On the design, modeling and control of a novel compact aerial manipulator

The aim of this article is to present a novel four-degree-of-freedom aerial manipulator allowing a multirotor Unmanned Aerial Vehicle (UAV) to physically interact with the environment. The proposed design, named CARMA (Compact AeRial MAnipulator), is characterized by low disturbances on the UAV flight dynamics, extended workspace (with regard to its retracted configuration) and fast dynamics (compared to the UAV dynamics). The dynamic model is formulated and a control structure consisting of an inverse kinematics algorithm and independent joint position controllers is presented. Furthermore, the design specifications of the prototype are analyzed in detail, while experimental evaluations are conducted for the extraction of the manipulator's workspace and the evaluation of system's tracking capabilities over pick-and-place trajectories. Finally, it is shown that the selected joint position sensors, combined with the derived inverse dynamic algorithm allow to determine the wrenches exerted at the base, due to swift motions of the arm.