Analysis method of a nonstationary waveform its application to engine vibration signals

This paper describes an analysis method of nonstationary waveforms based on a modulation model. First, a nonstationary waveform is represented by a waveform equation using the Vandermonde matrix and waveform vectors. Waveform parameters of amplitude, frequency and phase are all defined to be time-dependent. Second, a description method is then given of waveform features. Normalizations are carried out on waveform parameters using a fundamental vibration component. A complex vector is defined to describe a feature of the waveform. The proposed algorithm is applied to the analysis of automobile engine vibration signals