一种非定比多轴系自适应阶比分析方法的研究

Method of Adaptive Order Tracking for the Variable-ratio and Multi-axis System

非定比旋转机械故障多为非平稳信号,无法使用常规的特征提取方法进行有效分析,需要阶比分析方法对其进行采样。在非定比传动系统中存在多种轴系,因此需要进行多轴阶比分析。本文利用Wigner-Ville分布对振动信号进行时频分析,较大程度改善振动信号瞬时频率估计的精度。对获得的时频分布进行峰值搜索,自适应的获取不同阶比分量的峰值。最后,利用最小二乘法对获得的频率分量进行多项式拟合,经重采样后再进行快速傅里叶变换最终实现阶比分析。该方法避免了传统频谱分析中出现的频率模糊现象,提高了分析精度,为非定比多轴系传动系统故障诊断提供了一种新的方法。

The faults of variable-ratio rotary machinery are mostly non-stationary signals. It can not be analyzed effectively according to conventional methods of feature extraction. Therefore, it needs the method of ratio tracking to sample signals. There is more than one axis system in the variable-ratio transmission system. The multi-axis order tracking is needed. The time-frequency distribution obtained by Wigner-Ville analysis method can improve the precision of instantaneous frequency estimation about vibration signals. Ac- cording to the frequency peak coordinate, the peaks of different orders can be obtained adaptively. The different frequency compo- nents are fitted based on the least square polynomial. After re-sampling, order tracking spectrums are achieved by FFT. The method avoids the fuzzy phenomenon of frequency in the traditional frequency analysis. It improves the precision of analysis and provides a new method for fault diagnosis of the variable-ratio and multi-axis transmission system.