Spherical Actuation Using the Displaced Trapezoidal Winding

Previous work has shown that the segmented displaced trapezoidal winding produces Lorentz forces in two orthogonal directions on a permanent magnet rotor. This paper presents a unique collection of trapezoidal windings in a spherical geometry to provide active control of all 6 degrees of freedom. Equations for force and torque generation are presented, and a “decoupling� control scheme is applied to the actuator such that the 3 bearing forces and 3 control torques are decoupled and independent. The construction of a prototype is also discussed and experimental results are presented with good agreement with the theory.