3-D Magnetic Field Analysis of a Permanent Magnet Spherical Actuator Using Spherical Harmonics

This paper proposes a rotor permanent magnet array applied in the three degree-of-freedom (3-DOF) permanent magnet spherical actuator. To investigate the performance of the permanent magnet array, this paper presents an analytical model for calculating the magnetic field generated by the spherical rotor array using spherical harmonics. Compared with the numerical method 3-D finite element analysis, the spherical harmonics can obtain a closed-form function with the advantages of reasonable accuracy and rapid computational effort. Finally three structural parameters of rotor array are discussed by the analytical model.