Cooperative Aerial Manipulation Using Multirotors With Multi-DOF Robotic Arms

This paper investigates pose manipulation of a rod-shaped object using two aerial manipulators, which are multirotors combined with multi-degrees of freedom robotic arms. To achieve the cooperative aerial manipulation, we present motion control and planning methods for aerial manipulators. First, a robust multirotor motion controller is designed based on the thorough analysis on the dynamics of the aerial manipulator. By utilizing extended high-gain observer and disturbance observer techniques, each multirotor can be controlled regardless of the disturbances generated by the robotic arm, the object, and the peer aerial manipulator. Second, a motion planner that assures safety during the cooperative aerial manipulation is proposed. To achieve safe manipulation, we estimate and regulate the internal force between the aerial manipulators. In addition, an unilateral constraint is designed which imposes collision avoidance between the object and aerial manipulators. All the designed features are prioritized and transformed into the reference velocity of the aerial manipulators. The proposed control and guidance laws are validated by a successful autonomous aerial manipulation experiment.