Enabling robot assisted landing of heavy UAV rotorcraft via combined control and workload sharing

Abstract

In this paper, a tracking control approach for robot assisted landing of UAV rotorcraft, such as multicopters and helicopters, is presented. The aim is to safely land these type of flying vehicles under side wind conditions and on moving surfaces using a robot manipulator arm mounted on the ground. In our previous work, we have considered light UAVs compared to the robot's payload capabilities. In this work, we present a method that enables to realize robot assisted landing for arbitrary combinations of aerial vehicles and robot arms. We show that the combined system is overactuated. This allows to distribute the workload and enables to assist heavy rotorcraft, whose weight would otherwise exceed the nominal payload of the robot arm. The performance of the controller is evaluated in numerical simulations as well as in experiments using a custom-built hexacopter and a KUKA/DLR light-weight robot.