Optimal Formation Reconfiguration of Satellites with Attitude Constraints Using Thrusters

Abstract: An optimal reconfiguration control for satellites formation flying with attitude constraints by the use of a small number of thrusters is addressed. These thrusters are fixed to the satellite body and generate unilateral forces. This study assumes that the satellite’s attitude angle during the reconfiguration maneuver is restricted within a certain bound from a specified direction in an inertial frame. Such constraint arises from some requirements: electric power generation with fixed solar array panels, observation or communication with ground-based stations, and so on. Furthermore, the satellite is assumed to have a few number thrusters; for in-plane formation maneuver the number of thrusters is set to two. This latter assumption reduces the number of actuators required for formation flying, and thus this study is useful when several thrusters of a satellite fail due to malfunctions. The purpose of this paper is to derive an optimal controller to reconfigure the formation between two satellites by using a few number of thrusters under the satellite’s attitude constraints. To this end, firstly a control method to track reference inputs is derived, and then the reference input design and the condition to satisfy the attitude constraint are discussed. Numerical simulation results show that the designed reconfiguration method is effective for keeping the satellite attitude angle within a specified bound.