基于反馈混沌化方法的多线谱控制技术研究

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,混沌线谱控制技术利用混沌系统响应功率谱为宽频谱的特殊性质,把集中于某一频率的能量分散到较宽的频带上来抑制线谱成分,提高船舶的声隐身性能。利用反馈混沌化理论,对多谐波激励条件下隔振系统的混沌化进行了研究,提出了多谐波激励多自由度隔振系统的反馈混沌化方法,掌握了隔振系统进入混沌的条件和途径,突破了激励频率增加引起隔振系统混沌运动难以保持的技术难题。根据反馈混沌化原理设计了双层隔振系统试验装置,开展了隔振系统多线谱控制试验研究,试验结果证明了该方法的有效性,可作为混沌隔振系统设计的理论和试验依据。

Multi-line spectra reduction of vibration isolation system based on chaotification method

Line spectra in the radiated noise of marine vessels are the most visible signals,which can be detected,tracked and identified by passive sonar of the enemy,and hence it is of great significance to reduce the line spectra for improving the acoustic stealth of marine vessels.The technology of chaos spectra reduction was used to reduce line spectra in the radiated noise of submarines based on the fact that response spectrum of a nonlinear system under harmonic excitation is a continuous one when chaos occurs.The feedback chaotification of the single-degree-of-freedom vibration system and multi-degree-of-freedom vibration systems subjected to harmonic excitation were analyzed,and the chaotification method of the multi-degree-of-freedom vibration system subjected to multi-frequency excitation was proposed.The study discovered the condition and approach that the vibration system enters the chaos state subjected controller effect,and overcome the difficulties that how to maintain the chaotic motion when the operation condition and the environment change.The experimental platform of the two-degreeoffreedom VIS for discretization and chaotification was designed,and the dynamics of the system with different feedback plus was experimentally studied.The results confirmed the effectiveness of this method,and can provide the theoretical and experimental bases of design for chaos VIS.