高速度高精度光纤布拉格光栅解调的寻峰算法研究

为实现高速度、高精度的光纤光栅传感解调,提出了一种基于状态机的自适应半峰检测寻峰算法。算法通过对FBG反射波形的实时跟踪确定波形数据,通过对波形数据的统计分析得到寻峰阈值,通过校验与补偿精确得到峰值位置。实验测试表明,对于2kHz的解调速度,解调分辨率达到1pm,静态噪声在±2pm以内,长时间测试的稳定性误差在2pm以内,系统动态范围在0～-30db,光功率衰减导致的稳定性误差在4pm以内。这表明,本算法从速度、精度、抗干扰性、稳定性等方面都能够满足高速解调的需要。

Research on peak-detection algorithm for high-speed and high-precision FBG demodulation

To satisfy the requirements of high-speed and high-precision demodulation applications,an adaptive semi-peak-seek algorithm based on state machine is proposed.The proposed algorithm determines the waveform data by real-time tracking of the FBG reflection waveform.Through statistical analysis of the waveform data,a peak-seek threshold can be achieved,and then the precise position of the peak can be obtained by means of calibration and compensation.From the experimental results,the demodulation distinguishability can reach 1 pm while the demodulation speed is 2 kHz,at the same time the static noise is less than ±2 pm.The stability error of less than 2 pm is concluded in a long term test.As the system dynamic range is from 0 to ~-30 dB,the measurement error within the dynamic range is limited to 4 pm.Thus,the requirements of high-speed demodulation,such as speed,precision,stability and anti-interference properties,can be achieved by this algorithm.