Application of Bicoherence Analysis on Vibration Data for Condition Based Monitoring of Rotating Machinery

摘要

Bicoherence or Bispectrum analysis is emerging as a new powerful technique in signal processing, especially in areas where traditional linear spectral analysis provides insufficient information. It is most effective in analyzing systems with non-linear coupling between frequencies. Faults in rotating machineries leave their signature on the vibration signal sensors and generally manifest themselves as a non-linear transformation in the vibration signal. Bicoherence analysis detects and quantifies the presence of non-linearity in the signal and thus indicates the severity of the fault in the machine. This paper demonstrates the use of bicoherence analysis on both simulated and rig-generated vibration data from a rub-effected rotor-stator system, and shows the application of bicoherence analysis on industrial data from final tailing pumps to detect impeller wear in an oil-sands plant.