Control Framework for a UAV Slung-Payload Transportation System

This letter presents a control framework for transporting a UAV slung-payload, which can asymptotically stabilize not only the UAV but also the tether swing angles. By separating the system into two subsystems, the cascade control methodology is used to design the framework, which includes two sufficient conditions and suits for a large class of existing controllers. The control framework is strictly proved with the boundness of all states such that it can guarantee the asymptotic stability of the closed-loop overall system over the entire configuration space. Then, this framework is applied to a UAV trajectory tracking control problem with stability analysis. Samples of controllers are presented in the type of saturation or dynamic feedback. Finally, numerical and experimental validations are carried out on a UAV slung-payload transportation.