高精度光纤光栅振动解调系统研究与应用

为实现工程系统中对振动信号的检测，提出了一种基于衍射光栅的光纤布拉格光栅(FBG)振动解调系统。解调系统通过色散成像原理获取传感器反射光谱，由所设计的嵌入式单元进行信号处理，并通过专用的上位机解调软件完成数据处理与分析。将系统封装为解调仪器，能实际应用于振动信号的探测。所设计的系统波长解调范围为1 525～1 570 nm,波长重复性可达±1 pm,分辨率为0.5 pm,可实现8通道复用测量，最高光谱解调速度可达10 kHz。实验结果表明，该FBG振动解调系统能够高精度测量不同频率与幅度的振动信号，最小可探测应变约为0.319με/Hz^1/2,在结构安全监测等领域具有重要的应用前景。

Research and application of high-resolution fiber Bragg grating vibration demodulation system

To realize the detection of vibration signals in engineering systems, a fiber Bragg grating (FBG) vibration demodulation system based on diffraction grating is proposed. The demodulation system acquires the sensor reflection spectrum through the dispersion imaging principle, and the signal processing is carried out by the designed embedded unit, while the data processing and analysis are completed by the special upper computer demodulation software. The system is packaged as a demodulation instrument, which can be practically applied to the detection of vibration signal. The designed sensing system has a wavelength demodulation range from 1525 to 1570 nm, a wavelength repeatability of ±1 pm, a resolution of 0.5 pm, 8-channel multiplexing with a maximum spectral demodulation speed of 10 kHz. The experimental results show that the proposed FBG vibration sensing system can be used for high-accuracy measurements of vibration signals of different frequencies and amplitudes with a minimum detectable strain of about 0.319 /Hz1/2, which has potential applications in the field of structural health monitoring.