Computation of multi-rotor vibration phase under a single key phase measurement condition and its application in aero-engine

Abstract

The vibration phase is essential for fault diagnosis (e.g., rotor unbalance, rotor misalignment) and dynamic balancing. Accurate phase calculation relies on obtaining the key phase pulse signal associated with each rotor’s key phase reference point, capturing the phase zero point once per revolution. In complex gear systems, only some rotors’ key phase signals are measurable, which complicates the calculation of other rotors’ vibration phases. To address this challenge, we propose a method for calculating the multi-rotor vibration phase under a single key phase measurement condition. First, a phase zero point synchronization marking method is introduced to identify each rotor’s physical phase reference point. Then, a phase compensation calculation method based on the target rotor’s rotation angle is developed under a single key phase measurement condition. This method accounts for computer rounding errors when calculating the target rotor’s rotation angle. Finally, using the collected vibration data, key phase signal, and calculated phase compensation values, the cross-correlation method determines the target rotor’s vibration phase. Experimental results from the gear system test rig and aero-engine equipment validate the effectiveness of the proposed method, demonstrating that the vibration phase of multiple rotors can be accurately calculated with an error of less than 5°.