Design Of Virtual Experiment System On Acquisition And Analysis Of The Audio Signal Based On LabVIEW

In recent years, virtual instrument is gradually used in science and engineering classrooms and laboratories in domestic institutions of higher learning, and a growing number of schools cooperate with NI (National Instruments), spend hundreds of thousands or even millions RMB in purchasing virtual apparatus products from NI and form a virtual laboratory. The developers design virtual experiments on professional characteristics suitable in virtual instrumentation development platform LabVIEW (Laboratory Virtual instrument Engineering).The acquisition equipment from NI has a good performance, but constructing virtual experimental system will cause high cost. If the ordinary sound card with data transmission and A/D converter functions could be used for building virtual experiment system, it not only makes the process simple, but also greatly reduces the construction cost.Based on the above analysis, from the perspective of cost-effective, this thesis uses sound card as a general data acquisition equipment of the audio signal acquisition, designs the virtual experiment system based on LabVIEW, and implements it in the signal analysis experiments.The main contents are listed as follows:(1) An envisage for using sound card as a virtual data acquisition equipment to construct the experimental system is put forward. The necessity and feasibility by the sound card system to set up virtual experiment based on research of teaching program of experiments in the number of traditional college is analyzed.(2) Virtual audio signal acquisition and analyze experimental system is constructed based on LabVIEW. The experimental system has functions of virtual signal acquisition, analysis, waveform display, storage and transfer of data files to meet the needs of the experimental teaching.(3) The key issue of the system Construction is studied. Signal acquisition is basis of data analysis of the entire system. For the problems that common PC sound card is not real-time called in the LabVIEW, a method of calling CIN nodes on the audio signal to achieve the real-time data acquisition is raised.