Experimental study of sliding mode control for a benchmark magnetic bearing system and artificial heart pump suspension

This paper deals with the sliding mode control of a balance beam on two symmetric magnetic bearings. A state-space model of the system is developed and implemented. The sliding mode controller is separated into linear and nonlinear components. A reaching condition to bring the system states to a sliding surface is developed and a continuous function boundary layer is used to avoid chattering. The system performance with a small and large boundary layers is illustrated by experimental results. The effect of a nonlinear component gain to the system performance is analyzed. A new experimental setup is introduced using a real-time operating system, which gives a designer a convenient method to change the controller parameters. Experimental results verify the effectiveness of the sliding mode controller. A potential application of this study to an artificial heart pump system is demonstrated.