内燃机稳定工况下缸盖振动信号的3种时频分析技术比较研究

推导了3种联合时频分析技术——解析小波变换(AWT)、S变换(ST)、高斯窗STFT之间的精确关系,实现了S变换与AWT在数值算法上的统一。分析了稳态工况下内燃机振动信号的特点,并将3种技术用于实测信号,对它们在稳态下内燃机振动信号分析的适应性进行了探讨。研究结果表明:STFT的等分辨率特性对于稳态下内燃机振动信号时频分析而言未必是不利的,相反它有可能在时间分辨率牺牲不大的情况下对瞬态事件激起的响应分量频率进行更准确的定位。

Comparison of Three Time-Frequency Analysis Techniques for Engine Cylinder Head Vibration Signals under Stable Conditions

The precise relationships among three joint time-frequency analysis techniques,i.e.analytic wavelet transform(AWT),S transform(ST),Gaussian windowed STFT,were derived,the numerical implementations of AWT and ST were united,then the characteristics of IC engine vibration signals under stable conditions were examined.The three techniques were applied to real signals to be compared.It shows that equal resolution of STFT is not necessarily an adverse aspect for time-frequency analysis of these signals,to the co...