Aiming at the problem that diesel engine misfire is difficult to diagnose under strong noise interference

a diesel engine misfire fault diagnosis method based on variational mode decomposition(VMD) and cross wavelet transform(XWT) is proposed. Firstly

cylinder head vibration signal is decomposed

denoised and reconstructed by VMD

and then the time-frequency correlation analysis on any two consecutive operating cycle signals is carried out by using XWT to extract the diesel combustion features after eliminating the interference noise in the vibration signal

and finally the diesel engine misfire fault diagnosis is performed by calculating the energy ratio of each cylinder in the time frequency space. Simulation and analysis results show that the method can eliminate the strong noise interference

extract the transient vibration shock features in diesel engine combustion cycle and effectively identify the diesel engine misfire fault.