Adaptive time-scale decomposition and its application to gear fault diagnosis

Abstract:

Aiming at the problem of nonlinear, non-stationary and multi-components of fault gear vibration signal, and with defining the intrinsic time-scale function(ITF) whose instantaneous frequency has real physical significance, a new time-frequency analysis method named adaptive time-scale decomposition(ATD) is proposed based on the construction method of baseline signal of the intrinsic time scale decomposition (ITD). By the ATD method, a complex multi-components signal can be adaptively decomposed into the summation of a number of ITFs whose instantaneous frequencies own physical sense. The simulation results verify the effectiveness of the ATD method and the feasibility of the definition of ITF. Combined with envelop demodulation analysis, the ATD, the empirical mode decomposition(EMD), the local mean decomposition(LMD) and the intrinsic time scale decomposition(ITD) are respectively applied to the gear fault diagnosis. The experimental results show that the ATD method has obvious advantage in computational efficiency with the guarantee of decomposition correctness, and the method can effectively extract gear fault features combining with the envelope demodulation analysis.