Parametric modeling and control of a long-range actuator using magnetic servo levitation

A mechatronic device based on magnetic servo levitation (MSL) is proposed for long range and wide bandwidth actuation. The force capability of this type of actuator can be significantly larger than a linear motor or voice-coil actuator of similar dimensions. A novel parametric model of the electromagneto-mechanical coupled system has been developed to describe its behavior over a large range of motion and frequency, as opposed to more conventional attractive force small-perturbation models. It also provides a convenient way of devising a feedback linearizing control scheme that eliminates the need for high biasing currents present in most magnetic bearing systems. This paper presents a feedback-linearized controller coupled with a Kalman filter as a first approach to solve the tracking problem for such an actuator. Good tracking performance have been found both in simulation and experiments.