Study On Laser Doppler Vibrometer Photoelectric Signal Processing And Application

Laser Doppler vibrometer is an instrument for measuring vibration of object using laser Doppler effect, it has advantages such as high spatial resolution and fast response speed etc. and now it has been widely used in many fields such as aerospace, military, road and bridge monitoring, health and medical and so on.The actual vibration of object includes one-dimensional vibration,two-dimensional vibration and 3D vibration, therefore laser Doppler vibrometer includes one-dimensional, two-dimensional and three-dimensional vibration instruments, but due to the technical gap, three-dimensional laser Doppler vibrometer has not yet formed in China. Therefore, research and development of three dimensional laser Doppler vibrometer, not only has broad market prospects, has great significance.The paper introduces the research status of laser Doppler vibrometer and laser Doppler vibration technology at home and abroad. The theoretical knowledge of laser Doppler effect was mathematical derived, and expounds the basic principles of single point laser Doppler vibrometer and three-dimensional laser Doppler vibrometer. Through comparison analysis of the optical path of single point laser Doppler vibrometer, the optical path of laser Doppler vibrometer was determined, and the optical path was verified by ZEMAX software, through comparing and analyzing vibration signal processing methods,the laser vibrometer signal processing method which adapted complex frequency based on the FFT the is determined, and by LabVIEW and MATLAB programming for simulation of analog signal, proves that the signal processing method is feasible. According to the requirement of signal processing, the test system is set up, and the signal processing software of the upper computer is completed by using LabVIEW programming.The experimental results show that the vibration frequency measurement accuracy of the experimental equipment is 0.82%, the speed measurement accuracy is 1um/s, and the displacement measurement accuracy is 0.32 nm underthe condition of 20 k Hz. The average error is 1.72%.