Calculation method and calculation device for deviation angle of vehicle tire

Abstract

The invention provides a vehicle tire deviation angle calculation method and device, and the method comprises the steps: building an intermediate shaft coordinate system corresponding to a target vehicle when a simulation test is carried out on the target vehicle under a corner working condition, the centroid speed and the yaw velocity of the target vehicle under the intermediate shaft coordinate system and the wheel steering angle of each wheel are obtained; on the basis of the mass center speed, the yaw velocity and the size information of the target vehicle, the wheel center speed of each wheel under the intermediate shaft coordinate system is obtained through calculation; based on the wheel center speed and the wheel steering angle, obtaining the tire grounding point speed of each wheel under the own coordinate system; and based on the tire grounding point speed, calculating to obtain a tire side deviation angle corresponding to each wheel. Through the method, the problem of simulation precision of tire response under the corner working condition is solved, the accuracy of calculating the deviation angle of the vehicle tire is improved, and the safety of vehicle driving is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle and tire performance analysis, and in particular to a method and device for calculating a vehicle tire deflection angle. Background Art

[0002] As the only medium for contact between the vehicle and the ground, the mechanical properties of the tire play a vital role in the vehicle's handling and safety, especially under low-speed and large-angle conditions, such as frequent turns on narrow urban roads, fine operations in parking lots, and automatic parking. The tire's side slip characteristics affect the vehicle's control performance.

[0003] When the vehicle is in a low-speed, large-angle condition, although the steering angle of the wheel increases significantly, the tire slip angle remains in a relatively small range. Slight changes in the slip angle have a significant impact on the vehicle's handling performance. Therefore, accurate calculation of the tire slip angle is very important for the simulation and analysis of tire and vehicle performance.

[0004] At present, since a vehicle is usually considered to be in a steady-state steering state when traveling at a low speed, a bicycle model is generally used to simplify the vehicle dynamics model, and the tire slip angle is calculated using the bicycle model. However, this method has low accuracy in low-speed and large-angle scenarios, and there is a significant deviation between the calculated tire slip angle and the actual vehicle measured data, which causes the vehicle's yaw angular velocity and lateral acceleration values ​​to be over-amplified, and may even cause the vehicle to rotate unnecessary on the spot, reducing the accuracy of calculating the vehicle's tire slip angle, thereby reducing the safety of vehicle driving. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a method and device for calculating the deviation angle of a vehicle tire. By obtaining the center of mass velocity, yaw angular velocity and wheel steering angle in the intermediate shaft coordinate system when performing a simulation test on a target vehicle under a cornering condition, the wheel center velocity of each wheel in the intermediate shaft coordinate system is calculated, and the tire contact point velocity of each wheel in the said own coordinate system is converted, and the tire side slip angle corresponding to each wheel is calculated using the inverse tangent function expression, which solves the simulation accuracy problem of tire response under cornering conditions, improves the accuracy of calculating the vehicle tire deviation angle, and thus ensures the safety of vehicle driving.

[0006] The present application provides a method for calculating a tire deflection angle of a vehicle, the method comprising:

[0007] When performing a simulation test on a target vehicle under a cornering condition, an intermediate shaft coordinate system corresponding to the target vehicle is established, and the center of mass velocity and yaw angular velocity of the target vehicle in the intermediate shaft coordinate system, as well as the wheel steering angle of each wheel of the target vehicle in the intermediate shaft coordinate system are obtained;

[0008] Based on the mass center velocity, the yaw angular velocity and the size information of the target vehicle, the wheel center velocity of each wheel in the intermediate shaft coordinate system is calculated;

[0009] Based on the wheel center speed and the wheel steering angle, the intermediate shaft coordinate system is converted into the own coordinate system corresponding to each wheel to obtain the tire contact point speed of each wheel in the own coordinate system;

[0010] Based on the tire contact point speed, a preset inverse tangent function expression is used to calculate the tire slip angle corresponding to each wheel.

[0011] Furthermore, the establishing of the intermediate axis coordinate system corresponding to the target vehicle includes:

[0012] Based on a reference vertical axis in a preset global inertial reference system, determining a target vertical axis parallel to the reference vertical axis;

[0013] The vehicle heading angle of the target vehicle in the global inertial reference system is determined, and the global inertial reference system is rotated according to the vehicle heading angle with the target vertical axis as the center to establish an intermediate axis coordinate system corresponding to the target vehicle.

[0014] Further, the calculating the wheel center velocity of each wheel in the intermediate shaft coordinate system based on the mass center velocity, the yaw angular velocity and the size information of the target vehicle includes:

[0015] Based on the longitudinal velocity of the center of mass included in the center of mass velocity, the yaw angular velocity, and the wheelbase value included in the size information of the target vehicle, the longitudinal velocity of the wheel center of each wheel in the intermediate shaft coordinate system is calculated;

[0016] Based on the mass center lateral velocity included in the mass center velocity, the yaw angular velocity, and the wheelbase value and the front axle mass center longitudinal distance value included in the size information of the target vehicle, the wheel center lateral velocity of each wheel in the intermediate shaft coordinate system is calculated.

[0017] Further, the wheel center longitudinal velocity of each wheel in the intermediate shaft coordinate system is calculated based on the center of mass longitudinal velocity included in the center of mass velocity, the yaw angular velocity, and the wheelbase value included in the size information of the target vehicle, including:

[0018] Based on the yaw angular velocity and the wheelbase value, a rollover tendency parameter of the target vehicle is calculated;

[0019] Subtract the rollover tendency parameter from the longitudinal velocity of the center of mass, and determine the obtained subtraction calculation result as the longitudinal velocity of the wheel center of the left front wheel and the left rear wheel of the target vehicle in the intermediate shaft coordinate system;

[0020] The mass center longitudinal velocity is added to the rollover tendency parameter, and the addition result is determined as the wheel center longitudinal velocity of the right front wheel and the right rear wheel of the target vehicle in the intermediate shaft coordinate system.

[0021] Further, the wheel center lateral velocity of each wheel in the intermediate shaft coordinate system is calculated based on the center of mass lateral velocity included in the center of mass velocity, the yaw angular velocity, and the wheelbase value and the front axle center of mass longitudinal distance value included in the size information of the target vehicle, including:

[0022] Based on the yaw rate and the longitudinal distance value of the front axle center of mass, a front axle component of the lateral velocity of the target vehicle is calculated;

[0023] Adding the mass center lateral velocity to the lateral velocity front axle component, and determining the obtained addition result as the wheel center lateral velocity of the left front wheel and the right front wheel of the target vehicle in the intermediate shaft coordinate system;

[0024] Subtracting the wheelbase value from the longitudinal distance value of the front axle mass center to obtain the longitudinal distance value of the rear axle mass center of the target vehicle, and calculating the rear axle component of the lateral velocity of the target vehicle based on the yaw angular velocity and the longitudinal distance value of the rear axle mass center;

[0025] The mass center lateral velocity is subtracted from the lateral velocity rear axle component, and the subtraction result is determined as the wheel center lateral velocity of the left rear wheel and the right rear wheel of the target vehicle in the intermediate shaft coordinate system.

[0026] Furthermore, based on the wheel center speed and the wheel steering angle, the intermediate shaft coordinate system is converted into the own coordinate system corresponding to each wheel to obtain the tire contact point speed of each wheel in the own coordinate system, including:

[0027] Based on the wheel steering angle, a conversion matrix of each wheel is obtained using a preset matrix conversion expression;

[0028] Based on the wheel center speed and the conversion matrix, the wheel center speed in the intermediate shaft coordinate system is converted into the tire contact point speed of each wheel in the own coordinate system to obtain the tire contact point speed.

[0029] Furthermore, the tire slip angle corresponding to each wheel is calculated based on the tire contact point speed using a preset inverse tangent function expression, including:

[0030] Taking an absolute value of the longitudinal speed of the tire ground contact center included in the tire ground contact point speed, and comparing the absolute value with a preset threshold to determine a maximum value between the absolute value and the preset threshold;

[0031] Based on the maximum value, determining the actual tire ground contact center longitudinal speed corresponding to each wheel;

[0032] Based on the tire contact point speed including the tire contact center lateral speed and the actual tire contact center longitudinal speed, a preset inverse tangent function expression is used to calculate the tire slip angle corresponding to each wheel.

[0033] The present application also provides a device for calculating a vehicle tire deflection angle, the device comprising:

[0034] A data acquisition module, used to establish an intermediate shaft coordinate system corresponding to the target vehicle when performing a simulation test on the target vehicle under a cornering condition, and to obtain the center of mass velocity and yaw angular velocity of the target vehicle in the intermediate shaft coordinate system, as well as the wheel steering angle of each wheel of the target vehicle in the intermediate shaft coordinate system;

[0035] A first calculation module, configured to calculate the wheel center velocity of each wheel in the intermediate shaft coordinate system based on the mass center velocity, the yaw angular velocity and the size information of the target vehicle;

[0036] A data conversion module, configured to obtain a tire contact point speed of each wheel in the self-coordinate system by converting the intermediate shaft coordinate system into the self-coordinate system corresponding to each wheel based on the wheel center speed and the wheel steering angle;

[0037] The second calculation module is used to calculate the tire slip angle corresponding to each wheel based on the tire contact point speed using a preset inverse tangent function expression.

[0038] Furthermore, when the data acquisition module is used to establish the intermediate shaft coordinate system corresponding to the target vehicle, the data acquisition module is used to:

[0039] Based on a reference vertical axis in a preset global inertial reference system, determining a target vertical axis parallel to the reference vertical axis;

[0040] The vehicle heading angle of the target vehicle in the global inertial reference system is determined, and the global inertial reference system is rotated according to the vehicle heading angle with the target vertical axis as the center to establish an intermediate axis coordinate system corresponding to the target vehicle.

[0041] Further, when the first calculation module is used to calculate the wheel center velocity of each wheel in the intermediate shaft coordinate system based on the center of mass velocity, the yaw angular velocity and the size information of the target vehicle, the first calculation module is used to:

[0042] Based on the longitudinal velocity of the center of mass included in the center of mass velocity, the yaw rate, and the wheelbase value included in the size information of the target vehicle, the longitudinal velocity of the wheel center of each wheel in the intermediate shaft coordinate system is calculated;

[0043] Based on the mass center lateral velocity included in the mass center velocity, the yaw angular velocity, and the wheelbase value and the front axle mass center longitudinal distance value included in the size information of the target vehicle, the wheel center lateral velocity of each wheel in the intermediate shaft coordinate system is calculated.

[0044] Further, when the first calculation module is used to calculate the wheel center longitudinal velocity of each wheel in the intermediate shaft coordinate system based on the center of mass longitudinal velocity included in the center of mass velocity, the yaw angular velocity, and the wheelbase value included in the size information of the target vehicle, the first calculation module is used to:

[0045] Based on the yaw angular velocity and the wheelbase value, a rollover tendency parameter of the target vehicle is calculated;

[0046] Subtract the rollover tendency parameter from the longitudinal velocity of the center of mass, and determine the obtained subtraction calculation result as the longitudinal velocity of the wheel center of the left front wheel and the left rear wheel of the target vehicle in the intermediate shaft coordinate system;

[0047] The mass center longitudinal velocity is added to the rollover tendency parameter, and the addition result is determined as the wheel center longitudinal velocity of the right front wheel and the right rear wheel of the target vehicle in the intermediate shaft coordinate system.

[0048] Further, when the first calculation module is used to calculate the wheel center lateral velocity of each wheel in the intermediate shaft coordinate system based on the center of mass lateral velocity included in the center of mass velocity, the yaw angular velocity, and the wheelbase value and the front axle center of mass longitudinal distance value included in the size information of the target vehicle, the first calculation module is used to:

[0049] Based on the yaw rate and the longitudinal distance value of the front axle center of mass, a front axle component of the lateral velocity of the target vehicle is calculated;

[0050] Adding the mass center lateral velocity to the lateral velocity front axle component, and determining the obtained addition result as the wheel center lateral velocity of the left front wheel and the right front wheel of the target vehicle in the intermediate shaft coordinate system;

[0051] Subtracting the wheelbase value from the longitudinal distance value of the front axle mass center to obtain the longitudinal distance value of the rear axle mass center of the target vehicle, and calculating the rear axle component of the lateral velocity of the target vehicle based on the yaw angular velocity and the longitudinal distance value of the rear axle mass center;

[0052] The mass center lateral velocity is subtracted from the lateral velocity rear axle component, and the subtraction result is determined as the wheel center lateral velocity of the left rear wheel and the right rear wheel of the target vehicle in the intermediate shaft coordinate system.

[0053] Further, when the data conversion module is used to obtain the tire contact point speed of each wheel in the own coordinate system by converting the intermediate shaft coordinate system into the own coordinate system corresponding to each wheel based on the wheel center speed and the wheel steering angle, the data conversion module is used to:

[0054] Based on the wheel steering angle, a conversion matrix of each wheel is obtained using a preset matrix conversion expression;

[0055] Based on the wheel center speed and the conversion matrix, the wheel center speed in the intermediate shaft coordinate system is converted into the tire contact point speed of each wheel in the own coordinate system to obtain the tire contact point speed.

[0056] Further, when the second calculation module is used to calculate the tire slip angle corresponding to each wheel based on the tire contact point speed by using a preset inverse tangent function expression, the second calculation module is used to:

[0057] Taking an absolute value of the longitudinal speed of the tire ground contact center included in the tire ground contact point speed, and comparing the absolute value with a preset threshold to determine a maximum value between the absolute value and the preset threshold;

[0058] Based on the maximum value, determining the actual tire ground contact center longitudinal speed corresponding to each wheel;

[0059] Based on the tire contact point speed including the tire contact center lateral speed and the actual tire contact center longitudinal speed, a preset inverse tangent function expression is used to calculate the tire slip angle corresponding to each wheel.

[0060] An embodiment of the present application also provides an electronic device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate via the bus, and when the machine-readable instructions are executed by the processor, the steps of the method for calculating the vehicle tire deviation angle as described above are performed.

[0061] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method for calculating the vehicle tire deflection angle as described above are executed.

[0062] The embodiments of the present application provide a method and device for calculating the deviation angle of a vehicle tire. The method comprises: when performing a simulation test on a target vehicle under a cornering condition, establishing an intermediate axis coordinate system corresponding to the target vehicle, and obtaining the center of mass velocity and yaw angular velocity of the target vehicle in the intermediate axis coordinate system, as well as the wheel steering angle of each wheel of the target vehicle in the intermediate axis coordinate system; calculating the wheel center velocity of each wheel in the intermediate axis coordinate system based on the center of mass velocity, the yaw angular velocity and the size information of the target vehicle; obtaining the tire contact point velocity of each wheel in the self-coordinate system based on the wheel center velocity and the wheel steering angle; and calculating the tire side slip angle corresponding to each wheel using a preset inverse tangent function expression based on the tire contact point velocity.

[0063] Compared with the method in the prior art of simplifying the vehicle dynamics model by using a bicycle model and calculating the tire slip angle through the bicycle model, the method obtains the center of mass velocity, yaw angular velocity and wheel steering angle in the intermediate shaft coordinate system when performing a simulation test on the target vehicle under a cornering condition, calculates the wheel center velocity of each wheel in the intermediate shaft coordinate system, and converts it to obtain the tire contact point velocity of each wheel in the said own coordinate system, and uses the inverse tangent function expression to calculate the tire slip angle corresponding to each wheel, thereby solving the simulation accuracy problem of tire response under cornering conditions, improving the accuracy of calculating the vehicle tire slip angle, and thus ensuring the safety of vehicle driving.

[0064] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0066] Figure 1 A calculation diagram of a bicycle model provided in an embodiment of the present application;

[0067] Figure 2 A flow chart of a method for calculating a vehicle tire deflection angle provided in an embodiment of the present application;

[0068] Figure 3 A schematic diagram of calculating the wheel center speed in an intermediate shaft coordinate system provided in an embodiment of the present application;

[0069] Figure 4 A schematic diagram of the structure of a device for calculating the deflection angle of a vehicle tire provided in an embodiment of the present application;

[0070] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0071] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work belongs to the scope of protection of the present application.

[0072] Research has found that with the development of the automobile industry, the driving stability and handling performance of vehicles under various complex working conditions have become the focus of automobile manufacturers and scientific research institutions; among them, tires are the only medium for contact between vehicles and the ground, and their mechanical properties play a vital role in the vehicle's handling and safety, especially under low-speed and large-angle conditions, such as frequent turns on narrow urban roads, fine operations in parking lots, and automatic parking. The side slip characteristics of tires affect the vehicle's control performance.

[0073] Here, the tire's slip characteristics refer to the relationship between the tire's lateral force, righting torque and slip angle. The tire's slip characteristics are the basis for the vehicle to achieve precise control and stable driving in dynamic driving scenarios, especially under low-speed and large-angle conditions. The tire's slip angle refers to the angle between the wheel plane and the direction of movement of the wheel center.

[0074] When the vehicle is in a low-speed, large-angle condition, although the steering angle of the wheel increases significantly, the tire slip angle remains in a relatively small range. Slight changes in the slip angle have a significant impact on the vehicle's handling performance. Therefore, accurate calculation of the tire slip angle is very important for the simulation and analysis of tire and vehicle performance.

[0075] At present, since a vehicle is generally considered to be in a steady-state steering state when traveling at a low speed, a bicycle model is generally used to simplify the vehicle dynamics model, and the tire slip angle is calculated through the bicycle model.

[0076] For details, please refer to Figure 1 , Figure 1 The following is a calculation diagram of a bicycle model provided in an embodiment of the present application. Figure 1 As shown in , the bicycle model simplifies the vehicle into only the front and rear wheels and the connection between the front and rear wheels to ignore the roll and pitch motion of the vehicle and the differential effect between the left and right wheels.

[0077] like Figure 1 As shown in , x-0-y is the rectangular coordinate system of the vehicle body; v f and v r are the center speeds of the front and rear wheels respectively; v x,f and v x,r are the x-direction speeds of the front and rear wheels respectively; v y,f and v y,r are the y-direction speeds of the front and rear wheel centers respectively; β f and β r are the center slip angles of the front and rear wheels respectively; δ is the front wheel turning angle; β is the center of mass slip angle; α f and α r are the front and rear wheel slip angles respectively.

[0078] In such Figure 1In the bicycle model shown in , the calculation of the tire slip angle mainly depends on the front wheel turning angle and the front and rear wheel center slip angle; wherein, the slip angle refers to the angle between the longitudinal velocity and the resultant velocity, and is calculated by dividing the lateral velocity by the longitudinal velocity in the corresponding coordinate system and then taking the arc tangent. The positive and negative signs are determined according to the x-axis of the corresponding coordinate system. It reflects the degree of lateral deviation of the vehicle as a whole. At this time, the front wheel turning angle minus the front wheel center slip angle is equal to the front tire slip angle, and the rear wheel center slip angle is determined as the rear wheel slip angle.

[0079] Specifically, the expressions for calculating the front wheel slip angle and rear wheel slip angle of the vehicle under the bicycle model are as follows.

[0080]

[0081] Among them, α f and α t are the front and rear wheel side slip angles respectively; δ is the front wheel turning angle; β f and β r are the center slip angles of the front and rear wheels respectively; v x,f and v x,r are the x-direction speeds of the front and rear wheels respectively; v y,f and v y,r are the y-direction velocities of the front and rear wheels respectively.

[0082] For the calculation method of the bicycle model mentioned above, under complex conditions involving low-speed driving and large-angle operations, the vehicle's front wheel steering angle (δ) increases significantly. When only the bicycle model is used to simplify the vehicle dynamics to calculate the tire slip angle, there will be a problem of insufficient calculation accuracy in low-speed (for example, 0-10kmh) steering simulation conditions. In particular, in the extremely low-speed and large-angle scenario where the vehicle speed is less than 2km / h and the wheel steering angle is 30deg, the calculation method of the bicycle model has low accuracy in the low-speed and large-angle scenario, and there is a significant deviation between the calculated tire slip angle and the actual vehicle measured data, which makes the vehicle's yaw angular velocity and lateral acceleration values ​​excessively amplified, and may even cause the vehicle to rotate unnecessary on the spot, reducing the accuracy of calculating the vehicle tire slip angle, thereby reducing the safety of vehicle driving.

[0083] In addition, the current widely used autonomous driving control algorithms in vehicles generally use simplified methods such as bicycle models when estimating the wheel slip angle, which poses a safety hazard to vehicles under low-speed driving conditions. Due to the significant differences in tire response characteristics, the control accuracy of the algorithm will have an adverse effect on vehicle performance, especially in low-speed complex environments that require highly precise control, and the stability and safety of the vehicle face severe challenges.

[0084] Based on this, an embodiment of the present application provides a method for calculating the vehicle tire deviation angle. By obtaining the center of mass velocity, yaw angular velocity and wheel steering angle in the intermediate shaft coordinate system when performing a simulation test on the target vehicle under a cornering condition, the wheel center velocity of each wheel in the intermediate shaft coordinate system is calculated, and the tire contact point velocity of each wheel in the said own coordinate system is converted, and the tire side slip angle corresponding to each wheel is calculated using the inverse tangent function expression, which solves the simulation accuracy problem of tire response under cornering conditions, improves the accuracy of calculating the vehicle tire deviation angle, and thus ensures the safety of vehicle driving.

[0085] See also Figure 2 , Figure 2 The following is a flow chart of a method for calculating the tire deflection angle of a vehicle provided in an embodiment of the present application. Figure 2 As shown in , the method for calculating the vehicle tire deflection angle provided in the embodiment of the present application includes:

[0086] S101. When performing a simulation test on a target vehicle under a turning condition, an intermediate axis coordinate system corresponding to the target vehicle is established, and the center of mass velocity and yaw angular velocity of the target vehicle in the intermediate axis coordinate system, as well as the wheel steering angle of each wheel of the target vehicle in the intermediate axis coordinate system are obtained.

[0087] In the embodiment of the present application, the corner condition refers to the working state of the vehicle when turning, which involves multiple factors and technical considerations, including but not limited to the vehicle's dynamic characteristics, the performance of the steering system, driving strategies, and the external environment; here, the corner condition includes the vehicle's turning operation under any vehicle speed conditions, for example, low-speed corner conditions and high-speed corner conditions.

[0088] In this step, when it is specifically implemented, first, when calculating the tire deflection angle of the target vehicle, a simulation model of the vehicle is constructed using vehicle dynamics simulation software to perform a simulation test on the target vehicle and control the vehicle to be in a cornering condition; then, based on the global inertial reference system, an intermediate axis coordinate system corresponding to the target vehicle is established; finally, the vehicle dynamics simulation software or actual measurement acquisition equipment (for example, GPS and gyroscope, etc.) is used to obtain the center of mass velocity and yaw angular velocity of the target vehicle in the intermediate axis coordinate system, as well as the wheel steering angle of each wheel of the target vehicle in the intermediate axis coordinate system.

[0089] Here, the method of obtaining the center of mass velocity, the yaw angular velocity and the wheel steering angle may also include other indirect acquisition methods, which are not limited in this application.

[0090] Among them, the center of mass speed includes the center of mass longitudinal speed and the center of mass lateral speed; the center of mass longitudinal speed refers to the speed of the center of mass of the target vehicle under the X-axis of the intermediate axis coordinate system; the center of mass lateral speed refers to the speed of the center of mass of the target vehicle under the Y-axis of the intermediate axis coordinate system.

[0091] In one embodiment of the present application, during specific implementation, the step of establishing the intermediate axis coordinate system corresponding to the target vehicle in step S101 may include:

[0092] S1011. Based on a reference vertical axis in a preset global inertial reference system, determine a target vertical axis parallel to the reference vertical axis.

[0093] In an embodiment of the present application, the preset global inertial reference system is an earth-fixed axis coordinate system, and the global inertial reference system is a non-accelerating and non-rotating reference system. In this reference system, the movement of objects follows Newton's first law (law of inertia) and second law (F=ma).

[0094] In this step, the target vertical axis (Z axis) of the intermediate axis coordinate system corresponding to the target vehicle is parallel to the reference vertical axis (Z axis) in the global inertial reference system. E axis).

[0095] Here, the reference vertical axis (Z) in the global inertial reference system E axis) is parallel to the gravity vector and is usually defined as "up".

[0096] S1012: Determine a vehicle heading angle of the target vehicle in the global inertial reference system, and rotate the global inertial reference system according to the vehicle heading angle with the target vertical axis as the center to establish an intermediate axis coordinate system corresponding to the target vehicle.

[0097] In this step, during the specific implementation, first, the forward direction of the target vehicle is determined as the target longitudinal axis (X axis) of the intermediate axis coordinate system; then, the vehicle heading angle of the target vehicle in the global inertial reference system is determined; finally, with the target vertical axis as the center, the global inertial reference system is rotated according to the vehicle heading angle to establish the intermediate axis coordinate system (X axis, Y axis, Z axis) corresponding to the target vehicle.

[0098] Here, the intermediate axis coordinate system is a right-handed orthogonal axis coordinate system.

[0099] S102: Calculate the wheel center velocity of each wheel in the intermediate shaft coordinate system based on the center-of-mass velocity, the yaw angular velocity and the size information of the target vehicle.

[0100] Here, the size information of the target vehicle may include but is not limited to the wheelbase value, wheelbase value and the longitudinal distance value of the front axle center of mass; wherein the longitudinal distance value of the front axle center of mass refers to the longitudinal (X-axis direction of the intermediate axis coordinate system) distance from the center of mass of the vehicle to the front wheelbase part.

[0101] In an embodiment of the present application, the wheel center speed includes a wheel center longitudinal speed and a wheel center lateral speed; wherein the wheel center longitudinal speed is calculated by the center of mass longitudinal speed, the yaw angular velocity and the wheelbase value; the wheel center lateral speed is calculated by the center of mass lateral speed, the yaw angular velocity, the wheelbase value and the front axle center of mass longitudinal distance value.

[0102] For details, please refer to Figure 3 , Figure 3 The following is a schematic diagram of calculating the wheel center speed in an intermediate axis coordinate system provided in an embodiment of the present application. Figure 3 As shown in , each wheel (left front wheel LF, left rear wheel LR, right front wheel RF, right rear wheel RR) of the target vehicle in the intermediate shaft coordinate system corresponds to a wheel center longitudinal velocity (Vx_LF, Vx_LR, Vx_RF, Vx_RR) and wheel center lateral velocity (Vy_LF, Vy_LR, Vy_RF, Vy_RR); the center of mass longitudinal velocity (Vx), center of mass lateral velocity (Vy), yaw angular velocity (wr), the intermediate shaft coordinate system and the size information of the target vehicle (track value Track, wheelbase value Wheelbase, front axle center of mass longitudinal distance value Lf) are as follows Figure 3 The annotations shown in .

[0103] In one implementation of the present application, during specific implementation, step S102 may include:

[0104] S1021. Based on the longitudinal velocity of the center of mass included in the center of mass velocity, the yaw angular velocity, and the wheelbase value included in the size information of the target vehicle, calculate the longitudinal velocity of the wheel center of each wheel in the intermediate shaft coordinate system.

[0105] In this step, the longitudinal velocity of the center of mass, the yaw angular velocity and the wheelbase value of the target vehicle are input into a preset wheel center longitudinal velocity expression to calculate the wheel center longitudinal velocity of each wheel in the intermediate shaft coordinate system.

[0106] Specifically, the preset wheel center longitudinal velocity expression is as follows.

[0107] Vx_LF=Vx-wr×Track×0.5.

[0108] Vx_LR=Vx-wr×Track×0.5.

[0109] Vx_RF=Vx+wr×Track×0.5.

[0110] Vx_RR=Vx+wr×Track×0.5.

[0111] Among them, Vx_LF, Vx_LR, Vx_RF, and Vx_RR represent the longitudinal speeds of the wheel centers of the left front wheel, left rear wheel, right front wheel, and right rear wheel of the target vehicle respectively; Track represents the wheelbase value of the target vehicle; wr represents the yaw angular velocity of the target vehicle; and Vx represents the longitudinal speed of the center of mass of the target vehicle.

[0112] In one implementation of the present application, during specific implementation, step S1021 may include:

[0113] S10211. Based on the yaw angular velocity and the wheelbase value, calculate a rollover tendency parameter of the target vehicle.

[0114] In this step, the yaw angular velocity is multiplied by the wheelbase value, and the product is halved to obtain the rollover tendency parameter of the target vehicle.

[0115] Specifically, the expression of the rollover tendency parameter of the target vehicle is as follows:

[0116] K1=wr×Track×0.5.

[0117] Among them, K1 represents the rollover tendency parameter of the target vehicle; Track represents the wheelbase value of the target vehicle; wr represents the yaw angular velocity of the target vehicle.

[0118] S10212. Subtract the rollover tendency parameter from the longitudinal velocity of the center of mass, and determine the obtained subtraction calculation result as the longitudinal velocity of the wheel center of the left front wheel and the left rear wheel of the target vehicle in the intermediate shaft coordinate system.

[0119] In this step, for the wheel center longitudinal velocities of the left front wheel and the left rear wheel, it is necessary to subtract the longitudinal velocity of the center of mass of the target vehicle from the rollover tendency parameter of the target vehicle (K1=wr×Track×0.5) to obtain the wheel center longitudinal velocities (Vx_LF and Vx_LR) of the left front wheel and the left rear wheel in the intermediate shaft coordinate system.

[0120] S10213. Add the center-of-mass longitudinal velocity and the rollover tendency parameter, and determine the resulting addition result as the wheel center longitudinal velocity of the right front wheel and the right rear wheel of the target vehicle in the intermediate shaft coordinate system.

[0121] In this step, for the wheel center longitudinal velocities of the right front wheel and the right rear wheel, it is necessary to add the longitudinal velocity of the center of mass of the target vehicle and the rollover tendency parameter of the target vehicle (K1=wr×Track×0.5) to obtain the wheel center longitudinal velocities (Vx_RF and Vx_RR) of the right front wheel and the right rear wheel in the intermediate shaft coordinate system.

[0122] S1022. Based on the center-of-mass lateral velocity included in the center-of-mass velocity, the yaw angular velocity, and the wheelbase value and the front axle center-of-mass longitudinal distance value included in the size information of the target vehicle, calculate the wheel center lateral velocity of each wheel in the intermediate shaft coordinate system.

[0123] In this step, the center-of-mass lateral velocity, yaw angular velocity, and the wheelbase value of the target vehicle and the longitudinal distance value of the center of mass of the front axle are input into the preset wheel center lateral velocity expression to calculate the wheel center lateral velocity of each wheel in the intermediate shaft coordinate system.

[0124] Specifically, the preset wheel center lateral velocity expression is as follows.

[0125] Vy_LF=Vy+wr×Lf.

[0126] Vy_LR=Vy-wr×(Wheelbase-Lf).

[0127] Vy_RF=Vy+wr×Lf.

[0128] Vy_RR=Vy-wr×(Wheelbase-Lf).

[0129] Among them, Vy_LF, Vy_LR, Vy_RF, and Vy_RR represent the lateral wheel center velocities of the left front wheel, left rear wheel, right front wheel, and right rear wheel of the target vehicle respectively; Wheelbase represents the wheelbase value of the target vehicle; wr represents the yaw angular velocity of the target vehicle; and Lf represents the longitudinal distance value of the center of mass of the front axle.

[0130] In one implementation of the present application, during specific implementation, step S1022 may include:

[0131] S10221. Based on the yaw angular velocity and the longitudinal distance value of the front axle center of mass, calculate a front axle component of the lateral velocity of the target vehicle.

[0132] In this step, the yaw angular velocity and the longitudinal distance value of the front axle center of mass are multiplied to calculate the front axle component of the lateral velocity of the target vehicle.

[0133] Specifically, the calculation expression of the front axle component of the lateral velocity of the target vehicle is as follows.

[0134] K f =wr×Lf.

[0135] Among them, K f represents the front axle component of the lateral velocity of the target vehicle; wr represents the yaw angular velocity of the target vehicle; Lf represents the longitudinal distance value of the center of mass of the front axle.

[0136] S10222. Add the mass center lateral velocity and the lateral velocity front axle component, and determine the addition result as the wheel center lateral velocity of the left front wheel and the right front wheel of the target vehicle in the intermediate shaft coordinate system.

[0137] In this step, for the lateral velocities of the left and right front wheels of the target vehicle, the mass center lateral velocity (Vy) and the lateral velocity front axle component (K f =wr×Lf) are added to determine the obtained addition calculation result as the wheel center lateral speeds (Vy_LF and Vy_RF) of the left front wheel and the right front wheel in the intermediate shaft coordinate system.

[0138] S10223. Subtract the wheelbase value from the longitudinal distance value of the front axle center of mass to obtain the longitudinal distance value of the rear axle center of mass of the target vehicle, and calculate the rear axle component of the lateral velocity of the target vehicle based on the yaw angular velocity and the longitudinal distance value of the rear axle center of mass.

[0139] In this step, the calculation expression of the rear axle component of the lateral velocity of the target vehicle is as follows.

[0140] K r =wr×(Wheelbase-Lf).

[0141] Among them, K r It represents the rear axle component of the lateral velocity of the target vehicle; wr represents the yaw angular velocity of the target vehicle; Lf represents the longitudinal distance value of the center of mass of the front axle; Wheelbase represents the wheelbase value of the target vehicle.

[0142] S10224. Subtract the mass center lateral velocity from the rear axle component of the lateral velocity, and determine the subtraction result as the wheel center lateral velocity of the left rear wheel and the right rear wheel of the target vehicle in the intermediate shaft coordinate system.

[0143] In this step, for the lateral velocities of the left and right rear wheels of the target vehicle, the mass center lateral velocity (Vy) and the lateral velocity rear axle component (K r =wr×(Wheelbase-Lf)) to determine the subtraction calculation result as the wheel center lateral speed (Vy_LR and Vy_RR) of the left rear wheel and the right rear wheel in the intermediate shaft coordinate system.

[0144] S103: Based on the wheel center speed and the wheel steering angle, the intermediate shaft coordinate system is converted into the own coordinate system corresponding to each wheel to obtain the tire contact point speed of each wheel in the own coordinate system.

[0145] In this step, when converting the wheel center longitudinal velocity and wheel center lateral velocity of each wheel in the intermediate shaft coordinate system into the tire contact point velocity of each wheel in its own coordinate system, it is necessary to use a conversion matrix to convert the intermediate shaft coordinate system into the own coordinate system corresponding to each wheel.

[0146] The tire contact point speed includes the tire contact center longitudinal speed and the tire contact center lateral speed.

[0147] In one implementation of the present application, during specific implementation, step S103 may include:

[0148] S1031. Based on the wheel steering angle, obtain the transformation matrix of each wheel using a preset matrix transformation expression.

[0149] In an embodiment of the present application, the preset matrix conversion expression is as follows.

[0150]

[0151] Wherein, A represents the transformation matrix of each wheel; steer represents the steering angle of each wheel, and it is assumed that when the steering direction is counterclockwise, the wheel steering angle is positive.

[0152] S1032: Based on the wheel center speed and the conversion matrix, convert the wheel center speed in the intermediate shaft coordinate system into the tire contact point speed of each wheel in the own coordinate system to obtain the tire contact point speed.

[0153] In this step, the wheel center longitudinal velocity and wheel center lateral velocity of each wheel are converted into a first velocity matrix, and the velocity matrix is ​​multiplied by the inverse matrix of the conversion matrix to obtain a second velocity matrix to determine the tire ground contact center longitudinal velocity and tire ground contact center lateral velocity of each wheel in its own coordinate system in the second velocity matrix.

[0154] In the embodiment of the present application, the calculation expression of the tire contact point speed is as follows.

[0155]

[0156]

[0157] Among them, Vx_tire_LF, Vx_tire_LR, Vx_tire_RF and Vx_tire_RR represent the longitudinal speed of the tire ground contact center of each wheel in its own coordinate system; Vy_tire_LF, Vy_tire_LR, Vy_tire_RF and Vy_tire_RR represent the lateral speed of the tire ground contact center of each wheel in its own coordinate system; Vx_LF, Vx_LR, Vx_RF and Vx_RR represent the longitudinal speed of the wheel center of each wheel in the intermediate shaft coordinate system; Vy_LF, Vy_LR, Vy_RF and Vy_RR represent the lateral speed of the wheel center of each wheel in the intermediate shaft coordinate system; A -1 Represents the inverse of the transformation matrix for each wheel.

[0158] S104: Based on the tire contact point speed, a preset inverse tangent function expression is used to calculate the tire slip angle corresponding to each wheel.

[0159] In this step, it is necessary to first take the absolute value of the longitudinal speed of the tire's center of contact, and compare the absolute value with a preset threshold value to perform certain threshold protection on the tire slip angle, that is, zero-crossing protection, to solve the problem that when the longitudinal speed of the tire's center of contact is too small, the calculated tire slip angle is too large, and at the same time make the calculated tire slip angle at low speed smoother.

[0160] Furthermore, the absolute value, the maximum value in the preset threshold value and the lateral speed of the tire ground contact center are input into a preset inverse tangent function expression to calculate the tire slip angle corresponding to each wheel.

[0161] Specifically, the preset inverse tangent function expression is as follows.

[0162]

[0163] Among them, α LF , α LR , α RF and α RR are the tire slip angles corresponding to each wheel; Vx_tire_LF, Vx_tire_LR, Vx_tire_RF and Vx_tire_RR respectively represent the longitudinal speed of the tire contact center of each wheel in its own coordinate system; Vy_tire_LF, Vy_tire_LR, Vy_tire_RF and Vy_tire_RR respectively represent the lateral speed of the tire contact center of each wheel in its own coordinate system; m is the preset threshold.

[0164] In the embodiment of the present application, the preset threshold is usually set to the actual speed of the vehicle when driving at a low speed (in m / s), and can be specifically calibrated according to the actual driving conditions of the vehicle. For example, if the vehicle is driving at a low speed of 0.56 m / s, the preset threshold can be set to 0.56.

[0165] In one implementation of the present application, during specific implementation, step S104 may include:

[0166] S1041. Take an absolute value of the tire contact point center longitudinal speed included in the tire contact point speed, and compare the absolute value with a preset threshold value to determine a maximum value between the absolute value and the preset threshold value.

[0167] In this step, the longitudinal speed of the tire contact center of each tire is numerically compared with a preset threshold value to determine the maximum value between the longitudinal speed of the tire contact center of each tire and the preset threshold value.

[0168] S1042: Based on the maximum value, determine the actual tire ground contact center longitudinal speed corresponding to each wheel.

[0169] In this step, the maximum value between the tire contact center longitudinal speed of each tire and the preset threshold value is determined as the actual tire contact center longitudinal speed corresponding to each wheel.

[0170] S1043. Based on the tire contact point speed included in the tire contact center lateral speed and the actual tire contact center longitudinal speed, a preset inverse tangent function expression is used to calculate the tire slip angle corresponding to each wheel.

[0171] In this step, the lateral speed of the tire contact center and the actual longitudinal speed of the tire contact center are input into a preset inverse tangent function expression, and the tire slip angle corresponding to each wheel is obtained by calculation.

[0172] The method for calculating the vehicle tire slip angle provided in the embodiment of the present application obtains the center of mass velocity, yaw angular velocity and wheel steering angle in the intermediate shaft coordinate system when performing a simulation test on the target vehicle under a cornering condition, calculates the wheel center velocity of each wheel in the intermediate shaft coordinate system, and converts it to obtain the tire contact point velocity of each wheel in the said own coordinate system, and uses the inverse tangent function expression to calculate the tire side slip angle corresponding to each wheel, thereby solving the simulation accuracy problem of tire response under cornering conditions, improving the accuracy of calculating the vehicle tire slip angle, and thus ensuring the safety of vehicle driving.

[0173] See also Figure 4 , Figure 4 This is a schematic diagram of the structure of a device for calculating the tire deflection angle of a vehicle provided in an embodiment of the present application. Figure 4As shown in , the computing device 400 includes:

[0174] The data acquisition module 410 is used to establish an intermediate shaft coordinate system corresponding to the target vehicle when performing a simulation test on the target vehicle under a cornering condition, and to obtain the center of mass velocity and yaw angular velocity of the target vehicle in the intermediate shaft coordinate system, as well as the wheel steering angle of each wheel of the target vehicle in the intermediate shaft coordinate system;

[0175] A first calculation module 420, configured to calculate the wheel center velocity of each wheel in the intermediate shaft coordinate system based on the mass center velocity, the yaw angular velocity and the size information of the target vehicle;

[0176] A data conversion module 430 is used to obtain a tire contact point speed of each wheel in the own coordinate system by converting the intermediate shaft coordinate system into the own coordinate system corresponding to each wheel based on the wheel center speed and the wheel steering angle;

[0177] The second calculation module 440 is used to calculate the tire slip angle corresponding to each wheel based on the tire contact point speed using a preset inverse tangent function expression.

[0178] Furthermore, when the data acquisition module 410 is used to establish the intermediate shaft coordinate system corresponding to the target vehicle, the data acquisition module 410 is used to:

[0179] Based on a reference vertical axis in a preset global inertial reference system, determining a target vertical axis parallel to the reference vertical axis;

[0180] The vehicle heading angle of the target vehicle in the global inertial reference system is determined, and the global inertial reference system is rotated according to the vehicle heading angle with the target vertical axis as the center to establish an intermediate axis coordinate system corresponding to the target vehicle.

[0181] Further, when the first calculation module 420 is used to calculate the wheel center velocity of each wheel in the intermediate shaft coordinate system based on the center of mass velocity, the yaw angular velocity and the size information of the target vehicle, the first calculation module 420 is used to:

[0182] Based on the longitudinal velocity of the center of mass included in the center of mass velocity, the yaw angular velocity, and the wheelbase value included in the size information of the target vehicle, the longitudinal velocity of the wheel center of each wheel in the intermediate shaft coordinate system is calculated;

[0183] Based on the mass center lateral velocity included in the mass center velocity, the yaw angular velocity, and the wheelbase value and the front axle mass center longitudinal distance value included in the size information of the target vehicle, the wheel center lateral velocity of each wheel in the intermediate shaft coordinate system is calculated.

[0184] Further, when the first calculation module 420 is used to calculate the wheel center longitudinal velocity of each wheel in the intermediate shaft coordinate system based on the center of mass longitudinal velocity included in the center of mass velocity, the yaw angular velocity, and the wheelbase value included in the size information of the target vehicle, the first calculation module 420 is used to:

[0185] Based on the yaw angular velocity and the wheelbase value, a rollover tendency parameter of the target vehicle is calculated;

[0186] Subtract the rollover tendency parameter from the longitudinal velocity of the center of mass, and determine the obtained subtraction calculation result as the longitudinal velocity of the wheel center of the left front wheel and the left rear wheel of the target vehicle in the intermediate shaft coordinate system;

[0187] The mass center longitudinal velocity is added to the rollover tendency parameter, and the addition result is determined as the wheel center longitudinal velocity of the right front wheel and the right rear wheel of the target vehicle in the intermediate shaft coordinate system.

[0188] Further, when the first calculation module 420 is used to calculate the wheel center lateral velocity of each wheel in the intermediate shaft coordinate system based on the center of mass lateral velocity included in the center of mass velocity, the yaw angular velocity, and the wheelbase value and the front axle center of mass longitudinal distance value included in the size information of the target vehicle, the first calculation module 420 is used to:

[0189] Based on the yaw rate and the longitudinal distance value of the front axle center of mass, a front axle component of the lateral velocity of the target vehicle is calculated;

[0190] Adding the mass center lateral velocity to the lateral velocity front axle component, and determining the obtained addition result as the wheel center lateral velocity of the left front wheel and the right front wheel of the target vehicle in the intermediate shaft coordinate system;

[0191] Subtracting the wheelbase value from the longitudinal distance value of the front axle mass center to obtain the longitudinal distance value of the rear axle mass center of the target vehicle, and calculating the rear axle component of the lateral velocity of the target vehicle based on the yaw angular velocity and the longitudinal distance value of the rear axle mass center;

[0192] The mass center lateral velocity is subtracted from the lateral velocity rear axle component, and the subtraction result is determined as the wheel center lateral velocity of the left rear wheel and the right rear wheel of the target vehicle in the intermediate shaft coordinate system.

[0193] Further, when the data conversion module 430 is used to obtain the tire contact point speed of each wheel in the own coordinate system by converting the intermediate shaft coordinate system into the own coordinate system corresponding to each wheel based on the wheel center speed and the wheel steering angle, the data conversion module 430 is used to:

[0194] Based on the wheel steering angle, a conversion matrix of each wheel is obtained using a preset matrix conversion expression;

[0195] Based on the wheel center speed and the conversion matrix, the wheel center speed in the intermediate shaft coordinate system is converted into the tire contact point speed of each wheel in the own coordinate system to obtain the tire contact point speed.

[0196] Further, when the second calculation module 440 is used to calculate the tire slip angle corresponding to each wheel based on the tire contact point speed by using a preset inverse tangent function expression, the second calculation module 440 is used to:

[0197] Taking an absolute value of the longitudinal speed of the tire ground contact center included in the tire ground contact point speed, and comparing the absolute value with a preset threshold to determine a maximum value between the absolute value and the preset threshold;

[0198] Based on the maximum value, determining the actual tire ground contact center longitudinal speed corresponding to each wheel;

[0199] Based on the tire contact point speed including the tire contact center lateral speed and the actual tire contact center longitudinal speed, a preset inverse tangent function expression is used to calculate the tire slip angle corresponding to each wheel.

[0200] The device for calculating the vehicle tire deviation angle provided in the embodiment of the present application obtains the center of mass velocity, yaw angular velocity and wheel steering angle in the intermediate shaft coordinate system when performing a simulation test on the target vehicle under a cornering condition, calculates the wheel center velocity of each wheel in the intermediate shaft coordinate system, and converts it to obtain the tire contact point velocity of each wheel in the said own coordinate system, and uses the inverse tangent function expression to calculate the tire side slip angle corresponding to each wheel, thereby solving the simulation accuracy problem of tire response under cornering conditions, improving the accuracy of calculating the vehicle tire deviation angle, and thus ensuring the safety of vehicle driving.

[0201] See also Figure 5 , Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 5 As shown in , the electronic device 500 includes a processor 510 , a memory 520 and a bus 530 .

[0202] The memory 520 stores machine-readable instructions executable by the processor 510. When the electronic device 500 is running, the processor 510 communicates with the memory 520 via the bus 530. When the machine-readable instructions are executed by the processor 510, the above-mentioned Figure 2 The steps of the method for calculating the vehicle tire deflection angle in the method embodiment shown, the specific implementation method can be found in the method embodiment, and will not be repeated here.

[0203] The present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the computer program can execute the above-mentioned Figure 2 The steps of the method for calculating the vehicle tire deflection angle in the method embodiment shown, the specific implementation method can be found in the method embodiment, and will not be repeated here.

[0204] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0205] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0206] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0207] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0208] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application can essentially be embodied in the form of a software product, or in other words, the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0209] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for calculating the deflection angle of a vehicle tire, characterized in that: The calculation method includes: When performing a simulation test on a target vehicle under a cornering condition, an intermediate shaft coordinate system corresponding to the target vehicle is established, and the center of mass velocity and yaw angular velocity of the target vehicle in the intermediate shaft coordinate system, as well as the wheel steering angle of each wheel of the target vehicle in the intermediate shaft coordinate system are obtained; Based on the mass center velocity, the yaw angular velocity and the size information of the target vehicle, the wheel center velocity of each wheel in the intermediate shaft coordinate system is calculated; Based on the wheel center speed and the wheel steering angle, the intermediate shaft coordinate system is converted into the own coordinate system corresponding to each wheel to obtain the tire contact point speed of each wheel in the own coordinate system; Based on the tire contact point speed, a preset inverse tangent function expression is used to calculate the tire slip angle corresponding to each wheel.

2. The method according to claim 1, characterized in that The step of establishing the intermediate axis coordinate system corresponding to the target vehicle comprises: Based on a reference vertical axis in a preset global inertial reference system, determining a target vertical axis parallel to the reference vertical axis; The vehicle heading angle of the target vehicle in the global inertial reference system is determined, and the global inertial reference system is rotated according to the vehicle heading angle with the target vertical axis as the center to establish an intermediate axis coordinate system corresponding to the target vehicle.

3. The method according to claim 1, characterized in that The step of calculating the wheel center velocity of each wheel in the intermediate shaft coordinate system based on the mass center velocity, the yaw angular velocity and the size information of the target vehicle includes: Based on the longitudinal velocity of the center of mass included in the center of mass velocity, the yaw rate, and the wheelbase value included in the size information of the target vehicle, the longitudinal velocity of the wheel center of each wheel in the intermediate shaft coordinate system is calculated; Based on the mass center lateral velocity included in the mass center velocity, the yaw angular velocity, and the wheelbase value and the front axle mass center longitudinal distance value included in the size information of the target vehicle, the wheel center lateral velocity of each wheel in the intermediate shaft coordinate system is calculated.

4. The method according to claim 3, characterized in that The calculating the wheel center longitudinal velocity of each wheel in the intermediate shaft coordinate system based on the center of mass longitudinal velocity included in the center of mass velocity, the yaw angular velocity, and the wheelbase value included in the size information of the target vehicle comprises: Based on the yaw angular velocity and the wheelbase value, a rollover tendency parameter of the target vehicle is calculated; Subtract the rollover tendency parameter from the longitudinal velocity of the center of mass, and determine the obtained subtraction calculation result as the longitudinal velocity of the wheel center of the left front wheel and the left rear wheel of the target vehicle in the intermediate shaft coordinate system; The mass center longitudinal velocity is added to the rollover tendency parameter, and the addition result is determined as the wheel center longitudinal velocity of the right front wheel and the right rear wheel of the target vehicle in the intermediate shaft coordinate system.

5. The method according to claim 3, characterized in that: The step of calculating the wheel center lateral velocity of each wheel in the intermediate shaft coordinate system based on the center of mass lateral velocity included in the center of mass velocity, the yaw angular velocity, and the wheelbase value and the front axle center of mass longitudinal distance value included in the size information of the target vehicle comprises: Based on the yaw rate and the longitudinal distance value of the front axle center of mass, a front axle component of the lateral velocity of the target vehicle is calculated; Adding the mass center lateral velocity to the lateral velocity front axle component, and determining the obtained addition result as the wheel center lateral velocity of the left front wheel and the right front wheel of the target vehicle in the intermediate shaft coordinate system; Subtracting the wheelbase value from the longitudinal distance value of the front axle mass center to obtain the longitudinal distance value of the rear axle mass center of the target vehicle, and calculating the rear axle component of the lateral velocity of the target vehicle based on the yaw angular velocity and the longitudinal distance value of the rear axle mass center; The mass center lateral velocity is subtracted from the lateral velocity rear axle component, and the subtraction result is determined as the wheel center lateral velocity of the left rear wheel and the right rear wheel of the target vehicle in the intermediate shaft coordinate system.

6. The method according to claim 1, characterized in that The step of converting the intermediate shaft coordinate system into the own coordinate system corresponding to each wheel based on the wheel center speed and the wheel steering angle to obtain the tire contact point speed of each wheel in the own coordinate system includes: Based on the wheel steering angle, a conversion matrix of each wheel is obtained using a preset matrix conversion expression; Based on the wheel center speed and the conversion matrix, the wheel center speed in the intermediate shaft coordinate system is converted into the tire contact point speed of each wheel in the own coordinate system to obtain the tire contact point speed.

7. The method according to claim 1, characterized in that The step of calculating the tire slip angle corresponding to each wheel based on the tire contact point speed by using a preset inverse tangent function expression includes: Taking an absolute value of the longitudinal speed of the tire ground contact center included in the tire ground contact point speed, and comparing the absolute value with a preset threshold to determine a maximum value between the absolute value and the preset threshold; Based on the maximum value, determining the actual tire ground contact center longitudinal speed corresponding to each wheel; Based on the tire contact point speed including the tire contact center lateral speed and the actual tire contact center longitudinal speed, a preset inverse tangent function expression is used to calculate the tire slip angle corresponding to each wheel.

8. A device for calculating the deflection angle of a vehicle tire, characterized in that: The computing device comprises: A data acquisition module, used to establish an intermediate shaft coordinate system corresponding to the target vehicle when performing a simulation test on the target vehicle under a cornering condition, and to obtain the center of mass velocity and yaw angular velocity of the target vehicle in the intermediate shaft coordinate system, as well as the wheel steering angle of each wheel of the target vehicle in the intermediate shaft coordinate system; A first calculation module, configured to calculate the wheel center velocity of each wheel in the intermediate shaft coordinate system based on the mass center velocity, the yaw angular velocity and the size information of the target vehicle; A data conversion module, configured to obtain a tire contact point speed of each wheel in the self-coordinate system by converting the intermediate shaft coordinate system into the self-coordinate system corresponding to each wheel based on the wheel center speed and the wheel steering angle; The second calculation module is used to calculate the tire slip angle corresponding to each wheel based on the tire contact point speed using a preset inverse tangent function expression.

9. An electronic device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate via the bus, and the machine-readable instructions are executed by the processor to execute the steps of the method for calculating the vehicle tire deviation angle as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for calculating the vehicle tire deflection angle according to any one of claims 1 to 7 are executed.

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