1005-0086
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FBG振动传感器相位生成载波 解调算法研究
Research on phase generation carrier demodulation algorithm for FBG vibration sensor
为避免相位载波解调算法在解算FBG振动传感器信号时，调制深度不稳定导致的FBG中心波长解算存在的较大误差，本文提出了一种相位载波解调-反正切-寻峰（PGC-Arctan-FP）联合解调的算法。首先，将光路的输出信号分别与载波信号的基频和二倍频率相乘，经过低通滤波器，得到含有待测振动信息的不同幅值的正交信号；其次，对该正交信号逐一寻峰，分别计算两路信号的幅值均值，将幅值均值与两路信号交叉相乘，使正交信号幅度平齐；最后，进行反正切运算和高通滤波处理，准确解算出FBG中心波长的变化频率和幅度。通过仿真和实验验证了该算法的可行性。该算法可以准确解算100 ~ 1000 Hz的振动信号，FBG波长解算相对误差小于0.81%，可以有效避免调制深度起伏对算法解算精度的影响。
This paper proposes a PGC-arctangent-peak seeking (PGC-Arctan-FP) joint demodulation algorithm. The algorithm avoids the large errors in calculating the FBG’s center wavelength caused by the unstable modulation depth when the phase-generated carrier (PGC) method is used to demodulate FBG vibration sensors. Firstly, the output signal of the optical path multiplied with the fundamental frequency and the two-fold frequency of the carrier signal respectively. Then passing them through the low-pass filter to obtain quadrature signals of different amplitude containing the information to be measured. After that, the peaks of this orthogonal signal are searched one by one. The average amplitude of the two signals is calculated separately. The average amplitude is cross multiplied of the two signals to make the quadrature signals equal in amplitude. Finally, the frequency and amplitude of the FBG stretch are accurately solved after an inverse tangent operation and high-pass filtering. The feasibility of the PGC-Arctan-PS algorithm is verified by simulation and experiment. This algorithm can accurately solve the vibration signal from 100 Hz to 1000 Hz, and the relative error of FBG wavelength calculation is less than 0.81%. The PGC-Arctan-FP algorithm can effectively avoid the influence of unstable modulation depth on the solution accuracy.
FBG；相位生成载波解调；反正切算法；寻峰法
fiber bragg grating; phase generation carrier demodulation; phase generated carrie; peak search
段志霞,徐郁盛
Wang Wei,Xu yu sheng
1.济源职业技术学院基础部;2.西安工业大学光电工程学院
1.Basic Courses Department, Jiyuan Vocational &Technology College;2.School of Optoelectronic Engineering, Xi an Technological University
gdzjg/article/abstract/20230530