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:
Mar. 11, 1997
Filed:
May. 13, 1994
Richard A Fowell, Culver City, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A method for filtering actuator commands for a satellite control system to reduce resonant mode excitation despite uncertain knowledge of the resonance frequencies, due to parameter variations, nonlinearities, and the like. The present method filters the actuator commands with staggered proportional plus delay (posicast) filters having distinct delay values, chosen to provide a desired resonance attenuation over a resonance uncertainty range. The present method may be extended to filter multiple resonances by cascading the staggered filters for each resonance. The present invention has wide application, such as in spacecraft precession and translation maneuvers, as well as gimbaled payload stepping. A particular advantage of the present invention is its direct applicability to fixed-amplitude actuators (such as thrusters and stepper motors), and reduced excitation of resonances at frequencies above those of primary concern.