Fuzzy Logic Control of a magnetic bearing system

In this paper, a Fuzzy Logic Controller (FLC) has been designed to stabilize a MBC500 magnetic bearing system. The FLC uses error and rate of change of error in the position of the rotor as inputs and produces an output voltage to control the current of the amplifier in the magnetic bearing system. A model of the MBC500 magnetic bearing system for the purpose of dynamic simulation is identified from the collected frequency response data. Since there are resonant modes that can threaten the stability of the closed-loop system, notch filters are usually employed to secure stability when conventional PD controllers are employed. However, the FLC can stabilize the magnetic bearing system without the use of any notch filters. The FLC has been coded in C and implemented in real time on a Digital Signal Processor (DSP) card.