摘 要:虚拟仪器是一种将计算机资源与仪器硬件的测量、控制、数据采集能力结合在一起的数字化自动测试仪器,它在数据采集、计算机辅助测试和仪器控制等领域均得到广泛利用。基于LabVIEW平台的虚拟示波器的设计就是其中的主要应用领域之一。本文主要利用LabVIEW强大的虚拟仪器功能设计一台简单的虚拟数字示波器,考虑到实际情况,该示波器采用计算机自带的声卡代替传统的工业数据采集卡进行数据采集。文章阐述了虚拟仪器的概念、开发环境和发展趋势,介绍了虚拟示波器的设计理论、设计思路以及它的数据采集、波形显示、信号处理、波形存储和回放等功能。通过实验表明该示波器显示波形运行可靠、性能良好,能适用于普通实验室正常的使用需求。56956
毕业论文关键词:虚拟仪器,示波器,LabVIEW
Abstract:Virtual instrument is a kind of digital automatic test equipment which combines computer resources with measurement,control and data collecting capabilities of instrument hardware.It has been more widely used in many areas including data acquisition,computer aided test and instrument control.And the design of virtual oscilloscope based on LabVIEW platform is one of the major application areas.A simple virtual digital oscilloscope is designed in this paper by powerful virtual instrument function of LabVIEW mainly.Taking the actual situation into account,this oscilloscope collects data by the computer's own soundcard which replaces capture card of traditional industrial data.This paper introduces the concept of virtual instruments,exploitation environment,development trends,design theory and design ideas.The functions of data acquisition,waveform display,signal processing,waveform storage and playback are also introduced in this paper.Example shows that the oscilloscope displays reliable waveform running and good performance,and it can be applied to normal usage requirements of ordinary laboratory.
Key words:virtual instrument,oscilloscope,LabVIEW
目 录
1 引言 4
2 虚拟仪器的介绍 4
2.1 虚拟仪器的概念 4
2.2 虚拟仪器的开发环境 4
2.3 虚拟仪器的发展趋势 5
3 虚拟示波器的设计理论 5
3.1 台式数字示波器的工作原理 5
3.2 虚拟数字示波器的基本原理 6
3.3 虚拟数字示波器的声卡采集原理 6
4 虚拟数字示波器的硬件设计 7
4.1 声卡的硬件结构 7
4.2 声卡用于数据采集时的主要设置 8
5 虚拟数字示波器的软件设计 9
5.1 设计思路 9
5.2 数据采集模块设计 10
5.3 信号测量模块设计 11
5.4 数据滤波模块设计 13
5.5 频谱分析模块设计 14
5.6 波形显示模块设计 15
5.7 波形存储和回放模块设计 16
5.8 完整的程序与前面板设计 17