Motion planning and control for mothership-cable-drogue systems in aerial recovery of micro air vehicles

Aerial recovery of micro air vehicles (MAVs) presents a challenging problem in multi-vehicle dynamics and control. This paper presents a method for recovering MAVs in flight using a mothership and towed drogue, in which the mothership executes an orbit that places the drogue in a stable, slower orbit that can be tracked by a MAV. The differential flatness property of the system is exploited to calculate mothership trajectories from desired drogue orbits, and a backstepping controller is proposed that enables accurate mothership trajectory tracking. Simulation results based on multi-link cable-drogue systems verify the feasibility and robustness of the approach.