局部特征尺度分解方法及其在齿轮故障诊断中的应用

在定义瞬时频率具有物理意义的单分量信号——内禀尺度分量(Intrinsic scale component,ISC)的基础上,提出一种新的自适应信号分解方法——局部特征尺度分解(Local characteristic-scale decomposition,LCD)。LCD方法可以自适应地将任何一个复杂信号分解为若干个瞬时频率具有物理意义的ISC分量之和,非常适合于处理多分量的调幅—调频信号。当齿轮发生故障时,其振动信号一般为多分量的调幅—调频信号,因此局部特征尺度分解方法可以有效地应用于齿轮故障诊断。对LCD和经验模态分解(Empirical mode decomposition,EMD)、局部均值分解(Local mean decomposition,LMD)方法进行对比,结果表明了LCD方法的优越性。同时,针对齿轮故障振动信号的调制特征,将LCD方法和包络分析法相结合应用于齿轮故障诊断,对实际的齿轮故障振动信号进行分析,结果表明LCD方法可以有效地应用于齿轮故障诊断。

Local Characteristic-scale Decomposition Method and Its Application to Gear Fault Diagnosis

Based on the definition of the non-component signal,namely intrinsic scale component(ISC) whose instantaneous frequencies own physical sense,a newly self-adaptive signal decomposition method,the local characteristic-scale decomposition(LCD) is proposed.LCD can decompose any complicated signal into a number of ISC whose instantaneous frequencies own physical sense and is especially suitable for processing the multi-component amplitude-modulated and frequency-modulated signal.Since the gear fault vibration signal is multi-component amplitude-modulated and frequency-modulated signal,the local characteristic-scale decomposition method is especially applicable for the gear fault diagnosis.The LCD method is compared with the empirical mode decomposition(EMD) and the local mean decomposition(LMD) method;then the results show the superiority of the LCD method.Simultaneously,aiming at the modulated features of the gear fault vibration signal,the LCD is combined with the envelope analysis method and applied to the gear fault diagnosis.The analysis results from the actual gear fault vibration signal demonstrate that the LCD method can be applied to the gear fault diagnosis effectively.