Order analysis method based on instantaneous phase

Order analysis is an effective method to analyse non-stationary signal of rotating machinery. The key of this method is to acquire the time sequence under even angle re-sampling. This paper proposed an order analysis method based on instantaneous phase using HilbertHuang Transform (HHT), and achieved the order spectrums of torsional vibration signals of rotating machinery from simulation and experiment. Being different from the order analysis method based on instantaneous frequency, this method directly uses the instantaneous phases obtained by HHT to get rotating angle over time. Thus, it is faster and more convenient. Meanwhile, this method is less affected by the ‘boundary effect’. Hence, it can achieve higher precision. The simulating and experimental analysis both verified the feasibility and accuracy of this method.