Methods for condition monitoring and system-level diagnosis of electro-mechanical systems with multiple actuating components operating in multiple regimes

Abstract

The present invention discloses methods for condition-based monitoring of a system and its components using joint time-frequency analysis and signal demodulation. A first method allows construction of models of non-stationary signals having multiple time and frequency scales of interest. In particular, the method uses wavelet analysis to encode essential information in time-frequency transformations and provides a signal model for an operating fault or normal operation of a system of interest. A second method uses the signal models for condition-based monitoring to detect a change in a signal. In this method, the signal models are correlated with sensor signals to determine the operating condition of a system or system component. A third method for condition-based monitoring uses signal demodulation. In this method, a nominal response of a system component is subtracted from a detected signal to more reliably detect subtle changes in the signal due to component degradation.