H( Control Design of Flexible Rotor Magnetic Bearing System

A method to design robust controller for flexible rotor magnetic bearing system is considered using H8 multi-blocks standard problem optimization. We described how to take into account controller specifications such as disturbance rejection in bandwidth, modes damping, roll-off behaviour, model uncertainties, by elaborating an augmented plant model with supplementary degrees of freedom on the input and output of the flexible modes. A mathematical model of flexible rotor with six bending modes is taken as reference model and this approach allows to get a same order controller that we can reduce by an appropriate method. Continuous and digital syntheses are shown. This way should allow to conveniently tune closed loop behaviour while satisfying severe constraints on the control capability and should result in a practical realization for controller implementation.