Time-Frequency Domain Analysis of Vibration Signals for Machinery Diagnostics. 1:Introduction to the Wigner-Ville Distribution

摘要

The definition and some of the properties of the Wigner-Ville distribution forboth continuous and discrete signals are reported. A digital computer program implementing the discrete Wigner-Ville distribution is described and its performance is demonstrated by the analysis in the time frequency domain of a series of numerically generated test signals, showing the form of the Wigner-Ville distribution and the interference terms which can be generated due to its nonlinear behavior. The program is then applied to the analysis in the time frequency domain of experimentally measured time domain averages of the vibration of damaged gears in industrial and helicopter gearboxes, in order to detect early signs of impending mechanical failure. It is shown that the damage to the gears can be detected by visual inspection of the changes which occur in the pattern of the Wigner-Ville distribution, but that the damage can be detected more quickly and easily using an existing narrow band enhancement technique.