Spherical actuator design and operation based on magnetic profile

Abstract

A modified design of a spherical actuator with an impeded permanent magnetic dihedral cone in rotor is discussed in this paper. Its importance comes from the fast growing in several potential applications like robotics, medical surgery, manufacturing and complicated assembly systems which require the development of the Multi Degree Of Freedom (Multi-DOF) motors. The presented actuator design consists of a regular non-magnetic spherical rotor with impeded magnetic dihedral cones. Air core coils are carried on the internal surface of the spherical stator. The actuator design procedures are proposed, considering the optimal design parameters, to achieve the maximum output torque with specified position angles. According to the analytical magnetic field distribution, the actuator magnetic field is simulated and analyzed. The spherical motor torque model is studied to present the relationship between the motor coils input current set and the output equivalent targeted position. The torque and the coils input currents for different positions are derived. Both direct and inverse actuator models are simulated and connected together to produce a feedback system. The simulation and results of the developed spherical actuator are presented. It contains eight dihedral permanent magnets in the rotor and sixteen air core coils arranged into two eight groups around the equatorial line upper and lower.