Vibration Data Acquisition System Based On Wireless Technology

Environment of modern in-situ vibration measurement has become more complex, measurement points increased and the measurement range widened greatly with the coming forth of long, large, tall and flexile structures. Inevitability, it is a large waste of manpower and material resources if the vibration data acquisition still depends on the traditional wire transmission. Wireless transmission of experiment data based on the wireless technology, however, can make the measurement simplification and impel the development of measurement method research.Based on the fully analysis of modern wireless transmission technology and principle, reference of vast correlative papers and advanced wireless data transmission products in the world, summarization and reference of modem sensing technology and data acquisition technology, wireless data transmission module SA68D29M is selected, which satisfies the requirements of the modern in-situ vibration measurement.Wireless transmission between the data acquisition card and the upper computer is realized through the substitution of a couple of wireless data transmission modules for cables. As the remote forepart, data acquisition card not only has the ability of correspondence with wireless data transmission module and data signal serial port, but also has the ability of data conversation and data acquisition of sensor simulation signal under the acquisition frequency of 128Hz and 256Hz. The upper computer software of wireless data acquisition system is written in VB, which runs under WINDOWS operation system, makes the upper computer corresponds with wireless module through RS-232 serial port, and fulfills the acquisition and save of vibration signals. As the dialogue window of the operator and the computer, the software can select acquisition channels and frequency. The system introduces 991 ultra-low frequency pick up, and takes the vibration signal as the simulation input of practical measurement, which makes the system can measure the ultra-low frequency vibration of long, large, tall and flexible structures and the low frequency vibration of engineering and site. Enough measurement and comparison experiments of the whole system obtain satisfied results. The experiment results of sine and tremor signals under two acquisition frequencies are presented in the thesis.