Real-time terminal guidance for autonomous spacecraft capture of free floating objects using model predictive control

This paper investigates the optimal rendezvous with collision avoidance constraint. The classic Hill-Clohessy-Wiltshire (HCW) dynamic model is applied here to effectively describe the relative translation motion. Collisions are prevented through setting a safety sphere centred at the mass centre of the target. The rendezvous scenario of approaching with a three-axis attitude stabilised target is considered in this paper. A light-of-sight (LOS) tetrahedral path constraint is imposed for vision-based sensing and safety considerations. Then, the optimal-fuel rendezvous is transformed into a quadratic programming problem (QPP) using the model predictive control (MPC). Numerical simulations demonstrate that the proposed method can guarantee the safety of the autonomous rendezvous and to minimise the fuel consumption. In addition, this algorithm can be numerically solved rapidly.