Design, modeling, and control of an aerial manipulator for placement and retrieval of sensors in the environment

On-site inspection of large-scale infrastructure often involves high risks for the operators and high insurance costs. Despite several safety measures already in place to avoid accidents, an increasing concern has brought the need to remotely monitor hard-to-reach locations, for which the use of aerial robots able to interact with the environment has arisen. In this paper a novel approach to aerial manipulation is presented, where a compact manipulator with a single degree-of-freedom is tailored for the placement and retrieval of sensors in the environment. The proposed design integrates on-board sensing, a high-performance force controller on the manipulator, and a thrust-to-force mapping on the flight controller. Experimental results demonstrate the high reliability achieved during both placement and retrieval tasks on flat surfaces (e.g., a bridge wall) and cylindrical surfaces (e.g., tree trunks). A total number of 89 flight experiments were carried out to demonstrate the robustness and potential of the compact, bespoke aerial design.