Fault detection in complex mechanical systems such as wind turbine gearboxes remains challenging, even with the recently significant advancement of sensing and signal processing technologies. For example, the non-stationary nature of the wind load may require the joint time-frequency domain feature extraction methods for the signals collected from the gearbox. In this paper, a harmonic wavelet based method is adopted, and a speed profile masking technique is developed to account for tachometer readings and gear meshing relationship. In such a way, those features with fault-related physical meanings can be highlighted. While multiple sensors yield redundant features, we fuse them through a statistical weighting approach based on principal component analysis. The fused data are fed to a simple decision making algorithm to verify the effectiveness. Using experimental data collected from a gearbox testbed emulating wind turbine operation, we can detect gear faults statistically for a given confidence level.

This content is only available via PDF.
You do not currently have access to this content.