PD+ attitude control of rigid bodies with improved performance

We address the problem of state feedback attitude control of a rigid body in quaternion coordinate space through a modified PD+ tracking controller. The control law ensures faster convergence to the desired operating point during attitude maneuver, while keeping the gains small for station keeping. A direct consequence is a drop in energy consumption when affected by sensor noise. More precisely, we show uniform asymptotic stability for the system without perturbations and uniform practical asymptotic stability in the presence of unknown, bounded input disturbances. Simulation results illustrate the performance improvement with respect to classic PD+ control, especially in the presence of input perturbations.