Unbalancing estimation in active magnetic bearings

This paper deals with state reconstruction of a discrete linear time varying system which is influenced by constant disturbance adding to control input, and sinusoidal perturbations on measure signals. The process under consideration is composed of a horizontal rotating shaft, suspended by means of active magnetic bearings, that requires a control scheme. The control scheme is based on static state feedback, whose parameters are function of speed rotation in order to maintain fixed dynamic behavior independent of the evolution of the process dynamic and variations of the coupling terms. To determine the unmeasured components of state vector, a time varying observer including disturbance reconstruction has been set up