旋转机械转速波动检测及故障诊断
Fluctuation Detection and Fault Diagnosis of Rotating Machinery

针对旋转机械运行转速波动导致信息获取及诊断决策困难问题，以非平稳信号的瞬时频率估计为切入点，结合快速路径优化算法进行非平稳信号的瞬时频率估计，以实现转速波动信息的准确获取。基于参数化时频分析理论的短时阶比原理，依据估计的振动信号瞬时频率变化函数构造匹配旋转算子，将转速波动信号的时频特征进行旋转，获得各时频窗内的短时阶次谱，进而完整保留转速波动信号的瞬态信息。仿真及实验结果表明，该方法可以准确提取出旋转机械转速波动工况下的状态信息及故障特征，为后续故障精密诊断奠定基础。
The rotation speed of a rotating machine frequently fluctuates when approaching the machine’s working speed. Current non-stationary signal processing methods hardly detect the rotation speed fluctuations. To tackle the shortage of existing instantaneous frequency evaluation methods, this paper adopts a fast path optimization algorithm for instantaneous frequencies of for non-stationary signals, which is verified with simulation signals and actually measured signals. On this basis the short-time order tracking principle of the parameterized time-frequency analysis theory is elaborated in this paper. Based on the instantaneous frequency variation function of the estimated vibration signals, this method can construct corresponding rotation operators to rotate the time-frequency characteristics of the rotation speed fluctuation signals. Moreover, it can obtain the short-time order tracking spectrum of each time-frequency window which reserves all instantaneous information of the rotation speed fluctuation signals. Experiment results show that this method can accurately extract the characteristics of typical failures of rotating machines under the working conditions of fluctuating rotation speeds, providing a decent precision and reliability.