Research Article

Joint Amplitude and Frequency Demodulation Analysis Based on Variational Mode Decomposition for Multifault Diagnosis of a Multistage Reducer

Figure 5

Normal vibration signal analysis: (a) time-domain waveform of original vibration signal, (b) time-domain waveform of filtered vibration signal, (c) spectrum of filtered vibration signal, (d) envelope spectrum of filtered vibration signal, (e) time-domain and time-frequency VMD decomposition images, (f) envelope of VIMF1, and (g) envelope of VIMF3.
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