Tire Bead Acceleration Sensing for Longitudinal Force Detection

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Solution Overview

Problem

Conventional methods for determining tire longitudinal force are complex and limited to driven wheels, making it difficult to accurately assess tire forces at both driven and freely running wheels.

Innovation Solution

A method that uses an acceleration sensor in the tire bead to determine tire acceleration, calculating time or angular distances between tire contact patch entry and exit points, and deducing tire longitudinal force from symmetry shifts detected by a processor unit, which is independent of tire circumferential speed and accounts for driving, braking, and rolling resistance forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional torque ratio assessment methods are used to determine tire longitudinal force, then the determination can be performed, but the method is complicated and limited to driven wheels only

Engineering Contradiction:

Improveapplicability to both driven and freely running wheelsVSAvoidcomplexity of torque ratio assessment

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces the conventional mechanical torque ratio assessment method with an acceleration-based measurement system. An acceleration sensor mounted on the tire bead directly measures tire acceleration, which is then processed to determine longitudinal force. This substitution eliminates the need for complex torque calculations and enables application to both driven and freely running wheels, as the acceleration measurement is independent of drive train configuration.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If torque ratio assessment is used for tire longitudinal force determination, then force data can be obtained, but the method is exclusively applicable to driven wheels

Engineering Contradiction:

Improvewheel type compatibilityVSAvoidmeasurement complexity

Core Design Contradiction:

Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The tire itself serves as the measurement platform by mounting the acceleration sensor directly on the tire bead. The tire's own acceleration characteristics during rotation and contact with the ground provide direct information about longitudinal forces. This self-service approach eliminates the need for external torque measurement systems and enables universal application to any wheel type, whether driven or freely running.

Inventive Principle:

Principle #25Self-service

3Measurement precision

If symmetry shift analysis is used to determine tire longitudinal force, then accurate force determination is achieved, but real-time processing requirements increase

Engineering Contradiction:

Improvetire longitudinal force accuracyVSAvoiddata processing time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent pre-calculates and stores reference symmetry patterns for different tire contact conditions during system calibration. During operation, the processor compares real-time acceleration data against these pre-stored references to rapidly determine longitudinal force. This preliminary preparation of reference data significantly reduces real-time processing requirements while maintaining high measurement precision.

Inventive Principle:

Principle #10Preliminary action

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

Enables dynamic and accurate determination of tire longitudinal force at both driven and freely running wheels, providing real-time data on rolling resistance and driving/braking forces, improving data quality and traction management systems.

Implementation Method 1

a tire acceleration variable is determined by an acceleration sensor arranged in a tire bead, the variable characterizing an acceleration occurring within the tire bead

Methodology Applied

Scientific EffectAcceleration sensing: Accelerometer

Implementation Method 2

a first time interval or angular distance between a tire contact patch entry point and an acceleration vertex and a second time interval or angular distance between the acceleration vertex and a tire contact patch exit point are determined

Methodology Applied

Scientific EffectTime interval measurement: Time of Flight

Data Source

PatentUS11850895B2Method for dynamically determining a tire longitudinal force

Publication Date: 2023.12.26 DEERE & CO

AI summary

A method is provided for dynamically determining a tire longitudinal force. The method includes determining a tire acceleration variable by an acceleration sensor arranged in a tire bead, determining a first time interval between a tire contact patch entry point and an acceleration vertex by a processor unit, and determining a second time interval between the acceleration vertex and a tire contact patch exit point by the processor unit. The method also includes determining a magnitude or direction of a tire longitudinal force variable comprising a tire longitudinal force by the processor unit from a symmetry shift detected between the first and second time intervals.