Tire Parameter Estimation via Vehicle Movement Contrast
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for estimating tire parameters, such as tire pressure and cornering stiffness, are not precise due to varying environmental conditions and lack of accurate models that account for wheel-road contact information.
Innovation Solution
A method involving measuring a reference vehicle movement and modeling a movement based on estimated tire parameters, with iterative updates using a Kalman filter to refine estimates, ensuring accuracy by considering variance and noise in sensor data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If tire parameters are used in vehicle movement modeling, then the model accuracy improves, but the measurement precision of tire parameters deteriorates due to their variability from environmental conditions
Solution Approach 1:
The patent applies dynamics by making the tire parameters adaptive rather than fixed. The system continuously estimates tire parameters (cornering stiffness, slip stiffness, tire radii) based on real-time vehicle movement data and environmental conditions. This dynamic estimation allows the model to adapt to changing conditions while maintaining accurate parameter values for precise vehicle movement modeling.
Solution Approach 2:
The patent implements feedback through an iterative estimation process where the measured vehicle movement is compared with the modeled movement. The difference (error) between actual and modeled movement is used to update and refine the tire parameter estimates. This closed-loop feedback mechanism continuously improves measurement precision by correcting parameter estimates based on observed deviations.
2Measurement precision
If an exact vehicle model with tire parameters is created, then measurement precision improves, but device complexity increases due to multiple sensors and iterative processing
Solution Approach 1:
The patent applies universality by using a multi-functional sensor system where existing vehicle sensors (accelerometers, gyroscopes, wheel speed sensors) serve multiple purposes. These sensors not only monitor basic vehicle dynamics but also provide data for tire parameter estimation and model validation. This multi-functionality reduces the need for additional dedicated sensors while maintaining high measurement precision.
Solution Approach 2:
The system applies self-service by using the vehicle's own existing sensor data and movement information to estimate and refine tire parameters. The iterative estimation process utilizes data already collected during normal vehicle operation, eliminating the need for separate calibration procedures or additional measurement equipment. The system serves itself by continuously improving its own parameter knowledge from operational data.
3Measurement precision
If tire parameters are estimated iteratively, then measurement precision improves through convergence, but loss of time increases due to multiple estimation cycles
Solution Approach 1:
The patent applies preliminary action by using initial approximate tire parameters from manufacturer specifications or previous calibrations as starting values for the iterative estimation process. This preliminary information reduces the number of iterations needed to converge to accurate values, as the estimation starts from a reasonable baseline rather than from zero or arbitrary values.
Solution Approach 2:
The system applies continuity of useful action by performing tire parameter estimation continuously during vehicle operation rather than in discrete separate calibration sessions. The iterative process runs continuously using ongoing sensor data, allowing the estimation to converge while the vehicle is being used normally. This continuous operation minimizes the effective time loss by utilizing otherwise idle processing capacity during regular vehicle operation.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
a method for estimating tyre parameters (48) for a vehicle (2) is disclosed, comprising the following steps: - measuring (14) a reference movement (32) of the vehicle (2); - modelling (38) a model movement (46) of the vehicle (2) on the basis of a model (44) with the tyre parameters (48) to be estimated removed; and - estimating (50) the tyre parameters (44) of the vehicle (2) on the basis of a contrast of the reference movement (32) and the model movement (46).