【摘要】 提出一种基于局部特征尺度分解(Local characteristic-scale decomposition,LCD)和经验包络(Empirical envelope method,EE)解调的非平稳信号分析方法。该方法通过局部特征尺度分解将一个复杂信号自适应地分解为若干个内禀尺度分量之和,对得到的各个内禀尺度分量进行经验包络解调,得到各个分量信号的瞬时幅值和瞬时频率信息,从而得到原始信号完整的时频分布。采用仿真信号将基于LCD和EE解调的时频分析方法和希尔伯特黄变换方法进行对比,结果表明,新提出的信号分解和解调方法在抑制端点效应和迭代所需时间,瞬时特征的精确性等方面优于希尔伯特黄变换方法。针对滚动轴承和齿轮故障振动信号的调制特点,将基于LCD和EE的时频分析方法引入机械故障诊断中,对试验信号的分析结果表明,基于LCD和EE的时频分析方法能有效地提取机械故障振动信号的特征。更多还原

【Abstract】 Based on the local characteristic-scale decomposition(LCD) and the empirical envelope(EE) demodulation,a new non-stationary signal analysis method is put forward.By using the LCD a complex signal can be decomposed adaptively into some intrinsic scale components(ISC) and a trend.The EE technique is utilized to demodulate the ISCs and the instantaneous amplitudes and frequencies of them are obtained.The whole time-frequency distribution of the original signal is acquired.The newly proposed approach is compared with the Hilbert-Huang transforms(HHT) method as well by analyzing the simulation signals.The results indicate that the newly proposed method is superior to the HHT method in restraining the end effect,iteration time and the accuracy of the instantaneous characteristics.The time-frequency method based on the LCD and EE demodulation is applied to the mechanical fault diagnosis.By analyzing the experimental data,the results show that the time-frequency method based on the LCD and the EE demodulation approach can extract the fault characteristics of mechanical vibration signals and can fulfill the fault diagnosis efficiently.更多还原