Fault Diagnosis Method for Rolling Bearings in Helicopter Based on VMD-SE and DE-ELM

Aiming at difficulty in characteristic frequency extraction of fault for helicopter swashplate rolling bearings with a number of steel balls under low speed,the fault diagnosis forthe bearings is carried out based on VMD-SE and DE-ELM.Firstly,the variation mode decomposition is used to decompose vibration signal,the mode number is selected by center frequency method,and the features of mode components are extracted by sample entropy.Then,the differential evolution algorithm is used to optimize ELM.Finally,the real data are measured by research group to carry out fault diagnosis experiments.The results show that compared with ELM and BA-ELM methods,the bearing fault recognition rate obtained by DE-ELM method is more than 99％ in the case of fewer hidden nodes,and the validity of method is verified for fault diagnosis of helicopter swashplate rolling bearings.