【正文】 基于 LabVIEW 的材料測試系統(tǒng)設計 —— 載荷測量 1 基于 LabVIEW 的材料測試系統(tǒng)設計 —— 載荷測量 摘要 LabVIEW是 NI公司開發(fā)的圖形化編程開發(fā)平臺 ,具備強大的實時數(shù)據(jù)處理功能與顯示功能 .但是由于 LabVIEW的數(shù)據(jù)采集卡價格非常昂貴，所以本設計以 LabVIEW為軟件設計的核心， 以模 /數(shù)轉換器 ADC0809和 單片機 AT89C51為 硬件設計的 核心 來設計這個材料測試測量系統(tǒng)的。整個測試測量 系統(tǒng) 由四個部分組成 ： 信號 采集， 信號放大調理， 數(shù)據(jù) 轉換、傳送，計算機上 LabVIEW軟件接收和顯示 。 在設計中先是用載荷傳感器 LRK來采集拉力大小的信號，并由電橋輸 出，通過儀表放大器放大微弱的電橋模擬輸出的電壓信號，將調理過的信號送入 ADC0809進行模擬量和數(shù)字量的轉換，再利用 MCS51單片機的 TXD串行口發(fā)送數(shù)據(jù)，最后進行電平轉換后，由計算機上的 LabVIEW接收，并實時的顯示載荷的大小和載荷波形曲線。在設計中是 利用 LabVIEW提供的串行通信功能將單片機系統(tǒng)與 PC 機結合 ,既充分利用了 LabVIEW的強大功能 ,又降低了系統(tǒng)開發(fā)成本 ,擴展了 LabVIEW的應用。 本設計主要是在實驗室不斷地調試過程中得出需要的合理數(shù)據(jù)， 由于軟件控制方便，操作簡單，不占用空間，經(jīng)過 一系列的測試與實驗，證明了該測試系統(tǒng)具有智能化、可靠性高、實時性強等優(yōu)點，可以勝任材料測試系統(tǒng) — 載荷測量的測試。 關鍵字：數(shù)據(jù)采集， ADC0809，單片機，串口通信， LabVIEW 福州大學本 科生畢業(yè)設計（論文） 2 The designing of materials testing system based on the LabVIEW—— Load measurement Abstract LabVIEW is the NI pany’s graphic programming language that is able to fulfill ability on handling realtime data and showing. But the LabVIEW data collect card’s price is very expensive, the system which is base on the software nucleus of LabVIEW designing and the hardware nucleus of ADC0809 and AT89C51 to be design for material test. The whole material test system poses four parts: collect signal, blow up and condition signal, transform and transmit signal, incept and display on the pute of LabVIEW. First, in the designing, use loading sensor LRK to collect the signal of the pull force, export by bridge, get across the instrument amplifier blows up the delicacy voltage signal, put the conditional signal into the ADC0809 to convert, then send the data from the SCM’s serial interface to PC, take over by the LabVIEW on the pute, and display realtimely the magnitude of the loads and the curve of the wave. While the designing, it uses the serial munication’s functions of the LabVIEW to bine the PC and SCM system. On the one hand, it makes full use of the formidable functions of the LabVIEW, in the other hand, it depresses the price of system of exploitation, enlarge the applications of the LabVIEW. This design mainly gains the reasonable data go through the constantly testing in the lab. As the software is convenient for controlling, easy for conducting, take a little up space, and go through a serial of the debug and experiments, it proves that the testing system with the advantages of the intelligent, high reliability and realtime, is able to petent for the measure of the material’s testing system—— load measuring. Key Words: Data collection, ADC0809, SCM, serial munication, LabVIEW 基于 LabVIEW 的材料測試系統(tǒng)設計 —— 載荷測量 3 目 錄 摘要 ................................................................................................................................................... I Abstract ...........................................................................................................................................II 第 1 章 緒論 .................................................................................................................................... 1 引 言 .......................................................................................................................................... 1 研究的背景和意義 ................................................................................................................ 1 本設計所做的工作 ................................................................................................................ 2 難點與重點 .......................................................................................................................... 3 第 2 章 硬件設計 ............................................................................................................................... 4 信號采集 .............................................................................................................................. 4 放大器及其調理電路 ............................................................................................................ 4 A/D 轉換及其接口方法 ....................................................................................................... 6 A/D 轉換器的選取 ..................................................................................................... 6 ADC0809內部功能與引腳介紹 .................................................................................. 7 ADC0809的時序邏輯 .............................................................................................. 10 ADC0809與單片機的接口和工作 .............................................................................11 串行口通信 ........................................................................................................................ 12 MAX232簡介 ......................................................................................................... 12 RS232 接口標準 ..................................................................................................... 13 RS232 串行接口標準 .............................................................................................. 14 RS232 的電氣特性 ................................................................................................. 14 第 3 章 虛擬儀器的概述 .................................................................................................................. 15 虛擬儀器的概念 ................................................................................................................. 15 虛擬儀器的特點及優(yōu)勢 ....................................................................................................... 15 虛擬儀器和傳統(tǒng)儀器的比較 ................................................................................................ 16 虛擬儀器 測試系統(tǒng)的組成 ................................................................................................... 17 第 4 章 軟件設計 .......................................................................