University of Stuttgart researchers have created what some say is the first permanent building to be significantly designed and built using robotics.
The team employed a robotic arm and custom software to build the 250-square-meter geodesic structure—a curvy shell composed of self-bracing panels—faster and with greater precision than could be accomplished with human hands alone. And they did so while minimizing the project's environmental impact.
The result is a sinuous building called Landesgartenschau, or LaGa, Exhibition Hall in Schwäbisch Gmünd, Germany. The hall is made out of 243 geometrically unique plates of 50-millimeter-thick beech plywood designed and cut using robotics. Humans then assembled the plates like puzzle pieces, fitting together 7,356 finger joints so that the resulting structure could stand without supports. "If you didn't have the design, engineering and fabrication technology we assembled, you simply wouldn't be able to build anything like this," says LaGa team leader Achim Menges. "Proportionally, the timber shell is much thinner than an eggshell," Menges notes. Whereas eggshells have a thickness-to-span ratio of 1 to 100, LaGa's ratio is more than 1 to 200.
This project marks the first time builders have employed robotics, which had been considered too inflexible for use in iconoclastic architecture, so extensively on a permanent building, says Johannes Baumann, co-founder of the Association for Robots in Architecture. In fact, automation was the enabling factor in LaGa’s eye-catching design as well as the speed and efficiency involved in assembling the structure.
Team member Tobias Schwinn explains that the goal of the project was to create an exacting, lightweight structure that couldn't be built without robotics and demonstrate that robotics can fashion a structure beyond human capability.
The team wrote software, which generated the geometry of the hall and issued real-time alerts if it detected elements or processes that would make construction impossible. The Stuttgart tools worked within Grasshopper, a graphical algorithm editor that, in turn, worked within a three-dimensional modeling app called Rhinoceros. "We extended it (the custom software) to produce all of our computer-aided manufacturing data, to produce the simulation of the robot motion and, further downstream, generate control code for the robot," Schwinn says. A core project principle that added to its complexity was that any three plates needed to meet at a point, creating a Y juncture, he adds. Any deviation from this requirement would create a hinge joint. And with no supports for the shell, that hinge would fold, bringing down the shell. Tolerance for incorrect measurement of the materials are "submillimeter," according to Schwinn, compared with centimeter-scale tolerances for conventional geodesic domes.
Actual work on LaGa Hall began away from the construction site in January 2014. A Hundegger computer-aided manufacturing panel-cutter rough-cut each beech plate. Other computer-aided manufacturing tools cut insulation, waterproofing material and cladding.
A seven-axis Kuka Robotics system was then delivered to Müllerblaustein, the project's timber fabricator and builder, for bevelling and final cuts to the plates. Moving the hardware to a temporary basis and to a site not designed for robotics is unusual because the machines typically demand clean, structured surroundings, Menges says.* In this case they were employed primarily to show that it could be done and to reduce vehicle use, cutting LaGa's carbon footprint. The wood came from timber operations that were closer to the site than to a permanently placed robot.
Human assembly of the shell on temporary scaffolding and driving screws through each finger joint took three weeks. Although it is open now, LaGa Hall will be officially introduced to the public during the Rob|Arch conference for robotics in architecture in mid-May at the University of Michigan.
Some architecture scholars and practitioners see LaGa Hall as a major advance, giving designers more control over projects and shortening design cycles. Others, such as Thomas Bock, professor of architecture at the Technical University of Munich, disagree. Robotic prefabrication of construction materials is not unprecedented, he notes. Swiss robotics maker ABB, Ltd., fashions architectural elements such as metal sheets, for example.
Actual robotic construction should be the goal, Bock says, adding, "it's like we have a horse carriage without the horse, but we have a turbocharged engine.” There's a mismatch between what the design technology can do and what the technology could do, he concludes.
*Clarification (5/15/14): This and the previous sentence were edited after posting to better explain the process of setting up the Kuka Robotics system.