Drive-Over Magnetic Tread Measurement for Automatic Tire Wear Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current tire monitoring systems primarily focus on tire pressure and lack effective methods for automatically monitoring tire tread depth and wear, which can impact safety if not adequately addressed.

Innovation Solution

A magnetic sensor system using permanent or electromagnets and Hall effect sensors, integrated with a non-magnetic layer, measures tire tread thickness by detecting magnetic fields generated by the tire's steel belts, allowing for automatic and precise tread depth determination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual monitoring methods are used for tire tread depth, then device complexity is reduced, but measurement precision and reliability deteriorate due to lack of automatic monitoring

Engineering Contradiction:
Improvetread depth measurement precisionVSAvoidmonitoring system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces manual mechanical measurement methods with an automated magnetic sensing system. Magnetic sensors detect the magnetic field generated by steel belts in the tire to automatically determine tread depth, eliminating the need for manual visual inspection or physical measurement tools, thereby improving measurement precision while maintaining acceptable system complexity through the use of straightforward magnetic field detection principles

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

Solution Approach 2:

The tire itself generates the measurement signal through its steel belts creating a magnetic field that the sensors detect. The system uses the tire's own structural components (steel belts) as the source of measurement information, eliminating the need for external active transducers or power sources within the tire, thus improving reliability without significantly increasing complexity

Inventive Principle:
Principle #25Self-service

2Loss of information

If no automatic monitoring system is implemented, then device complexity remains low, but loss of information occurs due to inadequate monitoring of tire wear

Engineering Contradiction:
Improvetire wear informationVSAvoidmonitoring system structure
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The system substitutes manual inspection with automated magnetic field detection. Magnetic sensors continuously or periodically detect changes in the magnetic field generated by steel belts as the tire rotates, automatically capturing tread wear information without requiring driver intervention or complex mechanical measurement devices, thus reducing information loss while keeping the system relatively simple

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

Solution Approach 2:

The system provides feedback about tire tread depth by detecting magnetic field changes and translating them into measurable data. This feedback mechanism allows the system to continuously monitor tire wear and provide information about tread depth, preventing information loss while maintaining a relatively simple structure through direct magnetic field-to-data conversion

Inventive Principle:
Principle #23Feedback

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 accurate and automatic measurement of tire tread depth, enhancing safety by providing real-time monitoring of tire wear without manual intervention.

Implementation Method 1

the magnetic sensor is configured to detect a magnetic field resulting from the magnet and the tire on the drive over surface

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

A magnetic sensor system using permanent or electromagnets and Hall effect sensors

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP4042132B1Magnetic drive over system (DOS) providing tire tread thickness/depth measurement
Publication Date: 2025.12.17 BRIDGESTONE AMERICAS TIRE OPERATIONS LLC
  • EP4042132B1 patent drawingFigure 1
  • EP4042132B1 patent drawingFigure 2
  • EP4042132B1 patent drawingFigure 3

AI summary

According to some embodiments disclosed herein, a system is provided to measure a tread of a tire. The system includes a nonmagnetic layer providing a drive over surface, a magnet, and a magnetic sensor associated with the magnet. The drive over surface is adapted to receive the tire thereon including the tread to be measured. The magnet has opposing first and second magnetic poles, the nonmagnetic layer is between the drive over surface and the magnet, and the magnet is arranged so that the first magnetic pole is between the second magnetic pole and the nonmagnetic layer. The nonmagnetic layer is between the drive over surface and the magnetic sensor, and the magnetic sensor is configured to detect a magnetic field resulting from the magnet and the tire on the drive over surface.