Robust Orbit-Attitude Coupled Control for Proximity Operations of Multiple Space Debris

Close-range observation of space debris utilizing in-orbit service satellite is critical for proximity operations in-cluding debris removal, break-up investigation, and faint target detection. This necessitates the coupled control of the orbital trajectory and attitude pointing of the satellite, enabling collision-free approaching of multiple debris to obtain informative observations. A major challenge arises from the limited information regarding the state and number of debris, which introduces ambiguity to the coupled control and collision avoidance. This paper proposes a robust orbit-attitude coupled control method by utilizing outer probability measures to reasonably represent epistemic uncertainty caused by partial knowledge. The coupled control is constructed as an optimization process with the objective of max-imizing information gain assessed by the derived analytical Hellinger distance. Additionally, safety constraint which is constituted by void probability is derived, promoting effective collision avoidance even in the presence of epistemic uncertainty. Partitioned Pattern Search methods are developed to accelerate the entire optimization process, reducing the computational burden. Simulation results validated its robustness in collision scenarios.