Flying machines offer a number of advantages compared to traditional construction machines for example; they can reach any point in space and fly in or around existing objects. However, the loads drones can carry are currently limited, so the researchers opted to construct their bridge out of rope.
Apart from the scaffolds providing the anchor points at each end, the 7.4m long bridge is made from 120m or rope.Each drone was equipped with a motorised spool with a plastic tube located between two of the propellers that allowed control of the tension of the rope while the bridge was being built.
The drones utilised force-control technology to give their operators feedback on the tension of the rope or how close it was to the other quadrocopters.
"The rope bridge acts as a demonstrator, showing for the ?rst time that small ?ying machines are capable of autonomously realising load-bearing structures at full-scale and proceeding a step further towards real-world scenarios," the researchers wrote on the ETH website.