Tire Load Estimation via Road Profile Adaptive Filtering

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Solution Overview

Problem

Current tire monitoring systems can't accurately estimate tire loading in real-time during vehicle operation due to noise contributions from road roughness, which affects the accuracy of load estimates based on tire deformation measurements.

Innovation Solution

A dynamic load estimation system using a piezo-sensor to measure tire deformation, combined with an adaptive Kalman filter that filters out road roughness noise, and a road surface classification system to generate a filtered footprint length estimation, which is then used to calculate the estimated tire load along with tire-specific database information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If tire deformation measurements are used to estimate tire loading, then load estimation capability is provided, but accuracy deteriorates due to road roughness noise

Engineering Contradiction:
Improveload estimation accuracyVSAvoidroad roughness noise
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces road roughness estimation as an intermediary variable that mediates between the raw tire deformation measurements and the final load estimation. By estimating road roughness separately and using it to correct the deformation measurements, the system eliminates the harmful noise while preserving the useful load information, thereby resolving the contradiction between providing load estimation capability and maintaining accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If filtering is applied to reduce road roughness noise, then measurement precision improves, but device complexity increases

Engineering Contradiction:
Improveload estimation accuracyVSAvoidfiltering system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the estimated road roughness is continuously fed back into the load estimation process to correct ongoing measurements. This feedback loop allows the system to adaptively compensate for road roughness noise in real-time without requiring complex pre-processing or post-processing filtering stages, thereby improving precision while managing device complexity through an elegant feedback-based correction approach.

Inventive Principle:
Principle #23Feedback

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

This approach provides a more accurate and robust estimation of tire load, minimizing noise effects and reflecting real-world driving conditions, enabling better vehicle control and safety systems like advanced brake control systems.

Implementation Method 1

A dynamic load estimation system using a piezo-sensor to measure tire deformation

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP2774784B1Tire load estimation system and method using road profile adaptive filtering
Publication Date: 2016.11.09 THE GOODYEAR TIRE & RUBBER CO
  • EP2774784B1 patent drawingFigure 1
  • EP2774784B1 patent drawingFigure 2
  • EP2774784B1 patent drawingFigure 3

AI summary

A dynamic load estimation system and method for estimating a vehicle load is disclosed. The system comprises at least one tire (12) supporting a vehicle (10); tire sensor means (14) mounted to the one tire (12), the sensor means (14) being operable to measure a tire deformation of the one tire (12) and generate a load-indicative raw signal conveying measured deformation data; load estimation means for determining an unfiltered load estimation on the tire from the load-indicative raw signal; road roughness estimation means for determining a road roughness estimation; filtering means for filtering the unfiltered load estimation by the road roughness estimation; and load estimation means for determining a filtered load estimation on the one tire from the filtering means.