Computer simulation of magnetic levitation of thin steel plate in consideration of large scale transient response

This paper describes how to simulate magnetic levitation of a thin steel plate by using electromagnets. Since the levitation system is essentially unstable, the plate is levitated by controlling the attractive magnetic force produced by the electromagnets with feedback signals: the displacement and velocity of the plate and the current of the electromagnet. As the magnetic force is the same regardless of the current direction, a bias voltage is necessary for supplying an initial current to the electromagnet. The motion equation of the plate is solved by the finite difference method. The magnetic force is obtained by using the finite element method. In this paper, we study how to improve the control performance, which becomes better by adding a current feedback and adjusting the bias voltage.