信号采集与分析虚拟系统的设计毕设论文.doc

摘 要 随着计算机技术的发展，仪器工业正在经历一场巨变。计算机强大的处理和显示能力，使它可以在数据采集、分析和表达中的任意一个方面提升仪器的性能。以虚拟仪器为代表的新型仪器改变了传统仪器的思想，它们充分利用了计算机强大的软硬件资源，把计算机技术和测量技术紧密结合起来，是融合了电子测量、信号处理、计算机和网络技术的新型测量仪器，由于成本低、使用方便等优点得到了广泛的应用。 本文用计算机声卡代替普通采集卡作为硬件，用数据分析和处理功能非常强大的工程实用软件LabVIEW作为软件开发平台，设计了一个高采样精度、中等采样频率、灵活性好的声卡数据采集系统，实现了数据采集、信号分析(时域分析和频域分析)及信号发生等多种功能。其中，时域分析包括实时显示波形，测量信号电压、频率、周期等参数；频域分析包括幅值谱、相位谱、功率谱等；信号发生包括常用信号(如正弦波、方波、三角波等)的产生。该采集系统性价比高、通用性强、扩展性好、界面简单，在工程测量与实验室应用中具有广阔的前景。 关键词：虚拟仪器,LabVIEW,声卡数据采集,信号分析 ABSTRACT With the development of computer technology, equipment industry is under going a change. The powerful processing and display capabilities of computer enhance data collection, analysis and expression of any aspect of the performance of equipment. A virtual instrument as the representative new equipment has changed the traditional instruments, it takes full advantage of computer hardware and software resources. The computer technology is integrated with measurement technology. It integrate the electronic measurement, signal processing and computer and network technology in the new instrument. Taking the computex sound card instead of current acquisition card as hardware and the engineering software LabVIEW that data analysis and processing function is very powerful as software development platform，a kind of sound card data acquisition system with higher sampling precision，middling sampling frequency and better flexibility is designed．It has realized several functions such as data acquisition，signal analysis(i．e．time—domain analysis and frequency—domain analysis) and signal generator．The time—domain analysis includes the real—time display of the waveform．the signal parameter measurements of voltage，frequency and period．The frequency—domain analysis contains amplitude spectrum，phase spectrum，power spectrum．The signal generator can produce common signal like sine wave，square wave and triangular wave．The system has many advantages，for example，high cost performance，stron