Study And Development Of Programmer Control Dynamic Strain Measurement System Based On The Virtual Instrument

Strain measurement is one of the important means that analyses accessory or structure stress, validates structural intensity and stiffness, confirms complete machine load status when working or studies physical phenomenon mechanism in mechanical engineering. So with quick speed developing high-powered strain measuring instruments is needed. The paper firstly introduces the strain measurement present status and developing trend at home and abroad, analyses traditional hardware-based instrument for strain measurement key feature and existing shortages. Subsequently introduce the theory method of strain measurement and correlative signal processing knowledge. At the same time introduces conception, characteristic of virtual instrument technology.The virtual instrument and hardware-based instrument are contrasted, which stands out the superiority of virtual instrument. The virtual instrument is a sign that measurement system is transforming from hardware-based system to software-based system. Then bring forward changing tradition hardware-based instrument by virtual instrument technology, developing the strain measurement instrument based on virtual instrument technology.In this paper, it expatiate logic structure and software and hardware design of virtual strain measurement system. The instrument system using MCU implantation control technique and latest USB bus gather technique design complete. Those parameters of bridge balance, gain control, bridge voltage and low frequency through filter are controlled by computer software. Analysis software function include time domain, frequency domain amplitude item, at same time, Making use of the hard dish imitates process function same as magnetic tape record compete calculator, its function is powerful。In MicroSoft Visual C++ development platform using LabWindows/CVI software design method develop the virtual strain measurement instrument that its figure is true to nature, The software contains as follows function mold:Establishing document mark mold, single passage oscilloscope show mold, many passages oscilloscope show mold, data processing module and history data analysis and display function mold, time zone double tracking and double channels analysis mold. The system can realize real-time measurement for many parameters that correlate with strain. It can realize integration for sampling and processing of signal, visualization for data and result. At the same time within instrument do experiment on site testing, do error analysis to test result, bring forward resolve method and measure. It stand out that software is a pith of virtual instrument. The applied cost of virtual strain measurement system based on component technology is stressed. Lastly bring forward the further development of system that is distributing network measurementEngineering practice make show that virtual strain measurement instrument have the features that its function is powerful, its precision is high, its efficiency is high, its cost is low and its openness and expansibility is good. It can replace traditional hardware-based instrument for strain measurement completely, is a measurement instrument that can be extended abroad.