THE APPLICATION OF SOME NON-LINEAR METHODS IN ROTATING MACHINERY FAULT DIAGNOSIS

In this paper, some non-linear diagnostic methods for rotating machinery are introduced and evaluated from the view of diagnostic practice. The methods are pseudo-phase portrait, singular spectrum analysis and correlation dimension. The pseudo-phase portrait is simple, easy to draw, and is sensitive to some fault types. Singular spectrum analysis can reveal the complexity of a signal. By means of singular spectrum analysis one can reduce the noise of a signal. Correlation dimension can provide some intrinsic information of an underlying dynamical system, and can be used to classify different faults intelligently. Examples show that all these methods are advantageous in the field of non-linear diagnostics. Therefore, it is quite reasonable for effective fault diagnosis to use non-linear diagnostic methods in addition to the methods currently used, such as orbit portrait, FFT spectra, time–frequency analysis, etc.