Time-of-Flight Tire Tread Depth Sensing Without Embedded Sensors

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Solution Overview

Problem

Existing methods for monitoring tire tread depth are either invasive, costly, or limited in availability, making it difficult to accurately and economically measure tire wear across different locations.

Innovation Solution

A non-contact time-of-flight sensor system that emits pulses to the tire tread and groove base to calculate tread depth, using a processor to determine the depth difference and transmit data wirelessly for remote processing, allowing for accurate and adaptable tire tread depth estimation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electronic sensors are mounted in the tire tread to measure tire wear, then measurement precision is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvetread depth measurement accuracyVSAvoidtire structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a portable sensor unit as an intermediary device that externally measures tread depth without being integrated into the tire structure. This mediator contains the sensing elements (accelerometers, gyroscopes, magnets) and processes data to determine tread wear, thereby achieving precise measurement without modifying the tire itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces traditional mechanical contact sensors with a portable electronic sensing system that uses accelerometers, gyroscopes, and magnetic fields to measure tread depth. This substitution eliminates the need for mechanical sensors embedded in the tire, reducing complexity while maintaining measurement capability.

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

2Measurement precision

If drive over readers are used to measure tread depth, then measurement precision is improved, but ease of operation deteriorates due to limited availability

Engineering Contradiction:
Improvetread depth measurement accuracyVSAvoidmeasurement accessibility
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent transforms the static, location-fixed drive-over reader system into a dynamic, portable sensor unit that can be moved to any location. The sensor unit is designed to be handheld or mountable on various surfaces, enabling tread depth measurement anywhere rather than requiring the vehicle to travel to a specific station.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent creates a portable copy of the drive-over reader functionality that can be deployed anywhere. Instead of requiring vehicles to pass through a fixed infrastructure, the measurement capability is copied into a portable device that brings the measurement function to the vehicle location.

Inventive Principle:
Principle #26Copying

3Ease of operation

If tread wear indicators are provided in the tire tread, then ease of operation is improved for visual inspection, but measurement precision deteriorates due to difficulty in accurate determination

Engineering Contradiction:
Improvevisual inspection easeVSAvoidtread wear state accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements a feedback system where the portable sensor unit measures actual tread depth and provides quantitative data about tire wear state. This feedback replaces subjective visual assessment with objective numerical measurements, allowing users to accurately determine when tread wear reaches critical levels.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent incorporates visual indicators that change color or appearance based on measured tread depth values. The system can display different colors or patterns on the portable device screen or on the tire surface to indicate wear levels, combining visual ease of operation with precise measurement data.

Inventive Principle:
Principle #32Color changes

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, reliable, and cost-effective tire tread depth measurement, adaptable to various tire configurations, and integrates with tire pressure monitoring systems for comprehensive vehicle maintenance.

Implementation Method 1

a non-contact sensor including a time-of-flight sensor that determines the depth of the tread using time-of-flight

Methodology Applied
Scientific EffectTime-of-flight: Time of Flight

Implementation Method 2

The time-of-flight sensor includes an emitter that emits a pulse to a tread surface of the tire and a lens that captures the pulse after it reflects off of the tread surface

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4001833B1System for estimating tire tread depth
Publication Date: 2024.06.26 THE GOODYEAR TIRE & RUBBER CO
  • EP4001833B1 patent drawingFigure 1
  • EP4001833B1 patent drawingFigure 2
  • EP4001833B1 patent drawingFigure 3

AI summary

A system and method for estimating a tread depth of a tire (12) supporting a vehicle is disclosed. The system (10) includes a sensor unit (30). The sensor unit (30) includes a noncontact time-of-flight sensor (32), the time-of-flight sensor (32) including an emitter (36) for emitting a first pulse (38) to an outer surface (40) of the tread (22), and a lens (44), the lens (44) being configured for capturing the first pulse (38) after it reflects off of the outer surface (40) of the tread (22). The system (10) further includes a processor (76) for measuring a time from emission of the first pulse (38) to capture of the reflected first pulse (42) and for calculating a tread surface distance (56) from the time from emission of the first pulse (38) to capture of the reflected first pulse (42). The emitter (36) is configured for emitting a second pulse to a base (50) of a groove (52) formed in the tread (22). The lens (44) is configured for capturing the second pulse after it reflects off of the base (50) of the groove (52). The processor (76) is configured for measuring a time from emission of the second pulse to capture of the second pulse and for calculating a reference distance (54) from the time from emission of the second pulse to capture of the second pulse. The processor (76) is further configured for determining a depth of the tread (22) from a difference between the tread surface distance (56) and the reference distance (54).