激光诱导击穿光谱手持式仪器测控系统优化及地矿样品软件开发

发布时间：2018-01-25 03:27

本文关键词： 激光诱导击穿光谱测控系统主成分分析(Principal component analysis) 偏最小二乘回归(PLS-DA)　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：激光诱导击穿光谱(LIBS)技术是一种利用原子发射光谱进行物质元素检测的光谱分析技术,由于其具备实时原位分析、检测速度快、无需复杂样品前处理等诸多优点,已被广泛应用于多种不同领域。该技术利用一束高能激光脉冲,经过光学系统折射、聚焦等烧灼样品表面,在样品表面激发产生等离子体,并发射出含有物质元素信息的特征谱线信号,通过对所收集的光谱信号强度及波长信息进行分析,实现对样品组分的定性及定量分析。基于LIBS技术的仪器主要由激光器、光谱仪、光学器件、控制系统以及计算机等组成,该类型仪器具有原理简单、操作方便等优势,被越来越多的研究者所重视。本文在实验室原有台式LIBS仪器测控系统的基础上,对各控制部件进行优化,使其适用于手持式LIBS测控系统。同时,针对特定地矿勘探应用领域,开发具有一定数据处理功能的算法模块,使其更好的服务于野外地矿工作者,提高工作效率。本文的主要工作内容如下:(1)优化台式LIBS光谱仪测控系统软件,使其满足高能手持式LIBS光谱分析仪器测试需求手持式LIBS光谱分析仪不仅在大小、体积方面不同于台式LIBS光谱分析仪,而且在部件组成及各部件通讯连接方式方面也存在差异。当各部件型号发生改变时,开发及优化测控软件也需要相应的发生改变。在实验室原有插件式设计系统框架基础上,重新规划各个接口方式,扩展相应部件,使其适用于高能手持式LIBS测控系统。同时,对大量光谱数据进行实验优化,开发具有光谱数据定性定量分析功能模块,完成手持式LIBS测控系统软件的优化开发。在约2000次测试中,测控系统运行稳定无测控软件故障出现,有效控制各部件正常运行工作。(2)利用LIBS技术对地矿样品特征进行光谱特性分析,采用模式识别方法对样品进行分类,并实现定性软件开发研究地矿样品LIBS光谱特征信息,得到数量丰富的主量元素和微量元素的发射谱线,且谱线拥有较好的性噪比。不同物质由于其基质、元素含量不同,导致各个样品的LIBS光谱图存在差异,为模式识别提供了条件。本文采用无监督的主成分分析法提取大样品数据库中各个样品所占贡献率较大的主成分,对样品进行无监督分类识别。在Matlab平台上将主成分分析函数生成动态链接库,将数据格式从矩阵形式转化为NET平台能识别的数据格式。采用C#语言基于类型安全接口技术进行混合编程,首次将主成分分析算法应用于高能手持式LIBS测控分析软件中,实现未知样品主成分快速提取及定性软件混合开发。(3)地矿样品元素定量分析方法研究与定量软件开发通过大样本系统研究适合于地矿样品元素定量算法模型分析,为地矿勘探领域应用LIBS技术提供数据处理软件支持。本工作采用偏最小二乘回归的元素定量方法,能够有效地解决地矿样品标准样品库少于光谱变量个数的问题,采用LIBS全谱作为输入变量具有很好的拟合性能。通过实验优化,在Matlab平台生成DLL动态链接库。基于.NET框架开发的COM组件接口可与动态链接库进行兼容开发,因此采用C#语言调用函数DLL和MWArray.dll,实现混合编程,有效地将C#应用程序开发与数据处理功能结合在一起,提高了软件开发速度和效率。本文在优化高能手持式LIBS测控系统软件的同时,研究主成分分析和偏最小二乘回归分析算法,将其应用于手持式LIBS测控软件光谱数据处理中,不仅实现了各个部件的测控功能,同时研发了对光谱数据具有定性及定量分析功能的分析测控软件,成功的应用于地矿样品的定性及定量分析。
[Abstract]:Laser induced breakdown spectroscopy (LIBS) technology is a kind of material by atomic emission spectroscopy spectral element detection analysis technology, because of the real time and in situ analysis, fast detection speed, without complex sample pretreatment and many other advantages, has been widely used in various fields. A beam of high energy laser pulse using the technology, after the refractive optical system, focusing on the surface of the sample. The sample surface to generate plasma, and emits a line signal characteristics of material containing elements of information spectrum, through the analysis of the spectral signal intensity of the collected information and the wave length of samples, qualitative and quantitative analysis. The instrument is mainly composed of a laser LIBS technology. The spectrometer, based on optical devices, control system and computer, the instrument has simple principle, convenient operation and other advantages, more and more researchers are paying attention. Based on the original laboratory desktop LIBS measurement and control system, the control unit is optimized, which is suitable for handheld LIBS control system. At the same time, according to the specific geologic prospecting application development has certain algorithm module data processing function, make it better service in the field of Geology and mineral resources of workers, improve the work efficiency. The main work the contents of this paper are as follows: (1) the optimization of desktop LIBS spectrometer control software system, which can meet the high energy spectrum analysis instrument test requirements of handheld LIBS handheld LIBS spectrum analyzer not only in size, volume is different from desktop LIBS spectrum analyzer, and connected to the parts and components of communication are also different. When each component type change, development and optimization of control software also needs to be changed accordingly. In the basis of original laboratory frame plug-in design system On the re planning of the various interfaces, extensions of the corresponding components, which is suitable for high energy LIBS handheld control system. At the same time, a large number of experiments to optimize the spectral data, the development of functional modules. The qualitative and quantitative analysis of spectral data, optimize the development of handheld LIBS system software. In about 2000 test, measurement and control system is stable and no fault detection and control software, the effective control of all parts of the normal operation. (2) of spectral analysis on geological characteristics of samples by using LIBS technology, using pattern recognition method to classify samples, and realize the qualitative research software development geological samples LIBS spectral feature information obtained emission spectrum of major elements and trace elements in abundance and, the spectral line has a better signal-to-noise ratio. Because of the different material matrix elements in different samples, leading to the LIBS spectral differences in survival, to die Provide the conditions for recognition. This paper uses unsupervised principal component analysis method to extract each sample sample database for the principal component contribution rate is larger, the samples were unsupervised classification. The analysis function to generate the dynamic link library in the Matlab platform will be the principal component, the data format conversion from the matrix form for the NET platform can identify the format of the data. Using C# language type safety interface technology of mixed programming based on the first principal component analysis algorithm is applied to the high-energy handheld LIBS control and analysis software, realize the rapid extraction of unknown samples of main components and qualitative software development. (3) mixed method research and software development in Geological Samples by quantitative elemental quantitative model analysis algorithm suitable for large sample quantitative analysis of geological samples for mineral exploration field elements, the application of LIBS technology to provide data processing software support. This work. Using partial least squares regression quantitative analysis method, can effectively solve the geological standard sample library are less than the numbers of spectral variables, using LIBS spectrum as the input variables have good fitting performance. By optimizing experiment, in the Matlab platform to generate the dynamic link library DLL. COM.NET component interface framework can compatible development with the dynamic link library based on the C# language is used to call the function DLL and MWArray.dll mixed programming, effectively combining the C# application development and data processing function together, improve the speed and efficiency of software development. This paper focuses on optimizing energy measurement and control system of portable LIBS software at the same time, analysis of principal component analysis and partial least squares regression analysis the algorithm is applied to the measurement and control software, handheld LIBS spectral data processing, not only realize the control function of each component, while the development of The analytical and quantitative analysis and measurement software with qualitative and quantitative analysis functions has been successfully applied to the qualitative and quantitative analysis of ground and mineral samples.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH744.5;TP311.52

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