Deployment/Retrieval Control of a Tethered Satellite with Guarantee for the Region of Motion

Abstract

Simulations are performed for deployment and retrieval of a tethered satellite applying nonlinear receding horizon control. Since the tether cannot be pushed, the control tension is constrained to be nonnegative, and therefore, it is not necessarily guaranteed that the tethered satellite does not collide with the mother ship. To operate the satellite safely avoiding such a situation, switching conditions are given for the control input in this paper. As a result, it is guaranteed that the state of satellite can be restricted within a specified region even if it falls uncontrollable.