隨著計算機技術的飛速發展，虛擬儀器在自動測試及自動化領域起著越來越重要的角色。本文的動平衡測試系統采用LabView 軟件及其數據采集卡NI DAQ－6221，實現對凸輪軸轉速的精確控制和其振動信號的實時采集與動態性能的分析。系統主要有PC 機, 數據采集卡NI DAQ－6221,單向交流調壓模塊，電渦流位移(轉速)傳感器和凸輪軸動特性試驗平臺組成。充分利用Labview 的強大計算分析功能和虛擬儀器過程控制技術（實現帶通濾波器，PID 控制及參數整定）使整個控制系統具有優良的控制精度和穩定性。系統利用Labview 平臺編程，具有研制周期短，開發成本低，性能可靠，界面友好，易于功能擴展等優點。
關鍵詞 調壓模塊帶通濾波參數整定 PID 控制虛擬儀器
Abstract: With the development of computer technology, Virtual Instrument (VI) is playing a very important role in measurement, test and automation. In this paper, a dynamic balance testing system which includes PC, DAQ Card (PCI-6221) board, voltage regulating modulation ，and Position and velocity sensors, is presented. We take advantage of the computing and analyzing function of Labview and technology (band-pass filter, the incremental PID control and parameter adjustment) of process control to realize the real-time data acquisition and analyses of vibrating signals and the accurate control of speed of camshaft. The accuracy and stability of the whole control system has been proved satisfactory. The system software has been developed by Labview, which offers the system a lot of merits, such as friendly user interface, high development cost, short development period, and flexible functional-extension, etc.
Key words：voltage regulating modulation，band-pass-filter, parameters adjustment, PID control, virtual instrument