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
Stabilization of dicarbonate diesters with protonic acids
Method and device for reliable estimation of network traffic
Group control method for machine type communication and mobile communication system using the method
Web-based system and method for video analysis
Methods and apparatus for power amplifier calibration
MEMS structure and method for making the same
Method for preparing an organic film at the surface of solid support under non-electrochemical conditions, solid support thus obtained and preparation kit
  Randomly Featured Patents
Postage metering system having currency compatibility security feature
Storm panel system with continuous run rails and spring clips
Apparatus for the production of phosphoric acid
Wristwatch
Image display device and electronic apparatus
Centrifuge rotor having a closable windshield
Vein stripping device
Detecting and ranging system
Cytoplasmic male sterility DNA factor and utilization thereof
Scale