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Development of a Miniature, Two-Axis, Triple-Helmholtz-Driven GimbalThis paper details the development of a Helmholtz-driven, 2-axis gimbal to position a flat mirror within 50 microradian (fine positioning) in a space environment. The gimbal is intended to travel on a deep space mission mounted on a miniature "rover" vehicle. The gimbal will perform both pointing and scanning functions. The goal for total mass of the gimbal was 25 grams. The primary challenge was to design and build a bearing system that would achieve the required accuracy in addition to supporting the relatively large mass of the mirror and the outer gimbal. The mechanism is subjected to 100-G loading without the aid of any additional caging mechanism. Additionally, it was desired to have the same level of accuracy during Earth-bound, 1-G testing. Due to the inherent lack of damping in a zero-G, vacuum environment; the ability of the gimbal to respond to very small amounts of input energy is paramount. Initial testing of the first prototype revealed exceedingly long damping times required even while exposed to the damping effects of air and 1-G friction. It is envisioned that fine positioning of the gimbal will be accomplished in very small steps to avoid large disturbances to the mirror. Various bearing designs, including materials, lubrication options and bearing geometry will be discussed. In addition various options for the Helmholtz coil design will be explored with specific test data given. Ground testing in the presence of 1-G was compounded by the local magnetic fields due to the "compass" effect on the gimbal. The test data will be presented and discussed. Additionally, rationale for estimating gimbal performance in a zero-G environment will be presented and discussed.
Document ID
20000048399
Document Type
Conference Paper
Authors
Sharif, Boz (Aeroflex Labs., Inc. Farmingdale, NY United States)
Joscelyn, Ed (Aeroflex Labs., Inc. Farmingdale, NY United States)
Wilcox, Brian (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Johnson, Michael R. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Date Acquired
August 19, 2013
Publication Date
May 1, 2000
Publication Information
Publication: 34th Aerospace Mechanisms Symposium
Subject Category
Instrumentation and Photography
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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IDRelationTitle20000048380Analytic Primary34th Aerospace Mechanisms Symposium
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