scholarly journals A method of suppressing vibration for high precision broadband laser frequency scanning interferometry

2016 ◽  
Vol 65 (20) ◽  
pp. 209501
Author(s):  
Liu Guo-Dong ◽  
Xu Xin-Ke ◽  
Liu Bing-Guo ◽  
Chen Feng-Dong ◽  
Hu Tao ◽  
...  
Keyword(s):  
High Precision ◽  
Laser Frequency ◽  
Frequency Scanning ◽  
Broadband Laser ◽  
Frequency Scanning Interferometry

scholarly journals Absolute Distance Measurement Using Frequency-Scanning Interferometry Based on Hilbert Phase Subdivision

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5132 ◽  
Author(s):  
Shuo Jiang ◽  
Bo Liu ◽  
Huachuang Wang ◽  
Bin Zhao
Keyword(s):  
Laser Frequency ◽  
Optical Path Difference ◽  
Path Difference ◽  
Distance Measurement ◽  
Beat Signal ◽  
Interference Signal ◽  
Time Points ◽  
Frequency Scanning ◽  
Frequency Scanning Interferometry ◽  
External Clock

In order to eliminate the influence of laser frequency nonlinearity, the frequency-scanning interferometry (FSI) often uses the beat signal of an auxiliary interferometer as the external clock. The time points at every amplitude peaks and bottoms of the auxiliary beat signal are selected as the sampling time points for the main interferometer signal. To satisfy the Nyquist sampling requirement, the optical path difference (OPD) of the delay fiber in auxiliary interferometer should be at least twice longer than the measurement distance. In this paper, we proposed a method to shorten the length of delay fiber. The Hilbert transform was used to extract the phase of the auxiliary interference signal and calculate the time points corresponding to subdivided phase intervals. Then, the main interference signal was resampled at these moments, and the fast Fourier transform was performed on the resampled signal. The experimental results showed that the target at the distance of about 5 m was measured when the OPD of the auxiliary interferometer was about 4.5 m. The standard deviation of the distance measurement results could reach 4.64 μm.

scholarly journals An efficient method for the compensation of dispersion mismatch in the frequency-scanning interferometry

2021 ◽  
Author(s):  
Qiang Zhou ◽  
Tengfei Wu ◽  
Yang Liu ◽  
yue shang ◽  
Jiarui Lin ◽  
...  
Keyword(s):  
Efficient Method ◽  
Frequency Scanning ◽  
Frequency Scanning Interferometry

scholarly journals Vibration Compensation of the Frequency-Scanning-Interferometry-Based Absolute Ranging System

2019 ◽  
Vol 9 (1) ◽  
pp. 147 ◽  
Author(s):  
Fu-Min Zhang ◽  
Ya-Ting Li ◽  
Hao Pan ◽  
Chun-Zhao Shi ◽  
Xing-Hua Qu
Keyword(s):  
Standard Deviation ◽  
Vibration Frequency ◽  
Phase Modulation ◽  
Vibration Velocity ◽  
Sinusoidal Vibration ◽  
Vibration Effect ◽  
Frequency Scanning ◽  
Blind Area ◽  
Frequency Scanning Interferometry ◽  
Vibration Compensation

The frequency-scanning-interferometry-based (FSI-based) absolute ranging technology is a type of ranging technology possessing a high precision and no ranging blind area, so it can be used for non-cooperative targets. However, due to a tiny movement of a target, the Doppler shift and the phase modulation are introduced into the beat signal which results in ranging accuracy decrease. In order to solve this problem, first the model of vibration effect is established, and then the beat signals of two adjacent scanning periods are processed to produce a signal that is immune to vibration. The proposed method is verified by the experiments, and the experimental results show that the effect of vibration compensation is better for the target with a lower vibration velocity and at a lower vibration frequency (lower than 6 Hz). When the target is subjected to a sinusoidal vibration with an amplitude of 10 μm at a frequency of 1 Hz, by using the proposed method the standard deviation is reduced from 775 to 12 μm. Moreover, in the natural environment, by using vibration compensation the standard deviation is reduced from 289 to 11 μm.

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