A Signal Processing Method for Frequencysweeping Interferometry
WANG Xuan-ze1,2,ZHANG Shuai1,ZHAI Zhong-sheng1,2,YANG Lian-gen1,2,LIU Wen-chao1,2
1.School of Mechanical Engineering, Hubei University of Technology, Wuhan, Hubei 430068, China;
2.Key Lab of Modern Manufacture Quality Engineering, Wuhan, Hubei 430068, China
Abstract：A signal processing algorithm is designed for the absolute distance measurement system performed with frequency-sweeping interferometry. The system adopts frequency scanned method based on current modulation，and a comparing optical path and a measuring optical path are used to measure synchronously.The two interference signals are converted into electrical signals by two photodetectors and are used as input signals for absolute distance calculation.The principle of the measuring system and the characters of interference signals are presented，the difference smoothing convolution is used for processing the signals twice and the absolute distance is determined by the period or frequency information extracted from interference signals produced while scanning the laser frequency.The period calculating error of this algorithm is analyzed.The experiment results demonstrate that this method has major computing advantages.
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2013, Vol. 34 
