Space Junk - David Rogers (2021 February)

Overview: 

Orbital debris is a growing problem that poses a collision risk to spacecraft and is expected to worsen exponentially as each collision between two bodies fragments them into three or more. Active removal of debris is necessary to prevent runaway growth in the number of objects but removal is complicated by the presence of perturbation forces and lack of knowledge of debris parameters such as mass. Capturing and towing debris will require a control strategy that can perform trajectory tracking that is robust to these uncertainties. This thesis presents the use of Simple Adaptive Control (SAC), a direct adaptive control method, to perform trajectory tracking in the presence of mass and perturbation uncertainties. A new laboratory facility was developed to perform simulations and experiments. Both simulation and experimental results agree that SAC is a viable control strategy for this purpose that significantly outperforms a PD controller.