Stabilizing Nonlinear Adaptive Control of Spacecraft before and after Capture

Abstract

In future space infrastructure, missions for refueling and capturing inoperative spacecraft using an orbital servicing vehicle or a space robot have been considered. To realize these missions, six-degrees-of-freedom tracking control of a chaser spacecraft is required to approach the target spacecraft. Moreover, the stability of the system connecting the chaser and target must be ensured. It is also important to suppress position and attitude errors due to disturbances. In this study, our aim is to derive an adaptive proportional-integral-derivative (PID) controller that ensures the stability of a spacecraft system before and after capture, and that removes the state errors caused by a constant external disturbance. The effectiveness of the derived controller is verified by numerical simulations.