Plasma CNC Cutting with In-Situ Spectral Metal Identification

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Solution Overview

Problem

The challenge of determining the metallurgical composition of metals, particularly steel, is complicated by inconsistent quality from multiple sources and the need for specialized equipment like ED-XRF technology, which is expensive and impractical for workshops, while plasma cutters face interference from electromagnetic radiation and heat.

Innovation Solution

A plasma CNC cutting machine integrated with a spectrometer captures spectra of the plasma arc's electromagnetic radiation, specifically in the UV range, to analyze the metallurgical composition of the workpiece in real-time, using a fiber optic cable to shield electronics and a collimator to filter interference, enabling simultaneous cutting and analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If ED-XRF technology is used for spectral analysis of steel, then measurement precision is improved, but device complexity and cost increase significantly

Engineering Contradiction:
Improvemetallurgical composition analysisVSAvoidspectral analysis equipment
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the spectral analysis function with the plasma cutting machine by integrating a spectrometer that captures electromagnetic radiation from the plasma arc. This merging eliminates the need for separate ED-XRF equipment, reducing device complexity and cost while maintaining measurement precision for metallurgical composition analysis.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The plasma arc serves dual purposes: it performs the cutting function and simultaneously provides the electromagnetic radiation source for spectral analysis. This multi-functionality allows the same energy source to both process the material and enable composition analysis, avoiding additional expensive equipment.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If plasma cutting is used for metalworking, then productivity is improved, but electromagnetic radiation and heat interfere with spectral analysis

Engineering Contradiction:
Improvemetal cutting efficiencyVSAvoidelectromagnetic radiation interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful electromagnetic radiation and heat from the plasma arc into a beneficial signal source for spectral analysis. The plasma arc's electromagnetic radiation, which was previously considered interference, is now captured by the spectrometer to determine metal composition, turning a harmful factor into the basis for analysis.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The spectrometer acts as an intermediary device that selectively captures electromagnetic radiation from the plasma arc in specific wavelength ranges. It mediates between the high-energy plasma environment and the analysis system, filtering and processing the radiation to extract compositional information while protecting sensitive electronics.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If traditional chemical analysis is used to determine metallurgical components, then measurement precision is improved, but loss of time increases due to laboratory procedures

Engineering Contradiction:
Improvemetallurgical compositionVSAvoidanalysis time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces traditional mechanical/chemical laboratory analysis methods with optical/spectral analysis. Instead of physical sample preparation, chemical reagents, and laboratory procedures, the system uses electromagnetic radiation capture and spectral processing to rapidly determine composition, maintaining precision while dramatically reducing time loss.

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

Solution Approach 2:

The spectral analysis is performed in real-time during the plasma cutting process itself, rather than as a separate subsequent step. The composition determination occurs while the cutting is happening, eliminating post-processing time and enabling immediate quality verification.

Inventive Principle:
Principle #10Preliminary action

4Loss of time

If spectral analysis is performed during plasma cutting, then loss of time is reduced, but measurement precision deteriorates due to background light and heat interference

Engineering Contradiction:
Improveanalysis timeVSAvoidspectral line detection
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The patent applies local quality by focusing the spectral analysis on specific wavelength ranges where characteristic spectral lines of metal elements appear. The system selectively captures and analyzes only the relevant portions of the electromagnetic spectrum, filtering out background radiation and heat interference to maintain measurement precision during rapid analysis.

Inventive Principle:
Principle #3Local quality

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 integration allows for rapid, cost-effective, and practical metallurgical analysis of metals during cutting, identifying primary alloy constituents and impurities, ensuring compliance with specifications and preventing waste from incorrect compositions.

Implementation Method 1

captures spectra of the plasma arc's electromagnetic radiation

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

spectral analysis to determine metallurgical composition of metal

Methodology Applied
Scientific EffectSpectral analysis: Absorption Spectroscopy

Implementation Method 3

using a fiber optic cable to shield electronics

Methodology Applied
Scientific EffectOptical fiber transmission: Optical Fibre

Implementation Method 4

a collimator to filter interference

Methodology Applied
Scientific EffectCollimation: Lens

Implementation Method 5

a plasma formed of a gas heated by an electric arc serves to conduct electricity into, and remove melted metal from, a metal workpiece

Methodology Applied
Scientific EffectPlasma: Plasma

Implementation Method 6

a plasma formed of a gas heated by an electric arc

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Data Source

PatentEP3746251B1Metal analyzing plasma CNC cutting machine and associated methods
Publication Date: 2026.03.18 FAGAN MATTHEW
  • EP3746251B1 patent drawingFigure 1
  • EP3746251B1 patent drawingFigure 1A
  • EP3746251B1 patent drawingFigure 2

AI summary

A plasma computer numerically controlled (CNC) cutting machine is controlled by a computer s. In an embodiment, the computer executes a CNC program to control movement of a plasma torch to cut parts from a workpiece while a spectrometer determines emissions spectra of light emitted in a brief time window as the torch begins to cut the workpiece. The spectrometer cooperates with the computer to analyze the metal as it is being cut by the CNC cutting machine and determine a composition. In embodiments, the composition is compared to an expected composition and saved in a database with identifying information; in a particular embodiment the database is queried to provide identifying information of metal having similar composition to the workpiece.