Multivariable Disturbance Observer Based Control with the Experiment on an Active Magnetic Bearing Spindle

Abstract

This paper presents a new method of disturbance observer based control (DOBC) for multi-input-multi-output (MIMO) highly-coupled unstable systems based on the game theory and the H-infinity synthesis. First motivated by the Youla parameterization of full order state observer feedback control, a full order state observer (FOSO) based DOBC is proposed for single-input-single-output (SISO) systems. Then inspired by the FOSO based DOBC design, a disturbance decoupling method is proposed for MIMO systems using game theoretic observer design. By using error dynamics from the proposed observers, single-input-multi-output (SIMO) virtual plants are constructed. Inverses of those virtual plants for a certain bandwidth are found by solving the model matching problem using H-infinity solver. The proposed DOBC is applied to an open loop unstable MIMO Active Magnetic Bearing Spindle (AMBS). Simulation and experimental results show that the disturbances are effectively estimated and compensated.