【正文】 it, generated to drive signals through PID algorithm. Drive signals are delivered to drive device of linear motors to control the motion of linear motors. Here, motor drive signals are 010V simulation signals which are outputs from AO channel of collection card according to algorithm. There are four force sensors to be assembled on vibration laboratory platform, which are used to measure vibration of the platform aiming to observe vibration performance of the platform. The signal from force sensor is gathered to the controlling device through AI channel to be shown and attached to algorithm calculation. As the surroundings of vibration testing locale is bad and noise is paratively loud, given to the testing security, the whole system runs in V4159 978142448109 /10/$ 169。 furthermore, this operating mode exhausts memory and causes the system to run the case of data loss. As a result, when writing programs in the application of DAQmx, VI Server technology is utilized where VI is called dynamically to realize the effective running of program. The followings are on the analog and digital acquisition, and analog output of the programming method and the module configuration to do in detail. Four force sensors output 010V analog signals and the block diagram of acquisition card reading the force sensor analog signal and the virtual channel settings are as follows: DAQmx Virtual Channel is set to AIvoltage analog input, Dev1/ai0 selected to the physical channel。 VIreading is set to analog 2D DBL, Nchannel N sampling mode。 iT is integrating time constant。 () uk Δ is controller39。 () uk is controller39。 analog DBL singlechannel singlesampling.Figure 2. block diagram of acquisition card reading analog signalIV. PID CONTROL TOOLKIT In the vibration test system, PID control module mainly uses PID toolkit to plete its work, which is the application on the engineering control provided by NI Company. The PID tool bag joins the plex control algorithm in the LabVIEW procedure, unifies the PID control tool bag and the LabVIEW arithmetic and the logical function to generate automatic control program quickly. Because control based on the hypothesized instrument is one kind of sampling control, which is according to the sampling time deviation amount putation to control quantity. Therefore it can only use the numerical calculus to approach. That is in the sampling time t, PID controller may total the putation proportion, the differential, the integral three functions together to obtain the PID controller39。 starttriggerring mode is set to analog edge mode。 longdistance puter in control studio controls the hostputer to manipulate testing platform through DataSocket technology. III. DATA ACQUISITION SYSTEM Acquisition of multipath digital signal and simulation signal are realized by multifunctional data acquisition card PCI6229, as well as the output of motor drive simulation signal. NI PCI6229 is a type of data acquisition card based on puter PCI bussing technique, which belongs to M series cards. Its speed rate of data transmission is increased five times more than before and system architecture time is short. Basic parameter of NI PCI6229 follows: sampling speed rate at 250Ks/s, 16bit 32line simulation input channel, 16bit 4line simulation output (833KS/s), 48line digital I/O (32 lines can get maximum of 1MHZ), A/D convertor with 16line resolution, supporting digital triggering, two 32line counter, one frequency generator, patible with NI DAQmx drive procedure and testing software. The function of DAQmx data acquisition card is shown in rear panel of LabVIEW, ALL Function /NI Measurements / DAQmx, after installing drive of PCI6229 acquisition card properly. It contains all subVI that collocation acquisition needs. Here, it contains configuration access functions, taskstarting functions and datareading functions and so on. Analog amp。 Data Acquisition。 ExpositionCopyright 2002, American Society for Engineering Education．3639.[23] National Instruments Corporation. LabVIEW Function and VI ReferenceManual. Number 321526B01 January 19987102.[24] Nationl Intruments Corporation. Using LabVIEW with TCP/IP and Intruments Application Note 160. .[25] , Transfer Protocal HTTP/ ，1999:357363.[26] . Internet working with TCP/IP. PrenticeHall，Englewood Cliffs，NJ，1995,3,521～527.[27] GOLDBERG H. What is Virtual Instrument[ J ]. IEEE Instrumentation amp。在整個畢業(yè)設計期間，周老師傾注了很大的精力和心血，從論文的選題、開展、調(diào)研到設計調(diào)試階段，周老師都給予了很大指導和啟發(fā)，使的我的課題任務能順利完成。基于虛擬儀器的遠程測試系統(tǒng)除了具備虛擬儀器的優(yōu)點外，主要優(yōu)勢還在于用戶可以不受時間、地點和環(huán)境的限制，遠程完成測試任務；同時實現(xiàn)了資源共享，降低成本，許多昂貴的硬件設備的某些功能可以通過軟件完成；有些復雜的任務還可以通過網(wǎng)絡協(xié)同工作，共同完成。另外，隨著信息網(wǎng)絡技術(shù)的不斷深化，網(wǎng)絡信道容量和網(wǎng)絡速度將不再成為網(wǎng)絡應用的障礙，利用Internet進行遠程診斷、遠程教學、遠程控制等已成為人們十分關(guān)注的問題。同時在另一臺電腦上啟動客戶端程序，在客戶端的程序面板“數(shù)據(jù)傳輸?shù)刂贰敝刑顚懛掌魉诘挠嬎銠C的IP地址，即可讀出被測信號的加速度、速度、和位移量以及頻率值。圖48 消除趨勢項程序圖第五章遠程振動測試實驗調(diào)試部分( 1 ) 由于實驗條件的限制，沒有激振器，所以只能完成短時間的信號采集，首先，將壓電傳感器與電荷放大器相連，調(diào)節(jié)輸出電壓同時調(diào)節(jié)相應的靈敏度，將電荷放大器的輸出端與DAQ數(shù)據(jù)采集卡設置的通道ai0+，ai0相連。本系統(tǒng)構(gòu)造一個Detrend VI消除趨勢項。（6） 頻譜單位轉(zhuǎn)換VI將自功率譜轉(zhuǎn)換為需要的格式。（3） 在積分過程中，由于某些因素引起的隨時間變化的長周期的系統(tǒng)誤差。圖振動測試實驗客戶端程序前面板圖46構(gòu)建振動測試實驗客戶端程序前面板圖47 振動測試實驗客戶端程序框圖按圖47構(gòu)建振動測試實驗客戶端程序框圖。按圖46構(gòu)建振動測試實驗客戶端程序前面板。 m。數(shù)據(jù)傳輸?shù)刂穌stp://localhost/wave是本地服務器的地址，data是本地服務器DataSocket Write VI寫入DataSocket Server的采樣率和處理后的加速度信號的數(shù)據(jù)，當客戶端的DataSocket Read VI的數(shù)據(jù)傳輸?shù)刂窞閐stp:/，它等同于數(shù)據(jù)傳輸?shù)刂分械膌ocalhost，服務器進行頻率分析和測試數(shù)據(jù)存取便于客戶監(jiān)測和分析實驗過程。（8） 通過頻譜分析得到相應的頻率峰值。（4） 通過掃頻儀輸出的頻率的二倍為濾波的截止頻率。按圖43構(gòu)建振動測試實驗服務器程序前面板，并參考圖中的顯示進行采樣參數(shù)設置。通過自功率譜VI用傅里葉變換得到自功率譜，再通過頻率單位轉(zhuǎn)換VI將自功率譜格式進行變換，最后通過功率及頻譜估值VI計算出自功率譜中的頻率峰值。通過MAX中Data Neighborhood項進行設置，可以設置數(shù)據(jù)輸入的測試任務通道，由于電荷放大器將電荷量放大以電壓的形式輸出，所以選擇模擬輸入任務中的電壓項，并選選擇相應的模擬輸入“ai0”通道，這時雙擊數(shù)據(jù)采集助手，查看任務通道是否為“ai0”通道。（7） 通過屬性節(jié)點重新設置輸出刷新率。（4） 將波形數(shù)據(jù)寫到輸出緩沖區(qū)。掃描儀前面板和程序面板如下圖41和圖42：圖41 掃頻儀前面板圖42 掃頻儀程序框圖程序執(zhí)行的主要步驟是：（1） 創(chuàng)建一個輸出模擬電壓的虛擬通道。輸出的振動頻率為被測物體的固有頻率。存儲器緩沖器多路開關(guān)