Model Predictive Control for Spacecraft Swarm Proximity Operations

In this paper, the spacecraft swarm guidance and control is addressed by means of Model Predictive Control (MPC) algorithm. A novel distributed nonlinear MPC approach for formation acquisition is presented, with the purpose of minimizing data exchanged by each spacecraft, guaranteeing collision avoidance between each other and with non-collaborative obstacles. The main objective is to design a deterministic method for autonomous swarm formation acquisition around target. Providing only the target position and a distance from it, the swarm moves autonomously to the target, reaching the regular polygon shaped formation around it, and at the given distance. The main feature of the proposed algorithm is the formation adaptability to the number of spacecraft in the swarm, even considering variable-swarm. Finally, preliminary simulations are carried out for proximity operations scenario, both fixed and variable swarm formation. The method effectiveness, the independence of the results from the initial conditions, and closed-loop stability are verified by means of extensive simulations. Results makes this an interesting approach to be investigated, since it allows to not define a single reference for each spacecraft, and requires only the definition of the target position and the distance from it.