Complementary Orientation Control for Spherical Motors

In this paper, a novel approach is proposed for orientation control of spherical motors. First, a model is established for spherical motors based on the rotor dynamics and the multi-port operating principle of the motor. Then a robust complementary orientation control is presented using the developed model. The current vector is chosen to be the control variable, which are applied to drive the electromagnetic windings on the stator to generate the three dimensional electromagnetic torque acting on the rotor. Nonlinearity of motor dynamics is treated as uncertainty and it is shown that our approach is robust to the uncertainty while achieving the operating performance. Simulation results validate the effectiveness of the proposed method.