未知参数的舰船辐射噪声线谱Duffing振子检测方法

当被动声呐探测舰船目标时,舰船辐射噪声中的线谱成分是舰船分类识别及航行状态监测的特征参量,通常情况下线谱的频率及数量是未知的。针对现有未知频率的Duffing振子检测方法存在系统结构复杂,判别时间长,需要人为参与等问题,本文构造了变参数单一Duffing振子检测模型,并提出了变频频率切片小波变换的Duffing振子检测方法。该方法通过设置合理的频率灵敏度参数自动地调整系统内置策动力频率值,利用频率切片小波变换提升系统抗噪性能,结合Poincare映射特征函数的系统相态定量判决方法,变频搜索待测信号中的线谱分量。在实测数据的分析处理中,对不同观测时间内的数据进行检测,实现了线谱成分的检测跟踪与频率估计,并根据时间轨迹上的频率识别信息确定存在的稳定线谱成分。数据处理结果表明,该方法能够实现低信噪比下参数未知线谱的检测与频率估计。

The detection method of ship-radiated noise line spectrum based on Duffing oscillator

The passive detection of the line spectrum with unknown parameters by using Duffing oscillator was studied.The line spectrum of ship-radiated noise is an important characteristic parameter of ship classi⁃fication and navigation monitoring in the circumstances of sonar detecting ship targets passively.Usually,the frequency and the quantity of line spectrum are unknown.Aiming at resolving the problems with the current Duffing oscillator system in detecting unknown frequency signal,such as complex structure,lengthy distin⁃guishment and the need for human participation,a single Duffing oscillator detection model with variable pa⁃rameters is constructed,and a Duffing oscillator detection method with variable frequency scanning based on frequency slice wavelet transform was proposed.By setting a parameter of the frequency sensitivity,the fre⁃quency of the system driving force is adjusted automatically,and combining with the PMCF method,the com⁃ponents of the line spectrum are automatically detected.In this method,the anti-noise performance of the system can be improved by using the frequency slice wavelet transformation.In the processing of the mea⁃sured data,the method is used to detect data at different observation times in order to detect and trace the line spectrum and estimate frequency.The stable line spectrum is identified according to the frequency infor⁃mation on the time track.The processing results show that the method is feasible and effective.