The μ approach to control of active magnetic bearings

Many important industrial problems in the control of rotating machinery with active magnetic bearings concern the minimization of the rotor vibration response to poorly characterized disturbances at a single or several shaft locations, these typically not corresponding to those of a sensor or actuator. Herein, the examine experimental results of a multivariable controller obtained via mu synthesis with a laboratory test rig. These indicate that a significant improvement in performance can be obtained with a multivariable mu controller over that achieved with an optimal decentralized PD controller.