基于HHT的舰船地震波信号实时检测算法

Real-time Detection Algorithm for Ship Seismic Wave Signal Based on HHT

摘要:

针对舰船地震波信号的非平稳性，将希尔伯特–黄变换(HHT)应用于舰船地震波信号处理中， 并基于 Hilbert 能量谱提出舰船地震波信号实时检测算法。首先，对实测地震波信号进行 HHT 分析，获得信号的时频谱、边际谱、瞬时能量谱以及 Hilbert 能量谱。然后，基于舰船地震波信号 Hilbert 能量谱的特点，选取 Hilbert 能量谱中特定频带内的能量作为检测特征量，利用滑动窗截取数据更新特征量和相应的自适应阈值。 最终，根据一定的检测规则，提出了舰船地震波信号的实时检测算法。实测数据和仿真数据表明：该检测算法能够实时地完成对目标信号的检测，具有较远的检测距离，且在信噪比为–10 dB 时，检测概率达到 100%。

关键词:舰船地震波;HHT 能量谱;检测特征量;自适应阈值

Abstract:

Aiming at the non-stationarity of ship seismic wave signal，Hilbert-Huang transform(HHT)is applied to the ship seismic wave signal analysis，and the real-time detection algorithm for ship seismic wave signal is proposed based on Hilbert energy spectrum. First，the HHT analysis of the measured seismic wave signal is performed to obtain the time spectrum，the marginal spectrum，the instantaneous energy spectrum and the Hilbert energy spectrum of the signal. Then，based on the characteristics of the Hilbert energy spectrum of the ship seismic wave signal，the energy in the specific frequency band of the Hilbert energy spectrum is selected as the detection feature quantity，and the sliding window is used to update the feature quantity and the corresponding adaptive threshold value. Finally，according to certain detection rules，a real-time detection algorithm for ship seismic wave signals is proposed. The measured data and simulation data show that the detection algorithm can complete the detection of the target signal in real time and has a far detection distance. The detection probability reaches 100% when the signal-to-noise ratio is –10 dB.

Key words:ship seismic signal;HHT;detection feature quantity;adaptive threshold value