Eggshell crack detection based on the time-domain acoustic signal of rolling eggs on a step-plate

• Eggs roll over a plate which has seven steps.
• Areas of impacting sound signals of eggs rolling down the seven steps are calculated.
• Discriminant analysis based on Mahalanobis distance was used to analyze the areas.
• ROC curves and AUCs are applied to evaluate this detection method.
• A new eggshell crack detection method is proposed whose structure was much simpler than present detection methods.

Crack in the shell of eggs was detected by rolling eggs on a plate that had seven steps. This produced seven separate acoustic signals to produce characteristic vectors. The vectors from intact and cracked eggs were analyzed using the Mahalanobis distance so that intact and cracked eggs could be separated. The receiver operating characteristic curve and area under curve were employed to determine the discrimination threshold and optimize the step number – in this case being six. The analysis indicated that the method proposed in this paper could detect 90% of the cracks with a 10% false rejection.