将经验模态分解方法(EMD)和分数阶Fourier变换基本理论相结合,提出一种基于分数阶Fourier变换的经验模态分解的机械故障诊断方法.仿真结果表明,提出的方法是有效的,尤其是对于用EMD分解方法无法进行有效分解的信号.如果时频平面旋转一定的角度,将信号从EMD难以分离的区域变换到可以用EMD分解有效识别的区域,然后经过EMD分解和分数阶Fourier反变换,就可以实现分量的提取.诊断实例进一步验证方法的有效性.
Combining empirical mode decomposition(EMD) and fractional Fourier transform,a new fault diagnosis method based on fractional empirical mode decomposition is proposed.The proposed method is compared with the conventional time-frequency analysis method.The simulation result shows that the proposed method is very effective,especially for signal which can hardly be decomposed by conventional EMD method.The proposed method rotates the signal in the time-frequency plane,and transforms the signal from the hardly decomposable domain to easily decomposable domain,the component of the signal can be effectively extracted by EMD and fractional Fourier reverse transform.The experimental results further have verified the validity of the proposed method.