Research on Time-Frequency Characteristics of Engine Induction Noise and Time-Frequency Representation of the Acoustic Signals

It is necessary to have both time and frequency domain information from measured acoustic signals of internal combustion engine (ICE) for noise, vibration and harshness (NVH) performance improvement and evaluation. This paper focuses on the time-frequency representation (TFR) of acoustic signals and the study of engine induction noise characteristics. The time-frequency analysis techniques, like the short-time Fourier transform (STFT) and continuous wavelet transform (WT), are reviewed in this paper. It shows that the engine induction noise is typical of non-stationary and the time-frequency method is significant to reveal the temporal localization of the signal's spectral components and to predict the engine physical phenomena. The TFR of the induction noise signal with STFT and CWT and the time-frequency characteristics are shown in this paper.