Multi-fault diagnosis of rotor system based on differential-based empirical mode decomposition

Multi-fault diagnosis of rotor systems is a topical issue in the research of rotor dynamics. Empirical mode decomposition (EMD) has been introduced in fault diagnosis of rotor systems, which has proved to be usable and efficient in single fault diagnosis of a rotor system. However, in multi-fault diagnosis of a rotor system, because of the existence of a high-frequency fault signal, EMD is not as powerful as the diagnosis of a single fault in dealing with the decomposition of multi-faults. In this paper, differential-based empirical mode decomposition (DEMD) is introduced into multi-fault diagnosis of a rotor system. The analysis consequences show that the combination of any two faults among crack, rub-impact and pedestal looseness in multi-fault diagnosis can be decomposed successfully and efficiently under the application of the DEMD method, which is also more accurate and precise than the traditional EMD method.