Control of dual acting magnetic bearing actuator system using fuzzy logic

In this paper, a fuzzy logic scheme is developed to improve the performance of a magnetic bearing control system. The developed fuzzy logic strategy is utilized in the non-linear control of a dual-acting magnetic bearing actuator system. The mathematical model of a dual acting magnetic bearing axis has been developed. The non-linearity in this system is due to the relationship between the forces generated in the electromagnetic actuator and the coil current and the air gap between the rotor and the stator. Non-linearities in magnetic bearing systems limit the control effectiveness and the region of stable performance. The model is used for dynamic simulation purposes and it is not directly used in the fuzzy controller design. Active magnetic bearing with adaptive fuzzy control showed a good improvement in step response compared to a linear PID or a steady state controller. With the presented fuzzy logic based strategy, nonlinear controllers for nonlinear applications can be designed with little effort.