Defect Detection in Pre-impregnated Fiber Materials Using Infrared Imaging

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Metrological detection of manufacturing deviations in pre-impregnated fiber materials using light projection methods is hindered by complex reflection behavior due to matrix material deposits, resulting in insufficient measurement accuracy and detection rate.

Innovation Solution

Employing image sensors that record the fiber material surface in a wavelength spectrum outside the visible spectrum, such as infrared or ultraviolet, to generate digital image data that distinguish between fiber and matrix material reflections, enabling the detection of defects like air pockets, gaps, and foreign bodies, and using a multi-camera system to generate three-dimensional surface information for improved defect detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If light projection methods are used for metrological detection, then automated defect detection is achieved, but measurement accuracy deteriorates due to complex reflection behavior from matrix material deposits

Engineering Contradiction:

Improveautomated defect detectionVSAvoidmeasurement accuracy

Core Design Contradiction:

Extent of automationVSMeasurement precision

Solution Approach 1:

The patent changes the wavelength parameter of the light source from visible spectrum to infrared spectrum. This parameter change allows the light to penetrate through or bypass the matrix material deposits that cause complex reflection behavior, thereby restoring measurement accuracy while maintaining automated detection capability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediate substance (infrared light) that acts as a mediator between the detection system and the fiber material surface. This intermediate wavelength of light interacts differently with the matrix material deposits, reducing their harmful reflective effects and enabling accurate defect detection

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If manual inspection is used to ensure quality, then detection reliability improves, but productivity deteriorates due to extensive plant downtime

Engineering Contradiction:

Improvedetection reliabilityVSAvoidplant downtime

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent replaces the manual mechanical inspection system with an automated optical detection system using infrared light. This substitution eliminates the need for manual intervention, maintaining high detection reliability while completely eliminating the plant downtime associated with manual inspection

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The automated detection system performs quality inspection independently without human intervention. The system self-evaluates the fiber material quality by analyzing infrared light reflections, thereby maintaining reliability while freeing up production time

Inventive Principle:

Principle #25Self-service

3Device complexity

If visible light is used for imaging, then image capture is simple, but defect detection rate deteriorates due to diffuse reflection from matrix material

Engineering Contradiction:

Improveimaging system simplicityVSAvoiddefect detection rate

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent changes the wavelength parameter from visible light to infrared light. This change in electromagnetic radiation parameter allows the light to interact differently with the matrix material, reducing diffuse reflection and enabling accurate defect detection while maintaining relatively simple imaging system architecture

Inventive Principle:

Principle #35Parameter changes

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 allows for reliable and automatic detection of defects in pre-impregnated fiber materials, enhancing the quality assurance of fiber composite components by improving the measurement accuracy and detection rate, enabling immediate identification and correction of errors during the laying process.

Implementation Method 1

the fiber material surface of the deposited, pre-impregnated fiber material is recorded by at least two image sensors of an imaging recording device in a wavelength spectrum outside the visible spectrum

Methodology Applied

Scientific EffectElectromagnetic radiation reflection: Reflection

Data Source

PatentEP3628473B1Method and device for determining defects in fibrous materials

Publication Date: 2022.02.09 DEUTSCHES ZENTRUM FÜR LUFT UND RAUMFAHRT E V

Figure 1
Figure 2

AI summary

A method for detecting defects in pre-impregnated fiber material (15) of a fiber composite material deposited on a tool for the production of a fiber composite component, the method comprising the following steps: - recording the fiber material surface of the deposited pre-impregnated fiber material (15) by means of at least one image sensor of an imaging recording device (19) in a wavelength spectrum outside the visible spectrum in order to generate digital image data of the fiber material surface; and - detecting a defect in the deposited pre-impregnated fiber material (15) as a function of the digital image data of the fiber material surface recorded by the recording device (19) using an evaluation unit (21).