Safe On-Orbit Dislodging of Deployable Structures via Robust Adaptive MPC

This paper proposes a novel robust adaptive model predictive controller for on-orbit dislodging. We study on orbit dislodging where a servicing spacecraft uses a robotic arm to free a jammed and underpowered solar panel mounted on a hybrid hinge that acts as a time varying client on a space station Our method couples online set-membership identification with a robust adaptive MPC to enforce safety under bounded disturbances. The controller explicitly balances exploration to excite the system and shrink uncertainty and exploitation to improve control performance through a dual-mode cost. The feasibility of the developed robust adaptive MPC method is also examined through dislodging simulations and hardware experiments in zero-gravity and gravity environments, respec- tively. In addition, the advantages of our method are shown through comparison experiments with several state-of-the-art control schemes for both accuracy of parameter estimation and control performance.