The vehicles are equipped with a motorized spool that allows them to control the tension acting on the rope during deployment. A plastic tube guides the rope to the release point located between two propellers. The external forces and torques exerted on the quadrocopter by the rope during deployment are estimated and taken into account to achieve compliant flight behavior. The assembly of the bridge is performed by small custom quadrocopters and builds upon the Flying Machine Arena, a research and demonstration platform for aerial robotics. The arena is equipped with a motion capture system that provides vehicle position and attitude measurements. Algorithms are run on a computer and commands are then sent to the flying machines via a customized wireless infrastructure.
In order to be able to design tensile structures that are buildable with flying robots, a series of computational tools have been developed, specifically addressing the characteristics of the building method. The design tools allow to simulate, sequence, and evaluate the structure before building.
The location of the scaffolding structure is manually measured before starting the construction. The primary and bracing structure can then be realized without human intervention. Before realizing the stabilizers, the locations of the narrow openings of the bridge are measured and input to the system, which adapts the trajectories accordingly.
