Relative position and attitude coupled control with finite-time convergence for spacecraft rendezvous and docking

In this paper, the problem of relative position and attitude coupled control for rigid spacecraft in rendezvous and docking is investigated. We propose a control scheme with finite-time convergence based on the given coupled dynamics of relative position and attitude, in the presence of unknown but bounded external disturbance. Furthermore, we adopt a boundary layer function into the controller to alleviate the chattering phenomenon and maintain the finite-time convergence. Considering the existence of control saturation limit due to the physical structure and energy consumption, the control function is processed before introducing into the actuators. Finally, simulation results are presented to illustrate the effectiveness of our control scheme.