Decoupled, Closed-Loop, Multi-DoF Rotation of a Spherical Permanent Magnetic Dipole Actuator
Name
ASPE 2022 Final Paper Submission - ID 1022081 (Tyler Hamer).pdf
Size
9.25 MB
Format
Adobe PDF
Checksum (MD5)
66485f941229e63ae2f17803a7569419
Author(s)
Hamer, Tyler Thomas
Chabot, Joshua
Trumper, David
Date Issued
January 2023
Publisher
American Society for Precision Engineering | Proceedings of the Thirty-Seventh Annual Meeting of the American Society for Precision Engineering
Citation
T. T. Hamer, J. Chabot, and D. L. Trumper, “Decoupled, closed-loop, multi-DoF rotation of a spherical permanent magnetic dipole actuator,” in Proceedings of the Thirty-Seventh Annual Meeting of the American Society for Precision Engineering, Bellevue, WA, USA. ASPE, 2022, pp. 1–6.
Version
Author's final manuscript
Abstract
Momentum control systems (MCSs), sets of reaction wheels (RWs) or control moment gyroscopes (CMGs), exchange angular momentum with a spacecraft body’s to alter/maintain the spacecraft’s attitude (orientation) typically so as to not consume thrusters’ limited fuel. Less power efficient RWs are used more in smaller, less agile spacecraft for their compactness despite their lower torque generation, whereas power efficient CMGs are used more in larger or more agile spacecraft for their higher torque generation despite their large footprint due to their gimbal structure. Both actuators usually use rolling element bearings, whose stiction and vibration transmission, negatively impact pointing precision. Further, 2 RWs in both the Hubble-and Kepler-Space Telescopes as well as 1 CMG in the International Space Station and 2 CMGs in the WorldView-4 Imaging Satellite have malfunctioned due to their mechanical bearings [1], decreasing mission life unless serviced at high cost.
An alternative to RWs and CMGs are reaction spheres, which rotate a spacecraft with (1) an equaland-opposite torque about their rotation axis like RWs when accelerated about that axis or (2) a power efficient equal-and-opposite gyroscopic torque like CMGs when their rotation axis is reoriented. Reaction spheres are often magnetically levitated, eliminating (1) mechanical bearings for increased pointing accuracy and reliability, and (2) gimbal structures, resulting in a compact, multi-axis actuator able to replace multiple single-axis RWs and CMGs for a more compact MCS. Thus, reaction spheres operated as CMGs potentially eliminate the trade-off between compactness and power efficiency in MCS design.
While NASA first proposed reaction spheres over a half century ago, limitations with previous designs kept the technology from commercialization [2; 3]. Recently, reaction spheres with a dipole permanent magnet (PM) as the rotor have appeared promising for their mechanical-and modeling-simplicity despite their inherent underactuation [4; 5]. Torque cannot be generated about the rotor’s magnetization axis 𝑒m. Figure 1 depicts a reaction sphere bench-level prototype with such a rotor whose dynamics have been modeled [1; 6] to develop commutation laws [1; 7] which enabled simultaneous demonstration of decoupled, closed-loop, multi-DoF (degree of freedom) suspension [1; 8] and decoupled, open-loop, multi-DoF rotation [1; 6] of said rotor. Building on this work from [1; 6–9], this paper presents closed-loop rotation of the rotor about the stator’s X-, Y-, and Z-axes despite the prototype’s underactuation while maintaining closed-loop multi-DoF suspension.
Description
Thirty-Seventh Annual Meeting of the American Society for Precision Engineering. 10-14 October 2022, Bellevue WA USA
Subjects
Spherical Motor
Spherical Actuator
Spherical Reaction Wheel
Maglev Reaction Wheel
MIMO Rotation Control
Gimbaled Motion Control
Terms of Use
Creative Commons Attribution-NonCommercial-ShareAlike
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DOI of Published Version
https://www.proceedings.com/66902.html
