Pseudo Wigner-Ville Time-Frequency Distribution and Its Application to Machinery Condition Monitoring

Abstract

Machinery operating in a nonstationary mode generates a signature that at each instant of time has a distinct frequency. A Time-frequency domain representation is needed to characterize such a signature. Pseudo Wigner-Ville distribution is ideally suited for portraying a nonstationary signal in the time-frequency domain and is carried out by adapting the fast Fourier transform algorithm. The important parameters affecting the pseudo Wigner-Ville distribution are discussed and sensitivity analyses are also performed. Practical examples of an actual transient signal are used to illustrate its dynamic features jointly in time and frequency.