Spectroscopy and Spectral Analysis, Volume. 40, Issue 4, 1007(2020)
The Slight Vibrations Compensation of FMCW Ranging Method Based on Three Light Paths Structure
The re-sample frequency modulation technology is a kind of ranging method. The optical structure of this method has boarder frequency modulated bandwidth, higher spatial resolution and accuracy. However, in the processing of practice measurement, the re-sample measurement device and the object to be measured are easily disturbed by the vibration from the outside environment. This paper analyses the influence of the Doppler error and the re-sample frequency error from vibration. In order to compensate these errors from the two kinds of vibrations, we present a vibration compensation method based on three light paths structure, this method brings two partial reflectors on the measurement light path to produce two compensatory lights, and the Doppler error and the auxiliary fiber error can be reduced by the differential value of the measurement signal and the compensation signals. The experiment verifies that the ranging accuracy of the typical re-sample method is 23.6 μm, and the ranging accuracy of the three-light-paths ranging method can achieve to 11 μm. It is proved that the three-light-paths ranging method can effectively compensate the vibration error of the measurement system.
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ZHANG Tong, QU Xing-hua, ZHANG Fu-min. The Slight Vibrations Compensation of FMCW Ranging Method Based on Three Light Paths Structure[J]. Spectroscopy and Spectral Analysis, 2020, 40(4): 1007
Received: Mar. 14, 2019
Accepted: --
Published Online: Dec. 10, 2020
The Author Email: Fu-min ZHANG (zhangfumin@tju.edu.cn)