Eggshell Crack Detection Using Self Mixing Laser Vibrometer
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Solution Overview
Problem
Existing methods are inadequate for quickly and accurately detecting cracks in large numbers of eggs and determining their location, severity, and characterization, especially in industrial settings like egg sorters, as they lack efficient criteria for yes/no crack determination and comprehensive characterization.
Innovation Solution
A method and apparatus using a Self Mixing Laser Vibrometer (SMLV) with laser light of specific wavelengths to scan and process eggshell deformation signals, analyzing amplitude and intensity fluctuations to obtain crack information, and comparing these signals with preset criteria for characterization and sorting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If resonance monitoring is performed for relatively long periods of time after excitation, then crack detection sensitivity is improved, but productivity and processing time deteriorate
Solution Approach 1:
The patent applies preliminary action by analyzing the mixed signal during the deformation process itself rather than waiting for resonance to decay. The signal processing occurs in real-time during the brief deformation event, allowing crack detection without extended monitoring periods. This resolves the contradiction by performing the measurement action during the excitation phase rather than requiring post-excitation resonance monitoring.
2Measurement precision
If the entire eggshell surface is scanned to determine crack location, then measurement precision is improved, but device complexity and processing requirements increase
Solution Approach 1:
The patent extracts crack location information from the temporal and frequency characteristics of the mixed signal during deformation, rather than requiring spatial scanning across the entire eggshell surface. By analyzing when and how the mixed signal changes during deformation at a single location, the system determines crack presence and characteristics without complex multi-point scanning systems.
3Reliability
If clear criteria for yes/no crack determination are established, then reliability is improved, but the complexity of signal processing increases
Solution Approach 1:
The patent transforms the complex mixed signal into simplified decision criteria by analyzing specific parameters such as the number of intensity fluctuations, zero-crossings, and frequency shifts during deformation. These parameter-based criteria provide clear yes/no crack determination thresholds that maintain high reliability while keeping the processing logic relatively simple and implementable.
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
Enables rapid and accurate characterization of eggshell conditions, preventing contamination and wear, and allowing for efficient sorting of eggs based on well-defined characteristics, with improved reliability and hygiene in industrial applications.
Implementation Method 1
the principle of 'self mixing' realised by a Self Mixing Laser Vibrometer (SMLV)
Implementation Method 2
the mixed signal is obtained with the aid of Doppler shift upon movement of the eggs
Implementation Method 3
deforming at least a first part S1 of the eggshell of such an egg... will spread through the egg and especially over the eggshell and thereby cause a vibration of the egg as a whole
Data Source
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AI summary
This invention relates to a method and an apparatus for characterizing eggshells of eggs, the eggs being supported, comprising: - deforming the eggshell, - scanning the eggshell with a laser beam of a Self Mixing Laser Vibrometer (SMLV) with scanning signals, whereby a reflection light signal of reflection light is obtained, - processing scanning signal and the reflection signal with the SMLV, whereby a mixed signal with crack information is obtained, - during scanning moving the eggs relative to the SMLV, - comparing the signals with preset criteria and characteristics of such eggs, whereby comparative data are obtained, and - characterizing the eggshells on the basis of the comparative data.