Time-frequency Domain Secondary Denoising Method for Engine Vibration Signals
This paper proposed a time-frequency domain quadratic denoising method for engine block vibration signals.The vibration signals will be denoised twice from time domain and frequency domain.In the time domain denoising process,the envelope derivative operator and the concept of short-time energy were first used to identi-fy and segment the noise signal and the working feature signal in the time domain,and then the Non-Local Mean(NLM)method was used to achieve denoising.In the frequency domain denoising process,the vibration signal was extracted based on Time Varying Filtering-Empirical Mode Decomposition(TVF-EMD).Then a new NLM method with differential entropy was proposed for adaptive denoising of the extracted intrinsic mode functions.The proposed denoising method was used to analyze the measured vibration signals of diesel engine body.The re-sults showed that the method has remarkable denoising effect in time-frequency domain,and has great application potential in diesel engine condition monitoring and fault feature extraction.
EngineVibration signal denoisingTime-frequency characteristicsNLMTVF-EMD
NETL
NSTL
万方数据
