【作者】 王俊； 于勇； 姜瑞涉；

【Author】 J. Wang Y. Yu R. S. Jiang (Department of Agricultural Engineering, Zhejiang University, 268 Kaixuan Road, Hangzhou 310029, China P R )

【机构】 浙江大学生物系统工程系；

【摘要】 将有裂纹鸡蛋和无裂纹鸡蛋进行了敲击激励后,用加速度传感器获取时域特性信号,然后进行信号频域特征分析。结果表明:蛋壳无裂纹蛋的频域特征曲线有规律性,表现出有一个较明显的主频率值,峰值突出;有蛋壳裂纹蛋频域特征曲线无规律性,没有明显的主频率值,峰值较紊乱;且有裂纹蛋不同测点的频域特性有较大差异。提出了检测鸡蛋裂纹的主要因素如:主频率值、功率谱平均值、归一化平均值、X轴及Y轴质心等。主频率值、功率谱平均值、归一化平均值等可以来评价鸡蛋有无裂纹。采用主频率值、功率谱归一化平均值来评价时精度较高。更多还原

【Abstract】 In this research, an experimental system was set up to generate the impact force, measure the response signal, and analyse the frequency spectrum. The eggshell hairline crack were detected by the based on the analysis of the dynamically measured frequency response of an egg excited with a light mechanical impact on different locations of the eggshell. As a result of the analysis, the one dominant resonance frequency can be observed and the frequency value is lower in the intact eggs. From the cracked eggs, the magnitudes of some peak frequency were closer, and the frequency value is higher. The resonant frequency spectra and the dominant frequency variation are dependent on the relative position of excitation point towards the location of the crack on the shell. The excitation resonant frequency characteristic of crack egg may be consistent with that of intact egg, if the detect point was far from the crack position. Four variables were found to be significant for classifying eggs, which including dominant resonant frequency, normalization average of frequency spectrum, average of frequency spectrum, and average x- and y-coordinates of centroid. The variables of dominant frequency, average or normalization average of frequency spectrum could be used for classifying the intact and cracked eggs, and the variables of dominant frequency and normalization average of frequency spectrum were more precise than others in classification.更多还原