Abstract:In challenging terrains, constructing structures such as antennas and cable-car masts often requires the use of helicopters to transport loads via ropes. The swinging of the load, exacerbated by wind, impairs positioning accuracy, therefore necessitating precise manual placement by ground crews. This increases costs and risk of injuries. Challenging this paradigm, we present Geranos: a specialized multirotor Unmanned Aerial Vehicle (UAV) designed to enhance aerial transportation and assembly. Geranos demonstrates exceptional prowess in accurately positioning vertical poles, achieving this through an innovative integration of load transport and precision. Its unique ring design mitigates the impact of high pole inertia, while a lightweight two-part grasping mechanism ensures secure load attachment without active force. With four primary propellers countering gravity and four auxiliary ones enhancing lateral precision, Geranos achieves comprehensive position and attitude control around hovering. Our experimental demonstration mimicking antenna/cable-car mast installations showcases Geranos ability in stacking poles (3 kg, 2 m long) with remarkable sub-5 cm placement accuracy, without the need of human manual intervention.
Abstract:Drilling, grinding, and setting anchors on vertical walls are fundamental processes in everyday construction work. Manually doing these works is error-prone, potentially dangerous, and elaborate at height. Today, heavy mobile ground robots can perform automatic power tool work. However, aerial vehicles could be deployed in untraversable environments and reach inaccessible places. Existing drone designs do not provide the large forces, payload, and high precision required for using power tools. This work presents the first aerial robot design to perform versatile manipulation tasks on vertical concrete walls with continuous forces of up to 150 N. The platform combines a quadrotor with active suction cups for perching on walls and a lightweight, tiltable linear tool table. This combination minimizes weight using the propulsion system for flying, surface alignment, and feed during manipulation and allows precise positioning of the power tool. We evaluate our design in a concrete drilling application - a challenging construction process that requires high forces, accuracy, and precision. In 30 trials, our design can accurately pinpoint a target position despite perching imprecision. Nine visually guided drilling experiments demonstrate a drilling precision of 6 mm without further automation. Aside from drilling, we also demonstrate the versatility of the design by setting an anchor into concrete.