毕业设计（论文）
基于LabVIEW的音频信号数据采集和频谱分析
系别自动化工程系
专业名称测控技术与仪器
基于LabVIEW的音频信号数据采集和频谱分析
摘要
虚拟仪器是20世纪80年代兴起的一项新技术，是现代仪器仪表发展的重要方向，在建模仿真、设计规划和教育训练等方面都有应用。目前NI公司所提供数据采集设备性能好，但是价格昂贵，构建信号分析系统成本偏高。计算机声卡具备数据传输和A/D转换功能，作为数据采集卡具有价格低廉、开发容易和系统灵活等优点。基于上述分析，本文用计算机声卡代替普通采集卡作为硬件，在LabVIEW平台上设计了一个信号分析系统，并在信号分析实验中进行了应用。主要贡献为下述几点: l)提出了采用声卡作为数据采集设备构建虚拟音频信号分析系统并应用于实验教学的设想。通过高校实验室现状的调研和对声卡性能的分析，分析了由声卡组建可以用于实验教学的信号分析系统的必要性和可行性。
2)构建了基于LabVIEW的音频信号采集分析系统，具有信号采集、分析、波形显示、存储以及数据文件再调用分析等功能。分析、解决了设计及实现过程中出现的问题。
关键词：LabVIEW，声卡数据采集，信号分析
A Signal Analysis System Based on LabVIEW
Author：Du Wenjuan
Tutor：Jin Wei
Abstract
Virtual instrument technology is a new technology, and it is an important direction in modern instrumentation development. Virtual instruments are often used in modeling and simulation, design and planning, education and training. The acquisition equipment from NI has a good performance, but constructing signals analysis system will cause high cost.
Sound card with data transmission and A/D converter functions as a DAQ card has low-price, easy-developing and flexible-system such virtues. Based on the above analysis, taking the computer sound card instead of DAQ card as hardware, designs the system based on LabVIEW, and implements it in the signal analysis experiments. The main contents are listed as follows:
l)An envisage for using sound card as a virtual audio data acquisition equipment to construct the signals analysis system and implements it in the experiments is put forward. The necessity and feasibility by the sound card system to set up signals analysis system based on research of teaching program of experiments in the number of traditional college is analyzed.
2)Audio signal acquisition and analyze system is constructed based on LabVIEW, it has functions of virtual signal acquisition, analysis, waveform display, storage and transfer of data files to meet the needs of the experimental teaching.
Key Words：LabVIEW, Sound card data acquisition, Signals Analysis
目录
1 绪论 (1)
1.1 课题开发背景和发展现状 (1)
1.2 研究的意义 (2)
2 虚拟仪器、声卡及数据采集理论 (3)
2.1 虚拟仪器介绍 (3)
2.1.1虚拟仪器的特点 (3)
2.1.2虚拟仪器的组成 (4)
2.1.3 虚拟仪器与传统仪器的比较 (4)
2.2 LabVIEW简介 (6)
2.2.1 LabVIEW程序的基本构成 (6)
2.2.2 LabVIEW的应用 (7)
2.3声卡 (7)
2.3.1声卡的基本功能 (8)
2.3.2声卡的工作原理 (8)
2.3.3声卡的性能指标 (8)
2.4 信号分析理论 (10)
2.4.1 数据采集理论基础 (10)
2.4.2快速傅立叶变换（FFT） (11)
2.4.3 谐波分析理论 (14)
3 信号分析系统解决方案 (17)
3.1声卡作为数据采集卡的可行性分析 (17)
3.2信号分析系统设计方案比较 (18)
3.3 系统模块划分 (19)
4 信号处理程序设计 (20)
4.1 系统欢迎界面的设计 (21)
4.2系统主页面的设计 (22)
4.3实时采集信号模块的设计 (23)
4.4 历史重载信号模块的设计 (24)
