Tire Ground Contact Evaluation Using Terahertz Waves

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Solution Overview

Problem

Existing methods for evaluating tire ground contact properties on flat plates with unevenness are hindered by light scattering, making it difficult to accurately assess tire performance on real-world road surfaces with varying terrain.

Innovation Solution

The method employs terahertz waves with wavelengths greater than the surface roughness of the flat plate, allowing them to be irradiated and detected without scattering, enabling the evaluation of tire ground contact properties even on plates with predetermined unevenness, using an apparatus with a flat plate, irradiation, and reflected wave detection systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If visible light is used to evaluate tire ground contact property on an uneven flat plate, then the evaluation can be performed on a simple apparatus, but the light is scattered by the unevenness making accurate evaluation difficult

Engineering Contradiction:
Improveapparatus simplicityVSAvoidground contact property evaluation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent changes the wavelength parameter of the evaluation light from visible light to terahertz waves. This parameter change allows the evaluation to proceed on uneven surfaces because terahertz waves have wavelengths much longer than the surface roughness, preventing scattering and enabling accurate measurement of ground contact properties even on plates with unevenness.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If an uneven flat plate is used to simulate real road surfaces, then the evaluation better represents actual driving conditions, but visible light scattering occurs making measurement difficult

Engineering Contradiction:
Improvereal road surface simulation capabilityVSAvoidreflected light detection accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent changes the electromagnetic wave parameter from visible light to terahertz waves, which have wavelengths on the order of hundreds of micrometers. This allows the system to maintain adaptability to various road surface conditions (simulated by uneven plates) while avoiding the scattering problem that plagues visible light measurements, thereby preserving measurement precision.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If terahertz waves with wavelength greater than surface roughness are used, then light scattering is avoided and evaluation on uneven plates becomes possible, but the apparatus complexity increases

Engineering Contradiction:
Improvereflected wave detection accuracyVSAvoidirradiation and detection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the simple visible light illumination system with a terahertz wave generation and detection system. While this increases apparatus complexity, it enables measurements on uneven surfaces by substituting the physical mechanism from optical reflection to terahertz wave reflection, which is not scattered by surface roughness.

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

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 accurate evaluation of tire ground contact properties on flat plates with unevenness, enabling the calculation of wear energy and tread wear rate, effectively simulating real-world road conditions without light scattering issues.

Implementation Method 1

the tire is irradiated with visible light from below the flat plate, and the reflected light is detected

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

DE-10-2012-208177A1 discloses a method of evaluating a tire ground contact property based on the evaluation of a terahertz wave, radiated through a contact plate, reflected at the tire and detected by a respective detector

Methodology Applied
Scientific EffectTerahertz wave radiation: Microwave Radiation

Data Source

PatentEP3575769B1Method of evaluating tire ground contact property
Publication Date: 2023.03.01 BRIDGESTONE CORP
  • EP3575769B1 patent drawingFigure 1~3
  • EP3575769B1 patent drawingFigure 4
  • EP3575769B1 patent drawingFigure 5

AI summary

A method, of the present disclosure, of evaluating a tire ground contact property includes mounting a tire on one surface of a flat plate; placing a predetermined load on the tire or placing the tire in a no-load state; irradiating the tire with terahertz waves having a frequency of 0.1 THz to 10 THz from the other surface side of the flat plate or from inside the flat plate, the wavelength of the terahertz waves being greater than the roughness average length in at least a portion of the one surface of the flat plate and/or greater than the roughness average height in at least a portion of the one surface of the flat plate; detecting reflected terahertz waves from the tire; and evaluating the ground contact property of the tire on the basis of the detection result.