Tyre Normal Force Estimation Using Suspension and IMU Ranges
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining normal forces acting on vehicle tires are not robust enough, particularly for heavy-duty vehicles, which require more accurate and reliable estimates for advanced vehicle motion control and autonomous driving applications.
Innovation Solution
A method that uses two separate estimators operating on partially independent data sets: a suspension-based estimator and an inertial force-based estimator. These estimators provide a range of tyre normal force values, enhancing the robustness of the estimation by accounting for variations and uncertainties in the input data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single estimator is used to determine tyre normal force, then the device complexity is reduced, but the reliability of the estimation deteriorates
Solution Approach 1:
The estimation system is divided into multiple independent estimators: a suspension-based estimator using suspension compression data and an inertial force-based estimator using IMU data. Each estimator processes different data sources independently, and their results are combined to produce the final tyre normal force estimate, thereby improving reliability through diversity of measurement approaches
Solution Approach 2:
The patent merges the outputs of multiple independent estimators (suspension-based and inertial force-based) into a single comprehensive tyre normal force estimate. By combining results from different measurement principles, the system achieves higher reliability than any single estimator could provide alone
2Reliability
If a range of tyre normal force values is provided instead of a single value, then the reliability of the estimation is improved, but the complexity of data processing increases
Solution Approach 1:
The system performs preliminary estimation operations by each individual estimator to generate candidate ranges before combining them. The suspension-based estimator first determines a range based on suspension compression variations, and the inertial estimator independently determines another range, preparing the groundwork for subsequent reliable combination
Solution Approach 2:
The system uses feedback from multiple independent estimation paths to refine the final tyre normal force range. By comparing and combining results from suspension-based and inertial force-based estimators, the system validates and strengthens the reliability of the estimated range through cross-verification
Data Source
AI summary
A method for determining a tyre normal force range (Fz,min, Fz,max) of a tyre force (Fz) acting on a vehicle (100), the method comprising; obtaining (S1) suspension data (310) associated with a suspension system of the vehicle (100); obtaining (S2) inertial measurement unit, IMU, data (320) associated with the vehicle (100); estimating (S3), by a suspension-based estimator (330) a first tyre normal force range (Fz1,min, Fz1,max) based on the suspension data (310); estimating (S4), by an inertial force-based estimator (340), a second tyre normal force range (Fz2,min, Fz2,max) based on the IMU data (320); and determining (S5) the tyre normal force range (Fz,min, Fz,max) based on the first tyre normal force range (Fz1,min, Fz2,max) and on the second tyre normal force range (Fz2,min, Fz2,max).