Misfire Fault Diagnosis for Diesel Engine Based on EMD of Exhaust Noise

In view of misfire fault diagnosis for diesel engine,the misfire fault in actual vehicle was simulated,the exhaust noise signals in different conditions were analyzed by using empirical mode decomposition(EMD),and the instantaneous frequency function of main intrinsic mode fraction(IMF) was obtained by Hilbert transform.A diagnosis method for misfire fault of diesel engine was proposed by using the fluctuation variance and average transcendental ratio of instantaneous frequency function against the base frequency of periodic exhaust noise as characteristic parameters.The result indicates that this method is effective and feasible.