Cepstrum-assisted empirical wavelet transform (CEWT)-based improved demodulation analysis for fault diagnostics of planetary gearboxes

•A cepstrum-assisted empirical wavelet transform (CEWT) is proposed for fault diagnostics.•Cepstrum is adopted to identify the modulation sideband clusters around gear mesh harmonics.•Envelope averaging is proposed to improve demodulation analysis for fault diagnostics.•Simulation and experimental results demonstrate the superiority of the proposed method for fault diagnostics.