Online Motion Planning for Deforming Maneuvering and Manipulation by Multilinked Aerial Robot Based on Differential Kinematics

Abstract

State-of-the-art work on deformable multirotor aerial robots has developed a strong maneuvering ability in such robots, whereas there is no versatile aerial robot that can perform both deforming maneuvering and aerial manipulation yet. However, a novel multilinked aerial robot presented in our previous work, called DRAGON, has both potential because of its serial-link structure. Therefore, an online motion planning method for such a multilinked aerial robot is required. In this letter, we first reveal the general statics model of the multilinked aerial robot, which involves the influence of joint torque, rotor thrust force, external wrench, and gravity, and further discuss the necessary rotor thrust force and joint torque required to compensate for external force and gravity under the quasi-static assumption. Then, we propose a real-time motion planning method, which sequentially solves the differential kinematics problem. This method considers the limitations of rotor thrust force and joint torque, as well as kinematics constraints. Furthermore, we introduce the integrated control framework, which can follow a quasi-static multilinks' trajectory and compensate for the external wrench. Finally, experiments to squeeze a virtual hatch covered by a movable plate are performed with quad-type DRAGON to demonstrate the feasibility of the proposed motion planning method in real-time.