Real-time self-calibration PGC-Arctan demodulation algorithm in fiber-optic interferometric sensors
Real-time self-calibration PGC-Arctan demodulation algorithm in fiber-optic interferometric sensors
复制标题
光纤干涉传感器中的实时自校准PGC-Arctan解调算法
DOI：
10.1364/oe.27.023593
复制
发表时间：
2019-08-05
期刊：
影响因子：
3.8
通讯作者：
Yuan, Libo
中科院分区：
文献类型：
--
作者：
Qu, Zhiyu;Guo, Shuai;Yuan, Libo
光纤干涉传感器（FOIS）广泛应用于地震仪、水听器和陀螺仪。相位生成载波的反正切解调算法是FOIS解调的关键技术之一。传统的PGC-Arctan解调算法需要相位调制深度C的特定值才能正常工作。但在实际工作环境中，C会随激光波长、温度、湿度等因素的变化而变化，导致谐波失真，甚至解调失败。提出了一种新的PGC解调算法--自校准PGC-Arctan（PGC-Arctan-SC）解调算法。该算法利用椭圆参数和C相关分量联合估计准确的C值，同时利用椭圆拟合算法（EFA）抑制非线性失真。然后，可以通过闭环比例积分微分（PID）模块将C校准到特定的预定义的最优值。仿真结果与理论分析一致，并在嵌入式SoC上实现了全数字PGC-Arctan-SC解调系统。实验结果表明，C可以真实的实时准确估计和校准。PGC-Arctan-SC解调输出的信噪比（SINAD）达到61.57 dB。(C)根据OSA开放获取出版协议的条款，2019年美国光学学会
Fiber-optic interferometric sensors (FOISs) are widely used in seismometers, hydrophones, and gyroscopes. The arctangent approach of phase-generated carrier (PGC-Arctan) demodulation algorithm is one of the key demodulation techniques in FOISs. The conventional PGC-Arctan demodulation algorithm requires the specific value of the phase modulation depth C to work properly. However, C will variate with laser wavelength, temperature, and humidity in the actual working environment, which leads to harmonic distortion and even demodulation failure. In this paper, a novel PGC demodulation algorithm called self-calibration PGC-Arctan (PGC-Arctan-SC) demodulation algorithm is presented. The proposed algorithm can jointly estimate the accurate C value by the elliptical parameters and C-related components while suppressing nonlinear distortion by ellipse fitting algorithm (EFA). Then C can be calibrated to the specific predefined optimal value by the closed-loop proportion integration differentiation (PID) module. The simulation results are consistent with theoretical analysis, and the all-digital PGC-Arctan-SC demodulation system is implemented on the embedded SoC. The experimental results show that C can be estimated and calibrated accurately in real time. The signal-to-noise and distortion ratio (SINAD) of the PGC-Arctan-SC demodulation output achieves 61.57 dB. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement