Spectral analysis for non-stationary signals from mechanical measurements: A parametric approach

Non-parametric time-frequency methods for spectral estimation are increasingly used in the analysis of non-stationary signals. However, neither have their performance and limits of application been completely investigated nor has a comparison with other methods, such as parametric ones, been clearly established. This paper deals with the analysis of nonstationary signals of interest in mechanics, and more specifically, the performance of some non-parametric methods widely used for this analysis will be discussed; an autoregressive time-varying method, improved with respect to the classical parametric implementation, will be presented and its potential in analysing signals coming from mechanical systems will be shown; the performance of parametric and non-parametric methods will be compared. (C) 1999 Academic Press.