The Study On The Separation Of Diesel Engine Noise Based On Blind Source Separation

The development of marine transportation, ships tend to be large-scale and automated. To guarantee the security of maritime transportation, it is necessary to enhance the reliability of the marine machinery, most of all, the marine diesel engine, which Powers for the ship. Acoustic diagnostic technique, analyses the noise signal of the diesel to watch the running condition of the diesel and make fault diagnosis. It uses the non-contact measurement, this approach has advantages of more flexible choices of the assignment of the sensors. But signals mix together when transport to the sensors, we need the individual signal but the mixed one. This article aims at picking up the individual signal from the diesel noise mixture to improve the reliability of the acoustic diagnostic.In this paper, Blind Source Separation is used to pick up the individual signal. Based on the study of Blind Source Separation, MATLAB is used to simulate the mixing and separating progress of audio signals; then we collect the noise signals of the diesel engine MAN 5S35ME-B9, adopting Blind Source Separation on the seven mixtures, we pick up the noise of combustion. At last, we adopt Blind Source Separation on the Acoustic Emission mixtures which collected from the NO.1 cylinder, and analyze the correspondence between the separated signals and the original signals. Conclusions are as follows:(1)The simulating results show that the separated signals are perfectly match to the original sources, thus Blind Source Separation can be used to separation the mixtures of the diesel engine noise.(2)When adopting Blind Source Separation on the seven mixtures, we pick up the noise of combustion. Thus Blind Source Separation can be used to separate diesel engine noise, but it fails to separate all the original noises due to the complex environment.(3) When adopting Blind Source Separation on the Acoustic Emission mixtures which collected from the NO.1 cylinder, we successfully separated the AE caused by combustion and the AE caused by the relative motion between the Piston ring and cylinder. This proves that Blind Source Separation can separate noise mixtures of the individual cylinder.Above all, Blind Source Separation can pick up individual signal from themixtures caused by diesel engine, combining Blind Source Separation with traditional fault diagnosis technique can surely develop the reliability of the diesel engine.