Tire Tread Depth Determination via Acceleration Analysis

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Solution Overview

Problem

Existing methods for determining tire tread depth are inaccurate, particularly for worn tires, as they fail to provide high accuracy and reliability.

Innovation Solution

A method that involves deriving an analytical parameter from the acceleration of a vehicle tire, using a calibration curve for precise assignment of tread depth, allowing for accurate determination over the entire range, including small tread depths, by measuring acceleration at specific points and forming characteristic curves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If previous evaluation methods are used to determine tread depth from radial acceleration, then the determination can be performed without additional sensors, but the accuracy is very poor particularly when the tire is worn

Engineering Contradiction:
Improvetread depth determination accuracyVSAvoiddetermination reliability for worn tires
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent transforms the acceleration signal through multiple parameter changes: forming a characteristic curve over time or rolling circumference, deriving analytical parameters (zero crossings, extrema, integrals), and mapping these to tread depth via calibration curves. This multi-stage parameter transformation converts the raw acceleration data into progressively more meaningful metrics that accurately reflect tread depth even when worn

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces several intermediary elements: a tire sensor module as intermediary between the tire and measurement system, characteristic curves as intermediaries between raw acceleration and tread depth, and calibration curves as intermediaries that map analytical parameters to actual tread depth values. These intermediaries enable accurate measurement that directly comparing raw acceleration to tread depth would not achieve

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the acceleration measurement covers the entire tire contact area, then the analytical parameter determination becomes more accurate, but the observation window and processing complexity increase

Engineering Contradiction:
Improveanalytical parameter accuracyVSAvoidobservation window selection complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-defining the observation window to cover the tire contact area and transition areas before measurement begins. The calibration curves are pre-determined for different tire types and conditions. This preliminary setup enables accurate measurement without real-time complexity, as the measurement process simply needs to identify when the tire enters and exits the contact area within the pre-defined window

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3341222B1Method for determining a tread depth of a tyre profile and control device therefore
Publication Date: 2022.07.06 CONTINENTAL REIFEN DEUTSCHLAND GMBH
  • EP3341222B1 patent drawingFigure 1
  • EP3341222B1 patent drawingFigure 2~2a
  • EP3341222B1 patent drawingFigure 2b~3

AI summary

The invention relates to a method for determining a tread depth (D) of a tyre profile, said method comprising the following steps: a) detecting an acceleration (ar, at) of a measuring point (MP) on an inner side (2) of a vehicle tyre (1), wherein a change in the acceleration (ar, at) of the measuring point (MP) within a viewing window caused by contacting the vehicle tyre (1) with a road (8) is detected, b) deducing at least one analytical variable characterizing the course of the detected acceleration (a r, at) wherein the at least one analytical variable characterizes the non-periodic course of the detected acceleration (ar, at) within a tyre revolution, c) determining the tread depth in accordance with the at least one analytical characteristic variable, wherein the dependency between the analytical characteristic and the tread depth is a consequence of a calibration curve and the calibration curve of the deduced analytical characteristic is associated with a tread depth.