改进的椭圆拟合算法及振动传感相位解调  

Modified Ellipse Fitting Algorithm and Phase Demodulation of Vibration Sensing

作　　者：梅泽 吕海飞 文晓艳 黎敏[1] Mei Ze;Lv Haifei;Wen Xiaoyan;Li Min(School of Science,Wuhan University of Technology,Wuhan,Hubei 430070,China)

机构地区：[1]武汉理工大学理学院,湖北武汉430070

出　　处：《光学学报》2021年第24期102-107,共6页Acta Optica Sinica

基　　金：国家自然科学基金(62075174,11974266,11704293)。

摘　　要：已有的椭圆拟合算法利用李萨如图形解决了非理想3×3耦合器带来的解调结果误差问题,但是当信号变弱时,所对应的李萨如图形将偏离椭圆,造成解调困难。针对相位变化量极小的弱信号,基于同一系统中李萨如图形唯一的特点,提出利用参考信号确定椭圆参数并精准实现弱信号解调的改进椭圆拟合算法。实验结果显示,相较于常规椭圆拟合算法,改进的算法可以准确地解调弱振动信号,使探测分辨率提高400倍,且解调的相位与应变存在良好的线性关系。研究结果表明改进的算法可以很好地解决常规椭圆拟合算法无法解调弱信号的问题,提高了系统的测量分辨率。The existing ellipse fitting algorithm uses the Lissajous figure to solve the demodulation error caused by the non-ideal 3×3 coupler.However,it is difficult to demodulate the signal when it is weak and the corresponding Lissajous figure deviates from the ellipse.This paper proposes a modified ellipse fitting algorithm on the basis of a fixed Lissajous figure for the same system.The algorithm uses the reference signal to determine ellipse parameters and thereby accurately demodulate the weak signal with small phase changes.The experimental results show that compared with the conventional ellipse fitting algorithm,the modified algorithm can accurately demodulate the signals with weak vibration.The detection resolution is increased by 400 times and the demodulated phase has a good linear relationship with the strain.The results prove that the modified algorithm solves the problem that the conventional ellipse fitting algorithm cannot demodulate weak signals and improves the measurement resolution of the system.

关 键 词：测量 相位解调 非理想3×3耦合器 椭圆拟合算法 弱信号探测 振动传感 

分 类 号：O436[机械工程—光学工程]