Compact force sensor improves dual drone payload carrying control
Compact Force Sensor for Dual-UAV Cable-Suspended Payload Transport with Tension-Aware Outer-Loop Control
Robotics
Summary
Carrying large objects using two drones connected by cables is tricky because the drones must stay balanced and work together, especially if something unexpected happens. The authors created a small, lightweight sensor that measures the force on the cables attaching the drones to the object. This sensor helps the drones adjust their movements by using a special control setup, making it easier to carry the load steadily and safely. Their tests show this method helps the drones handle disturbances better and keep the payload balanced.
What this means in practice
- •For drone delivery operators: Integrate force sensing at cable anchors to improve dual-drone payload stability and disturbance handling during transport.
- •For robotics research teams: Use compact force sensors with tension-aware control loops to advance cooperative aerial manipulation and coordinated flight.
Authors
Andrea Delbene, Giorgio Cannata, Giorgio Carlini, Filippo Sante, Marco Baglietto
Abstract
Cooperative payload transportation using multiple \textit{Unmanned Aerial Vehicles} (UAVs) poses challenges in stability, coordination, and robustness, especially under external disturbances and unmodeled dynamics. This work proposes a dual-UAV payload transportation framework supported by a compact, custom-designed force sensor measuring the interaction force at the UAV cable anchor point. The sensor design and mathematical model are presented, and its performance is characterized through static and dynamic tests evaluating linearity, hysteresis, repeatability, and crossload. The control architecture follows a cascade structure: fast inner loops handle vehicle stabilization, while outer loops are designed to compensate for the measured forces. The approach is validated through simulations and indoor experiments under position uncertainty. Payload-drop and constrained-space tests assess the proposed sensing and control architecture against literature-based distributed references, showing improved stabilization, coordination, and disturbance rejection. A video of the experiments is available at: https://youtu.be/rIw9-fvV8Qw.