A method for predicting tire mechanical properties under combined lateral slip and longitudinal slip conditions

Abstract

This invention belongs to the field of tire dynamics, specifically relating to a method, application, and computer program product for predicting tire mechanical properties under combined lateral and longitudinal slip conditions. This method uses reference tire information to accurately correct the total shear force direction angle of the target tire, significantly improving the prediction accuracy of longitudinal and lateral forces under combined conditions. The predicted data obtained by this method under combined lateral and longitudinal slip conditions can replace experimental data, playing a vital role in improving tire modeling efficiency and reducing testing costs.

Description

Technical Field

[0001] This invention belongs to the field of tire dynamics characteristics, specifically relating to a method, application, and computer program product for predicting the mechanical characteristics of tires under combined lateral slip and longitudinal slip conditions, which is of great significance for improving tire modeling efficiency and reducing costs. Background Technology

[0002] The study of tire mechanical properties under combined slip conditions is of great significance for the ultimate safety and stability control of automobiles. Domestic and international scholars have long studied the prediction of combined slip conditions, with typical prediction methods and models including: Combinator, Lund, Similarity, and the state stiffness method. The Combinator model assumes that the direction of the total shear force is the same as the direction of the total slip ratio. This assumption is reasonable for large slip conditions, but it is obviously inaccurate for small slip conditions, thus the Combinator model has significant limitations. While the Lund model considers the variation in the total shear force direction angle, it contains many simplifications and assumptions. The Lund model has good predictive ability at small sideslip angles, but its prediction accuracy decreases significantly as the sideslip angle increases. Both the Similarity method and the State Stiffness method calculate the total shear force direction angle under combined working conditions using dimensionless longitudinal and lateral forces under pure working conditions, based on the combined slip ratio. However, because the models assume that the starting points corresponding to the dimensionless longitudinal and lateral slip ratios are the same as those under combined working conditions, the prediction of the total shear force direction angle is not accurate enough, thus affecting the prediction accuracy of the tire's longitudinal and lateral forces under combined working conditions. In conclusion, to accurately predict the tire's longitudinal and lateral forces under combined working conditions, it is necessary to develop a high-precision and high-efficiency method for predicting combined working conditions. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, this invention provides a method for predicting lateral and longitudinal slip combined driving conditions (hereinafter referred to as UPM) based on the UniTire tire model. Its key feature is the use of reference tire information to accurately correct the total shear force direction angle of the target tire, significantly improving the prediction accuracy of the tire's longitudinal and lateral forces under combined driving conditions. For ease of writing, the target tire and reference tire are defined as follows: the tire to be predicted is defined as the target tire, and the tire used as a reference by the target tire is defined as the reference tire. A suitable reference tire can be selected from previous test samples.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A method for predicting tire mechanical properties under combined lateral slip and longitudinal slip conditions. This method includes the following steps:

[0006] First, install the target tire onto a suitable tire six-force testing machine, set specific test conditions according to test requirements, and perform pure lateral slip test and pure longitudinal slip test respectively to measure the tire mechanical characteristic data under pure lateral slip and pure longitudinal slip conditions.

[0007] Second, using the UniTire tire model, lateral force modeling and longitudinal force modeling were performed on the measured pure sideslip and pure longitudinal slip test data, respectively. The model parameters were used as inputs to the UPM, and the total shear force under the combined slip condition was predicted based on the UPM.

[0008] Third, select a suitable reference tire based on the anisotropic characterization parameters of the target tire, obtain the total shear force value and total shear force direction angle using UPM, and then correct the direction angle using composite working condition test data to obtain the total shear force direction angle correction coefficient. ;

[0009] Fourth, the total shear force direction angle correction factor of the reference tire. Total shear force direction angle applied to the target tire Correction, to obtain the corrected target tire total shear force direction angle. , The UPM (Universal Power Analyzer) is used to accurately predict the lateral and longitudinal forces of the target tire under combined operating conditions; that is:

[0010]

[0011]

[0012] in, It is the total shear force under combined working conditions. This refers to the total shear force direction angle; This refers to the longitudinal force under combined working conditions. This refers to the lateral force under combined working conditions.

[0013] Preferably, the model parameters in step two include the longitudinal slip ratio. Longitudinal curvature factor Dimensionless longitudinal slip ratio and lateral slip ratio Lateral curvature factor and dimensionless lateral slip ratio .

[0014] As a preferred embodiment, step two, predicting the total shear force under the combined slip condition based on UPM, includes the following steps:

[0015] 1) Calculate the total slip under combined working conditions :

[0016] ;

[0017] 2) Calculate the coefficient of dynamic friction under combined working conditions :

[0018]

[0019] In the formula, The coefficient of longitudinal dynamic friction is The coefficient of lateral dynamic friction;

[0020] 3) Calculate the relative comprehensive slip ratio under combined working conditions. :

[0021] ;

[0022] 4) Calculate the combined curvature factor under combined working conditions :

[0023] ;

[0024] 5) Calculate the dimensionless total shear force under combined working conditions. :

[0025] ;

[0026] 6) Calculate the total shear force under the combined working conditions. :

[0027]

[0028] 7) Calculate the total shear force direction angle under the combined working conditions. :

[0029] ,

[0030] , ;

[0031] In the formula, For tire longitudinal stiffness. This refers to the tire's lateral stiffness.

[0032] As a preferred option, the total shear force direction angle correction coefficient Based on reference tire test data and model prediction data, the specific calculation process is as follows:

[0033] ;

[0034] In the formula, For slip ratio, Side slip angle, The roll angle is... For vertical loads; This is the calculated value of the total shear force direction angle of the reference tire. It is the predicted value of the total shear force direction angle model of the reference tire.

[0035] Preferably, in step one, the target tire is mounted on a suitable tire six-force testing machine, and the following test conditions are set to measure the tire's mechanical properties under pure lateral deviation conditions:

[0036] 1) Set the test pressure to 245 kPa;

[0037] 2) Set the roll angle to 0°;

[0038] 3) Set the road speed to 60 kph;

[0039] 4) The vertical loads are, in order: 2800N, 5600N, and 8400N;

[0040] 5) The sideslip angle is executed using a quasi-steady-state sweep method, sweeping from the starting point of -2° to 16° at a rate of 2° / s, then sweeping to -16° at the same rate, and finally returning to a sideslip angle of 2°.

[0041] As a further optimization, the tire mechanical property data measured in step one under pure sideslip conditions are obtained using the same test air pressure, road speed and sideslip angle as in the pure sideslip test. The quasi-steady-state sweep method is also used, sweeping from the starting point of 2% to -30% at a rate of 10% / s, then sweeping to 30%, and finally returning to -2% slip ratio.

[0042] Furthermore, this invention also discloses the application of the aforementioned method for predicting tire mechanical properties under combined lateral slip and longitudinal slip conditions in tire simulation modeling.

[0043] Furthermore, the present invention also discloses a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the method.

[0044] Furthermore, the present invention also discloses a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implement the method.

[0045] Furthermore, the present invention also discloses a computer program product, including a computer program or instructions that, when executed by a processor, implement the method.

[0046] The beneficial effects of this invention are:

[0047] 1. The total shear force calculation of the composite working condition tire of the present invention is accurate, with an error of ≤3% compared with the test data.

[0048] 2. The method of correcting the total shear force direction of the target tire using a reference tire is reliable, with an error of ≤3% compared to experimental data.

[0049] 3. The longitudinal and lateral forces of the tire under combined slip and lateral conditions predicted by this invention have high accuracy, with an average deviation of ≤5% from the experimental data.

[0050] 4. Based on this invention, the prediction data of the combined lateral slip and longitudinal slip condition can replace the test data of the combined lateral slip and longitudinal slip condition, which plays a very important role in improving tire modeling efficiency and reducing test costs. Attached Figure Description

[0051] Figure 1 Flowchart for predicting longitudinal and lateral forces of tires under combined lateral slip and side slip conditions.

[0052] Figure 2 Example of comparison between predicted and measured total shear force values.

[0053] Figure 3 Example of comparison between predicted and measured values ​​of total shear force direction angle.

[0054] Figure 4 Example of comparison between predicted and measured values ​​of longitudinal force of tire under combined lateral slip and longitudinal skidding conditions.

[0055] Figure 5 Example of comparison between predicted and measured values ​​of tire lateral force under combined lateral slip and longitudinal slip conditions. Detailed Implementation

[0056] The present invention will be further described in detail below with reference to the accompanying drawings: This embodiment is implemented under the premise of the technical solution of the present invention, and detailed implementation methods are given, but the protection scope of the present invention is not limited to the following embodiments.

[0057] The derivation process of the prediction model for the combined lateral slip and longitudinal slip conditions of the present invention is as follows:

[0058] Based on a steady-state brush model that considers the complex deformation of the tire body, it can be derived that:

[0059] (1)

[0060] (2)

[0061] in:

[0062] (3)

[0063] (4)

[0064] In the formula, For tire longitudinal stiffness. This refers to the tire's lateral stiffness.

[0065] The magnitude of the overall slip ratio for:

[0066] (5)

[0067] Relative overall slip ratio for:

[0068] (6)

[0069] Comprehensive curvature factor for:

[0070] (7)

[0071] Dimensionless total shear force for:

[0072] (8)

[0073] coefficient of kinetic friction for:

[0074] (9)

[0075] in: The coefficient of longitudinal dynamic friction is The coefficient of lateral dynamic friction;

[0076] Therefore, the total shear force value for:

[0077] (10)

[0078] The total shear force direction angle can be calculated using the following formula:

[0079] (11)

[0080] The total shear force direction angle calculated by the above method has a certain deviation. Considering this, the following method is used to correct the total shear force direction angle, and the expression is:

[0081] (12)

[0082] In the formula, The heading angle correction factor is obtained based on reference tire test data and model prediction data. The specific calculation process is as follows:

[0083] (13)

[0084] In the formula, For slip ratio, Side slip angle, The roll angle is... This is a vertical load. This is the calculated value of the total shear force direction angle of the reference tire. It is the predicted value of the total shear force direction angle model of the reference tire. The calculation process is shown in formula (11).

[0085] Therefore, the longitudinal force of the tire under combined working conditions can be predicted as follows:

[0086] (14)

[0087] The lateral force of the tire under combined operating conditions is:

[0088] (15)

[0089] The following uses a 215 / 60R17 radial passenger car tire as an example to predict the longitudinal and lateral forces under combined working conditions. Figure 1 As shown, the specific implementation process of the present invention is as follows:

[0090] 1. Install the target tire onto a suitable tire six-component force testing machine, set the test conditions as follows, and measure the tire mechanical characteristics data under pure lateral deviation conditions.

[0091] 1) Set the test pressure to 245 kPa (pressure control mode);

[0092] 2) Set the roll angle to 0°;

[0093] 3) Set the road speed to 60 kph;

[0094] 4) The vertical loads are, in order: 2800N, 5600N, and 8400N;

[0095] 5) The sideslip angle is executed using a quasi-steady-state sweep method, sweeping from the starting point of -2° to 16° at a rate of 2° / s, then sweeping to -16° at the same rate, and finally returning to a sideslip angle of 2°.

[0096] Second, using the same test air pressure, road speed and side tilt angle, and the same quasi-steady-state sweeping method, sweeping from the starting point of 2% to -30% at a rate of 10% / s, then sweeping to 30%, and finally returning to -2% slip ratio.

[0097] Third, based on the measured pure lateral slip and pure longitudinal slip test data, the UniTire tire model was used to model the lateral and longitudinal forces respectively, and then... , , and , , The model parameter identification results are input into the UPM prediction model.

[0098] IV. Using UPM, the total shear force and direction angle under combined slip conditions are predicted, specifically including:

[0099] 1) Calculate the total slip under combined working conditions ;

[0100] 2) Calculate the coefficient of dynamic friction under combined working conditions ;

[0101] 3) Calculate the relative comprehensive slip ratio under combined working conditions. ;

[0102] 4) Calculate the combined curvature factor under combined working conditions ;

[0103] 5) Calculate the dimensionless total shear force under combined working conditions. ;

[0104] 6) Calculate the total shear force under the combined working conditions. ;

[0105] 7) Calculate the total shear force direction angle under the combined working conditions. .

[0106] V. A radial passenger car tire of 195 / 55R16 was selected as the reference tire (a complete set of tire force data has been measured, meeting the reference tire criteria mentioned above). The total tangential force direction angle was obtained using a composite driving condition prediction model, and the direction angle was corrected based on the measured data to obtain the direction angle correction coefficient. .

[0107] VI. Based on the previously predicted direction angle and the reference tire's steering angle correction factor The corrected total shear force direction angle of the target tire was calculated. .

[0108] VII. Using UPM, the longitudinal and lateral forces under the target tire's combined operating conditions are predicted, i.e.:

[0109]

[0110]

[0111] in, It is the total shear force under combined working conditions. This refers to the total shear force direction angle; This refers to the longitudinal force under combined working conditions. This refers to the lateral force under combined working conditions.

[0112] The experimental results of this embodiment are as follows:

[0113] Figure 2 This shows an example comparing the predicted and measured values ​​of total shear force. Figure 3 This shows an example comparing the predicted and measured values ​​of the total shear force direction angle; Figure 4 Showing a comparison example of the predicted and measured values ​​of the longitudinal force of the tire under combined lateral slip and longitudinal skid conditions; Figure 5 This example shows a comparison between the predicted and measured values ​​of the tire's lateral force under combined lateral slip and longitudinal slip conditions.

[0114] As can be seen from the above attached figures:

[0115] 1. The total shear force calculation of the composite working condition tire of the present invention is accurate, with an error of ≤3% compared with the test data;

[0116] 2. The method of correcting the total shear force direction of the target tire using a reference tire in this invention is reliable, with an error of ≤3% compared to experimental data;

[0117] 3. The longitudinal and lateral forces of the tire under combined slip and lateral conditions predicted by this invention have high accuracy, with an average deviation of ≤5% from the experimental data.

[0118] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A method for predicting tire mechanical properties under combined lateral slip and longitudinal slip conditions, characterized in that, The method includes the following steps: First, install the target tire onto a suitable tire six-force testing machine, set specific test conditions according to test requirements, and perform pure lateral slip test and pure longitudinal slip test respectively to measure the tire mechanical characteristic data under pure lateral slip and pure longitudinal slip conditions. Second, using the UniTire tire model, lateral force modeling and longitudinal force modeling were performed on the measured pure sideslip and pure longitudinal slip test data, respectively. The model parameters were used as inputs to the UPM, and the total shear force under the combined slip condition was predicted based on the UPM. Third, select a suitable reference tire based on the anisotropic characterization parameters of the target tire, obtain the total shear force value and total shear force direction angle using UPM, and then correct the direction angle using composite working condition test data to obtain the total shear force direction angle correction coefficient. ; Fourth, the total shear force direction angle correction factor of the reference tire. Total shear force direction angle applied to the target tire Correction, to obtain the corrected target tire total shear force direction angle. , The UPM (Universal Power Analyzer) is used to accurately predict the lateral and longitudinal forces of the target tire under combined operating conditions; that is: ， ， in, It is the total shear force under combined working conditions. This refers to the total shear force direction angle; This refers to the longitudinal force under combined working conditions. This refers to the lateral force under combined working conditions. Step 2: Model parameters include longitudinal slip ratio Longitudinal curvature factor Dimensionless longitudinal slip ratio and lateral slip ratio Lateral curvature factor and dimensionless lateral slip ratio The prediction of total shear force under combined slip conditions based on UPM includes the following steps: 1) Calculate the total slip under combined working conditions : ； 2) Calculate the coefficient of dynamic friction under combined working conditions. : ； In the formula, The coefficient of longitudinal dynamic friction is The coefficient of lateral dynamic friction; 3) Calculate the relative comprehensive slip ratio under combined working conditions. : ； 4) Calculate the combined curvature factor under combined working conditions : ； 5) Calculate the dimensionless total shear force under combined working conditions. : ； 6) Calculate the total shear force under the combined working conditions. : ； 7) Calculate the total shear force direction angle under the combined working conditions. : ， ， ； In the formula, For tire longitudinal stiffness. This refers to the tire's lateral stiffness. Total shear force direction angle correction factor Based on reference tire test data and model prediction data, the specific calculation process is as follows: ； In the formula, For slip ratio, Side slip angle, The roll angle is... For vertical loads; This is the calculated value of the total shear force direction angle of the reference tire. It is the predicted value of the total shear force direction angle model of the reference tire.

2. The method for predicting tire mechanical properties under combined lateral slip and longitudinal slip conditions according to claim 1, characterized in that, Step 1: Mount the target tire onto a suitable tire six-force testing machine, set the test conditions as follows, and measure the tire's mechanical properties under pure lateral deviation conditions: 1) Set the test pressure to 245 kPa; 2) Set the roll angle to 0°; 3) Set the road speed to 60 kph; 4) The vertical loads are, in order: 2800N, 5600N, and 8400N; 5) The sideslip angle is executed using a quasi-steady-state sweep method, sweeping from the starting point of -2° to 16° at a rate of 2° / s, then sweeping to -16° at the same rate, and finally returning to a sideslip angle of 2°.

3. The method for predicting tire mechanical properties under combined lateral slip and longitudinal slip conditions according to claim 2, characterized in that, In step one, the tire mechanical properties data measured under pure sideslip conditions were obtained using the same test air pressure, road speed and roll angle as in the pure sideslip test. The quasi-steady-state sweep method was also used, sweeping from the starting point of 2% to -30% at a rate of 10% / s, then sweeping to 30%, and finally returning to -2% slip ratio.

4. The application of the method for predicting the mechanical properties of tires under combined lateral slip and longitudinal slip conditions as described in any one of claims 1-3 in tire simulation modeling.

5. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the method according to any one of claims 1-3.

6. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by a processor, they implement the method described in any one of claims 1-3.

7. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by a processor, they implement the method described in any one of claims 1-3.

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