Sliding Mode Observer for Vehicle Wheel Rolling Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for monitoring tire inflation pressure in vehicles are inadequate as they cannot accurately measure rolling resistance in real-time while the vehicle is in motion, relying on static finite element models or equipment that requires specific devices for measurement.
Innovation Solution
A method using an observer based on the theory of sliding modes, which estimates rolling resistance by measuring angular speed and torque applied to the wheel, allowing for robust and reliable real-time monitoring of tire pressure through data from ABS sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If static finite element models are used to estimate rolling resistance, then the model can be simplified and computed easily, but the estimation cannot be performed in real-time while the vehicle is in motion
Solution Approach 1:
The patent replaces the static finite element mechanical model with a dynamic observer-based estimation system that uses measured angular speed and torque signals processed through sliding mode theory, enabling real-time rolling resistance estimation during vehicle operation
Solution Approach 2:
The invention transitions from a static estimation approach to a dynamic observer that continuously adapts to changing vehicle conditions, using real-time measurements of angular speed and torque to estimate rolling resistance as the vehicle moves
2Measurement precision
If measurement benches with sensors are used to measure rolling resistance, then measurement precision can be improved, but the measurement cannot be performed when the vehicle is in use
Solution Approach 1:
The vehicle uses its own existing sensors (ABS system angular speed sensors and torque measurements) to perform self-diagnosis of tire pressure through rolling resistance estimation, eliminating the need for external measurement benches or additional dedicated measurement devices
Solution Approach 2:
The patent makes existing vehicle sensors serve multiple functions: the ABS angular speed sensors and torque measurements originally designed for braking control are repurposed to also estimate rolling resistance and monitor tire pressure, eliminating the need for separate measurement equipment
3Measurement precision
If additional measurement devices are installed to measure rolling resistance in real-time, then the measurement precision and real-time capability are improved, but the device complexity increases
Solution Approach 1:
The vehicle uses its own existing sensors (ABS system angular speed sensors and torque measurements) to perform self-diagnosis of tire pressure through rolling resistance estimation, eliminating the need for external measurement benches or additional dedicated measurement devices
Solution Approach 2:
The patent makes existing vehicle sensors serve multiple functions: the ABS angular speed sensors and torque measurements originally designed for braking control are repurposed to also estimate rolling resistance and monitor tire pressure, eliminating the need for separate measurement equipment
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The present invention relates to a method for estimating the rolling resistance of a wheel of a moving vehicle, said vehicle having at least two wheels (1) fitted with tires, the method including: measuring or estimating the value of the angular velocity Omega of the rotation of at least one wheel (1); and measuring or estimating the value of the torque Ʈ applied to said wheel (1), characterised in that the method uses an observer of the dynamics of the wheel (1) that is based on the sliding mode control theory, in which the input signals are the value of the angular velocity Omega of the wheel (1) and the value of the torque Ʈ applied to the wheel (1).