Tire Strain Sensor for Per-Wheel Lateral Force Detection

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Solution Overview

Problem

Existing tire sensor technologies struggle to accurately calculate lateral forces acting on individual wheels due to reliance on vehicle body weight and barycenter acceleration, lacking consideration for occupant and load variations, which affects the accuracy of damper control.

Innovation Solution

A physical quantity detection device using strain sensors in each tire to detect load and lateral acceleration, calculating lateral force as the product of load and lateral acceleration, thereby enabling precise control of each wheel independently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If lateral force is calculated using vehicle body weight and barycenter acceleration, then the calculation method is simple, but the accuracy of lateral force detection is low

Engineering Contradiction:
Improvelateral force detection accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the vehicle into four independent wheel units, each equipped with its own strain sensor for detecting load and lateral acceleration. This segmentation allows independent measurement at each wheel location, eliminating the need for complex vehicle-level calculations while providing accurate per-wheel lateral force data.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces the mechanical calculation method (using vehicle body weight and barycenter acceleration) with direct strain measurement using strain sensors mounted on each wheel. The strain sensors directly measure the physical quantities needed, substituting indirect calculation with direct detection.

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

2Adaptability or versatility

If vehicle body weight is used for lateral force calculation, then the calculation is straightforward, but it cannot account for occupant and load variations

Engineering Contradiction:
Improveadaptability to load variationsVSAvoidlateral force calculation accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The strain sensors mounted on each wheel automatically detect the actual load conditions at that specific wheel location. The system serves itself by directly measuring the physical quantities needed without requiring external input about occupant distribution or cargo placement, adapting automatically to any loading condition.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If a single vehicle-level lateral force calculation is used, then the system is simple, but independent control of each wheel is impossible

Engineering Contradiction:
Improveindependent wheel control capabilityVSAvoidnumber of sensors required
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The patent segments the detection system into four independent units, one for each wheel. Each unit includes a strain sensor that independently measures load and lateral acceleration at its specific wheel location, enabling independent control decisions for each wheel based on local conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The strain sensor serves multiple functions: it detects both the load (vertical force) and lateral acceleration acting on the wheel. This multi-functionality allows the single sensor at each wheel to provide all necessary data for independent wheel control without requiring additional specialized sensors.

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

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 highly accurate detection and control of lateral forces on each tire, improving vehicle safety and comfort by accounting for real-time load and acceleration variations.

Implementation Method 1

A tire strain sensor can detect a load or a lateral acceleration acting on a tire, by detecting strain or deformation of the tire

Methodology Applied
Scientific EffectStrain detection: Deformation

Data Source

PatentEP4679047A1Physical quantity detection device
Publication Date: 2026.01.14 ASTEMO LTD
  • EP4679047A1 patent drawingFigure 1
  • EP4679047A1 patent drawingFigure 2
  • EP4679047A1 patent drawingFigure 3

AI summary

Provided is a physical quantity detection device that can detect load information and a lateral acceleration for each wheel, the load information including information on not only a vehicle weight but also occupants and a load weight, allows damper control for separating controlling four wheels, and can provide a lateral force calculated with high accuracy. The physical quantity detection device according to the present invention calculates a lateral force, using a load detected in real time by a strain sensor and a lateral acceleration detected from characteristics of a sensor signal waveform, detects the load from a magnitude of a strain peak amplitude, and detects the lateral acceleration from a difference between a magnitude of the strain peak amplitude at the time of making a turn (at the time of the lateral acceleration being applied) and a magnitude of the strain peak amplitude at the time of traveling straight ahead.