Ground tests for vision based determination and control of formation flying spacecraft trajectories

The advances in the computational capabilities and in the robustness of the dedicated algorithms are suggesting vision based techniques as a fundamental asset in performing space operations such as rendezvous, docking and on-orbit servicing. This paper discusses a vision based technique in a scenario where the chaser satellite must identify a non-cooperative target, and use visual information to estimate the relative kinematic state. A hardware-in-the-loop experiment is performed to test the possibility to perform a space rendezvous using the camera as a standalone sensor. This is accomplished using a dedicated test bed constituted by a dark room hosting a robotic manipulator. The camera is mounted on the end effector that moves replicating the satellite formation dynamics, including the control actions, which depend at each time step by the state estimation based on the visual algorithm, thus realizing a closed GNC loop.