The Optimal Location of Electromagnets in Multiple Degree-of-Freedom Magnetically Suspended Actuators

Abstract

This paper discusses a systematic design approach to the optimal location of electromagnets in a multiple degree-of-freedom (DOF) magnetically suspended actuator (MSA). An electromagnet location matrix is defined from the geometrical arrangement. Three design conditions for the optimal location are proposed and their criteria are formulated. These conditions are (1) arbitrarily manipulating the controlled body by electromagnets which actuate only in the attractive direction, (2) mechanically decoupling the linearized MSA dynamics, and (3) being robust against the nonlinearity of electromagnets. Simulation results for a simple 3-DOF model are given to confirm the validity of these conditions. An optimal design for a practical 6-DOF model is also included.