Inertial Centering of Magnetically Suspended Flexible Rotors

When an unbalanced flexible rotor reaches a steady state, where it is not vibrating but spinning with a constant geometric shape, it can be assumed (to some extent) a rigid body. Under this assumption, an inertial centering controller is developed for a general flexible AMB-rotor system with multiple mass imbalances. It is shown that in the absence of gyroscopic effects, the inertial center of a discretized flexible rotor can be observed as an independent set of coordinates with static and dynamic imbalance. However, more information is needed to implement an imbalance compensation in the presence of gyroscopic effects. In addition, the stability of the closed loop system is discussed and a case study of 8-DoF flexible rotor is presented. The theory is approved by numerical simulations which result in a complete suppression of more than 420N synchronous force.