Vibration Analysis Based on Differential Evolution Mode Decomposition for Crack Identification of Helicopter Planetary Gearboxes

As a core deceleration component of the transmission system, planetary gear trains' fault monitoring is crucial for helicopter flight safety. However, the complex and unique gear transmission structure causes vibration signals to exhibit extremely complicated signal forms. To address the problem of extracting fault features in a complex signal background, a Differential Evolution Variational Mode Decomposition (DEVMD) based method is proposed for monitoring the planetary gear train faults in helicopters. The method integrates the Overlapping Group Shrinkage (OGS) algorithm as a pre-filter to suppress background noise and combines the high-performance mode decomposition capability of DEVMD to strip out signal components from other rotating parts, obtaining planetary gear train fault-sensitive signal components. Finally, the higher-order differential energy kurtosis is extracted as a fault indicator for monitoring the planetary gear train faults in helicopters. The experimental results prove the effectiveness of the method.