非平稳数据处理方法与瞬时频率

利用“经验模式分解”(EMD)方法,任何复杂的数集都能够被分解为有限且通常数量较少的“本征模式函数”。“本征模式函数”产生瞬时频率,最终结果表示为H ilbert谱规定的能量-频率-时间分布。应用“经验模式分解”方法表示自然现象中的传统非线性平衡系统及其数据的数值结果,同时给出实例展示了这种新方法的作用和效果。这种方法阐明了能量-频率-时间分布,进一步显示出对非线性非平稳系统的处理效果———精确化、形象化和可视化。

Non-stationary Data Processing Methods and Instantaneous Frequency

By using the empirical mode decomposition method,any complicated data set can be decomposed into a finite and often small number of intrinsic mode functions that admit well-behaved Hilbert transforms.The intrinsic mode functions yield instantaneous frequencies.The final presentation of the results is an energy-frequency-time distribution,designated as the Hilbert spectrum.Examples from the numerical results of the classical nonlinear equation systems and data representing natural phenomena are given to demonstrate the power of this new method.Classical nonlinear system data are especially interesting, for they serve to illustrate the roles played by the nonlinear and non-stationary effects in the energy-frequency-time distribution.The effect of this method for nonlinear and non-stationary system is exact,visual and obvious.