摘要：仪器技术领域在飞速发展，虚拟仪器技术在其中扮演着重要的角色，它不仅能够完成传统仪器的全部工作，而且还有许多传统仪器所没有的功能，被广泛应用在各行各业中。LABVIEW是图形化开发环境，因而又被成为G语言，它既有图形化编程的高性能和灵活性，也有专为运用设计的高性能模块和配置性能，为广大工程师、技术人员、科学家提供了便捷、轻松的开发实验平台。

本文首先是对虚拟仪器和LABVIEW软件做了介绍，介绍了LABVIEW的一些特点以及其中的一些模块及其作用，还对IIR虚拟数字滤波器的特点和设计方法进行了分析。最后，利用LABVIEW设计了一个带有均匀白噪声的IIR虚拟数字滤波器，给出了设计方案，将该程序分为3个模块：信号产生模块、滤波模块和显示模块。信号生成模块可以生成一定可调节的正弦波、矩形波、锯齿波和三角波。滤波器模块可以选择不同参数、不同的拓扑结构。显示模块通过前面板的图形控件可以显示滤波前后的波形、滤波器的幅频相频特性、滤波前后波形的频谱。以低通巴特沃斯滤波器为例，将添加了均匀白噪声的波形与经过滤波后的波形相比，发现噪声一定程度上滤除了。并通过IIR滤波，比较不同拓扑结构、不同阶数滤波器的滤波性能，得出这几种滤波器的优缺点。

关键词：虚拟仪器；IIR；LabVIEW

Abstract：In the field of instrument technology, virtual instrument technology plays an important role in it. It not only can complete the whole work of traditional instruments,  but also has many functions that traditional instruments do not have, which are widely used in all walks of life. LABVIEW is a graphical development environment, which has become a G language, it is both graphical programming of high performance and flexibility, but also designed for the use of design of high-performance modules and configuration performance for the majority of engineers, technicians, scientists Convenient and easy to develop experimental platform.

This paper introduces the virtual instrument and LABVIEW software, introduces some features of LABVIEW and some of them, and analyzes the characteristics and design methods of IIR virtual digital filter. Finally, an IIR virtual digital filter with uniform white noise is designed with LABVIEW. The design scheme is given. The program is pided into three modules: signal generation module, filter module and display module. The signal generation module can generate a certain adjustable sine wave, rectangular wave,  sawtooth wave and triangular wave. The filter module can select different parameters, different topologies. Display module through the front panel of the graphical control can display the waveform before and after filtering, the frequency band frequency characteristics of the filter, filter the waveform before and after the waveform. To low pass Butterworth filter, for example, will add a uniform white noise waveform and filtered after the waveform, found that the noise to a certain extent, the filter out. And the advantages and disadvantages of these filters are obtained by comparing the filtering performance of different topologies and different order filters by IIR filtering.

Keywords: virtual instrument；IIR；LabVIEW

目录

第一章绪论 1

1.1课题背景 1

1.2虚拟仪器的研究现状及未来发展趋势 1

1.3研究内容和目的 2

第二章虚拟仪器以及LABVIEW 4

2.1虚拟仪器概述 4

2.1.1虚拟仪器的定义 4

2.1.2虚拟仪器的分类及组成 4

2.1.3虚拟仪器的特点 7

2.2LABVIEW简介 8

2.2.1LABVIEW概述 8

2.2.2LABVIEW程序的基本构成 10

2.2.3LABVIEW的程序设计步骤 10

第三章滤波器的介绍和设计 12

3.1滤波器定义及其分类 12

3.1.1定义 12

3.1.2滤波器分类 12

3.2数字滤波器 13