Active formation along an eccentric orbit

In this paper, a formation problem of a spacecraft with a leader in an elliptic orbit is considered, where the follower is required to track asymptotically a given periodic relative orbit. The linearized equations of relative motion along an eccentric orbit are known as Tschauner-Hempel equations. The Tschauner-Hempel equations are transformed into simpler ones by the change of variables. For the transformed system, the active formation problem is formulated, and feedback controllers are designed by the regulator equations associated with the Hill-Clohessy-Wiltshire equations. Feedback controllers are also designed using a DRE associated with the TH equations, and the Li-norms of designed controllers are compared.