If you were building a complex wooden structure by hand, it would be quite difficult to lift the heavy wooden components, place them in precise alignment, then keep them aligned as they were glued together. That’s why a Swiss team is using robots to shoulder much of the workload.

The outdoor structure is called Semiramis, which is the name of the queen who is believed to have commissioned the ancient Hanging Gardens of Babylon. Plans call for it to stand 22.5 meters tall (73.8 ft), and to incorporate five plant-filled wooden-shell pods which will be supported by eight steel pillars. It will be located at a technology park in the Swiss town of Zug.

Semiramis was designed by Zurich-based Müller Illien Landscape Architects and Swiss timber construction company Timbatec. Its multi-faceted pods are being manufactured at ETH Zurich’s Robotic Fabrication Laboratory. There, four robotic arms work in unison to select and lift pre-cut plywood panels, place them next to one another in the desired configuration, then hold them in place while human workers apply a casting resin to bond them together.

It’s a big job, as each pod consists of 51 to 88 such panels. A special control algorithm ensures that the arms don’t collide with one another as they’re putting the pods together.

Pascal Bach/Gramazio Kohler Research, ETH Zurich

Custom software was also used in the design process, automatically adjusting the entire geometry of each pod if a single point on a computer model of that pod was moved. The program also indicated how different design choices would affect factors such as irrigation, the manufacturing process, and the pod’s load-bearing capacity.

Plans call for Semiramis to be completed and fully planted by next spring. The robotic assembly process can be seen in the video below.

“Semiramis has been a beacon project for architectural research, bringing together people inside and outside ETH and advancing the key research topics of the present, such as interactive architectural design and digital fabrication,” says ETH Zurich’s Prof. Matthias Kohler.

Sources: ETH Zurich, Timbatec