Bounded finite-time coordinated attitude control via output feedback for spacecraft formation

In this paper, finite-time output feedback coordinated attitude control for spacecraft formation subject to input saturation is investigated. More specifically, a finite-time observer is first designed to remove the requirement of measureable angular velocity. Rigorous proof shows the observer can achieve finite-time stability within given attractive region, which implies that the estimated values can be taken into use instead of the real angular velocity after a certain convergence time. Then, a bounded finite-time control law for the spacecraft formation is designed to render the attitude of each spacecraft to converge to reference attitude provided by the virtual leader in finite time. Finally, numerical simulation results show that the proposed schemes can guarantee the spacecraft formation achieve coordinated attitude consensus and tracking, with high accuracy and fast convergence.