Tire Force Estimation via CAN-Bus Sensor Fusion

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Solution Overview

Problem

Current systems fail to accurately and robustly estimate tire normal, lateral, and longitudinal forces in real-time during vehicle operation, especially over the lifetime of a tire tread, due to reliance on indirect and load-dependent sensor measurements.

Innovation Solution

A tire state estimation system utilizing CAN-bus accessible vehicle sensors for input data, including acceleration, angular velocities, and steering wheel angle, employs normal, lateral, and longitudinal force estimators to calculate tire forces without relying on GPS or suspension sensors, using models for wheel rotational dynamics, planar vehicle models, and adaptive inertial parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If GPS and suspension sensors are used for tire force estimation, then measurement data availability is improved, but system reliability deteriorates due to load-dependent inertial parameters and sensor errors

Engineering Contradiction:
Improvesensor data availabilityVSAvoidtire force estimation accuracy
Core Design Contradiction:
Loss of informationVSReliability

Solution Approach 1:

The patent extracts and removes GPS and suspension sensors from the tire force estimation system. By eliminating these sensors that introduce load-dependent inertial parameters and measurement errors, the system achieves more reliable and accurate tire force estimates without compromising data availability through alternative sensor fusion approaches.

Inventive Principle:
Principle #2Taking out (Extraction)

2Device complexity

If indirect sensor measurements are used for tire force estimation, then system complexity is reduced, but measurement precision deteriorates over tire tread lifetime

Engineering Contradiction:
Improvesystem structureVSAvoidtire force estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent changes the parameters used in tire force estimation by eliminating load-dependent inertial parameters from the estimation algorithm. This parameter change allows the system to maintain simplicity while improving measurement precision across the entire tire tread lifetime, as the estimation no longer degrades with tire wear or load variations.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If load-dependent inertial parameters are included in the estimation model, then model completeness is improved, but estimation robustness deteriorates during vehicle operation

Engineering Contradiction:
Improvemodel completenessVSAvoidestimation robustness
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent extracts and removes load-dependent inertial parameters from the tire force estimation model. This extraction eliminates the source of estimation errors and degradation over time, achieving robust real-time estimation that maintains accuracy throughout the tire's operational lifetime without requiring complex compensations.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3153375B1Robust tire forces estimation system
Publication Date: 2018.09.19 THE GOODYEAR TIRE & RUBBER CO
  • EP3153375B1 patent drawingFigure 1
  • EP3153375B1 patent drawingFigure 2
  • EP3153375B1 patent drawingFigure 3A~3B

AI summary

A tire state estimation system is provided for estimating normal force, lateral force and longitudinal forces based on CAN-bus accessible sensor inputs; the normal force estimator generating the normal force estimation from a summation of longitudinal load transfer, lateral load transfer and static normal force using as inputs lateral acceleration, longitudinal acceleration and roll angle derived from the input sensor data; the lateral force estimator estimating lateral force using as inputs measured lateral acceleration, longitudinal acceleration and yaw rate; and the longitudinal force estimator estimating the longitudinal force using as inputs wheel angular speed and drive/brake torque derived from the input sensor data.