Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Methods for controlling spacecraft attitudes without exciting spacecraft resonances










Image Number 6 for United States Patent #6076772.

Attitude-control methods are provided which eliminate or reduce structural resonances in spacecraft that are excited by momentum wheel imperfections. The methods are preferably practiced with an over-determined attitude-control system which is typically available because spacecraft often carry backup momentum wheels to insure against failure of primary momentum wheels. In a method embodiment, a set of angular-velocity waveforms is selected that substantially realizes a commanded momentum vector when applied to a corresponding set of momentum wheels wherein none of the selected angular-velocity waveforms dwells at a resonant frequency of the spacecraft. The angular velocity of the corresponding set of momentum wheels is then conformed to the selected set of angular-velocity waveforms to realize a spacecraft attitude that corresponds to the commanded momentum vector without exciting the resonance. The step of selecting the angular-velocity waveforms can include the steps of offsetting a constant rotational frequency and of adding a velocity modulation to avoid dwelling at the resonant frequency.








 
 
  Recently Added Patents
Request routing based on class
Managing a spinlock indicative of exclusive access to a system resource
Estimating optical characteristics of a camera component using sharpness sweep data
Method and system for reduction of quantization-induced block-discontinuities and general purpose audio codec
LED driving circuit, LED illumination appliance, LED illuminator, and LED illumination system
Device for preparing a body fluid for a bacteriological analysis
Touch-sensitive device and communication device
  Randomly Featured Patents
Power actuated device for installing metal corner strip
Mobile phone
Method and system for managing line topology
Process for making a silicone mold and baking a food product therein
Active implantable medical device including means for the evaluation of intracardiac volume
Bottle cap
Soybean cultivar 4513420
Seal plate for aircraft movable flight control surfaces
Hydridotris(pyrazolyl)borate metal complexes and polymerization process
Microwave food boiling controlled with sensors