Output feedback control for spacecraft with coupled translation and attitude dynamics

In this paper, we address a tracking control problem for a spacecraft with coupled translation and attitude motion, in the absence of translation and angular velocity measurements. We begin by describing the mutually coupled translation and attitude dynamics of the spacecraft. Next, a suitable high-pass filter is employed to estimate the spacecraft translation and angular velocities using measurements of its translational position and attitude orientation. Using a Lyapunov framework, a nonlinear output feedback control law is designed that ensures the semi-global asymptotic convergence of the spacecraft translation and attitude position tracking errors, despite the lack of translation and angular velocity feedback.