Abstract :
[en] The use of electric low-thrust propulsion systems for orbit maneuvers is
becoming a popular choice among satellite manufacturers due to their inherent
merits over their chemical counterparts. Many designers choose to incorporate
multiple of such thrusters to insure omnidirectional orbit maneuverability,
while others choose to equip their satellite with only one thruster nozzle,
aiming to reduce the required power, weight, and size of the orbit control
system. This paper proposes guidance and control schemes to address the problem
of autonomous optimal relative orbit reconfiguration for a formation of two
satellites, one of which utilizes a single low-thrust throttleable nozzle. Such
under-actuated orbit control system requires the controlled spacecraft to
constantly slew to direct the nozzle to the desired thrust direction. These
redirection attitude maneuvers are treated within the guidance layer by
accommodating recurrent no-thrust periods during which slew maneuvers take
place. The control loop is then closed with an MPC-like scheme. The main
motivation of this article is to support the future missions of LuxSpace's
flagship satellite, Triton-X. Since the proposed guidance and control schemes
are meant to answer realistic market needs, they are designed to have some
specific qualities that makes them attractive from the practical point of view.
Namely, they require minimal computational loads, besides being able to
accommodate operational time constraints, e.g. no thrusting during eclipse or
during ground contact, within the guidance layer.
