局域波法通过局域波分解和瞬时频率的求解,将任何复杂的信号分解成为有限数目并且具有一定物理意义的基本模式分量,每一个分量描述了时变信号中不同频率和尺度范围的固有振动模式,所获得的各分量局域波时频分布具有多分辨分析特征.由于局域波分解是自适应的,它的多分辨分析特征也是自适应的.经理论分析与对变速箱轴承座处拾取的振动信号的分析验证了方法的有效性,局域波法为工程测试中的时频分析提供了一种有效的手段.
Local wave method can decompose any complicated signal into a finite number of intrinsic mode functions(IMF) by using Local wave decomposition and defining instantaneous frequency and local wave functions, which is based on the instantaneous frequency of signals. Every IMF describes different frequency and scale of the inherence oscillation mode. Multi-resolution analysis of local wave time-frequency distribution can give enough information in both time domain and frequency domain. After theoretical analysis and experimental simulation, local wave method is proved to be efficient and can provide the engineering world good means for time-frequency analysis.