Energy Aware Impedance Control of a Flying End-effector in the Port-Hamiltonian Framework

The extension of variable stiffness impedance control for safe wrench regulation using the concept of energy tanks is tackled in this paper, where both the modeling and the control are carried out in the port Hamiltonian framework. We exploit previous well-known results in the literature of ground manipulators and extend them to be applied for novel and challenging aerial physical interaction applications. The energy-awareness of the presented control method guarantees the stability of the aerial robot in both free-flight and in-contact scenarios together with a level of safety in the case of contact-loss with the unknown environment. To the best of our knowledge, this is the first time an energy-based impedance controller for aerial robots is derived, extended to accomplish interaction control, enhanced to account for safety behavior entirely in the port-Hamiltonian framework, and extensively tested with real experiments on a fully-actuated multirotor aerial vehicle.