Abstract: The HILBERT-HUANG transform consists of two steps: empirical mode decomposition (EMD) and HILBERT tr- ansform. The end effects produce both in the decomposition process of EMD and HILBERT transforms applied to the intrinsic mode functions (IMFs). A novel wave characteristic matching extending method is proposed to overcome the end effects of EMD and HILBERT transform. Therefore, the decomposition precision is improved, the accurate instantaneous frequencies and instantaneous amplitudes could be obtained. The extending data derived from the original signal by the simple algorithm, only once extending needed in HILBERT-HUANG transform processing. The simulation and fault test analysis demonstrate the effectiveness of the method.

Key words: End effects, Characteristic matching, Empirical mode decomposition, Fault diagnosis, HILBERT-HUANG transform