3D Particle Shape Characterization via Projection Coefficients

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Solution Overview

Problem

Current methods for evaluating the morphology of particles, particularly in railway ballast, are insufficiently precise due to their reliance on two-dimensional imaging, which fails to accurately capture the complex shape of particles, leading to incomplete assessment of particle properties and wear.

Innovation Solution

An automated particle size measurement process that acquires a cloud of three-dimensional points of a particle's surface using an optical device, characterizes the global shape using projection coefficients on a determined projection base, and evaluates morphological deformation by comparing these coefficients with a reference population.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If two-dimensional imaging methods are used to measure particle size, then the measurement process is simple and fast, but the precision of particle shape characterization is insufficient

Engineering Contradiction:
Improveparticle shape characterization precisionVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transitions from two-dimensional imaging to three-dimensional point cloud acquisition, enabling comprehensive characterization of particle shape, surface area, and volume. The optical device captures multiple points in three-dimensional space to reconstruct the particle geometry, resolving the contradiction by adding dimensional information without significantly increasing system complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent creates a digital copy of the particle's three-dimensional surface through point cloud acquisition. This digital representation allows precise measurement and analysis of particle morphology without physical contact or complex mechanical measurement systems, maintaining simplicity while improving precision.

Inventive Principle:
Principle #26Copying

2Measurement precision

If automated three-dimensional measurement methods are implemented, then particle shape characterization precision is improved, but the measurement time and processing complexity increase

Engineering Contradiction:
Improveparticle morphology assessment precisionVSAvoidmeasurement and processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces complex mechanical measurement systems with an optical device that captures three-dimensional point clouds. This substitution enables automated, high-precision measurement of particle morphology without time-consuming mechanical analysis, reducing measurement time while maintaining or improving precision through digital processing.

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

3Reliability

If reference particle databases are established for comparison, then the accuracy of wear assessment is improved, but the complexity of data processing and comparison increases

Engineering Contradiction:
Improvewear assessment accuracyVSAvoiddata processing system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent establishes a feedback mechanism by comparing measured particle point clouds against reference particle databases. This comparison provides quantitative feedback on wear and morphological changes, improving assessment reliability through systematic reference comparison while managing processing complexity through automated algorithms.

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

This method provides a precise characterization of particle shape, enabling accurate comparison of particle populations and quantification of wear, thereby improving the assessment of railway ballast quality and maintenance needs.

Implementation Method 1

acquisition of a three-dimensional point cloud of the surface of the particle to be examined by passing the said particle in front of an optical device

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3146309B1Method for automated particle size measurement of particles, and method for assessing the morphological deformation of a population of particles
Publication Date: 2022.08.10 SNCF RESEAU
  • EP3146309B1 patent drawingFigure 1~4
  • EP3146309B1 patent drawingFigure 5~6
  • EP3146309B1 patent drawing

AI summary

The invention relates to a method for automated particle size measurement of particles, which is essentially characterised in that it comprises at least the following steps: acquiring a three-dimensional scatterplot of the surface of the particle to be examined by passing said particle in front of an optical device (2); using the scatterplot to characterise the overall shape of the particle (4) by the play of projection coefficients CE on a projection base [F], said projection base [F] being determined by the steps of: acquiring a three-dimensional scatterplot of the surface of at least one reference particle by passing said particle (4,6) in front of an optical device (2,2a), reducing the characterisation of the surface of the reference particle (4,6) to a vector R with N dimensions from the cloud of points obtained in the preceding step, and determining the projection base [F] making it possible to characterise the overall shape of the reference particle by the play of the projection coefficients CE on said base [F]. The invention also relates to a method for assessing the morphological deformation of a population of q particles to be examined relative to a t population of p reference particles using the aforementioned automated particle size measurement method.