Optimal Glideslope Guidance Algorithm for Minimum-Fuel Fixed-Time Elliptic Rendezvous
Résumé
This paper presents a new minimum-fuel glideslope guidance algorithm for approaching autonomously a target evolving on an elliptic orbit. In addition to the usual rectilinear profile to follow as in Hablani's seminal paper, two new features are requested for the new algorithm. The first one imposes bounds on the guidance error inherent to chemical propulsion glideslope guidance, such that the chaser's trajectory does not escape from an admissible domain. The second one minimizes the consumption during rendezvous. Indeed, unlike the classical glideslope algorithm for which there is no direct control on the fuel consumption, additional degrees of freedom and relevant decision variables may be identified. By combining a useful parametrization of the Tschauner-Hempel relative equations of motion and results from polynomial optimization, a semidefinite formulation of the constraints on the maximal guidance error is obtained. For a fixed-time glideslope rendezvous with a pre-assigned number of maneuvers, a fuel-optimal solution with a bounded guidance error is obtained by solving a semidefinite programming problem. Two numerical examples illustrate the usefulness of the method compared to the classical ones when the approach corridor has to verify stringent geometrical restrictions such as line-of-sight constraints.
Origine : Fichiers produits par l'(les) auteur(s)