The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 31, 2000
Filed:
Mar. 02, 1998
Richard A Noyola, Torrance, CA (US);
Che-Hang C Ih, Rancho Palos Verdes, CA (US);
Hughes Electronics Corporation, El Segundo, CA (US);
Abstract
Autonomous slewing of a spacecraft about a desired axis using reaction wheels permits a maximum slew rate without wheel saturation even with one wheel failure. The slew is carried out if the total angular momentum of the spacecraft is less than a momentum storage threshold determined from reaction wheel availability. The momentum threshold may be found as the radius of a sphere inscribed in a polyhedron in momentum space, the polyhedron based on the maximum single wheel capacity and the geometry of the reaction wheel system as well as the reaction wheel availability. The momentum available for the slew is determined from the total angular momentum and the availability of each reaction wheel. The slew rate magnitude and slew direction are based on the available momentum. The available momentum calculation may include factors to accommodate noise and model uncertainties, to prevent the slew from placing the total angular momentum into a state overly limiting the rate of a subsequent slew, and to avoid numerical problems.