A simple fuzzy controller for the magnetic suspension system: A paper for 2009 FUZZ-IEEE conference competition

This year, the competition challenge is to develop a fuzzy controller for a nonlinear multi-input multi-output (MIMO) magnetic suspension system with satisfactory performance under different initial conditions. This paper aims at developing a concise but effective fuzzy controller, for the reason that the MIMO system can be divided into four physically independent single-input single-output (SISO) magnetic suspension systems which can be successfully controlled by a fuzzy controller with simple structure that is easy to be created, modified and understood. More specifically, a two-stage control strategy is adopted, consisting of an individual control stage that each SISO subsystem is controlled by a simple Mamdani-type fuzzy controller with intuitive rules, and a coordination stage to balance the four subsystems for the overall performance requirement. Simulation results are provided to show the performance for the required tasks.