A paper describes attitude-control algorithms using the combination of magnetic actuators with reaction wheel assemblies (RWAs) or other types of actuators such as thrusters. The combination of magnetic actuators with one or two RWAs aligned with different body axis expands the two-dimensional control torque to three-dimensional. The algorithms can guarantee the spacecraft attitude and rates to track the commanded attitude precisely.
A design example is presented for
nadir-pointing, pitch, and yaw maneuvers.
The results show that precise attitude
tracking can be reached and the
attitude-control accuracy is comparable
with RWA-based attitude control. When
there are only one or two workable
RWAs due to RWA failures, the attitudecontrol
system can switch to the control
algorithms for the combined magnetic
actuators with the RWAs without going
to the safe mode, and the control accuracy
can be maintained.
The attitude-control algorithms of the combined actuators are derived, which can guarantee the spacecraft attitude and rates to track the commanded values precisely. Results show that precise attitude tracking can be reached, and the attitude-control accuracy is comparable with 3-axis wheel control.
This work was done by Zhiqiang Zhou of Langley Research Center. LAR-17862-1