Trajectory‐keeping in satellite formation flying via robust periodic learning control

This paper proposes an iterative learning control (ILC) scheme to ensure trajectory‐keeping in satellite formation flying. Since satellites rotate the earth periodically, position‐dependent disturbances can be considered time‐periodic disturbances. This observation motivates the idea of repetitively compensating for external disturbances such as solar radiation, magnetic field, air drag, and gravity forces in an iterative, orbit‐to‐orbit manner. It is shown that robust ILC can be effectively utilized for satellite trajectory tracking, thus enabling time‐variant formation flying between the leader‐ and follower‐satellites. The validity of the results is illustrated through computational simulations. Copyright © 2009 John Wiley & Sons, Ltd.