Sensing and Commutation of a Spherical Permanent Magnetic Dipole Actuator
Name
ASPE 2019 Final Paper Submission - ID 35 (Tyler Hamer).pdf
Size
1.09 MB
Format
Adobe PDF
Checksum (MD5)
92d02fe2f95496262af8d2ba42dbbb34
Author(s)
Hamer, Tyler Thomas
Chabot, Joshua
Trumper, David
Date Issued
December 2019
Publisher
American Society for Precision Engineering | Proceedings of the Thirty-Fourth Annual Meeting of the American Society for Precision Engineering
Citation
T. T. Hamer, J. Chabot, and D. L. Trumper, “Sensing and commutation of a spherical permanent magnetic dipole actuator,” in Proceedings of the Thirty-Fourth Annual Meeting of the American Society for Precision Engineering, Pittsburgh, PA, USA. ASPE, 2019, pp. 115–120.
Version
Author's final manuscript
Abstract
Spacecraft attitude control systems (ACS) utilize multiple actuators, such as reaction wheels, control moment gyroscopes (CMGs), or thrusters, to rotate the spacecraft in 3 degrees of freedom (DoF). An ACS’s quality is commonly judged on SWaP (Size, Weight, and Power), torque generation, momentum storage, pointing stability, and reliability. Reaction wheels are inefficient at generating torque and storing momentum while CMGs typically have large footprints. Additionally both reaction wheels and CMGs rely on mechanical bearings, which can introduce pointing jitter and are a common point of failure. Thrusters use propellant, a finite resource, thus limiting mission duration.
Reaction spheres can rotate a spacecraft about an arbitrary axis, reducing the ACS from three or more single-axis actuators down to a single multi-axis actuator. Reaction spheres rotate the spacecraft either with an equal-and-opposite torque about their axis of rotation when accelerated about that axis, similar to reaction wheels, or with a gyroscopic torque used to reorient their axis of rotation, similar to CMGs. When operated similar to CMGs, reaction spheres generate higher torque per unit of power than reaction wheels. Lastly, reaction spheres can be magnetically levitated, eliminating the need for mechanical bearings, resulting in increased pointing accuracy, momentum storage, and ACS life.
While NASA first proposed reaction spheres over a half century ago, limitations with previous designs have kept the technology from commercialization [1]. Recently, reaction spheres with a dipole permanent magnet as the rotor have appeared promising due to their mechanical simplicity and simple modeling despite being unable to generate torque about their rotor’s axis of magnetization [2, 3]. In fact, a prototype reaction sphere with a dipole permanent magnet as the rotor was modeled, designed, and vertically suspended [4]. This paper continues the work from [4] on the permanent magnetic dipole reaction sphere bench-level prototype depicted in Figure 1 by presenting the sensing and commutation of the bench-level prototype for multi-DoF suspension and rotation.
Description
Thirty-Fourth Annual Meeting of the American Society for Precision Engineering. 28 October - 1 November 2019, Pittsburgh PA USA
Subjects
Spherical Motor
Spherical Actuator
Spherical Reaction Wheel
Motor Commutation
Attitude Sensing
Terms of Use
Creative Commons Attribution-NonCommercial-ShareAlike
Persistent DSpace Link
DOI of Published Version
https://www.proceedings.com/51098.html
