The Quanser Magnetic Levitation device is a single degree of freedom electromagnet-based system that allows users to levitate a ball vertically up and down. The overhead electromagnet generates an attractive force on the metal ball that initially sits on the post. The position of the ball is measured using a photo-sensitive sensor embedded inside the post. The system also includes a current sensor to measure the current inside the electromagnet’s coil.
The force between electromagnet and ball is highly nonlinear. Further, the electromagnet itself has its own dynamics that must be compensated for. The challenging dynamics of the system make it perfect for teaching modeling, linearization, current control, position control, and using multiple loops (i.e. cascade control). It could also be used to test and implement more advanced control strategies, such as multi-variable, gain scheduling, and nonlinear control.