Tire Crushed Radius Estimation Using Segmented Formula
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Solution Overview
Problem
Current methods for estimating the crushed radius of a tire lack accuracy and complexity, particularly in accounting for various factors such as load, speed, inflation pressure, transverse thrust force, and camber angle, which are crucial for simulating tire behavior and predicting vehicle dynamics.
Innovation Solution
A method using a simplified formula to estimate the crushed radius, incorporating coefficients derived from physical tests, which accounts for the influence of speed, inflation pressure, transverse thrust force, and camber angle, implemented within the TameTire software for improved accuracy and ease of implementation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex formulations like MF-5.2 or MF-6.1 are used to account for multiple factors (load, speed, pressure, transverse force, camber angle), then the accuracy of crushed radius estimation is improved, but the device complexity and ease of implementation deteriorate
Solution Approach 1:
The patent segments the crushed radius estimation into distinct components, each influenced by specific parameters. The formula RI = R0 - FZ/KZZ + RV*V^2 + RY1*Pg*FY + RY2*FY + Rγ*γ separates the effects of vertical load, speed, inflation pressure, transverse thrust force, and camber angle into additive terms with dedicated coefficients. This segmentation allows accurate modeling of each factor's contribution while maintaining computational simplicity and ease of implementation.
2Reliability
If multiple parameters (load, speed, inflation pressure, transverse thrust force, camber angle) are incorporated into the estimation formula, then the reliability of tire behavior prediction is improved, but the device complexity increases
Solution Approach 1:
The patent employs parameter changes by introducing specific coefficients (R0, RV, RY1, RY2, Rγ) that quantify the influence of each physical parameter on the crushed radius. These coefficients transform complex physical relationships into straightforward mathematical terms that can be easily computed. The linearized stiffness model KZZ = KZZ0 + KZZp*Pg further simplifies the pressure-dependent stiffness behavior, enabling reliable multi-parameter prediction without excessive complexity.
3Ease of operation
If a simplified formula is used for estimating crushed radius, then the ease of implementation is improved, but the measurement precision deteriorates
Solution Approach 1:
The patent achieves both simplicity and accuracy through parameter changes. The estimation formula uses straightforward arithmetic operations (addition, multiplication) with clearly defined parameters, making it easy to implement. Meanwhile, the coefficients RV, RY1, RY2, and Rγ capture the nuanced physical effects of speed, pressure, transverse force, and camber angle, ensuring high measurement precision. The linearized stiffness model further enhances computational efficiency while maintaining accuracy across varying operating conditions.
Data Source
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AI summary
The invention concerns a method for producing a motor vehicle tyre, comprising a step of estimating a deflection radius Rl of the tyre by using a formula of the following form: (I) in which KZz is written in the form of (II)