Wednesday, October 5, 2022

Robots and AI assist in building wooden hanging gardens in Switzerland

Working with Müller Illien Landscape Architects, Timbatec, and other partners from industry and research, researchers from ETH Zurich are building a planted architectural sculpture for the Tech Cluster Zug. The 22.5-meter-high structure consists of five geometrically complex wooden shells that are slightly offset from each other and supported by eight thin steel pillars.

The sculpture called Semiramis, named after the Babylonian queen to whom the ancient Hanging Gardens of Babylon have been attributed is being designed and built using innovative digital methods that were developed as part of the project. The sculpture is being developed with the help of artificial intelligence and four collaborative robots.

Its multi-faceted pods are being manufactured in the Robotic Fabrication Laboratory at ETH Zurich. Always in sync, four suspended robotic arms pick up the wooden panel assigned to them, perform a high-precision dance and finally place the panels in space according to the computer design. An algorithm calculates the movements of the robots in such a way that no collisions occur during execution. Once the machines have placed their four panels next to each other, craftsmen first temporarily join them before gluing them together with a special casting resin. Each of Semiramis’s five wooden pods comprises between 51 and 88 of these wooden panels.

The model of the finished. 22.5 meter high sculpture.
The model of the finished. 22.5-meter high sculpture. Credit: ETH Zurich

In contrast to traditional wood construction, robotic manufacturing has several advantages: on the one hand, the robots relieve humans of the heavy lifting and precise positioning; and on the other hand, the assembly process requires no costly, resource-intensive substructures.

Computer software developed jointly with ETH’s Computational Robotics Lab was also used in the designs of the wooden shells, automatically adjusting the entire geometry of each pod if a single point on a computer model of that pod was moved. The proposals differed as to the shapes of the pods and their spatial arrangement relative to each other. They also highlighted how each design affected individual target variables, such as pod irrigation.

“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 Matthias Kohler, Professor of Architecture and Digital Fabrication at ETH Zurich.

Robotic prefabrication is currently running at full speed. Individual pod segments are being shipped to Zug by a lorry on a regular basis, where the architectural sculpture will be erected and finally planted out in spring 2022. Starting that summer, people will be able to view the wooden structure from the ground on from nearby buildings and catch a glimpse of the greenery in the pods.

New Discoveries