Dynamic hybrid position/force control for the quadrotor with a multi-degree-of-freedom manipulator

In the field of aerial robotics, physical interaction with the surrounding environment is currently receiving a considerable attention. One of the key challenges is to control not only the position, but also the force exerted by the end-effector while performing complex tasks such as object manipulation, inspection, and assembly/disassembly. To meet these demands, this paper proposes a dynamic hybrid position/force controller for a quadrotor-borne multi-degree-of-freedom manipulator. The system is modeled under the situation that the constraints on the end-effector are described by a set of hypersurfaces, and system dynamics are then developed while taking into account the redundancy of the system. To verify the effectiveness of the proposed hybrid controller, we carried out numerical simulations for two different application scenarios which include (1) placement of a sensor unit on a vertical wall and (2) inspection with contact on a curved-shape wall. The results show that the system is able to maintain the desired force and position simultaneously in both cases.