Identification and control of a flexible rotor supported on active magnetic bearings

The focus of this paper is the development and demonstration of adaptive control algorithms for active magnetic bearings (AMBs) that account for uncertainties associated with flexible vibration modes. The flexible rotor and electromechanical actuators were designed and verified using finite element analysis (FEA). The reduced-order adaptation algorithm is attractive for flexible rotor systems as it eliminates the need for explicitly modeling large numbers of modes. An adaptive multivariable controller is developed to levitate a flexible rotor supported on AMBs and track reference inputs. The control strategy adapts to modeling uncertainties and parameter variations, and uses this knowledge to improve overall system performance. Model parameters are identified on-line using recursive least squares, and are used to update a self-tuning pole-placement controller. A flexible rotor AMB test rig is designed and fabricated to experimentally validate the system identification and control algorithms