U-Joint CAAMS: Experimental Evaluation of a Universal-Joint Continuum Manipulator for Aerial Manipulation
2026-07-03 • Robotics
Robotics
AI summaryⓘ
The authors developed a new flexible arm (continuum manipulator) for drones that is better at resisting twisting and bending caused by the drone's propellers and extra weight. They designed it with special joints and a strong backbone to keep the arm steady during flight. Tests showed their design outperformed a previous version by reducing movements that can affect accuracy. They also tested how well the drone flies with this arm carrying different loads and demonstrated it doing tasks like water sampling and spraying. This work helps drones handle delicate tasks more precisely while flying.
continuum manipulatoruniversal jointmulti-rotor UAVpropeller downwashend-effector accuracypayloadNitinol backbonehover stabilityaerial manipulationbench testing
Authors
Anuraj Uthayasooriyan, Musab Alibrahim, Krishna Manaswi Digumarti, Fernando Vanegas, Felipe Gonzalez
Abstract
Continuum manipulators mounted on multi-rotor UAVs enable compliant aerial manipulation, but payloads and propeller downwash amplify out-of-plane bending and twisting that degrade end-effector pose accuracy. To address this problem, we present a universal-joint-based continuum manipulator designed to improve resistance to out-of-plane deformation during aerial manipulation. The proposed design uses a tubular backbone with spring-reinforced universal joints and an integrated conduit for internal routing and fluid delivery. We evaluate the design in still air and under peak propeller downwash across varying payloads, and benchmark it against a prior Nitinol-backbone CM. Bench tests show improved resistance to out-of-plane deformation across all conditions. Under peak downwash, the proposed design reduces mean error by 2.5-4x in yaw, 2-45x in y-axis, and up to 5x in roll compared to the NiTi-backbone design. We further analyze hover stability through in-flight coupled-disturbance tests over varying payloads and actuation speeds, and demonstrate the system in water sampling, spot spraying, and object transport.