Metal canned product quality on-line detection method based on sound frequency-spectrum fitting

Abstract

The invention discloses a metal canned product quality on-line detection method based on sound frequency-spectrum fitting. The method comprises the following steps: applying excitation to the detected metal canned product to vibrate the product; acquiring the sound generated by the vibrations by using a microphone, sampling the acquired sound signal to obtain a digitized sound signal; processing the sound signal to obtain a sound signal frequency spectrum; carrying out curve fitting on the sound signal frequency spectrum to acquire a curve function and a coefficient set thereof {C}; normalizing {C} to obtain a new coefficient set {C'}; using {C'} as the input parameter of the product quality computation model to acquire the model operation result product quality R; computing the absolute value |D| of the difference between R and qualified product standard value delta; and if |D| is less than the threshold T, determining the detected product is qualified, and contrarily, determining the detected product is unqualified. The method can implement on-line high-speed detection on the metal canned product, effectively avoids the influence of the production technique difference of metal cans and the changes in the distance between the microphone probe and metal can on the detection result, and obviously enhances the detection accuracy.

Description

technical field [0001] The invention relates to the field of quality detection of metal canned products, and more specifically relates to an online detection method for the quality of metal canned products based on sound spectrum fitting. Background technique [0002] Unqualified products will not only cause the same batch of products to be recalled forcibly, bring huge losses to the manufacturer, and affect the reputation of the manufacturer, but also may cause a series of dangerous situations when using unqualified products. Therefore, it is of great significance to study product quality inspection, which can detect defective products before leaving the factory, avoid business losses and ensure consumer safety. Metal cans are generally used as containers to package products, which can play the role of sealing and aesthetics. They are widely used in the food industry. Unqualified metal cans may cause food quality problems. Once unqualified food is eaten by mistake, it is ve...

AI Technical Summary

Problems solved by technology

[0010] Although the above two schemes use the frequency domain information of the sound, they simply select the frequency domain peak value and its frequency as the basis for judging the inspected product. The difference in the production process of the metal can and the change in the distance between the microphone probe and the metal can have a significant impact on the quality of the product. The test results are affected

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