哈密瓜糖度可见近红外光谱在线检测系统设计研究

发布时间：2018-01-26 04:30

本文关键词： 近红外在线检测哈密瓜糖度　出处：《石河子大学》2017年硕士论文　论文类型：学位论文

【摘要】：哈密瓜作为新疆的特色水果,深受人们的喜爱。近年来,哈密瓜每年的出口量逐年增加,但其产值却未增长。哈密瓜在田间地头不经过任何检测处理就直接进入市场售卖,将会影响哈密瓜的品质及售卖价格,不能做到按质定价。本研究以新疆特色水果哈密瓜为研究对象,以哈密瓜糖度作为检测指标,设计并搭建了基于可见近红外光谱技术的哈密瓜糖度在线检测系统,该系统主要包含硬件部分和光谱采集软件部分的设计。为验证设计搭建的检测系统的可行性和有效性,基于该平台进行一系列的试验研究。同时运用不同的建模方法和不同的光谱预处理方法对哈密瓜样品光谱及糖度进行建模研究分析。本文主要完成的工作及得出的结论如下:(1)设计并搭建了哈密瓜糖度可见近红外光谱在线检测系统,该系统主要包含硬件和光谱采集软件两部分的设计。硬件部分完成了输送装置、光照模块、光谱采集装置中相关仪器的选型及相关部件的设计;光谱采集软件完成了光谱采集相关功能模块的设计。(2)完成哈密瓜糖度可见近红外光谱在线检测系统的测试与集成,并进行了在线试验。利用该系统采集了哈密瓜三种不同速度下(0.1235m/s、0.15m/s、0.19675m/s)的在线光谱数据,采用多元散射校正(MSC)、标准正态变量变换(SNV)、导数(SD)及其组合的方法对采集到的哈密瓜在线光谱进行预处理,建立偏最小二乘法(PLS)模型分析不同预处理方法对其建模精度的影响,综合对比三种速度下的偏最小二乘法(PLS)建模结果可得,选取的较优预处理方法为SNV和SD结合的方法,选取的较优在线光谱采集速度为0.1235m/s。(3)根据选取的较优在线速度,建立了SMLR模型,尽量减少波段数量,为下一步快速检测提供支持。结果表明,波段数在10到15时的限制条件下,波段数量为15时,所建模型效果相对较好,此时的相关系数rcv和交互验证均方根误差RMSECV分别为0.6187和0.741。模型所选择的15个波段分别为437.76nm,476.33nm,536.11nm,580.47nm,593.97nm,619.04nm,638.32nm,659.54nm,667.25nm,673.03nm,703.89nm,752.10nm,819.60nm,865.88nm,925.66nm。(4)通过在线试验验证了设计搭建的哈密瓜糖度可见近红外在线检测系统具有一定的可行性。
[Abstract]:Hami melon, as the characteristic fruit of Xinjiang, is deeply loved by people. In recent years, the annual export volume of Hami melon has increased year by year. But its output value has not increased. Hami melon in the field without any test treatment directly into the market, will affect the quality and sale price of Hami melon. This study took Hami melon as the research object and the sugar content of Hami melon as the detection index. An on-line detection system for sugar content of Hami melon was designed and built based on visible near infrared spectroscopy. The system mainly includes the design of hardware and spectrum acquisition software. The feasibility and effectiveness of the detection system designed to verify the design. Based on this platform, a series of experiments were carried out. At the same time, different modeling methods and different spectral pretreatment methods were used to model and analyze the spectrum and sugar content of Hami melon sample. The conclusions are as follows:. (. 1) the on-line detection system of sugar content of Hami melon by visible near infrared spectroscopy was designed and built. The system mainly includes the design of hardware and spectrum acquisition software. The hardware part completes the selection of related instruments and the design of related parts in the transport device, illumination module, spectral acquisition device. Spectral acquisition software completed the design of spectral acquisition related function module. 2) completed the sugar content of Hami melon visible near infrared spectrum on-line detection system testing and integration. The on-line spectral data of 0.1235m / s 0.15m / s 0.19675m / s of Hami melon were collected by using the system. Multivariate scattering correction (MSCT), standard normal variable transform (SNV), derivative SDI) and their combination were used to preprocess the collected on-line spectrum of Hami melon. The partial least square (PLS) model is established to analyze the influence of different preprocessing methods on the modeling accuracy. The optimal pretreatment method is the combination of SNV and SD, and the optimal on-line spectral acquisition speed is 0.1235 m / s. The SMLR model is established to reduce the number of bands as much as possible and to provide support for the next rapid detection. The results show that the number of bands is 15:00 when the number of bands is limited from 10 to 15:00. The effect of the model is relatively good. The correlation coefficient rcv and the root-mean-square error (RMSECV) of cross-validation are 0.6187 and 0.741 respectively. The 15 bands selected by the model are 437.76 nm. 476.33nm,536.11nm,580.47nm,593.97nm,619.04nm,638.32nm,659.54nm. 667.25nm,673.03nm,703.89nm,752.10nm,819.60nm,865.88nm. 925.66 nm.f.) the feasibility of the system was verified by on-line test.
【学位授予单位】：石河子大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S652.1;TP274

【参考文献】