Robust UDE-based control of active magnetic bearing for flywheel applications

In this paper, a feedback linearization control strategy, robustified by an uncertainty and disturbance estimator (UDE) is proposed for a two axis active magnetic bearing (AMB). An experimentally derived dynamical model of an AMB, employed in a flywheel, is utilized. The couplings between the axes as well as the uncertainties are treated as additional disturbances to the system. These terms are quickly estimated and compensated by an UDE observer, allowing the classical feedback linearization controller to operate on a nearly nominal system. Extended simulation results are presented to demonstrate the feasibility and effectiveness of the proposed control structure.