A Novel Approach for Gearbox Compound Fault Diagnosis and Classification Using Multidimensional Vibration Signal: Integrating Two Stage NA-MEMD, IMPE-Correlation Based IMFs Selection, and W-kNN
摘要
This study presents a novel methodology for diagnosing and classifying compound gearbox faults under variable loading conditions. The research focuses on the simultaneous detection of pitting and full tooth breakage using multivariate vibration signals and evaluates the effectiveness of a two-stage NA-MEMD framework for improving diagnostic performance.
MethodsMultidimensional vibration signals were collected from a two-stage gearbox operating under torque loads of 0 Nm, 10 Nm, 20 Nm, and 30 Nm. A two-stage NA-MEMD decomposition approach was applied, and the most informative Intrinsic Mode Functions (IMFs) were selected using Improved Multiscale Permutation Entropy (IMPE) and correlation coefficient criteria. Features extracted from the reconstructed effective IMFs were classified using the W-kNN algorithm. FFT analysis was performed to identify gear mesh frequencies (GMFs), harmonics, and sidebands associated with compound faults. The proposed method was further compared with CEEMD.
ResultsThe two-stage decomposition strategy improved classification accuracy compared with the first-stage decomposition. Using RMS as the feature, accuracy increased by approximately 10.0%, 8.6%, and 6.2% under 10 Nm, 20 Nm, and 30 Nm loading conditions, respectively. FFT analysis successfully identified two fundamental GMFs and their harmonics corresponding to faults on different gearbox shafts. Comparative results demonstrated superior fault diagnostic capability of NA-MEMD over CEEMD.
ConclusionThe proposed framework provides a robust and effective approach for compound fault diagnosis in gearboxes operating under varying load conditions. The integration of multivariate signal decomposition, optimized IMF selection, frequency-domain analysis, and W-kNN classification significantly enhances fault detection and classification performance in noisy environments.