Early Fault Detection of Planetary Gearbox Based on Acoustic Emission and Improved Variational Mode Decomposition

Abstract

Planetary gearbox is applied more and more extensively in the modern industry. Its condition directly determines the availability and the operation safety of the machinery system that utilizes it for power transmission. To enhance its reliability, an early fault detection method is proposed in this study, which is based on the acoustic emission (AE) technique and the improved variational mode decomposition (VMD). AE data are expected to contain more valuable information about the early fault than the vibration data. Mutual information is used to determine its layer that can avoid over-decomposition or under-decomposition. Then, energy entropy is used to analyze intrinsic mode functions extracted by the improved VMD. By comparing values of energy entropy, it is easy to distinguish different working conditions. The main contributions of this study include: 1) An improved VMD method for fault detection of planetary gearbox is proposed. 2) This method provides a novel strategy for detecting early fault in different positions of planetary gearbox by utilizing the advantages of AE technique.