Study Of Laser Nano-Vibration Measurement Method Based On Virtual Instrument Technology

The measurement of micro-vibration is significant to our life,it can be used to forecast the earthquake and detect micro-vibration caused by gravitation wave.With the rapid development of modern engineering technology,especially development of aviation,aerospace, marine engineering,machinery manufacture,and other technology, micro-low-frequency vibration measurement increasingly shows its importance.This paper combined with interferometry technology,virtual instrument technology,computer technology and digital signal processing,from the point of view of simplification,practicality, high-precision,high-sensitivity,to construct a low-frequency vibration laser interferometer measurement system with the hardware and software platform.Based on the phase generate carrier modulation (PGC) principle and virtual instrument technology,laser vibration measurement signal demodulation hardware and software processing platform was established.The experiment results indicate that the PGC signal demodulation scheme based on virtual instrument technology reduced drift and noise by traditional analog PGC hardware circuit such as analog multiplier and differentiator,enhanced accuracy of signal demodulation, improved system Signal-to-Noise.High accuracy measurement of the low-frequency vibration signals ranging from 10-200Hz comes true,the measuring resolution is better than 0.5nm,and the dynamic range is 100dB.