Magnetic force model of spherical actuators with three-dimensional magnet array

This paper presents a force model of three-degree-of-freedom (3-DOF) spherical actuator. Due to the friction between rotor and stator decreases the torque output of spherical actuator, in order to increase output torque, we can use levitation force in reasonable control to decrease the friction. This paper proposes three components of magnetic flux density based on Laplace equation. A force model described according to magnetic model. The levitation force model will facilitate the analysis of relationship between levitation force and output torque. Furthermore, the force in reasonable control is beneficial to deduce friction and improve work efficiency.