基于非线性混沌理论的非平稳信号的比较分析

COMPARATIVE ANALYSES OF NON- STATIONARY SIGNALS BASED ON NONLINEAR CHAOTIC THEORIES

本文研究采用基于非线性混沌理论的两种非线性参数估计方法(代替数据法和Lyapunov指数估计法)对非平稳信号进行分析.首先对上述两种非线性方法的具体算法进行介绍,然后对两组本质不同的非平稳振动信号进行对比分析.这两组信号是通过测试具有不同非线性约束边界条件的薄壁构件获得.分析结果表明,在时域波形上直观相似的非平稳信号,用上述非线性混沌分析的方法可以有效地加以定量区分.

In the paper,two nonlinear estimation methods based on nonlinear chaotic theory,surrogate data method and Lyapunov exponents,are used to distinguish the difference of non-stationary signals.After brief introduction of the corresponding algorithms,two typical different non-stationary signals measured from a thin-plate structure with different nonlinear constraining boundaries are taken to compare by using the above two methods respectively.The obtained results demonstrate that the apparently similar signals are distinguished effectively in quantitative way with applying above nonlinear chaotic analyses.