Real-Time Tire Adhesion Estimation Using Sensor Fusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods fail to efficiently and in real-time estimate the coefficient of adhesion of each tire as a function of tire structural features, physical conditions, and vehicle kinematic and dynamic conditions.
Innovation Solution
A modular device equipped with electronic computing means, sensors (triaxial accelerometer, temperature sensors, pressure sensors, GPS, and extensometers) that acquires and processes signals to estimate tire temperature, angular velocity, slip ratio, and force components, considering tire wear and thermodynamic conditions to calculate both instantaneous and potential coefficients of adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sensors and computing means are integrated to estimate adhesion considering tire structural features and physical conditions, then measurement precision and reliability are improved, but device complexity increases
Solution Approach 1:
The device segments the adhesion estimation process into distinct functional modules: sensor acquisition module (accelerometers, gyroscopes, encoders, temperature sensors, pressure sensors), signal processing module (computing means that calculates tire forces, moments, slip ratios), and estimation module (determines instantaneous and potential adhesion coefficients). This modular segmentation allows each component to specialize in specific measurements and calculations, improving overall precision while managing complexity through organized functional separation.
Solution Approach 2:
The computing means serves multiple functions simultaneously: it processes data from various sensors (accelerometers, gyroscopes, encoders, temperature sensors, pressure sensors), calculates tire forces and moments in different directions, determines both instantaneous and potential adhesion coefficients, and can adapt to different tire conditions (temperature, pressure, wear). This multi-functionality consolidates what would otherwise require separate devices into a single integrated system, improving measurement precision without proportionally increasing device complexity.
2Reliability
If real-time estimation is performed considering multiple tire conditions (temperature, pressure, wear), then reliability is improved, but use of energy increases
Solution Approach 1:
The system performs preliminary calculations by pre-establishing the relationships between tire forces, moments, and adhesion coefficients through signal processing algorithms. The computing means continuously processes sensor data to maintain updated estimates of tire conditions (temperature, pressure, wear) and their impact on adhesion, so that when adhesion estimation is needed, the system already has processed information ready, reducing the computational energy burden during critical real-time estimation moments.
Solution Approach 2:
The system monitors changes in tire parameters (temperature, pressure, wear) and adjusts the adhesion estimation accordingly. By detecting when these parameters change significantly, the system can trigger more intensive processing only when necessary, rather than continuously at maximum computational intensity. This parameter-based triggering optimizes energy consumption while maintaining reliability by ensuring accurate estimation when tire conditions actually change.
3Measurement precision
If comprehensive sensor integration is implemented to capture all tire and vehicle conditions, then measurement precision is improved, but ease of manufacture deteriorates
Solution Approach 1:
The computing means is designed as a universal platform that can process data from multiple sensor types (accelerometers, gyroscopes, encoders, temperature sensors, pressure sensors) and perform various calculations (tire forces, moments, slip ratios, adhesion coefficients). This universal design allows the same core computing unit to be manufactured and deployed across different vehicle configurations, improving measurement precision while simplifying manufacture by avoiding the need for custom-built systems for each specific sensor combination.
Solution Approach 2:
The device incorporates dynamic adaptation capabilities where the computing means can adjust its processing algorithms and data acquisition strategies based on the specific vehicle configuration and available sensors. This dynamic flexibility allows the system to be manufactured with a standardized sensor suite while still achieving precise condition detection for different vehicle types through software configuration rather than hardware redesign, thereby improving measurement precision without proportionally increasing manufacturing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Provides accurate, real-time estimation of tire adhesion by explicitly considering tire and vehicle conditions, enhancing reliability and adaptability to various configurations, and enabling optimization of vehicle performance and consumption.
Implementation Method 1
a plurality of temperature sensors, configured to acquire the outer temperature of each tyre
Implementation Method 2
pressure sensors configured to acquire the inner air pressure of each tyre
Implementation Method 3
a plurality of encoders, configured to measure the angular velocity of each wheel of said vehicle
Implementation Method 4
at least a triaxial accelerometer integral to the vehicle and connected to said electronic computing means
Implementation Method 5
The temperature estimation occurs preferably by using a Kalman filter, discretizing the tyre according to the Fourier equations, by applying the finite volume method
Data Source
AI summary
Device for the estimation of a land vehicle adhesion, comprising electronic computing means installed in a vehicle, configured to acquire the signals detected by at least a triaxial accelerometer integral to the vehicle; a steering angle meter; a plurality of encoders, configured to measure the angular velocity of each wheel of said vehicle; a plurality of temperature sensors, configured to acquire the outer temperature of each tyre; pressure sensors configured to acquire the inner air pressure of each tyre, characterized in that computer programs are loaded on said electronic computing means, and are configured: (100) to estimate the inner temperature of each tyre as a function of the outer temperature and inner air pressure; (200) to calculate the angular velocity (w) and the components of the velocity of translation (Vx, Vy) for each tyre; (300) to determine the slip ratio (sr) and the slip angle (sa) for each tyre, as a function of the velocity of translation (Vx, Vy), of the angular velocity (w) and of the tyre rolling height (R); (400) to calculate the longitudinal, lateral and vertical components (Fx, Fy, Fz) of the forces exchanged by each tyre with the ground; (500) to estimate the values of the instantaneous coefficient of friction from the equations of dynamic balance on each tyre; (600) to compare the values of the coefficient of friction calculated at point (550) with the estimation of the maximum coefficient of friction estimated in the same vertical load (Fz), kinematic and thermodynamic conditions.