Trajectory monitoring method of rotation shaft center based on swept-source optical coherence multi-point vibrometer

A trajectory monitoring method and system of rotation shaft center based on swept-source optical coherence multi-point vibrometer (SSOCMV) were proposed by the combination of frequency-division multiplexing technique and swept-source optical coherence vibrometer, which have advantages of non-contact, non-invasive, high accuracy and simultaneous muti-point vibration measurement. Firstly, the system composition and measurement principle of SSOCMV were introduced and analyzed. Then, the experimental comparison system was set up to verify the measurement accuracy of the SSOCMV system, and the eddy current sensor was installed in a symmetrical position of the probe of the SSOCMV system to synchronously monitor the trajectory of rotation shaft center, so as to compare the measurement results of these two systems. The experimental results show that the trajectory monitoring system of rotation shaft center based on SSOCMV has a higher displacement resolution and a better signal to noise ratio (SNR) than eddy current sensor. Therefore, the SSOCMV has a good application prospect in the rotating mechanical condition monitoring, parameter identification and fault diagnosis.