基于BOTDA的海缆监测系统振动信号降噪方法研究

Research on Noise Reduction Method of Vibration Signal in Submarine Cable Monitoring System Based on BOTDA

摘要:

搭建了基于布里渊光时域分析(BOTDA)的海底电缆(海缆)振动信号监测模拟实验系统,通过实验获得了锚砸、冲刷、摩擦3种工况下的海缆振动信号。针对振动信号含有大量噪声,提出TSA-VMD-MPE降噪方法。利用被囊群算法(Tunicate Swarm Algorithm,TSA)优化变分模态分解(Variational Mode Decomposition,VMD),获取VMD分解层数与惩罚因子的最优值,对振动信号分解获得本征模态函数(Intrinsic Mode Functions,IMF)分量；利用IMF与原始信号的相关性及IMF的方差贡献率联合来确定IMF的多尺度排列熵(Multi-Scale Permutation Entropy,MPE)阈值,对振动实验信号进行降噪。实验结果表明:所提降噪算法使3种海缆振动信号信噪比平均提高了12.0296dB；将提出的MPE阈值方法应用于EEMD与CEEMD算法也获得了良好的降噪效果。

Abstract:

A monitoring experiment system of submarine cable vibration signal was set up based on Brillouin optical time domain analysis (BOTDA). The vibration signals of submarine cable under three working conditions of anchor smashing, scouring and friction were obtained. The TSA-VMD-MPE method was proposed to reduce the noise of vibration signal. The tunicate swarm algorithm (TSA) was applied to optimize decomposition level and penalty factor of variational mode decomposition (VMD) to obtain intrinsic mode functions (IMF) components. The correlation between the IMF and original signal, and the IMF variance contribution rate were considered comprehensively to determine the multi-scale permutation entropy (MPE) threshold to reduce the noise of the vibration experimental signal. The experimental results show that the signal-to-noise ratio of the three kinds of submarine cable vibration signals is improved by 12.0296dB on average. The proposed MPE threshold determination method was applied to EEMD and CEEMD algorithms, and good noise reduction effect was obtained.