A New 6-DOF Quadrotor Manipulation System: Design, Kinematics, Dynamics, and Control

TLDR: In this paper, a 2-DOF manipulator is attached to the bottom of a quadrotor to enable the end-effector to track a desired 6DOF trajectory with minimum possible actuators.

Abstract: The research on aerial manipulation has increased rapidly in recent years. In the previous work, a manipulator or a gripper is attached to the bottom of a quadrotor to facilitate the interaction with the environment. However, the previously introduced systems suffer from either limited end-effector degrees of freedom (DOF) or small payload capacity. In this paper, a quadrotor with a 2-DOF manipulator that has a unique topology to enable the end-effector to track a desired 6-DOF trajectory with minimum possible actuators is investigated. The proposed system is designed and modeled. However, such a system produces complexity in its inverse kinematics and control. A novel solution to the inverse kinematics problem is presented, which requires a solution of complicated algebraic/differential equations. Its accuracy is verified via numerical results. In order to solve the control problem, the system nonholonomic constraints are utilized with a model-free and low computation cost robust control technique. Moreover, the system stability proof under the proposed controller is carried out. A prototype of the proposed system is built and its design is verified via a flight test. In addition, the system feasibility and efficiency are enlightened.