Design Of Platform Virtual Instrument Technology-based Vibration Testing And Modal Analysis

The research purpose of this thesis is to design a platform for vibration measurement-and-analysis as well as modal analysis in mechatronics systems. The function of this platform includes: real-time data acquisition of multi-channel signal,measuring and real-time displaying,data storage and analysis etc.With the development of computer technique, the enhancement of computer performance and the progress on professional software, virtual instrument technique is getting a deeper development. Vibration measurement-and-analysis based on virtual instrument technique has become a development trend. Therefore, the author develops a multi-channel vibration measurement-and-analysis system based on PC as hardware workbench, laboratory virtual instrument workbench (LabVIEW) developed by America National Instruments corporation as development software, essential sensor, signal conditioner and data acquisition cards.In this paper, firstly, the author gives a brief introduction on the theory and composition of vibration measurement-and-analysis systerm Digital Signal Processing(DSP) technique,and virtual instrument technique, then makes a deeper analysis and research on vibration measurement-and-analysis technique. Mode analysis is key point, author analyses stochastic subspace identification theory and illuminates the application in mode analysis, later gives a brief introduction in virtual instrument technique and LabVIEW software, finally defines the design process of vibration measurement -and-analysis hardware and software platform and makes a test validation.Test results prove that this system can implement functions such as data acquisition wave display,datastorage,data replay,mode analysis,print etc, based on LabVIEW software which provides stronger data processing function, and MATLAB software which provides plentiful mathematics operation functions.This measurement-and-analysis system is based on data acquisition cards (located in PC's slots) and LabVIEW software. This plan is fit for engineer and lab cause of advantages as follows: excellent expanding performance,high precision,and friendly interface.