Finite-time output feedback attitude control of spacecraft

This paper discusses the finite-time attitude control problem for spacecraft without angular velocity measurements. Based on the finite-time control technique, output feedback attitude control algorithms are proposed for spacecraft with attitudes represented by the modified Rodrigues parameter. First, an output feedback attitude controller of a single spacecraft is proposed, which guarantees the finite-time reachability of the given desired attitude of a rigid spacecraft without angular velocity feedback. Secondly, a distributed output feedback coordinated attitude controller for multiple spacecraft is proposed without the requirement of absolute angular velocities and relative angular velocities, which guarantees the coordinated attitude regulation in finite time. Rigorous proof is given by using the Lyapunov theory and graph theory. Finally, numerical simulation and verification are performed for the proposed control schemes. The results show that the proposed output feedback attitude control algorithms are feasible and effective.