Model-based fuzzy control system design for magnetic bearings

This paper describes the application of a model-based fuzzy control technique to active magnetic bearing systems. The stabilization problem of the magnetic bearing systems is reduced to a two degrees-of-freedom control problem about rotational motion including interaction. We derive a multivariable fuzzy controller for this problem from the fuzzy model of rotor dynamics using the concept of parallel distributed compensation. Moreover, the stability of the designed control system is proved by means of the Lyapunov stability condition. A common Lyapunov function is found by solving an optimization problem based on linear matrix inequality conditions. The performance of the developed fuzzy controller is verified through simulation.