【摘要】 为达无损检测西瓜糖度目的,本研究在自主搭建的声学检测台上采集西瓜声学信号,提取声振动从敲击点传到接收点过程中声透过率参数(δ)。利用Matlab软件中的线性回归函数,将δ与西瓜糖度分别做线性回归,得到1 024个相关系数。从中选取相关系数前20位的声透过率值,借助软件中多元线性回归函数建立多元线性回归方程。研究比较不同敲击点和信号接收点组合所建模型的预测值和实测值相关系数(R),最高可达0.884 2。试验结果表明,敲击点和接收点位于赤道部位能获得较好的测定模型。更多还原

【Abstract】 To detect the watermelon sugar content nondestructively,an acoustic system is set up the acoustic penetration ratio(δ) from the signal tapping point to the receiving point can be calculated from the amplitude spectrum.With the help of the regression function in Matlab,1 024 correlation coefficients can be obtained from the regression analysis of δ and sugar content. The top 20 δ values are chosen to be analyzed with the sugar content in the multiple liner regression function.Then the correlation coefficients between the predictive value and the real value of different tapping-receiving groups are compared,with the highest R value 0.884 2.The results show that the equator part has the relatively better results.更多还原