Attitude control system with reaction wheel friction compensation
US5201833A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1991 |
| Grant date | Apr 13, 1993 |
| Priority date | — |
| Expiry date | Jul 19, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64G1/285
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A spacecraft attitude control system uses one or more momentum or reaction wheels. Wheel bearing viscous (velocity-dependent) friction reduces the actual torque imparted to the spacecraft in response to a torque command signal. Friction compensation is provided by applying the torque command signal to a model of an ideal, friction-free wheel, and calculating the speed which the ideal wheel achieves in response to the torque command. An error signal is generated from the difference between the ideal wheel speed and the actual wheel speed. The error signal is summed with the torque command signal to produce the wheel drive signal. This results in a closed-loop feedback system in which the actual wheel speed tends toward the ideal wheel speed, thereby causing a torque on the spacecraft which is substantially equal to that commanded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.