µ-SYNTHESIS CONTROL OF FLEXIBLE MODES OF AMB ROTOR

Abstract: In the paper the optimal robust vibration control of flexible rotor supported by the active magnetic bearings (AMBs) is investigated. The purpose of the control system is stabilization of the high speed rotor and effective control of the rotor vibration due to noncollocation, gyroscopic effects and model uncertainties. The noncollocation effect is considered and frequency modal analysis of the noncollocated AMBs system with gyroscopic effects is presented. The µ-Synthesis control is applied to stabilize the rigid and flexible critical frequency modes of the rotor, with emphasis structural and parametric uncer-tainty. The input and output signals in AMBs system are limited by the weighting functions. The singular value analysis is used to obtain the robust performances of the closed-loop system. The stable operation and good stiffness of the high speed rotor supported magnetically is reached. The dynamical behaviour of the AMBs rotor is evaluated in the range up to 21 000 rpm. The experimental tests show the effectiveness of the robust control system as well as good vibrations reduction and robustness of the designed controllers. 1