Abstract:

Line spectra in the radiated noise of marine vessels are the most visible signs, which can be detected, tracked and identified by enemy’s passive sonar, and hence it is of great significance to reduce the line spectra for improving the acoustic stealth of marine vessels. In this paper, a anticontrol of chaos method based on chaotification is prososed for a vibration isolation system (VIS) of on board machinery to make the chaotic motion in nonlinear VIS persistent. In this way, the line spectra in the radiated noise can be reduced effectively because the response spectrum of a chaotic system under harmonic excitations is a continuous and reduced one. Numerical simulations are carried out and the results confirm the effectiveness of this method.

摘要：

船舶辐射水声中的线谱成分是被动声纳在水声对抗中检测、跟踪和识别目标的主要特征信号，对线谱成分进行控制能有效提高船舶的水声隐声性能。传统的隔振方法无法改变隔振系统的线谱成份，利用反馈混沌化控制原理，采用时变反馈参数的离散混沌化方法，通过调整和优化控制器参数，使基于柔性基础的隔振系统在谐波激励下能够产生稳定的混沌，改变通过隔振系统输入到船体的频谱结构，从而改变船舶辐射水声的频谱结构，并降低辐射水声中的线谱成分，达到有效降低辐射水声线谱成分的目的。

关键词: 振动与波, 线谱, 隔振, 柔性基础, 混沌