FINITE ELEMENT TORQUE MODELING FOR THE DESIGN OF A SPHERICAL MOTOR

This paper presents the method of modeling the torquc generated by a variable reluctance spherical motor W S M) that presents some attractive possibilities by combining pitch, roll, and yaw motion in a single joint. Unlike prior works on the torque formulation of a VRSM, which were based on a lumped-parameter approach using equivalent magnetic circuits (widely ised in developing forceitorque models for electromechanical devices), this paper presents a distributed-parameter approach to predict the motofs magnetic field distribution for formulating the torque of a VRSM. A detailed three-dimensional finite-element (FE) analysis has been performed on a VRSM configuration that consists of both permanent magnet (PM) poles and aircored electromagnets. The model obtained using FE methods offers more insight and an accurate representatio