基于线调频小波路径追踪阶比循环平稳解调的滚动轴承故障诊断

针对变转速工况下滚动轴承的故障诊断问题,提出一种将线调频小波路径追踪算法与阶比循环平稳解调方法相结合的滚动轴承故障诊断方法.该方法先利用线调频小波路径追踪算法提取轴承的故障特征频率,再根据轴承的故障特征频率对变转速下时域振动信号的包络在角域等角度重采样,并对获取的角域平稳信号进行循环平稳解调,计算得到切片解调谱;最后根据切片解调谱识别滚动轴承故障.仿真分析和应用实例表明:该方法能准确提取变转速工况下滚动轴承的外圈与内圈故障故障特征,提取效果明显优于基于Wigner-Ville峰值跟踪法的包络阶次谱方法.

Fault diagnosis of roller bearings based on chirplet path pursuit and order cyclostationary demodulation

Aim at the problem of fault diagnosis of roller bearings with rotating speed fluctuation, a method for the fault diagnosis of roller bearings was proposed by combining the chirplet path pursuit algorithm with the order cyclostationary demodulation method. In this proposed method, the chirplet path pursuit algorithm was used to obtain the bearing fault characteristic frequency. According to the bearing fault characteristic frequency, the envelope of the time domain vibration signal with rotating speed fluctuation was resampled at constant angle increments in angular domain, and the obtained angular domain steady signal was dealt by cyclostationary demodulation. The slice demodulation spectrum was then acquired and used to diagnose the fault of roller bearings. Simulation analysis and application examples show that the proposed method can exactly extract the outer and inner fault characteristics of roller bearings with rotating speed fluctuation. Compared with the envelope order spectrum method based on Wigner-Ville distribution, the proposed method can obtain more distinct fault characteristic of roller bearings.