【作者】 杨娜；

【导师】 徐喆；

【作者基本信息】 北京工业大学 ， 控制科学与工程， 2011， 硕士

【摘要】 便携式光谱仪可对农作物的光谱数据进行实时的在线测量和预处理,不受室内外条件的限制,进而分析农作物的品质参数。光谱分析研究主要集中在确定作物农学参数与光谱反射数据之间的定性及定量关系,从而建立作物农学参数的光谱诊断和预测模型。本论文在分析国内外便携式光谱仪发展现状及趋势的基础上,根据作物农学参数测量对微型光谱仪智能化的需要,应用嵌入式系统技术和光谱分析技术,设计了便携式光谱仪的测量操作软件系统,以满足光谱仪操作和维护简单的使用要求,论文完成的主要工作包括:(1)论文论述了微型光谱仪软件测量系统的发展现状及趋势,结合光谱分析技术在农作物参数测量中的应用,论证了嵌入式光谱仪实现软件系统智能化的必要性。在现有光谱仪嵌入式系统的基础上,选用QT/Embedded进行应用软件开发,实现了触摸屏对该应用程序的支持,并对文件系统作出相应修改。(2)针对光谱仪的应用需求,进行了软件架构设计、人机交互界面设计,实现了光谱数据采集、谱图实时显示和多种数据处理的功能,满足了便携式光谱仪对于光谱数据分析的基本需求,实现了光谱采集的智能化。(3)基于PC机构建了光谱仪数据分析系统,主要包括白板校正、基线校正、光谱数据去噪。同时,完成不同光谱去噪的算法比较。并将田间试验获取的数据在该系统中进行处理。在算法研究中,针对便携式光谱仪的信号特点,使用小波降噪算法、小波包降噪算法和不同的阈值化方法分别对含有噪声的光谱信号进行预处理,仿真结果表明:新阈值的小波包降噪算法信噪比提高到37.5986,均方根误差降低为2.6104。(4)本文论述了光谱分析技术在农作物参数测量中的应用,主要包括该技术反映的农学参数,理论基础,同时综述了利用光谱数据反演农学参数方法的研究进展,并采用经验模型法中最小二乘法进行农学模型的初建。更多还原

【Abstract】 Portable spectrometer can measure and preprocess spectral data of crops in real time from indoor and outdoor, to analyze crops’quality parameters. Spectral studies focused on determining relationship between crop agronomic parameters and spectral data, and establishing the spectral prediction model for agronomic parameters. Based on the development of spectrometer in domestic and international, this paper analyzed the needs of intelligent micro-spectrometer. Embedded system and spectrum analysis technique were applied in portable spectrometer, measurement operation software system was designed to meet easy operation and maintenance requirements. Obtained research results are as follows:Firstly, portable spectrometer’s software measurement system was analyzed. With applications of spectrum analysis for crop parameters, the necessity for intellectualization of software was demonstrated. Based on embedded system of the spectrometer, selected QTE to design and develop software, achieve touch-screen‘s support for software, and make consequential changes to the file system.Secondly, the software architecture and human-computer interface software were designed for spectroscopy applications, and functions of spectral data acquisition, real-time display and a variety of data processing were achieved. The software met the basic needs for spectral analysis, realize intellectualization of spectrum collection.Thirdly, based on PC spectrometer data analysis system, including white board correction, baseline correction, spectral data denoising, was constructed; and different spectral denoising algorithms were compared. Datas from field experimental were processed in the system .In the algorithms research, for the signal characteristics of portable spectrometer, noisy signals were preprocessed using wavelet, wavelet packet and different threshold noise eliminating algorithm Simulation results indicate:the SNR of new threshold of wavelet packet algorithm increased to 37.5986, RMSE error reduced to 2.6104 .At the end, applications of spectral analysis technology for crop parameters were discussed, including the agronomic parameters,the theoretical basis and summary the research progress on inversion methods of Agronomy by spectral data, and the agronomy model was built by least squares method in empirical model.更多还原