基于广义解调时频分析和瞬时频率计算的阶次谱方法在齿轮故障诊断中的应用

Application of order spectrum method based on generalized demodulation time-frequency analysis and instantaneous frequency calculation to gear fault diagnosis

针对齿轮启停过程中故障振动信号的调频特性,提出了基于广义解调时频分析和瞬时频率计算的阶次谱方法,并将其应用于齿轮瞬态信号的分析。广义解调时频分析是一种新的时频分析方法,它可以将多分量的信号分解为若干个瞬时频率具有物理意义的单分量信号,每个单分量信号可以是调幅-调频信号,因此非常适合处理多分量的调幅-调频信号。而当齿轮发生故障时,其启停过程中的振动信号就表现为多分量的调幅-调频特征。在基于广义解调时频分析和瞬时频率计算的阶次谱方法中,首先采用广义解调时频分析方法将齿轮瞬态信号分解为若干个单分量信号,然后计算各个分量的瞬时频率,再对其瞬时频率信号进行重采样,最后对重采样信号进行频谱分析得到阶次谱,从而提取齿轮振动信号的故障特征,判断齿轮的工作状态。仿真信号和实验信号的分析结果表明了该方法的有效性。

Taking into consideration the frequency modulation characteristics of the gear fault vibration signal in the start-stop process,the order spectrum method based on the generalized demodulation time-frequency analysis and the instantaneous frequency calculation was proposed and applied to process gear transient signals.When gear fault occurs,the gear vibration signal in the start-stop process presents the multi-component amplitude and frequency modulated characteristics.In the order spectrum method presented,the vibration signal of a fault gear,which is a multi-component signal,was decomposed into some single-component signals by using the generalized demodulation time-frequency analysis method;the instantaneous frequency of each single-component signal was calculated;each instantaneous frequency signal was resampled in angle-domain;and the spectrum analysis was applied to each resampled signal to achieve the order spectrum.The fault characteristics of the gear vibration signal can be then obtained and the gear working state can be subsequently identified according to the order spectrum.The analysis results of the simulated and experimental signals show the effectiveness of the proposed method.