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为提高爆震检测精度,研究了离散小波变换在爆震信号分析中的应用.利用离散小波变换从汽油机的振动信号中提取出了轻微爆震特征,提出了一种根据离散小波变换特征域子带信号能量大小来评价爆震强度的指标,根据爆震发生时特征域子带信号能量阶跃变化的特性,提出了确定爆震阈值的方法,该方法经检验能准确判断发生爆震的临界值.研究成果为将小波变换应用于汽油机爆震的实时精确控制打下基础,可进一步通过点火提前控制使汽油机在轻微爆震区工作,汽油机的动力性、经济性都能够得到提高.
In order to improve the detonation detection precision, the application of discrete wavelet transform in knocking signal analysis is studied.The discrete wavelet transform is used to extract the slight detonation characteristics from the vibration signal of gasoline engine, and a new method based on the discrete wavelet transform domain According to the characteristics of the step energy of the sub-band signal in the characteristic domain when the detonation occurs, a method of determining the detonation threshold is proposed. The method can accurately determine the detonation threshold The research results provide a foundation for applying wavelet transform to real-time precise control of gasoline engine knocking, and can further improve the power and economy of the gasoline engine by operating ignition pre-ignition control in a slight detonation zone.