基于LabVIEW的液位测控系统设计.doc

本科毕业设计论文摘要液位计算机测量与控制实验系统是为西北工业大学航空学院民航工程系综合实验平台而开发的课程教学实验系统。液位测量与控制系统集传感器信号的采集、调理、转换、检测和控制为一体，是实时交互式图形界面应用系统。该系统采集液位信号并用计算机可视化界面实时显示液位高度的变化过程；通过交互式对话框设置期望的液位高度，在检测当前液位的基础上控制进/出水阀门，从而对实际液位高度进行控制。论文介绍了液位计算机测量与控制系统的结构与功能；分析了硬件系统中测量与控制电路的组成及工作原理；计算了信号调理电路中测量放大器的增益及各元件参数；使用PROTEL软件绘制了信号调理电路图；介绍了多功能数据采集卡NIUSB-6008的特点、功能及软件开发平台LabVIEW；分析了系统的软件程序；介绍了液位计算机测控系统的用户使用界面所能实现的功能。针对实验系统对液位进行开关控制所带来的问题，提出了用PID控制方法进行改进的措施。关键词：液位测控，压力传感器，信号调理，NIUSB-6008，LabVIEWABSTRACTTheliquidlevelmeasurementandcontrolcomputerexperimentalsystemisacourseteachingexperimentalsystemwhichisusedtodevelopthecomprehensiveexperimentalplatformforAviationInstituteofCivilEngineeringofNWPU.Theliquidlevelmeasurementandcontrolsystemwithreal-timeinteractivegraphicalinterfaceisofthesensorsignalacquisition,conditioning,conversion,testingandcontrolfunctions.Thesystemacquiresthesignalsofliquidlevelandcomputerinterfacereal-timetoshowtheliquidlevelchangingprocess.Throughaninteractivedialogbox,thedesiredwaterlevelisset.Theactualwaterleveliscontrolledbasedonthecurrentliquidleveldetectionthroughtheimport/outletvalves.Thestructureandfunctionoftheliquidlevelmeasurementandcontrolcomputerexperimentalsystemisintroducedatfirst.Thehardwaresystemcompositionandworkingprincipleisanalyzed,andthegainandeachcomponentsparametersofmeasuringamplifierinsignalconditioningcircuitarecalculated.ThesignalconditioningcircuitisdrawnwithPROTEL,andthefeaturesandfunctionsofthemulti-functiondataacquisitioncardNIUSB-6008andsoftwaredevelopmentplatformLabVIEWareintroduced.Thesystemsoftwareprogramisalsoanalyzed.Forthecontrolproblemsofimport/outletvalvesoftheliquidlevelmeasurementandcontrolcomputerexperimentalsystem,aPIDcontrolmethodisproposedtoimprovethesystemperformances.KEYWORDS：liquidlevelmeasurementandcontrol，pressuresensor，signalconditioning，NIUSB-6008，LabVIEW目录TOC\o"1-3"\h\z\uHYPERLINK\l"_Toc263429605"摘要IHYPERLINK\l"_Toc263429606"ABSTRACTIIHYPERLINK\l"_Toc263429607"第一章绪论PAGEREF_Toc263429607\h1HYPERLINK\l"_Toc263429609"1.1课题背