Method for testing dynamic impression profile and normal stress distribution of tire by sensor array

Abstract

The invention relates to a method for testing a dynamic impression profile and normal stress distribution of a tire by using a sensor array. A plurality of sensor units are arranged in a contact area of a tire and the ground, so that the normal stress and the grounding form of each position are monitored in real time. In the running process of the tire, the multi-point sensor array collects contour and normal stress distribution data of a tire grounding mark in real time and transmits the contour and normal stress distribution data to the data processing system. The data processing system processes data through methods of filtering, noise suppression, interpolation, numerical simulation and the like, generates a three-dimensional model of a tire grounding mark, and calculates a grounding area, stress distribution and a stress concentration area, thereby evaluating the dynamic performance of the tire. According to the method, high-precision and real-time tire grounding mark and stress distribution monitoring can be achieved under the working conditions of different speeds, loads, side slip angles and the like, and the method is suitable for evaluation and optimization of tire performance.

Description

Technical Field

[0001] The invention relates to the technical field of tire testing, and in particular to a method for testing a tire dynamic footprint profile and normal stress distribution using a sensor array. Background Art

[0002] In the field of tire design and manufacturing, the dynamic contact patch and normal stress distribution of the tire have an important impact on the vehicle's driving performance, stability, wear characteristics and safety. Accurately obtaining the dynamic contact patch and normal stress distribution of the tire under different working conditions (such as different speeds, loads and sideslip angles, etc.) can not only help optimize the structural design of the tire, but also provide an important basis for the vehicle's handling and comfort. Therefore, tire contact characteristics testing technology has become a research hotspot in the current tire and automotive engineering fields.

[0003] In the prior art, the testing of tire dynamic contact patch and normal stress distribution usually relies on a roller test bench or a flat test bench. The traditional testing methods mainly include the following: Roller test bench test: The tire is mounted on a roller test bench and the tire contact footprint is recorded by simulating different speed and load conditions. However, this method can usually only obtain static contact information and it is difficult to monitor dynamic contact characteristics in real time. In addition, the contact area of ​​the test is often limited, making it difficult to achieve a comprehensive analysis of the tire contact stress.

[0004] Pressure sensing film test: A thin film pressure sensor is laid under the tire contact surface, and the contact pressure distribution data is recorded by the sensor. This method can obtain the tire contact pressure distribution, but due to its low resolution, it is difficult to provide high-precision stress distribution data. In addition, the durability and ability to adapt to different environments of thin film sensors are limited, and they are easily damaged under high load and dynamic conditions.

[0005] Laser scanning and visual analysis: Some test systems use laser scanning or visual sensors to capture and analyze tire footprints to obtain contact shape data. Although this method can provide tire contact profile information with a certain degree of accuracy, it has high requirements for ambient light and test conditions, and it is difficult to directly measure normal stress distribution, resulting in low data accuracy.

[0006] Although the above test method can reflect the ground contact characteristics of the tire to a certain extent, it has the following shortcomings: Lack of dynamic real-time monitoring capabilities: Traditional testing methods can often only obtain the tire's contact patch and stress distribution under specific conditions. It is difficult to achieve real-time monitoring of the tire during driving and cannot effectively reflect the dynamic contact change characteristics.

[0007] Limited data collection accuracy and coverage: Many existing technologies have deficiencies in ground contact data collection accuracy, especially pressure film sensors, which have a low density of collection points and cannot accurately reflect stress concentration areas. In addition, the limited collection coverage makes it difficult for the test results to truly and comprehensively reflect the stress distribution in the tire ground contact area.

[0008] Poor adaptability, difficult to meet the needs of multi-condition testing: Existing methods have limited adaptability to testing under complex conditions such as different speeds, loads and slip angles. Especially when simulating high-speed driving and slip angle changes, the accuracy and stability of traditional testing methods are poor, making it difficult to support dynamic performance evaluation of tires.

[0009] To this end, we designed a method of using a sensor array to test the dynamic tire footprint profile and normal stress distribution to solve the above problems. Summary of the invention

[0010] The present invention provides a method for testing the dynamic footprint profile and normal stress distribution of a tire by using a sensor array, so as to solve the defects in the prior art.

[0011] In one aspect, a method for testing a tire dynamic footprint profile and normal stress distribution using a sensor array comprises the following steps: Arrange multiple sensor units in the tire-ground contact area, wherein the sensor units include piezoelectric film sensors, stress sensors or force sensors, and are used to detect normal stress and contact morphology information at their locations in real time; During the operation of the tire, the profile information of the tire contact patch and the normal stress distribution data are collected in real time through a multi-point sensor array, wherein the sensor array can cover the entire tire contact area and reflect the tire contact changes in real time; Transmitting the data collected by the sensor unit to a data processing system, wherein the data processing system is used to process and analyze the received data; Based on the data processing results, the tire's contact patch, footprint shape and normal stress distribution are analyzed, a tire contact model is established, and the dynamic performance of the tire is evaluated.

[0012] On the other hand, the arrangement of the sensor units in the sensor array in the tire contact area is designed according to the size, working state and contact stress distribution of the tire, so that the detection area of ​​each sensor unit covers all points of the contact surface, ensuring uniform collection of contact stress.

[0013] On the other hand, the data of the sensor unit is transmitted to the data processing system by wireless or wired means, and the dynamic change data of the tire under different working conditions is transmitted in real time to achieve dynamic monitoring and efficient data processing.

[0014] On the other hand, the data processing system comprises the following processing steps: Perform filtering, noise suppression and signal gain adjustment preprocessing operations on the collected original signal to remove environmental interference and improve signal quality; Based on the processed signal and the known sensor calibration coefficients, the local normal stress value at each sensor point is calculated. , and construct a stress distribution image based on this value; The data of each sensor point is spatially interpolated to generate a normal stress distribution map of the complete tire contact area; Finite element analysis (FEA) or other numerical simulation methods are used in combination with normal stress distribution data to further calculate the overall stress distribution and stress concentration area in the tire contact area.

[0015] On the other hand, the local normal stress Calculated by the following formula:

[0016] in, is the normal force at a point in the contact area, is the contact area at that point, is the normal stress at that point.

[0017] On the other hand, the data processing system further includes a contact model generation module for generating a contact footprint profile of the tire based on the collected data. , the profile is described by the following formula:

[0018] in, Indicates the outline of the tire's contact patch. is the normal stress at each sensor point in the ground area, To measure time, is the time variable, is the number of sensor points.

[0019] On the other hand, the tire contact model further includes a stress concentration area on the tire contact area The normal stress in the stress concentration area is calculated by the following formula:

[0020] in, is the stress concentration area, is the normal stress value of each sensor point, is the maximum value of normal stress at all sensor points, is the number of sensor points.

[0021] On the other hand, the data processing system uses the following algorithm to perform dynamic data analysis to calculate the normal stress distribution and contact area of ​​the tire contact, and the normal stress distribution is calculated by the following discretization model:

[0022] in, For at point The normal stress at is the contact area at that point, For the The normal force collected by the sensor points is is the number of all sensor points.

[0023] In another aspect, the method further comprises evaluating the dynamic performance of the tire by dynamically changing the tire contact area, wherein the tire contact area Calculated by the following formula:

[0024] in, For the The local contact area of ​​each sensor point, is the number of sensor points, For test time, is the change of tire contact area over time.

[0025] On the other hand, the method generates a three-dimensional model of the tire contact footprint profile through real-time analysis by a data processing system, and dynamically calculates the tire contact pressure distribution, contact area change and wear characteristics under different speeds, loads and road conditions, including the following steps: The real-time data of the multi-sensor units are multi-dimensionally interpolated using a data processing system to generate a three-dimensional stress distribution map of the tire contact area; Calculate the real-time tire contact pressure center position under different speed and load conditions based on the dynamic changes of the contact patch profile model and pressure distribution variance , to characterize the balance of the tire; Calculate the dynamic friction coefficient based on the stress changes between the tire and the ground , expressed by the following formula:

[0026] in, is the tangential force on the tire contact surface, The normal stress is used to evaluate the traction performance and wear trend of the tire.

[0027] The present invention proposes a method for testing the dynamic footprint profile and normal stress distribution of tires using a sensor array. Through the combination of high-density sensor array layout and data processing system, the present invention can monitor the tire's contact footprint and normal stress distribution in real time under multiple working conditions such as different speeds, loads, and sideslip angles. Compared with traditional testing methods, it can more accurately reflect the dynamic contact changes of tires, is suitable for complex testing conditions, and improves the real-time and accuracy of data.

[0028] The multi-point sensor array is arranged to cover the entire tire contact area, so that the present invention can more comprehensively record the local stress changes in each area. This high-precision, high-density data acquisition makes up for the problem of insufficient sampling point density in traditional methods, and helps to generate detailed contact footprint profiles and normal stress distribution maps.

[0029] The data processing system of the present invention can use the collected high-precision data to construct a three-dimensional stress distribution model, and analyze the stress concentration area and dynamic contact area changes through multi-dimensional interpolation and numerical simulation technology. This multi-dimensional analysis capability not only supports the accurate evaluation of tire performance, but also provides data basis for tire structure design and optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a flow chart of a method for testing tire dynamic footprint profile and normal stress distribution using a sensor array provided in an embodiment of the present invention; Figure 2 The longitudinal distribution diagram of normal stress in the longitudinal direction of the tire footprint is obtained in Embodiment 1 of the present invention; Figure 3 is a transverse distribution diagram of normal stress in the longitudinal direction of the tire footprint obtained in Example 1 of the present invention; Figure 4 It is the tire footprint profile at different side slip angles. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The following is combined with Figure 1 With reference to the accompanying drawings and a number of embodiments, specific embodiments of the present invention are described in detail.

[0034] Embodiment 1: This embodiment provides a method for detecting the dynamic footprint profile and normal stress distribution of a tire through a sensor array, so as to achieve real-time monitoring and performance evaluation of the tire under different working conditions.

[0035] Sensor layout and data collection: Multiple sensor units are laid out in the tire-ground contact area, including piezoelectric film sensors, stress sensors or force sensors. The layout of the sensor array is designed according to the size, working state and ground stress distribution of the tire, so that each sensor unit can cover all points of the ground contact surface to ensure uniform collection of ground stress. The sensor unit detects the normal stress and contact morphology information at its location in real time.

[0036] During the operation of the tire, the multi-point sensor array collects the tire contact patch profile information and normal stress distribution data in real time, as shown in the attached figure. Figure 3 As shown, the sensor array covers the entire contact area and can reflect tire contact changes in real time.

[0037] Data transmission and processing: The sensor unit transmits the collected data to the data processing system by wireless or wired means to ensure dynamic monitoring and efficient data processing under different speed, load, side slip angle and other working conditions. The data processing system is responsible for processing and analyzing the received raw signals, including pre-processing steps such as filtering, noise suppression, and signal gain adjustment to improve signal quality.

[0038] Normal stress calculation: The data processing system calculates the local normal stress value of each sensor point based on the processed signal and the known sensor calibration coefficient, and constructs a stress distribution image based on this value. The calculation formula for local normal stress is:

[0039] in, is the normal force at a point in the contact area, is the contact area at that point, is the normal stress at that point.

[0040] Normal stress distribution map generation: The data processing system spatially interpolates the data of each sensor point to generate a complete normal stress distribution map of the tire contact area.

[0041] The system uses finite element analysis (FEA) or other numerical simulation methods to combine the normal stress distribution data to further calculate the overall stress distribution and stress concentration areas in the tire contact area.

[0042] Ground contact model generation: The data processing system includes a ground contact model generation module, which generates the profile of the tire ground contact footprint based on the collected data.

[0043] The mathematical description formula of the contact patch profile is:

[0044] in, Indicates the outline of the tire's contact patch. is the normal stress at each sensor point in the ground area, To measure time, is the time variable, is the number of sensor points.

[0045] Stress concentration area calculation: Based on the generated ground contact model, the system further calculates the stress concentration area of ​​the tire ground contact area. The normal stress calculation formula for the stress concentration area is:

[0046] in, is the stress concentration area, is the normal stress value of each sensor point, is the maximum value of normal stress at all sensor points, is the number of sensor points Dynamic normal stress distribution calculation: The data processing system uses dynamic data analysis algorithms to calculate the normal stress distribution and contact area of ​​the tire.

[0047] The normal stress distribution is calculated using the following discretization model:

[0048] in, For at point The normal stress at is the contact area at that point, For the The normal force collected by the sensor points is is the number of all sensor points.

[0049] Calculation of dynamic contact area: Evaluate the dynamic performance of the tire through the dynamic changes of the tire contact area.

[0050] The formula for calculating the contact area is as follows:

[0051] in, For the The local contact area of ​​each sensor point, is the number of sensor points, For test time, is the change of tire contact area over time; 3D contact patch profile generation: Under different speeds, loads and road conditions, the data processing system generates a 3D model of the tire contact patch through real-time analysis, dynamically calculating the tire's contact pressure distribution, contact area changes and wear characteristics.

[0052] The following steps are involved: The data processing system is used to perform multi-dimensional interpolation on the real-time data of the multi-sensor units to generate a three-dimensional stress distribution map of the tire contact area.

[0053] According to the dynamic changes of the contact patch profile model, the real-time contact pressure center position and pressure distribution variance of the tire under different speed and load conditions are calculated to characterize the balance of the tire.

[0054] Calculation of dynamic friction coefficient: Based on the stress changes in the contact between the tire and the ground, the dynamic friction coefficient is calculated to evaluate the tire's traction performance and wear trend.

[0055] The formula for the coefficient of friction is:

[0056] in, is the tangential force on the tire contact surface, The normal stress is used to evaluate the traction performance and wear trend of the tire.

[0057] Example 2: Basic measurement of tire dynamic footprint profile and calculation of normal stress distribution: Experimental environment and equipment configuration: The test tire is installed on a roller test bench covered with a multi-point sensor array to detect the tire's contact patch profile and normal stress distribution.

[0058] The sensor unit of the roller test bench adopts piezoelectric sensor. The sampling frequency of each sensor is 500Hz, which can monitor the normal force in real time.

[0059] Sensor array layout: According to the tire contact area (such as 300mm×200mm), the sensor array is arranged at a density of 10mm×10mm, covering a total of 3000 Array formation Sensor units with a total of 600 detection points ensure that the measurement accuracy is sufficient to cover the ground area.

[0060] Data acquisition and signal processing: Signal filtering: The sensor data is transmitted to the data processing system and firstly subjected to bandpass filtering to filter out high-frequency noise. The bandpass frequency range is 1Hz to 250Hz.

[0061] Stress calculation formula: After filtering, the data processing system calculates the local normal stress of each unit

[0062]

[0063] in is the normal force per sensor unit, is the contact area of ​​the sensor (100 .

[0064] Example calculation: If the normal force collected by a sensor unit , then the normal stress is calculated as: .

[0065] Generate the contact patch contour: The data processing system performs two-dimensional interpolation processing on the stress data of each sensor point to generate a complete contact patch contour map, with the color depth indicating the stress magnitude in different areas.

[0066] Output and analysis: Output tire contact area is 0.03 Imprint diagram and normal stress distribution diagram.

[0067] Based on the stress distribution diagram, the tire's pressure center position, uniformity and stress concentration area are analyzed to evaluate the tire's ground contact and wear potential. Figure 2 and Figure 1 .

[0068] Example 3: Analysis of dynamic stress distribution of tires at different speeds: Experimental environment and configuration: The test was conducted under actual road conditions, and data was collected by installing a portable sensor array under the vehicle chassis. The test vehicle was driven at speeds of 30km / h, 60km / h, and 90km / h. The impact of speed changes on tire ground stress distribution was evaluated by comparing data at different speeds.

[0069] Data collection process: Real-time stress detection: The sensor array transmits the real-time normal force through the wireless transmission module. and contact area The data is transferred to a data processing system.

[0070] Dynamic stress calculation: Under different speed conditions, the system calculates the normal stress distribution of each sensor unit separately.

[0071]

[0072] Friction coefficient calculation and analysis: Calculate the friction coefficient according to the formula in the claim , and analyze the dynamic friction characteristics at different speeds:

[0073] in: is the tangential force, and the collected value is 50N; is the normal force, the normal stress measured at the highest speed is 4000N, and the friction coefficient is: ; Analysis of speed and ground contact changes: The ground contact areas under different speed conditions are: At 30km / h, the ground contact area is

[0074] At 60km / h, the contact area is ; At 90km / h, the contact area is .

[0075] The results show that as the speed increases, the contact area decreases and the normal stress is more concentrated in the center area of ​​the tire contact.

[0076] Example 4: Analysis of stress concentration areas and imprint profiles under different load conditions: Experimental environment and configuration: The tire is installed on a load test bench, and the load is gradually increased (500kg, 1000kg, 1500kg) through a hydraulic loading system, and the tire's contact print and stress distribution are collected in real time.

[0077] Stress concentration area calculation: The data processing system calculates the stress concentration area under different load conditions through formulas

[0078]

[0079] Example calculation: When the load is 1000kg, the local stress in a certain area is measured as Pa, maximum stress for Pa, the number of sensors is 10.

[0080] Stress concentration area Calculated as: .

[0081] Load and footprint variation analysis: The system generates a footprint contour map and normal stress distribution map for each load. Figure 4 , tire footprint profiles at different slip angles.

[0082] When the load increases, the changes in the contact area and stress distribution diagram are: Under 500kg load, the contact area is 0.045 ; Under 1000kg load, the contact area is 0.065 Under 1500kg load, the contact area is 0.08 ; Result analysis and output: Output the contact patch profile, stress distribution diagram, and stress concentration area analysis diagram under each load, and form a report on the impact of load changes on tire contact performance.

[0083] Example 5: Three-dimensional dynamic stress modeling of tire contact: Experimental environment and configuration: A three-dimensional dynamic test bench is used to measure tire ground contact stress by covering a three-dimensional sensor matrix. The sensor matrix covers the tire ground contact area with a sampling frequency of 2kHz.

[0084] Three-dimensional stress distribution modeling formula: The data processing system generates a three-dimensional stress distribution model of tire contact through the following formula

[0085]

[0086] Data processing and 3D model generation: is the normal stress value at each sensor point, To measure time, is the total number of sensor points.

[0087] Three-dimensional interpolation processing: The data processing system generates a stress distribution model through three-dimensional interpolation to display the stress intensity of the tire contact patch.

[0088] High stress area marking: The system automatically marks high stress concentration areas, such as high stress points located in (0.1,0.2,0.05)m.

[0089] The analysis and application outputs a three-dimensional grounding model and a distribution map of stress concentration areas to identify potential tire wear and high stress areas.

[0090] The results are used to optimize the tire's contact patch design, improving the tire's overall durability and stability.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for testing tire dynamic footprint profile and normal stress distribution using a sensor array, characterized in that: The following steps are involved: A plurality of sensor units are arranged in the contact area between the tire and the ground, wherein the sensor units include piezoelectric film sensors, stress sensors or force sensors, and are used to detect normal stress and contact morphology information at their locations in real time; During the operation of the tire, the profile information of the tire contact patch and the normal stress distribution data are collected in real time through a multi-point sensor array, wherein the sensor array can cover the entire tire contact area and reflect the tire contact changes in real time; Transmitting the data collected by the sensor unit to a data processing system, wherein the data processing system is used to process and analyze the received data; Based on the data processing results, the tire's contact patch, footprint shape and normal stress distribution are analyzed, a tire contact model is established, and the dynamic performance of the tire is evaluated.

2. The method for testing tire dynamic footprint profile and normal stress distribution using a sensor array according to claim 1, characterized in that: The arrangement of the sensor units in the sensor array in the tire contact area is designed according to the size, working state and contact stress distribution of the tire, so that the detection area of ​​each sensor unit covers all points of the contact surface, ensuring uniform collection of contact stress.

3. The method for testing tire dynamic footprint profile and normal stress distribution using a sensor array according to claim 1, characterized in that: The data of the sensor unit is transmitted to the data processing system by wireless or wired means, and the dynamic change data of the tire under different working conditions is transmitted in real time to achieve dynamic monitoring and efficient data processing.

4. The method for testing tire dynamic footprint profile and normal stress distribution using a sensor array according to claim 1, characterized in that: The data processing system comprises the following processing steps: Perform filtering, noise suppression and signal gain adjustment preprocessing operations on the collected original signal to remove environmental interference and improve signal quality; Based on the processed signal and the known sensor calibration coefficients, the local normal stress value at each sensor point is calculated. , and construct a stress distribution image based on this value; The data of each sensor point is spatially interpolated to generate a normal stress distribution map of the complete tire contact area; The finite element analysis numerical simulation method is used, combined with the normal stress distribution data, to further calculate the overall stress distribution and stress concentration area in the tire contact area.

5. The method for testing tire dynamic footprint profile and normal stress distribution using a sensor array according to claim 4, characterized in that: The local normal stress Calculated by the following formula: in, is the normal force at a point in the contact area, is the contact area at that point, is the normal stress at that point.

6. The method for testing tire dynamic footprint profile and normal stress distribution using a sensor array according to claim 4, characterized in that: The data processing system also includes a contact model generation module for generating a contact footprint profile of the tire based on the collected data. , the profile is described by the following formula: in, Indicates the outline of the tire's contact patch. is the normal stress at each sensor point in the ground area, To measure time, is the time variable, is the number of sensor points.

7. The method for testing tire dynamic footprint profile and normal stress distribution using a sensor array according to claim 6, characterized in that: The tire contact model further includes a stress concentration area on the tire contact area The normal stress in the stress concentration area is calculated by the following formula: in, is the stress concentration area, is the normal stress value of each sensor point, is the maximum value of normal stress at all sensor points, is the number of sensor points.

8. The method for testing tire dynamic footprint profile and normal stress distribution using a sensor array according to claim 4, characterized in that: The data processing system uses the following algorithm to perform dynamic data analysis to calculate the normal stress distribution and contact area of ​​the tire, and the normal stress distribution is calculated by the following discretization model: in, For at point The normal stress at is the contact area at that point, For the The normal force collected by the sensor points is is the number of all sensor points.

9. The method for testing the dynamic footprint profile and normal stress distribution of a tire by using a sensor array according to claim 1, characterized in that the method further comprises evaluating the dynamic performance of the tire by dynamically changing the tire contact area, wherein the tire contact area Calculated by the following formula: in, For the The local contact area of ​​each sensor point, is the number of sensor points, For test time, is the change of tire contact area over time.

10. The method for testing tire dynamic footprint profile and normal stress distribution using a sensor array according to claim 1, characterized in that: The method generates a three-dimensional model of the tire contact footprint profile through real-time analysis by a data processing system, and dynamically calculates the tire contact pressure distribution, contact area change and wear characteristics under different speeds, loads and road conditions, including the following steps: The real-time data of the multi-sensor units are multi-dimensionally interpolated using a data processing system to generate a three-dimensional stress distribution map of the tire contact area; Calculate the real-time tire contact pressure center position under different speed and load conditions based on the dynamic changes of the contact patch profile model and pressure distribution variance , to characterize the balance of the tire; Calculate the dynamic friction coefficient based on the stress changes between the tire and the ground , expressed by the following formula: in, is the tangential force on the tire contact surface, The normal stress is used to evaluate the traction performance and wear trend of the tire.

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