Development of a novel knock characteristic detection method for gasoline engines based on wavelet-denoising and EMD decomposition

The main contribution of this paper is inventing a novel knock characteristic extraction method using vibration signals. Engine knock reduces the thermal efficiency and restricts performance improvement of a gasoline engine. Reliable and rapid detection of engine knock characteristics (including light knock) is key for the engine knock control. Based on the wavelet-denoising and empirical mode decomposition (EMD) methods and the analysis results, this paper discovers that the wavelet-denoising can eliminate the high frequency noise that was not generated by the engine knock. After the wavelet-denoising, EMD decomposition can effectively identify the knock characteristics (include the light knock) from a vibration signal. Compared to existing knock detection methods, the new method in this paper can reduce the computational time while ensuring the reliability of the knock detection.