A Flatness-Based Predictive Controller for Six-Degrees of Freedom Spacecraft Rendezvous

Julio C Sanchez (1) , Francisco Gavilan (1) , Rafael Vazquez , Christophe Louembet (2)

1 Universidad de Sevilla = University of Seville
2 LAAS-MAC - Équipe Méthodes et Algorithmes en Commande

This work presents a closed-loop guidance algorithm for six-degrees of freedom spacecraft rendezvous with a passive target flying in an eccentric orbit. The main assumption is that the chaser vehicle has an attitude control system, based on reaction wheels, providing the necessary torque to change its orientation whereas the number of thrusters is arbitrary. The goal is to design fuel optimal manoeuvres while satisfying operational constraints and rejecting disturbances. The proposed method is as follows; first, the coupled translational and angular dynamics are transformed to equivalent algebraic relations using the relative translational states transition matrix and the attitude flatness property. Then, a direct transcription method, based on B-splines parameterization and discretization of time continuous constraints, is developed to obtain a tractable static program. Finally, a Model Predictive Controller, based on linearization around the previously computed solution, is considered to handle disturbances. Numerical results are shown and discussed.

Mots clés: Impulsive rendezvous; Attitude control; Model predictive control; Flatness theory

Domaines: Automatique / Robotique

Julio C Sanchez, Francisco Gavilan, Rafael Vazquez, Christophe Louembet. A Flatness-Based Predictive Controller for Six-Degrees of Freedom Spacecraft Rendezvous. IFAC Workshop on Networked & Autonomous Air & Space Systems, Jun 2018, Santa Fe, Nouveau Mexique, United States. ⟨hal-02071291⟩