Development of a Two-DoF Three-Parallelogram Aerial Manipulator for Pipeline Crack Repair Using a Two-Tool End-Effector and Onboard Sensor-Based Localization

Unmanned aerial manipulators (UAMs) play a key role in ensuring human safety by performing tasks in unreachable or dangerous locations, including pipeline repairs. However, developing a more practical, real-world approach for pipeline repairs using UAMs is still necessary. Numerous challenges remain in applying actual repair methods, resolving design complexities, and ensuring energy and workspace efficiency while effectively in tegrating the UAMs. Moreover, the integration process must con sider size, payload, flight duration constraints, and effective control in dynamic environments, with attention to maneuverability and stability in the air. To achieve this, this paper develops a UAM that uses a two-degree-of-freedom (DoF) three-parallelogram manipulator with actuators at its base. It is equipped with tools and mechanisms for adapting a conventional pipeline repair method for aerial settings. We performed a detailed compact design of the manipulator and repair mechanisms, integrated them with a quadcopter, and modeled a quadcopter with a three-parallelogram manipulator. The experimental verification of the proposed system for repairing pipeline cracks using a minimal number of actuators and onboard sensors for localization was successfully demonstrated. The experimental results showed that the root mean square errors for the x, y, and z axes were 0.0222, 0.0467, and 0.0170 m for the drone and 0.0224, 0.048, and 0.0294 m for the end-effector. These findings underscore the system’s precision and effectiveness during the repair tasks. The outcomes highlight the potential of the proposed system to achieve reliable, accurate, and efficient pipeline repairs in challenging environments.