Model-Based Motion Control of a Robotic Manipulator With a Flying Multirotor Base

This article presents new model-based adaptive motion control algorithms for an underactuated aerial robotic manipulator comprised of a conventional multirotor unmanned aerial vehicle (UAV) and a multilink serial robotic arm. Two control strategies are proposed to allow the manipulator to operate in the joint and task spaces. The proposed controllers incorporate the combined dynamics of the UAV base and the serial arm, and properly account for the two degrees of underactuation in the plane of the propellers. The control developments follow the so-called method of virtual decomposition, which by employing a Newtonian formulation of the UAV-manipulator dynamics, sidesteps the complexities associated with the derivation and parametrization of a lumped Lagrangian dynamics model. The algorithms are guaranteed to produce feasible control commands as the constraints associated with the underactuation are explicitly considered in the control calculations. A Lyapunov analysis demonstrates the stability of the overall system and the convergence of the motion tracking errors. Experimental results show the effectiveness of the proposed control strategies.