This paper describes a magnetic levitation system that uses a planar array of 16 cylindrical
coils to levitate a platform containing two permanent disk magnets. Position and orientation …

This paper presents an alternative method utilizing real-time measurements of existing rotor
magnetic field in the feedback loop for multi degree-of-freedom (DOF) orientation control of a …

This paper presents an analytical model for the force and torque developed by a reaction
sphere actuator for satellite attitude control. The reaction sphere is an innovative momentum …

As a device characterized by multiple degrees of freedom in one driving unit, analytical
electromagnetic torque modeling is needed for the rotor position tracking control of a …

Permanent magnet spherical motors (PMSMs) operate on the principle of the dc excitation of
stator coils and three freedom of motion in the rotor. Each coil generates the torque in a …

This paper describes the design and implementation of a novel spherical actuator that can
generate two tilt-motion degrees of freedom. Voice coil motors were adopted as actuators in …

This paper presents a new method, referred to here as back-EMF method, for sensing the
multi-DOF motion of a permanent magnet spherical motor (PMSM). With an explicit model …

The paper studies the magnetic field distribution of three degree-of-freedom (3-DOF)
permanent magnet (PM) spherical motor adopting the 3-D magnetic equivalent circuits …

We propose a camera actuating system using a spherical ultrasonic motor for inspection of
the inside wall of a small pipe. The spherical ultrasonic motor has advantages that include …

This paper presents control system design of a multi degrees-of-freedom (DOF) spherical
wheel motor (SWM) in a class of ball-joint-like direct drive actuators to control orientation of …