μ synthesis of flexible rotor-magnetic bearing systems

The μ synthesis design method was evaluated for a flexible rotor magnetic bearing system with a five-axis-control system using both simulations and experiments. After modeling the full-order system using the finite element method, the autors obtained a reduced-order model in the modal domain by truncating the flexible modes. After choosing appropriate weighting functions with respect to frequency, they designed the μ-synthesis control system using the μ-toolbox in MATLAB. They then carried out simulations of the control system for a flexible rotor magnetic bearing system with a five-axis-control system and obtained good performance. Next, they conducted experiments to verify the robustness of the controllers on a test rig during initial levitation. The μ controllers provided robust stability and performance over a wide range of parameter variations in the test rig