Separation of piston-slap and combustion shock excitations via MEEMD method

A modified ensemble empirical mode decomposition(MEEMD) was proposed here,and its basic principles were discussed.Numerical simulation showed that MEEMD is a better adaptive signal decomposed method,not only suppresses the mode mixing problem of EMD,but also overcomes non-IMFs,mode splitting and noise residue problems of EEMD.MEEMD was then used to analyze vibration signals of a diesel engine.The analysis results showed that the mechanical excitation component induced by piston-slap can be successfully separated from the combustion shock excitation component,and the main vibration sources can be obtained.