Dual-quaternion based distributed coordination control of six-DOF spacecraft formation with collision avoidance

This paper investigates the collision-free distributed coordination control of six-DOF spacecraft formation flying. Dual quaternions are used to develop the kinematic and dynamic models of relative translational and rotational motion between spacecraft. By assuming that the reference relative orbit and attitude information is only available to a subset of members in formation, an observer is introduced to estimate the reference information in finite time. With the estimates provided by the observer, a sliding mode controller is then designed for the coordination of six-DOF formation flying. Meanwhile, the artificial potential function method is employed to design evasive maneuvers in case of any collisions during orbital maneuvering. The overall stability of the closed-loop system is guaranteed by a Lyapunov-based method. The feasibility of the proposed control scheme is then demonstrated by a typical formation reconfiguration mission in a low Earth orbit environment.