MODELING AND POSITION CONTROL OF A MAGNETIC LEVITATION SYSTEM CALCULATING EDDY CURRENT BASED DAMPING FORCE

摘要

In this paper a magnetic levitation system is modeled and an eddy current based damping force is identified and used for position control of the levitated object in the system. In the magnetic levitation technology, contactless manipulation of a levitated object is done by use of magnetic fields. Also, the eddy-current based force is used to damp the motion of the levitated object. Eddy-current is generated in a plate which is placed underneath the levitated object due to the change of current in an electromagnet and the motion of the levitated object. First, using finite element method (FEM), the magnetic levitation system is modeled and the eddy-current based force acting on the levitated object is obtained. The thickness of the plate and the magnetic dipole moment of the levitated object are optimized so that the maximum value of the eddy current based force is gained. The effect of the eddy-current based force on the 2-D motion of the levitated object is studied. Also a controller using the damping effect of the eddy force is designed to control the position of the levitated object in one particular dimension. Results show that the controller can effectively regulate the position of the levitated object.