Robust Control and Loop Shaping Design with the Application to Flexible Rotor Levitated with AMBs

The aim of this research is to ensure stable operation at a nominal rotation speed (above the first critical speed) of a flexible rotor levitated with active magnetic bearings (AMBs) and to guarantee good performance of the rotor/AMB system. Initially, minimizing the ITAE performance index, PID control system is designed to stabilize the rotor. The obtained transfer function is adopted as a compensator to shape the singular values of the nominal plant. By applying the Glover-McFarlane control method, a robust controller which includes coprime factor uncertainties is designed. The results show that the AMB system satisfies Zone A specifications defined by the ISO 14839 standard for newly commissioned machines with magnetic bearings.