Hyperspectral Composite Inspection via Modal Dispersion

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Solution Overview

Problem

Hyperspectral cameras used in composite manufacturing face challenges with slow image processing times due to large data volumes and susceptibility to signal noise, making them inefficient for in-process evaluations.

Innovation Solution

A spectral sensing system utilizing a multi-mode fiber to time-shift and bin wavelength components, allowing for efficient sampling and identification of material types or conditions on a composite workpiece surface, reducing processing time and noise interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If typical hyperspectral cameras are used to collect spectral data at every pixel, then comprehensive material analysis capability is improved, but image processing time increases significantly

Engineering Contradiction:
Improvematerial analysis capabilityVSAvoidimage processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The spectrum at each pixel is segmented into multiple wavelength bins, with each bin processed independently through separate optical paths and detectors. This segmentation transforms the complex full-spectrum analysis into parallel simpler measurements, reducing processing time while maintaining material identification capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of analyzing the complete spectral range at every pixel, the system performs partial spectral analysis by measuring only specific wavelength bins. This partial action approach provides sufficient information for contaminant detection without the computational burden of full hyperspectral processing

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If complex hyperspectral imaging arrays are used, then spectral detection capability is improved, but device complexity and computer resources required increase

Engineering Contradiction:
Improvespectral detection capabilityVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The spectral detection system is segmented into multiple discrete wavelength channels, each handled by simple optical components rather than a complex hyperspectral imaging array. This segmentation reduces device complexity while maintaining spectral detection capability through parallel simplified measurement paths

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The complex mechanical hyperspectral imaging array is replaced with a stationary optical system using fixed wavelength-selective filters and detectors. This substitution eliminates the need for moving parts and complex image processing hardware, reducing device complexity while preserving spectral analysis functionality

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

3Quantity of substance

If hyperspectral cameras are used in ambient light environments, then comprehensive spectral data collection is improved, but signal noise from ambient light increases

Engineering Contradiction:
Improvespectral data volumeVSAvoidsignal noise
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The ambient light noise is segmented and addressed individually for each wavelength bin through separate optical paths. This allows targeted noise filtering at each wavelength channel, reducing the overall noise impact while maintaining comprehensive spectral data collection across multiple wavelength ranges

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses periodic modulation of the light source and synchronous detection at each wavelength bin to distinguish signal from ambient light noise. This periodic action enables temporal separation of the desired spectral signal from continuous ambient light interference, reducing noise while maintaining data quality

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 significantly reduces processing time and simplifies the system, enabling faster in-process non-destructive evaluation without slowing manufacturing, while minimizing the need for extensive computer resources and noise reduction measures.

Implementation Method 1

time shifting the multiple wavelength components with respect to each other by passing the response through the multi-mode fiber

Methodology Applied
Scientific EffectModal dispersion: Dispersion (of waves)

Data Source

PatentEP3404381B1System and method for high speed low noise in-process hyperspectral non-destructive evaluation for rapid composite manufacturing
Publication Date: 2024.12.04 THE BOEING CO
  • EP3404381B1 patent drawingFigure 1
  • EP3404381B1 patent drawingFigure 2
  • EP3404381B1 patent drawingFigure 3

AI summary

A method may include scanning a surface of a composite workpiece with multiple electromagnetic pulses, each of the multiple electromagnetic pulses being associated with a respective location on the surface of the composite workpiece. The method may further include, for each respective location on the surface of the composite workpiece, receiving a response to one of the multiple electromagnetic pulses at a multi-mode fiber, the response including multiple wavelength components, time shifting the multiple wavelength components with respect to each other by passing the response through the multi-mode fiber to produce a wavelength-binned pulse, sampling the wavelength-binned pulse at time intervals corresponding to the multiple wavelength components to determine a set of wavelength intensity levels corresponding to the multiple wavelength components, and identifying a type or condition of material at the respective location on the surface of the composite workpiece based on the set of wavelength intensity levels.