Design and operation of a force-reflecting magnetic levitation coarse-fine teleoperation system

This paper describes the design and operation of a coarse-fine teleoperation system with bilateral force reflection. The system uses a 6-DOF magnetic levitation device (MLD) master to control a 6-DOF fine-positioning MLD slave mounted on a 6-DOF coarse positioner arm. Coarse-fine teleoperation expands the workspace of the slave MLD while retaining its frictionless characteristics, fine position resolution and high bandwidth. Several modes of operation are explored. In unilateral coarse-fine mode (UCF) the master controls the wrist position which in turn controls the coarse positioner. In master deadband rate control mode (MDRC) the master position controls the coarse positioner velocity while wrist position is used to reflect contact forces to the master. In symmetric bilateral control (SBC) mode the wrist and master servo to each other´s positions providing force reflection during fine manipulation. Operation of each system mode is investigated during a simple assembly task.