Two-dimensional fuzzy sliding mode control of a field-sensed magnetic suspension system

Magnetic suspension techniques have been widely used in different fields of industrial applications such as levitation of high speed trains, frictionless bearings, and magnetically suspended wind tunnels. Magnetic suspension systems are nonlinear and inherently unstable systems. Therefore, they are good engineering benchmarks for verifying different control theories. This paper presents the two-dimensional fuzzy sliding mode control of a field-sensed magnetic suspension system. The fuzzy rules include both of the sliding manifold and its derivative. The fuzzy sliding mode control has advantages of the sliding mode control and it can minimize rules of the fuzzy control. In this paper, new design circuits are proposed. The implemented driver, sensor and control circuits are more simple, inexpensive and effective. ARM Cortex-M3 microcontroller is utilized as a digital controller. In the hands-on experiments, this proposed control technique markedly improves performances of the field-sensed magnetic suspension system.