基于三次Hermite插值的局部特征尺度分解方法

Local Characteristic-scale Decomposition Method Based on Cubic Hermite Interpolation

内禀时间尺度分解(Intrinsic time-scale decomposition,简称ITD)方法采用线性变换获得基线信号,使得分解结果出现毛刺和瞬时频率失真现象。因此,在定义瞬时频率具有物理意义的内禀尺度分量(Intrinsic scale component,简称ISC)基础上,提出基于三次Hermite插值的局部特征尺度分解方法(Cubic Hermite interpolation-Local characteristicscale decomposition,简称CHLCD),该方法能够自适应地将一个复杂信号分解为若干个瞬时频率具有物理意义的内禀尺度分量之和。首先对CHLCD方法的原理进行分析,然后给出采用CHLCD对信号进行分解的详细步骤,最后采用仿真信号和滚动轴承信号对CHLCD进行验证,结果表明了CHLCD方法的有效性。

Since linear transformation is used to obtain baseline signal in intrinsic time scale decomposition (ITD) method, burr and instantaneous frequency distortion will appear in the decomposition results. Therefore, a rational Cubic Hermite interpolation-Local characteristic-scale decomposition (CHLCD) method is presented. In this method, any complex signal can be adaptively decomposed into a sum of several independent rational intrinsic scale components (ISCs), whose instantaneous frequencies have obvious physical meanings. Firstly, the principle of the CHLCD method was analyzed. Then, the detailed steps of CHLCD of signal were given. Finally, a simulation signal was adopted to verify the CHLCD method. Experimental results show that the CHLCD method can effectively decompose signals.