Pivoted wheel roll control with automatic offset
US5354016A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1992 |
| Grant date | Oct 11, 1994 |
| Priority date | — |
| Expiry date | Jul 30, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64G1/36
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A 3-axis stabilized spacecraft includes roll and yaw magnetic torquers, and a momentum wheel oriented with its spin axis orthogonal to, and pivotable about, the roll axis. Roll control may be applied by pivoting the wheel. Secular increases in pivot angle may result in loss of control authority when the mechanical limits of the pivot are reached. The pivot angle is sensed, and an unloading control loop is closed, by which magnetic torquers are energized to torque the spacecraft, to return the pivot angle toward zero. The unloading control loop includes a bandpass filter, which eliminates constant components of pivot angle offset. This prevents the unload control loop from attempting to maintain the pivot at a position in which the wheel axis is offset from the desired normal to the orbit plane. Consequently, the magnetic torquers do not expend system energy attempting to maintain an undesirable attitude.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.