Uncertainty estimation based game control for attitude regulation during on-orbit assembly

On-orbit assembly is one of the key technologies for space constructions. Assembly robots are required to assembly the substructures while stabilizing attitude of main structure. One of the major challenges would be the external disturbance and uncertainty caused by the moving assembly robots or the new adding substructures. In this paper, an uncertainty estimation based game control scheme which includes triggered identification and observer-based differential game controller is designed to stabilize the attitude of combination which consists of assembly robots and the main structure. Once there is new substructure constructed to the main structure, the identification of nominal inertia matrix and rotation matrices is triggered to avoid control failures which results from large model deviation. Based on the identified model, the game-based controller is designed. By optimizing individual performance index function of each robot, pseudo-linear quadratic differential game controllers are developed to get the feedback control for each robot, which avoids control allocation. Rather than dividing the control strategies into compensate control part and virtual control part, the proposed method can directly get the optimized control strategies to improve the robustness. Stability and optimality are proofed. Numerical simulations verify the effectiveness of the uncertainty estimation based game control method for the attitude regulation of the space structure during assembly.