Method suitable for evaluating fruit hardness of pears with irregular fruit shapes

Abstract

The invention discloses a method suitable for evaluating the fruit hardness of pears with irregular fruit shapes. The method comprises the following specific steps: 1, preparing a pear sample; 2, performing modal analysis on the pear test; 3, performing finite element modal analysis on the pears; 4, extracting a fruit shape contour; 5, calculating a Fourier descriptor of the fruit shape contour sequence of the pear; 6, performing normalization processing on the inherent frequency of the pear; 7, analyzing the influence of the fruit shapes of the pears on the resonant frequency; 8, constructing a new hardness evaluation index; and 9, analyzing the evaluation capability of the new hardness evaluation index on the hardness change of the pears. According to the method, Fourier descriptors are adopted to describe the characteristics of the fruit shapes of the pears, and the description capability of the Fourier descriptors on the fruit shapes of the pears is analyzed; a finite element modal calculation result is corrected by using a test modal analysis result to obtain an effective finite element result; and a finite element modal analysis method is used for analyzing an influence rule of the Fourier descriptor on a pear modal frequency, and then a pear hardness evaluation index suitable for evaluating the irregular fruit shape is constructed based on the resonant frequency and the Fourier descriptor, so that accurate evaluation of the hardness of the pear with the irregular fruit shape is realized, and a research basis and a strategy are provided for an on-line hardness detection technology of pear fruits by a resonance method in the future.

Description

technical field [0001] The invention relates to hardness evaluation of irregular fruit-shaped pome, in particular to a hardness evaluation index of irregular fruit-shaped pome based on Fourier descriptors and resonance frequencies. Background technique [0002] China is a big country in the production and consumption of pome fruit, with a large planting area, wide area and rich varieties of pome fruit. The annual consumption of pome fruit in my country is second only to apples and citrus. In recent years, with the improvement of national consumption level, consumers have higher requirements for the quality of pome fruit. Hardness is one of the important internal quality indicators of pome fruit, which reflects the maturity, taste, texture and resistance to mechanical damage of pome fruit, and is an important indicator for internal quality inspection of pome fruit. At present, my country usually relies on the experience of industrial workers to judge the firmness of pome fru...

AI Technical Summary

Problems solved by technology

Most fruit shape description methods are single-feature description shape description methods, which are not enough to fully describe the shape characteristics of fruits and vegetables. For pears with complex and changeable fruit shapes (such as pears), it is not suitable to use simple shape feature parameter descriptions.

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