A cyclic angle-frequency methodology for the analysis of IC engine vibrations

The aim of this paper is to propose a methodology for vibration analysis of internal combustion engines. The main issue is to deal with nonstationary mechanical vibrations. For this purpose, special attention is paid to the first conditional spectral moments of the Wigner-Ville distribution and guidelines are given to interpret them. The proposed methodology is applied to the diagnosis of petrol and diesel engine malfunctions. It should be useful for condition monitoring, diagnosis and noise analysis of reciprocating engines, in the same way as spectral analysis is for rotating machinery.