Stabilization of Centrifuges with Instabilities Dueto Fluid-Structure Interactions: VariousControl Approaches

摘要

Partially filled centrifuges exhibit unstable behavior over particular rotational speedranges. To remove this unstable behavior, three different control approaches arepresented which are experimentally implemented using a magnetic bearing. First, bymeans of a PD-controller the system stiffness is changed leading to a shift of the instabilityregion. Second, the instability region is removed by a cross coupled feed backof the rotor vibration velocities. This cross coupling directly counteracts the fluid excitationmechanism. Third, a disturbance observer is presented which allows to estimateand compensate the not exactly known fluid force.