Internal Tire Microphone for Rolling Condition Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for determining tire rolling conditions on the ground, such as weather state, tire wear, and tread type, rely on multiple sensors and additional parameters, increasing costs and complexity, while failing to accurately assess certain rolling conditions.

Innovation Solution

A method using a microphone inside the tire to measure acoustic signals across multiple frequency bands, combined with discriminant analysis based on a learning base, to determine the state of firmness and other rolling conditions, such as slip level and tire pressure, without the need for external sensors or additional parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple sensors and additional parameters are used to determine tire rolling conditions, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvedetermination accuracy of rolling conditionsVSAvoidnumber of sensors and parameters
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention extracts only the essential acoustic information needed to determine rolling conditions by placing a microphone inside the tire. This selective extraction of useful information (acoustic signals from tire-ground interaction) eliminates the need for multiple sensors while maintaining determination accuracy through focused measurement of the most relevant physical phenomenon.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The internal microphone serves multiple functions: it detects acoustic signals related to ground firmness, tire slip, and rolling conditions simultaneously. By making the acoustic measurement system multi-functional through signal processing and analysis, the invention replaces multiple specialized sensors with a single versatile acoustic sensor that can determine various rolling conditions through different acoustic characteristics.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If multiple sensors and parameters are combined to assess rolling conditions, then reliability is improved, but cost increases

Engineering Contradiction:
Improvereliability of rolling condition determinationVSAvoidcost of implementation
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The tire itself serves as the measurement medium by generating acoustic signals during normal operation. The tire-ground interaction naturally produces sounds that contain information about rolling conditions, eliminating the need for additional power-consuming sensors or complex measurement systems. The system uses the tire's own operational characteristics as the measurement source, reducing implementation cost while maintaining reliability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention replaces complex mechanical sensor systems with an acoustic measurement approach. By using sound waves to detect ground firmness and rolling conditions, the system substitutes mechanical contact sensors with a non-contact acoustic field-based measurement method, reducing hardware cost while improving reliability through indirect measurement that doesn't interfere with tire operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If external microphones are used to record tire acoustic signals, then ease of installation is improved, but measurement precision deteriorates

Engineering Contradiction:
Improveease of microphone installationVSAvoidaccuracy of acoustic signal measurement
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

Instead of placing the microphone outside the tire to record sounds, the invention inverts the approach by placing the microphone inside the tire. This reversal allows direct capture of acoustic signals generated at the tire-ground interface, improving measurement precision by eliminating external noise interference and signal attenuation, while the standardized internal mounting position ensures consistent and reliable data collection.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The tire interior acts as an acoustic intermediary chamber that transmits sounds from the tire-ground contact point to the internal microphone. This intermediary space allows the microphone to capture pure acoustic signals without direct exposure to external environmental noise, improving measurement precision while the simple internal mounting provides ease of installation and positioning.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 allows for precise determination of tire rolling conditions, including ground firmness, slip level, and tire pressure, using a single sound recording, reducing costs and complexity while improving accuracy and reliability.

Implementation Method 1

a measurement of an acoustic signal produced by the tire rolling on the ground surface is acquired by a microphone

Methodology Applied
Scientific EffectSound: Sound

Data Source

PatentEP3634779B1Method controlling or tracking the operation of a tire
Publication Date: 2021.04.07 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP3634779B1 patent drawingFigure 1~2
  • EP3634779B1 patent drawingFigure 3
  • EP3634779B1 patent drawingFigure 4

AI summary

The invention relates to a method for determining the rolling conditions of a tyre (1) on the ground, said tyre being mounted on a vehicle (9), said method comprising the steps wherein: - a measurement of an acoustic signal produced by the tyre (1) rolling on the surface of the ground is acquired by a microphone (10) arranged inside the tyre, - for each of a plurality of frequency bands, association with said frequency band of data representative of an average acoustic output measured in said frequency band based on the measurement of the acoustic signal acquired, the representative data associated with different frequency bands and based on the same measurement forming the variables of a vector associated with said measurement, - determination of a firmness condition of the ground by carrying out a discriminative analysis of data based on findings.