obtained;

[0199] According to the first calculation formula of the front and rear wheel slip angles and the vehicle wheelbase, a calculation formula of the steady-state steering angle is obtained;

[0200] The understeering coefficient of the vehicle is obtained according to the calculation formula of yaw angular velocity and steady-state steering angle.

[0201] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0202] The vehicle wheelbase includes a first distance between the center of mass of the vehicle and the front axle, and a second distance between the center of mass of the vehicle and the rear axle;

[0203] Get the longitudinal velocity of the vehicle's center of mass;

[0204] According to the yaw angular velocity, the first distance, the second distance, and the longitudinal velocity of the center of mass of the vehicle, a front wheel longitudinal velocity calculation formula and a rear wheel longitudinal velocity calculation formula are respectively obtained;

[0205] According to the front wheel longitudinal speed calculation formula and the rear wheel longitudinal speed calculation formula, a second calculation formula for the front and rear wheel sideslip angles is obtained;

[0206] Obtaining a rear wheel cornering stiffness parameter calculation formula of the vehicle according to the first calculation formula and the second calculation formula of the front and rear wheel slip angles;

[0207] The calculation formula for the vehicle's front wheel cornering stiffness parameters is determined based on the rear wheel cornering stiffness parameter calculation formula and the understeer coefficient.

[0208] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0209] Get the steering wheel angle;

[0210] The steering ratio parameter calculation formula of the vehicle is determined based on the yaw rate, vehicle wheelbase, wheel lateral velocity, steering wheel angle and understeer coefficient.

[0211] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0212] Real-time driving data includes high-speed small-angle steering driving data and low-speed large-angle steering driving data;

[0213] According to the driving data of high-speed small-angle steering, the cornering stiffness parameters of the vehicle are obtained using the cornering stiffness parameter calculation formula;

[0214] And, according to the driving data of low-speed and large-angle steering, the steering transmission ratio parameter of the vehicle is obtained by using the steering transmission ratio parameter calculation formula.

[0215] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0216] According to the driving data of high-speed small-angle steering, the rear wheel cornering stiffness parameter of the vehicle is obtained by using the rear wheel cornering stiffness parameter calculation formula, and the front wheel cornering stiffness parameter of the vehicle is obtained by using the front wheel cornering stiffness parameter calculation formula;

[0217] The rear wheel cornering stiffness parameter and the front wheel cornering stiffness parameter are weighted averaged to obtain the vehicle cornering stiffness parameter.

[0218] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the following steps:

[0219] Obtain the vehicle's front and rear wheel axle weights, wheel lateral velocity, yaw rate and vehicle wheelbase;

[0220] Obtain the understeering coefficient of the vehicle according to the front and rear wheel axle weights, wheel lateral velocity, yaw angular velocity and vehicle wheelbase;

[0221] According to the understeering coefficient, the calculation formula of the vehicle's cornering stiffness parameter and the calculation formula of the steering transmission ratio parameter are determined;

[0222] Obtain real-time driving data of the vehicle;

[0223] According to the real-time driving data, the cornering stiffness parameter and the steering transmission ratio parameter of the vehicle are obtained by using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula.

[0224] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0225] According to the front and rear wheel axle weights and wheel lateral speeds of the vehicle, the tire force parameter calculation formula of the front and rear wheels is obtained;

[0226] According to the tire force parameter calculation formula of the front and rear wheels, a first calculation formula for the front and rear wheel sideslip angles is obtained;

[0227] According to the first calculation formula of the front and rear wheel slip angles and the vehicle wheelbase, a calculation formula of the steady-state steering angle is obtained;

[0228] The understeering coefficient of the vehicle is obtained according to the calculation formula of yaw angular velocity and steady-state steering angle.

[0229] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0230] The vehicle wheelbase includes a first distance between the center of mass of the vehicle and the front axle, and a second distance between the center of mass of the vehicle and the rear axle;

[0231] Get the longitudinal velocity of the vehicle's center of mass;

[0232] According to the yaw angular velocity, the first distance, the second distance, and the longitudinal velocity of the center of mass of the vehicle, a front wheel longitudinal velocity calculation formula and a rear wheel longitudinal velocity calculation formula are respectively obtained;

[0233] According to the front wheel longitudinal speed calculation formula and the rear wheel longitudinal speed calculation formula, a second calculation formula for the front and rear wheel sideslip angles is obtained;

[0234] Obtaining a rear wheel cornering stiffness parameter calculation formula of the vehicle according to the first calculation formula and the second calculation formula of the front and rear wheel slip angles;

[0235] The calculation formula for the vehicle's front wheel cornering stiffness parameters is determined based on the rear wheel cornering stiffness parameter calculation formula and the understeer coefficient.

[0236] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0237] Get the steering wheel angle;

[0238] The steering ratio parameter calculation formula of the vehicle is determined based on the yaw rate, vehicle wheelbase, wheel lateral velocity, steering wheel angle and understeering coefficient.

[0239] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0240] Real-time driving data includes high-speed small-angle steering driving data and low-speed large-angle steering driving data;

[0241] According to the driving data of high-speed small-angle steering, the cornering stiffness parameters of the vehicle are obtained using the cornering stiffness parameter calculation formula;

[0242] And, according to the driving data of low-speed and large-angle steering, the steering transmission ratio parameter of the vehicle is obtained by using the steering transmission ratio parameter calculation formula.

[0243] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0244] According to the driving data of high-speed small-angle steering, the rear wheel cornering stiffness parameter of the vehicle is obtained by using the rear wheel cornering stiffness parameter calculation formula, and the front wheel cornering stiffness parameter of the vehicle is obtained by using the front wheel cornering stiffness parameter calculation formula;

[0245] The rear wheel cornering stiffness parameter and the front wheel cornering stiffness parameter are weighted averaged to obtain the vehicle cornering stiffness parameter.

[0246] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0247] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0248] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0249] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A vehicle parameter calibration method, characterized in that: The method comprises: Acquiring historical driving data of the vehicle, wherein the historical driving data includes front and rear wheel axle weights, wheel lateral speeds, yaw angular speeds, and vehicle wheelbase; Obtaining a calculation formula for tire force parameters of the front and rear wheels according to the front and rear wheel axle weights and wheel lateral speeds of the vehicle; According to the tire force parameter calculation formula of the front and rear wheels, a first calculation formula of the front and rear wheel sideslip angles is obtained, and the first calculation formula is: ； Among them, C f is the front wheel cornering stiffness parameter calculation formula, C r is the rear wheel cornering stiffness parameter calculation formula, α f is the front wheel slip angle, α r is the rear wheel slip angle, F yf is the tire force parameter of the front wheel, F yr is the tire force parameter of the rear wheel, m f is the weight of the front wheel axle of the vehicle, m r is the weight of the rear wheel bearing of the vehicle, R is the driving radius, v x is the lateral speed of the wheel; Obtaining a steady-state steering angle calculation formula according to the first calculation formula for the front and rear wheel sideslip angles and the vehicle wheelbase; Obtaining an understeering coefficient of the vehicle according to the yaw angular velocity and the steady-state steering angle calculation formula; According to the understeering coefficient, a calculation formula for the cornering stiffness parameter and a calculation formula for the steering transmission ratio parameter of the vehicle are determined; wherein the vehicle wheelbase includes a first distance between the center of mass of the vehicle and the front axle, and a second distance between the center of mass of the vehicle and the rear axle; Get the longitudinal velocity of the vehicle's center of mass; Obtaining a front wheel longitudinal velocity calculation formula and a rear wheel longitudinal velocity calculation formula respectively according to the yaw angular velocity, the first distance, the second distance, and the longitudinal velocity of the vehicle center of mass; According to the front wheel longitudinal speed calculation formula and the rear wheel longitudinal speed calculation formula, a second calculation formula for the front and rear wheel sideslip angles is obtained, and the second calculation formula is: ； Among them, δ is the steady-state steering angle, α f is the front wheel slip angle, α r is the rear wheel slip angle, v x is the lateral speed of the wheel, l f is the first distance between the vehicle's center of mass and the front axle, l r v is the second distance between the vehicle's center of mass and the rear axle; yf Front wheel longitudinal speed calculation formula; v yr The rear wheel longitudinal velocity calculation formula, ω is the yaw angular velocity; Obtaining a rear wheel cornering stiffness parameter calculation formula of the vehicle according to the first calculation formula and the second calculation formula of the front and rear wheel slip angles; Determining a front wheel cornering stiffness parameter calculation formula for the vehicle according to the rear wheel cornering stiffness parameter calculation formula and the understeer coefficient; Obtain real-time driving data of the vehicle; According to the real-time driving data, the cornering stiffness parameter and the steering transmission ratio parameter of the vehicle are obtained by using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula.

2. The method according to claim 1, characterized in that The calculation formula for determining the steering transmission ratio parameter of the vehicle according to the understeering coefficient includes: Get the steering wheel angle; A calculation formula for a steering transmission ratio parameter of the vehicle is determined according to the yaw angular velocity, the vehicle wheelbase, the wheel lateral velocity, the steering wheel angle and the understeering coefficient.

3. The method according to claim 1, characterized in that The real-time driving data includes driving data of high-speed small-angle steering and driving data of low-speed large-angle steering; the method of obtaining the cornering stiffness parameter and the steering transmission ratio parameter of the vehicle according to the real-time driving data by using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula includes: According to the driving data of the high-speed small-angle steering, the cornering stiffness parameter of the vehicle is obtained by using the cornering stiffness parameter calculation formula; And, according to the driving data of the low-speed large-angle steering, the steering transmission ratio parameter calculation formula is used to obtain the steering transmission ratio parameter of the vehicle.

4. The method according to claim 3, characterized in that The method of obtaining the cornering stiffness parameter of the vehicle according to the driving data of the high-speed small-angle steering and using the cornering stiffness parameter calculation formula includes: According to the driving data of the high-speed small-angle steering, the rear wheel cornering stiffness parameter of the vehicle is obtained by using the rear wheel cornering stiffness parameter calculation formula, and the front wheel cornering stiffness parameter of the vehicle is obtained by using the front wheel cornering stiffness parameter calculation formula; A weighted average calculation is performed on the rear wheel cornering stiffness parameter and the front wheel cornering stiffness parameter to obtain a cornering stiffness parameter of the vehicle.

5. A vehicle parameter calibration device, characterized in that: The device comprises: An acquisition module, used to acquire historical driving data of the vehicle, wherein the historical driving data includes front and rear wheel axle weights, wheel lateral speeds, yaw angular speeds, and vehicle wheelbase; The calculation module is used to obtain a calculation formula for the tire force parameters of the front and rear wheels according to the front and rear wheel axle weights and the lateral speed of the wheels of the vehicle; and obtain a first calculation formula for the sideslip angles of the front and rear wheels according to the calculation formula for the tire force parameters of the front and rear wheels, the first calculation formula being: ； Among them, C f is the front wheel cornering stiffness parameter calculation formula, C r is the rear wheel cornering stiffness parameter calculation formula, α f is the front wheel slip angle, α r is the rear wheel slip angle, F yf is the tire force parameter of the front wheel, F yr is the tire force parameter of the rear wheel, m f is the weight of the front wheel axle of the vehicle, m r is the weight of the rear wheel bearing of the vehicle, R is the driving radius, v x is the lateral speed of the wheel; According to the first calculation formula of the front and rear wheel slip angles and the vehicle wheelbase, a steady-state steering angle calculation formula is obtained; according to the yaw angular velocity and the steady-state steering angle calculation formula, an understeering coefficient of the vehicle is obtained; according to the understeering coefficient, a cornering stiffness parameter calculation formula and a steering transmission ratio parameter calculation formula of the vehicle are determined; wherein the vehicle wheelbase includes a first distance between the center of mass of the vehicle and the front wheel axle, and a second distance between the center of mass of the vehicle and the rear wheel axle; The acquisition module is also used to obtain the longitudinal velocity of the center of mass of the vehicle; The calculation module is further used to obtain a front wheel longitudinal velocity calculation formula and a rear wheel longitudinal velocity calculation formula according to the yaw angular velocity, the first distance, the second distance, and the longitudinal velocity of the vehicle center of mass; and obtain a second calculation formula for the front and rear wheel sideslip angles according to the front wheel longitudinal vehicle speed calculation formula and the rear wheel longitudinal vehicle speed calculation formula, the second calculation formula being: ； Among them, δ is the steady-state steering angle, α f is the front wheel slip angle, α r is the rear wheel slip angle, v x is the lateral speed of the wheel, l f is the first distance between the vehicle's center of mass and the front axle, l r v is the second distance between the vehicle's center of mass and the rear axle; yf Front wheel longitudinal speed calculation formula; v yr The rear wheel longitudinal velocity calculation formula, ω is the yaw angular velocity; According to the first calculation formula and the second calculation formula of the front and rear wheel slip angles, a calculation formula of the rear wheel cornering stiffness parameter of the vehicle is obtained; according to the calculation formula of the rear wheel cornering stiffness parameter and the understeering coefficient, a calculation formula of the front wheel cornering stiffness parameter of the vehicle is determined; The calculation module is further used to determine a calculation formula for a cornering stiffness parameter and a calculation formula for a steering transmission ratio parameter of the vehicle according to the understeering coefficient; The acquisition module is also used to acquire real-time driving data of the vehicle; The calculation module is also used to obtain the vehicle's cornering stiffness parameter and steering transmission ratio parameter according to the real-time driving data using the cornering stiffness parameter calculation formula and the steering transmission ratio parameter calculation formula.

6. The device according to claim 5, characterized in that The acquisition module is also used to obtain the steering wheel angle; The calculation module is also used to determine a calculation formula for a steering transmission ratio parameter of the vehicle according to the yaw angular velocity, the vehicle wheelbase, the wheel lateral velocity, the steering wheel angle and the understeering coefficient.

7. The device according to claim 5, characterized in that The real-time driving data includes driving data of high-speed small-angle steering and driving data of low-speed large-angle steering; The calculation module is also used to obtain the vehicle's cornering stiffness parameters based on the driving data of the high-speed small-angle steering by using the cornering stiffness parameter calculation formula; and to obtain the vehicle's steering transmission ratio parameters based on the driving data of the low-speed large-angle steering by using the steering transmission ratio parameter calculation formula.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

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