Capacitive Tire Sensor Patch for Direct Deformation Sensing

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Solution Overview

Problem

Current tire sensors using accelerometers provide indirect and noisy measurements, leading to less accurate and time-consuming calculations for tire parameters like contact length, slip angle, and road conditions, which are further complicated by tire conditions such as tread wear.

Innovation Solution

A tire sensor module with a detector patch containing variable capacitors adhered to the tire's tread or sidewall, utilizing an electronics unit to estimate parameters based on electrostatic capacity, providing real-time information on strain and bending across whole areas of the tire.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If accelerometers are used in a single package to measure acceleration, then the device complexity is reduced, but the measurement precision deteriorates due to noise and indirect measurement

Engineering Contradiction:
Improvesensor package structureVSAvoidtire parameter measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent divides the tire into multiple sensor regions (tread region, sidewall region, shoulder region) with separate capacitive sensors in each region. This segmentation allows direct measurement of strain and bending in different tire areas, improving measurement precision while distributing the sensor package complexity across multiple locations rather than consolidating into a single noisy accelerometer package.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces the mechanical accelerometer-based indirect measurement system with a capacitive sensor system that directly measures strain and bending through electrostatic capacity changes. This substitution eliminates the noise and indirect calculation requirements of accelerometer-based systems, directly measuring tire deformation parameters with higher precision.

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

2Device complexity

If accelerometers are used to estimate tire parameters through formulas, then the device complexity is reduced, but the productivity deteriorates due to time-consuming calculations

Engineering Contradiction:
Improvesensor and calculation systemVSAvoidparameter estimation speed
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent replaces the accelerometer-based indirect measurement system requiring complex formulas and time-consuming calculations with a capacitive sensor system that directly measures tire parameters. The capacitive sensors provide real-time strain and bending measurements through electrostatic capacity changes, eliminating the need for computational estimation and significantly improving productivity.

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

Solution Approach 2:

The capacitive sensors directly measure tire parameters without requiring external calculation systems. The electrostatic capacity changes self-indicate the strain and bending values, providing immediate readings that eliminate the need for time-consuming formula-based estimations and post-processing calculations.

Inventive Principle:
Principle #25Self-service

3Device complexity

If a single-point accelerometer measurement is used, then the device complexity is reduced, but the reliability deteriorates for deducing road and tire conditions

Engineering Contradiction:
Improvesensor configurationVSAvoidroad and tire condition assessment
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the tire into multiple monitoring zones (tread, sidewall, shoulder) with dedicated capacitive sensors in each zone. This multi-point measurement approach provides comprehensive data on tire deformation patterns, enabling reliable deduction of road conditions (dry, wet, snow, rough) and tire conditions (tread wear, pressure) that cannot be obtained from single-point accelerometer measurements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces the unreliable single-point accelerometer system with a distributed capacitive sensor network that directly measures strain and bending across multiple tire regions. This substitution provides robust, noise-free data that reliably indicates road surface conditions and tire health status through direct mechanical deformation measurement rather than indirect acceleration inference.

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 solution enhances the accuracy and speed of tire parameter estimation, reducing noise and improving the comprehensive monitoring of tire conditions and road classification, leading to better vehicle performance and safety.

Implementation Method 1

each of which has an electrostatic capacity that is variable due to at least deformation of each capacitor

Methodology Applied
Scientific EffectElectrostatic capacity: Capacitance

Data Source

PatentEP4107015B1Tire and tire sensor
Publication Date: 2024.12.25 NITTO BEND TECHNOLOGIES INC
  • EP4107015B1 patent drawingFigure 1
  • EP4107015B1 patent drawingFigure 2A~3
  • EP4107015B1 patent drawingFigure 4A~4B

AI summary

In an example, a vehicle tire includes a tread portion, a sidewall portion, and a sensor module for estimating one or more parameters of the tire. The sensor module includes a detector patch that includes one or more capacitors, each of which has an electrostatic capacity that is variable due to at least deformation of each capacitor. The sensor module also includes an electronics unit connected to each capacitor and configured to control the sensor module. The detector patch is adhered to an inside of at least one of the tread portion or the sidewall portion. At least one of the capacitors is located on the inside of the at least one of the tread portion or the sidewall portion. The electronics unit is configured to estimate at least one of the parameters based on the electrostatic capacity of each capacitor.