Tyre Crown Motion Spectrum Filtering for Wear Detection

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Solution Overview

Problem

Existing methods for monitoring tire wear and structural integrity, such as those disclosed in EP2813378, EP3330106, EP3210799, and EP2837510, rely on unprocessed accelerometric or speed signals, which can introduce noise from macro-deformations, reducing the reliability and accuracy of tire status evaluation.

Innovation Solution

A method and system that filter the motion signal corresponding to the tire's footprint area to isolate frequency information related to the tire's vibration modes, using techniques like window functions to reduce noise and improve spectral analysis, allowing for precise determination of tire status through filtered frequency spectra.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If unprocessed accelerometric or speed signals are used for tire status monitoring, then the system complexity is reduced, but the measurement precision and reliability deteriorate due to noise from macro-deformations

Engineering Contradiction:
Improvesignal processing complexityVSAvoidtire status evaluation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The signal processing is segmented into distinct stages: pre-processing (filtering macro-deformation noise), frequency transformation (FFT to obtain spectrum), and analysis (identifying vibration mode frequencies). This segmentation allows targeted noise removal while preserving useful signal components, resolving the contradiction between simplicity and precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary filtering actions before frequency analysis to remove noise components related to macro-deformations. By pre-processing the signal to eliminate harmful noise before the main analysis stage, the system achieves high measurement precision without requiring overly complex processing during the main evaluation phase.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If the motion signal corresponding to the footprint area is filtered, then the measurement precision of vibration mode frequencies is improved, but the device complexity increases due to additional signal processing steps

Engineering Contradiction:
Improvevibration mode frequency accuracyVSAvoidsignal processing system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes the specific noise components corresponding to the footprint area from the motion signal. By identifying and extracting only the harmful frequency components related to macro-deformations while preserving the vibration mode frequencies, the system achieves high precision without requiring complete signal reconstruction or overly complex processing systems.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces intermediate processing steps (filtering and frequency transformation) that act as mediators between the raw signal and the final analysis. These intermediary processes systematically transform the signal domain, making it easier to separate useful information from noise while maintaining manageable system complexity through standardized signal processing techniques.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If frequency processing is applied to isolate vibration modes, then the reliability of tire status monitoring is enhanced, but the loss of time increases due to additional processing steps

Engineering Contradiction:
Improvetire status monitoring reliabilityVSAvoidsignal processing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent employs periodic frequency analysis at selected time intervals rather than continuous processing. By performing FFT and vibration mode identification periodically at strategically chosen moments, the system maintains high reliability for detecting tire status changes while minimizing the total processing time required, thus resolving the contradiction between reliability and time loss.

Inventive Principle:
Principle #19Periodic action

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 approach enhances the reliability and accuracy of tire status monitoring by isolating tire-specific vibration modes, enabling effective detection of wear and structural integrity changes, such as tread wear and damage, through filtered frequency analysis.

Implementation Method 1

a frequency processing of a motion signal representative of a motion of a crown portion (31) of the tyre (99), in which the part of the signal corresponding at least to each passage of the crown portion (31) in the footprint area (13) of the tyre (99) is previously filtered

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

obtaining a frequency spectrum of the filtered motion signal; determining a status of the tyre (99) on the basis of the frequency spectrum

Methodology Applied
Scientific EffectFrequency spectrum analysis:

Data Source

PatentEP4271577B1Method and system for monitoring a status of a tyre
Publication Date: 2024.12.11 PIRELLI TYRE SPA
  • EP4271577B1 patent drawingFigure 1
  • EP4271577B1 patent drawingFigure 2
  • EP4271577B1 patent drawingFigure 3

AI summary

Method (200), and related system (100), for monitoring a status of a tyre (99) fitted on a vehicle, the method comprising: - with the vehicle in motion and the tyre (99) in rotation, acquiring (3, 6) a motion signal representative of a motion of a crown portion (31) of the tyre (99), wherein the motion signal temporally corresponds to a plurality of turns of the tyre (99); - filtering (15, 42) from the motion signal a part of the motion signal temporally corresponding at least to each passage of the crown portion (31) in a footprint area of the tyre (99), for obtaining a filtered motion signal; - obtaining (4, 7) a frequency spectrum of the filtered motion signal; - determining (11 ) the status of the tyre (99) based on the frequency spectrum.