Gearbox fault detection based on EMD and Hilbert demodulation

LIU Zujing, JIA Minping, XV Feiyun

(School of Mechanical Engineering, Southeast University, Nanjing 211189, China)

Abstract: Aiming at solving the problem that the complex fault signal of gearbox is difficult to detect, a fault diagnosis method based on empirical mode decomposition(EMD) and Hilbert demodulation was presented. Firstly, the EMD was used to decompose the original complex signal to obtain the intrinsic mode functions(IMFs). Secondly, the Hilbert demodulation technique was applied to the selected IMFs to extract the modulated signal. Then, the gearbox faults can be diagnosed by the frequency of the extracted signal. Thirdly, with setting the meshing frequency as the center frequency, a band pass filter was used to filter the signal which was reconstructed by some selected IMFs based on the cross correlation coefficient. And then, the Hilbert demodulation was used again to extract the modulating signal to verify the diagnosed result. The results of applying to a real inspected signal indicate that this method is effective in gearbox fault detection.

Key words: gearbox; empirical mode decomposition(EMD); Hilbert demodulation; fault diagnosis