Multiple Magnet Independent Levitation and Motion Control using a Single Coil Array

In this paper we investigate and demonstrate independent control and manipulation of multiple levitated magnets using a single planar array of cylindrical coils. Tracked motion results are given for two levitated magnets where each magnet follows a motion trajectory in close proximity to the other. Stable levitation of both magnets together requires accurate modeling and real-time calculation of force and torque interactions between all coils and magnets, as well as between the two levitated magnets. We aim to further develop the concept of multiple magnet levitation to enable the use of magnets as robotic fingers to grasp and manipulate small objects.An optical motion tracking system supplies the rigid-body position and orientation of the magnets as needed for feedback control, using three infrared emitters fixed to each magnet as markers. Each cylindrical magnet is controlled in three degrees of freedom in position and two degrees of freedom in rotation, leaving the rotation about the cylindrical axis uncontrolled. The forces and torques on the two magnets are generated by an array of 22 cylindrical coils, as a redundant control system. We plan to extend and improve these preliminary results to more complex motions and interactions through more sophisticated control and calibration methods.