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
Method and apparatus for exercise monitoring combining exercise monitoring and visual data with wireless internet connectivity
Methods of reverse link power control
Communication system including a switching section for switching a network route, controlling method and storage medium
Online data conversion technique using a sliding window
Mounting structure, electro-optical apparatus, and touch panel
Liquid crystal display device
Pandemic protocol for emergency dispatch
  Randomly Featured Patents
Flexible synthesizer for multiplying a clock by a rational number
Converter arrangement having a low-inductance commutation circuit
Apparatus for reproducing charge latent image with vibration of electrode to modulate field generated by image thereby electro-optically modulating a reading light
Secure multi database system including a client, multi database server, and database server
Apparatus for pulling and replacing heat exchange tubing
Apparatus, system, and method for rendering objects with position and orientation computed on a graphics processing unit
Tablecloth covering and method of covering and skirting a table
Electronic module with power components
Bak binding protein, DNA encoding the protein, and methods of use thereof
Adaptor for reducing and locating bolt hole in a larger opening