Misalignment Detection of Rotor System Based on Adaptive Input-output Model Identification of Motor Speed

Traditionally, the misalignment detection of rotor system is based on vibration signal analysis. However, the vibration-based method is high-cost and limited by the installation space due to the need of vibration sensors. To solve the problems, this paper employs the speed signal which has already been collected for motor control to detect the misalignment. Furthermore, fault features, the speed ripples related to rotation frequency f
_r
and its second-harmonic 2f
_r
, are modeled using input-output identification method. Compared to Fast Fourier Transform, the amount of data needed is greatly reduced. The effectiveness of the proposed method is validated with the experimental platform.