【正文】
求學(xué)歷程是艱苦的,但又是快樂(lè)的。 % 構(gòu)造橢圓濾波器data=filter(b,a,data2)。,2) % 定義超時(shí)值Fs = ActualRate。,39。)。Frequency (Hz)39。, 1)。,chan)。)對(duì)聲卡產(chǎn)生的模擬輸入對(duì)象進(jìn)行操作。需要注意的是,執(zhí)行完一次數(shù)據(jù)采集工作后應(yīng)刪除設(shè)備對(duì)象,將內(nèi)存中的數(shù)據(jù)存儲(chǔ)在硬盤(pán)上之后釋放數(shù)據(jù)存儲(chǔ)所占用的內(nèi)存空間,以備下一次采集能有足夠的內(nèi)存空間存儲(chǔ)新的數(shù)據(jù),聲音信號(hào)采集的實(shí)現(xiàn)程序?yàn)閏lear data1。TriggerConditionValue39。,10000) % 設(shè)置采樣速率為10000HzActualRate = get(AI,39。(5)其他功能。靈活性強(qiáng)。在設(shè)計(jì)研究單位和工業(yè)部門(mén),MATLAB被廣泛用于科學(xué)研究和解決具體問(wèn)題。這些同步數(shù)據(jù)可以描述各路信號(hào)的相位關(guān)系,所以這種結(jié)構(gòu)被稱(chēng)為同步型數(shù)據(jù)采集系統(tǒng)。采集速率又稱(chēng)為系統(tǒng)通過(guò)速率或吞吐率,是指在滿(mǎn)足系統(tǒng)精度指標(biāo)的前提下,系統(tǒng)對(duì)輸入的模擬信號(hào)在單位時(shí)間內(nèi)所能完成的采集次數(shù),或者說(shuō)是系統(tǒng)每個(gè)通道、每秒鐘可采集的有效數(shù)據(jù)的數(shù)量。(1)現(xiàn)代采集系統(tǒng)一般都由計(jì)算機(jī)控制,使得數(shù)據(jù)采集的質(zhì)量和效率等大為提高,也節(jié)省了硬件投資。 (2)并行式采集(Parallel Acquisition):多個(gè)通道同步并行采集,每個(gè)通道采用一個(gè)獨(dú)立的A/D轉(zhuǎn)換器,通道采集速率只取決于A/D的轉(zhuǎn)換速率,與通道數(shù)無(wú)關(guān)。首先,分布式控制應(yīng)用場(chǎng)合中的智能數(shù)據(jù)采集系統(tǒng)正在發(fā)展。數(shù)據(jù)采集(Data Acquisition)是將被測(cè)對(duì)象(外部世界、現(xiàn)場(chǎng))的各種參量(可以是物理量,也可以是化學(xué)量、生物量等)通過(guò)各種傳感元件作適當(dāng)轉(zhuǎn)換后,再經(jīng)信號(hào)調(diào)理、采樣、量化、編碼、傳輸?shù)炔襟E,最后送到控制器進(jìn)行數(shù)據(jù)處理或存儲(chǔ)記錄的過(guò)程。關(guān)鍵詞:基于MATLAB;基于聲卡;數(shù)據(jù)采集The System Design Of Data Acquisition Based On The MATLABAbstract:MATLAB has the function of highperformance numerical putation and visual scientific engineering puting. It supports explanatory language input and the sound card, contains rich mathematical functions and has powerful data acquisition toolbox with simple programming. As the MATLAB data collection card, the sound card, pared to the conventional data collection card, endows with a low price, simple development and convenient system. This paper has discussed a design that bines the two kinds to conduct data collection.This paper has specifically introduced the background of this topic, the structure and the characteristics of nowadays data collection system. It has also introduced MATLAB and its data collection toolbox. By using the A/D, D/A conversion technique of the sound card and the function of MATLAB, I have presented a costeffective data collection and analysis design based on the sound card, and analyzed and described thoroughly the course and methods of data collection and analysis system by using MATLAB language programming. Finally, this paper has provided some examples which have applied this data collection system.Key words: Based on MATLAB。數(shù)據(jù)采集技術(shù)已經(jīng)成為一種專(zhuān)門(mén)的技術(shù),在工業(yè)領(lǐng)域得到了廣泛的應(yīng)用。(4)變速率變分辨率采樣。 圖2給出了基于MATLAB的數(shù)據(jù)采集系統(tǒng)的簡(jiǎn)圖,主要部件數(shù)據(jù)采集工具箱提供了硬件驅(qū)動(dòng)程序和MATLAB環(huán)境之間“對(duì)話(huà)”所需的硬件驅(qū)動(dòng)程序適配器、數(shù)據(jù)采集引擎和M文件函數(shù)。因?yàn)橄到y(tǒng)精度取決于系統(tǒng)的各個(gè)環(huán)節(jié)(子系統(tǒng))的精度,如前置放大器、濾波器、模擬多路開(kāi)關(guān)等。多通道同步數(shù)據(jù)采集系統(tǒng)其結(jié)構(gòu)如圖4所示,也屬于分時(shí)轉(zhuǎn)換系統(tǒng)。如果配上數(shù)據(jù)采集線(xiàn)路,該系統(tǒng)就可以作為一個(gè)虛擬儀器來(lái)使用?;谟?jì)算機(jī)聲卡的數(shù)據(jù)采集系統(tǒng)有以下特點(diǎn)。(2)實(shí)現(xiàn)將采集到的聲音信號(hào)數(shù)據(jù)進(jìn)行頻譜分析,畫(huà)出頻譜圖以圖形方式很直觀地反映出信號(hào)特征。chan = addchannel(AI,1)。rising39。 % 設(shè)置采樣速率...% 其它的相關(guān)設(shè)置啟動(dòng)設(shè)備對(duì)象,控制聲卡開(kāi)始采集數(shù)據(jù),采集過(guò)程中可以向聲卡發(fā)送控制命令,如暫停采集、退出采集等。Frequency (Hz)39。)。,)。 % 此函數(shù)為MATLAB自帶 subplot(2,1,2)plot(f,mag)grid on ylabel(39。第 20 頁(yè)[參考文獻(xiàn)][1] JI Xiaosong,LI and Realization of Highspeed Data Acquisition Card[J]Modern Electronics ,(1):1618.[2] 陳志勇,[J].計(jì)量技術(shù),2010,(1):1215.[3] 李亞微,[J].電聲技術(shù),2007,31(3):1214.[4] 陳小異,劉軍安,[J].新技術(shù)新工藝,2007(10):1011.[5] 王紅兵,王國(guó)棟,金翔,[J].物理實(shí)驗(yàn),2005,(4):2225.[6] 王琳,商周,[J].電測(cè)與儀表,2004,(8):1719.[7] 趙祚喜,羅錫文,[J].2003,(3):1316.[8] [J].2003,30(4):912.[9] 賴(lài)?yán)蝻w,[J].(7):1012.[10] [J].(13):2325.[11] 張金玉,張優(yōu)云,[J].(10):38.[12] VINAY K I。)。)。 % 計(jì)算窗函數(shù)長(zhǎng)度window = hanning(blocksize)。])致謝行文至此,我的這篇論文已