基于实时校准技术的光纤光栅传感解调系统

报道了一种采用实时校准技术的数字化光纤光栅传感解调方案。解调系统利用锯齿波电压信号和数字相位同步信号控制可调谐光纤法布里一珀罗(TFFP)滤波器，对光纤光栅传感器阵列进行扫描式寻址，同时采用非测量环境中的参考光栅和数字温度计提供精确的参考波长，并由高速数字信号处理器(DSP)实时校准滤波器的波长读取值，很好地消除了滤波器渊谐的温度漂移、非线性和蠕动性引起的测量误差。结果表明，实验系统的波长寻址范围为1520～1570nm，扫描频率为100Hz，波长测量分辨率为5pm，应变测量分辨率为4．13με。

Demodulation System for Fiber Bragg Grating Sensors Based on a Real-Time Calibration Technique

This paper reports a digital demodulation scheme for interrogating fiber Bragg grating (FBG) sensors based on a real-time calibration technique. The system controls a tunable fiber Fabry-Perot filter (TFFP) with sawtooth wave voltage and synchronous signal of its digital phase to interrogate FBG sensors in a single fiber. Meantime, a reference FBG and a digital thermometer provide an accurate reference wavelength, which is used to calibrate the wavelength readout of the TFFP in real-time by a digital signal processor (DSP). This method eliminates the measurement error induced by temperature drift, nonlinearity and creepage of TFFP. The result demonstrates that this experimental system has scanning range of 1520～1570 nm, scanning frequency of 100 Hz, measured wavelength resolution of 5 pm, and measured strain resolution of 4.13 με.