M.K. Rashid (Sultanate of Oman)
robotic joint, robot wrist, spherical
motor, intelligent wrist.
Reducing the number of joints in 3-dimensional motion
can save both space and required number of actuators.
Such improvement can be achieved by using a spherical
stepper motor SSM, It is basically a spherical rotor
(rotating ball) placed inside a semi-spherical cavity (the
stator). The developed electromagnetic forces between
the permanent magnets that arranged on rotor surface
(rotor poles) and the electromagnetic poles grouped at
the inside surface of the stator can produce the essential
torque for such motion. This work presents modeling
and configuration design for such joint and suggest
intelligent scheme for activating group of
electromagnets to achieve the targeted motion. An
algorithm is developed for obtaining the number,
position, and, the effective arrangement of rotor and
stator poles. The selection of acceptable arrangement
allows the rotation in different directions and a broader
motion range. Finite element method (FEM) is used to
calculate the electromagnetic forces. The calculated
forces are used in investigating a single step motion
using a simple intelligent scheme.