摘要
针对开口与未开口松子结构差异,利用声学测试系统,对开口松子与未开口松子声学特性进行测试,以区分开口与未开口松子。试验中,松子在一定高度下落,碰撞到陶瓷板,微音计接收到声音,输入计算机,利用计算机进行分析计算,得到波形图和频谱图。对开口松子与未开口松子的波形和频谱进行分析,计算其分形维。通过试验和分析计算,发现开口松子的波形分形维小于未开口松子分形维,开口松子波形分形维平均值为1.4097,而未开口松子波形分形维平均值1.6576;开口松子的频谱图分形维大于未开口松子,开口松子频谱分形维平均值为1.3497,未开口松子频谱分形维平均值为1.1846。松子波形和频谱的分形维可以作为用于判别松子是否开口的一个指标。
According to the structure differences of open pine nuts and closed pine nuts, the acoustical characteristics of them were tested in order to distinguish whether the pine nut was open or not. In the experiment, pine nuts dropped from a certain height, the impinging sound on ceramic board was collected by a microphone. The sound wave graph and frequency spectral curves were obtained while the impinging sound was analyzed by computer. Fractal dimension was calculated on sound wave graph and frequency spectral graph of open pine nuts and closed pine nuts. The result of test and analysis show that the sound wave fractal dimension of open pine nuts was smaller than that of closed pine nuts. The even value of the former was 1. 4097, while the latter was 1. 6576. And the frequency spectrum fractal dimension of open pine nuts was larger than that of closed pine nuts. The even value on the frequency spectrum fractal dimension of open pine nuts was 1. 3497 and the one of closed pine nuts was 1. 1846. Fractal dimension of sound wave and frequency spectrum could be used as an important index to distinguish whether the pine nut was open or not.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2006年第3期15-18,共4页
Transactions of the Chinese Society of Agricultural Engineering
关键词
松子
声学特性
频谱
分形维
pine nut
acoustical characteristics
frequency spectrum
fractal dimension
