【正文】 內(nèi)蒙古科技大學(xué)畢業(yè)設(shè)計(jì) 說(shuō)明書(shū) （畢業(yè) 論文 ） 畢業(yè)設(shè)計(jì)說(shuō)明書(shū) 基于單片機(jī)的超聲波流量計(jì) 內(nèi)蒙古科技大學(xué)畢業(yè)設(shè)計(jì) 說(shuō)明書(shū) （畢業(yè) 論文 ） 摘 要 測(cè)量流體流量的儀表統(tǒng)稱為流量計(jì)或流量表，流量計(jì)是工業(yè)測(cè)量中重要的儀表之一。超聲波流量計(jì)與以往傳統(tǒng)的流量計(jì)相比，具有 很多 優(yōu)點(diǎn)，是一種非常理想的節(jié)能型流量計(jì)。 本設(shè)計(jì)在查閱大量文獻(xiàn)資料的基礎(chǔ)上，選擇了時(shí)差法超聲波流量計(jì)為研究對(duì)象，對(duì)如何提高系統(tǒng)的精度及系統(tǒng)穩(wěn)定性和可靠性問(wèn)題進(jìn)行了深入的理論研究。主要進(jìn)行了以下的詳細(xì)研究： 1. 研究了時(shí)差法超聲波流量計(jì)的測(cè)量原理，對(duì)超聲波在流體中傳播特性及超聲波換能器的特性及安裝選擇進(jìn)行了深入研究； 2. 在測(cè)量精度的提高方面， 討論并采用了超聲波時(shí)差測(cè)量的新方法 — 多脈沖測(cè)量法。 3. 對(duì)流量計(jì)的硬件電路及軟件編程進(jìn)行了詳細(xì)的設(shè)計(jì)分析 關(guān)鍵詞： 超聲波流量計(jì) ； 單片機(jī) ； 超聲波換能器 ； 時(shí)差法 ； 多脈沖聲循環(huán)法 內(nèi)蒙古科技大學(xué)畢業(yè)設(shè)計(jì) 說(shuō)明書(shū)（畢業(yè) 論文 ） The ultrasonic flowmeter based on Monolithic integrated circuit Abstract The appliance to measure the rate of fluid flow is generally called flowmeter or flow indicator and is an important appliance in industrial measurements. Compared with traditional flowmeter, the ultrasonic flowmeter has many advantages. This design based on mass research of data and finally took the traveltimedifference method ultrasonic flowmeter as the object of study and made deep theoretical research of how to improve the accuracy, stability and reliability of the system. 1. Studies on the measurement principles of traveltimedifference method ultrasonic flowmeter were made. The dissemination features of ultrasonic wave in fluid and the features of Ultrasonic wave transducer and the choice of different methods of installation. 2. From the aspect of the enhancement of measure accuracy, it discussed the new method of traveltimedifferencemultibeams measurements and further put it into application. 3. Detailed design and analysis of the hardware circuit and software programming of the flowmeter were made. Key words: ultrasonic flowmeter； Monolithic integrated circuit； ultrasonic transducer； traveltimedifference method； multibeams Sound cyclic method 內(nèi)蒙古科技大學(xué)畢業(yè)設(shè)計(jì) 說(shuō)明書(shū)（畢業(yè) 論文 ） 目 錄 摘 要 ........................................................................................................................................ II Abstract......................................................................................................................................III 第一章 概述 .............................................................................................................................. 1 超聲的相關(guān)概念 ......................................................................................................... 1 超聲的相關(guān)概念 .............................................................................................. 1 超聲的研究發(fā)展和應(yīng)用 .................................................................................. 1 流量計(jì)的發(fā)展歷史及現(xiàn)狀 ......................................................................................... 2 流量計(jì)的分類(lèi)及特點(diǎn) ................................................................................................. 3 超聲波流量計(jì)概述 ..................................................................................................... 3 超聲波流量計(jì)的發(fā)展及現(xiàn)狀 .......................................................................... 3 超聲波流量計(jì)的特點(diǎn) ...................................................................................... 3 超聲波流量計(jì)兩種主要測(cè)量原理及對(duì)比 ...................................................... 4 第二章 超聲波流量計(jì)的總體設(shè)計(jì) .......................................................................................... 5 超聲波換能器概述 ..................................................................................................... 5 超聲波換能器能量轉(zhuǎn)換原理 .......................................................................... 5 超聲波換能器的類(lèi)型及主要性能指標(biāo) .......................................................... 5 超聲波換能器的選擇及設(shè)計(jì) .................................................................................... 7 超聲波換能器的主要參數(shù) .............................................................................. 7 超聲波換能器的選擇 ...................................................................................... 8 超聲波換能器的安裝方式及選擇 .................................................................. 8 時(shí)差法測(cè)量原理及影響測(cè)量的主要因素 ................................................................. 9 內(nèi)蒙古科技大學(xué)畢業(yè)設(shè)計(jì) 說(shuō)明書(shū)（畢業(yè) 論文 ） Z 型安裝方式時(shí)差法測(cè)流量的測(cè)量原理 ........................................................ 9 影響測(cè)量的主要因素 .................................................................................... 11 V 型安裝方式時(shí)差法原理介紹 ...................................................................... 11 多脈沖測(cè)量原理 ....................................................................................................... 12 第三章 超聲波流量計(jì)一次儀表部分硬件設(shè)計(jì) .................................................................... 15 超聲波發(fā)射電路的選擇與設(shè)計(jì) .............................................................................. 15 超聲波接收信號(hào)調(diào)理電路選擇與設(shè)計(jì) .................................................................. 16 一級(jí)放大電路 ................................................................................................ 16 帶通濾波電路 ................................................................................................ 17 二級(jí)放大電路 ................................................................................................ 18 第四章 超聲波流量計(jì)二次儀表部分硬件設(shè)計(jì) .................................................................... 19 系統(tǒng)工作原理概述 ................................................................................................... 19 芯片資料 ................................................................................................................... 21 總線收發(fā)器 74LS245..................................................................................... 21 計(jì)數(shù)器 74S196 ............................................................................................... 21 4040CMOS12 級(jí)二進(jìn)制計(jì)數(shù)分頻器 ............................................................. 22 AT89C51 .......................................................................................................... 23 超聲波順流逆流發(fā)射接收控制電路 ...................................................................