毕业论文《基于STC89C58RD+单片机的超声波流量计设计》.doc

超声波流量计设计摘要：超声波流量计是利用超声波在流体中的传播特性来测量流量的计量仪表。凭借其非接触测流、仪表造价基本上与被测管道口径大小无关、精度高、测量范围大、安装方便、测试操作简单等自身的优势被认为是较好的大管径流量测量仪表，在电力、石油、化工特别是供水系统中被广泛应用。然而，由于超声波流量计只是在近几十年才出现的一种新型仪表，还有很多不完善的地方，比如成本较高、精度不够等，有必要对其加以改进和提高。 本设计与传统的机械式流量仪表不同，它具有机械式仪表所不具备的优点，而且因其采用高精度时间测量芯片 TDC-GP2 进行时间测量，保证了测量的精度。本设计采用时差法原理进行测量流体流速，进而计算出瞬时流量。 论文从流量计的发展历史和背景到超声波流量计的原理、特点以及国内外发展概况，详细地介绍了超声波流量计。另外，论文又详细研究了时差法超声波流量计的理论知识，并在理论基础上研究了超声波流量计的硬件电路与软件部分，其中所用的高精度时间测量芯片 TDC-GP2 以及单片机 STC89C58RD是本设计的核心部分。本设计成功实现了瞬时流量的测量与辅助功能的实现，有较广阔的研究前景。Abstract: Ultrasonic flowmeter is the use of ultrasound inthe propagation characteristics of the fluid to measure theflow measurement instrumentation. With its non-contactflow measurement instrumentation cost essentiallynothing to do with the measured pipe diameter size highaccuracy wide measurement range easy installationsimple operation testing their advantages are consideredbetter large diameter flow measurement instruments inelectric power petroleum chemical especially watersupply system has been widely used. However since theultrasonic flowmeter only in recent decades the emergenceof a new type of instrument there are many imperfectionssuch as high cost lack of precision etc. it is necessaryto be improved and enhanced.The design with traditional mechanical flow meter aredifferent it has a mechanical instruments which do nothave the advantages but also because of its high-precisiontime measurement chip TDC-GP2 for time measurement toensure measurement accuracy. This design uses theprinciple of transit-time measurement of fluid flow thencalculate the instantaneous flow.Papers from the meter to the history and background of thedevelopment of the principle of ultrasonic flowmetercharacteristics and domestic development overviewdetailed description of the ultrasonic flowmeter. Inaddition the paper has a detailed study of transit-timeultrasonic flowmeter theoretical knowledge and based onthe theory of ultrasonic flowmeter hardware circuits andsoftware components which are used in h