Drones are capable of far more than fancy photography. A team of researchers from ETH Zurich are using drones to build functional structures. A new video uploaded by the team shows a small team of quadcopters building a rope bridge that the men then walk across the 7.4 m structure. The bots build the bridge by carefully weaving ropes around two scaffolding structures located at either end of a room draped in white sheets.
The bridge is made of nine pieces of Dyneema rope that is released from a motorized spool on board each custom quadcopter. The motor on the spool allows the bot to control the tension on the rope as it weaves the bridge. Dyneema features the low weight-to-strength ratio required for such endevours. A 4 mm-diamter rope can support 1300 kg.
The white room where the bots were deployed, called the Flying Machine Arena, has motion capture system that provide vehicle position and attitude measurements. Computers on the ground calculate the correct flying patterns and send commands to the drones via a special wireless system devices by the researchers.
Special software was also created to design the tensile structures. According to the researchers, these computational tools simulate, sequence, and evaluate the structure before it is built. The location of the scaffolding is initially measured by humans, however. A bit more human help is required in order to build the stabilizers, too. After the primary and bracing structures were complete, the locations of the narrow openings of the bridge are measured add inputted into the computational tools, so that the trajectory of the drones can be adjusted.