THE INTERPRETATION OF BISPECTRA OF VIBRATION SIGNALS .2. EXPERIMENTAL RESULTS AND APPLICATIONS

Bispectral analysis is emerging as a new powerful technique in signal processing, offering insight into non-linear coupling between frequencies and having potential applications in many areas where traditional linear (i.e. power spectral) analysis provides insufficient information. However, it is more difficult to interpret bispectral features than power spectral features, and this has hindered the applications of the theory. In this paper a normalised bispectral measure is used in the analysis of vibration signals containing periodic components and noise. Part I of the paper presented bispectral features associated with various signal types, and discussed practical matters regarding the choice of sampling rate. In Part II these theoretical results are used to interpret the bispectra of data collected from a variety of vibration sources, showing that there is potential for using these measures for machine condition monitoring.