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Robots Show Promise for Construction

By Kevin Wilcox

Researchers use a combination of robotics and humans to quickly assemble intricate, undulating brick walls with creative void patterns. Is this the future of construction?

As more sectors of the construction industry experience recovery from the Great Recession, economic analysts are increasingly concerned about the possible effects of a labor shortage. Approximately 2 million workers were laid off or left the industry during the downturn—the majority never to return. In the coming decades, some of those workers might be replaced by technological advances—possibly robots. Several research teams are developing such robots now and this research shows promise, but challenges remain in moving robotic technology from the controlled environment of a factory to ever-changing construction sites.

"[Robots] allow us to do things that we could not do otherwise manually," said Jan Willmann, Ph.D., the chair of architecture and digital fabrication at the Institute of Technology in Architecture at ETH Zurich—a prominent engineering, science, and technology university in Switzerland—who responded in writing to questions posed by Civil Engineering. "The robot's potential is the ability to do things beyond mere manual operation, but also beyond industrial repetition, and to be directly controlled by digital data. They can assemble objects free in space without, for example, needing measuring devices, additional tools, or time."

Willmann is part of a research team at ETH Zurich that has successfully developed and tested a robotic system that enables humans to interact with robots at construction sites, effectively capitalizing on the benefits of both human and machine capabilities to create novel construction processes and building methods.

In the group's research into on-site robotic construction, a human and a robot are viewed as collaborators, each bringing strengths to the process that complement the partner's weaknesses.

For instance, humans possess exceptional skills in recognizing and functioning in complex environments but must use constant, time-consuming visual references to build a block wall. Robots, on the other hand, have difficulty orienting to complex environments, but, when guided by detailed localization and control software, can place materials into complex designs rapidly, and with precision.

"Indeed, robots are good at doing certain things that humans cannot do efficiently or naturally, and this is complementary to our own capacities as intelligent, thinking humans," Willmann explained. "For architecture and engineering, the robot is more than a utilitarian tool. It empowers us to directly connect [computational] design and [physical] making, and this is obviously one of the strongest points."

Willmann said he believes this collaboration between human designers and robotic workers could result in sweeping changes to the architecture, engineering, and construction processes, changes that go well beyond mere automation to actually changing the very logic behind the processes, opening new avenues of creativity. "Such 'intelligent' on-site fabrication robots would...directly collaborate with the human worker, and execute digital designs directly on-site," Willmann said. For example, sensors can be used to adapt the computational design specifically to what is being created at the site, he explained. "In fact, at ETH Zurich, we are currently pursuing this research within the National Competence Centre in Research (NCCR) Digital Fabrication …and are optimistic of bringing robotic fabrication directly on-site in the next years," Willmann added.

This research, which is being led by Fabio Gramazio and Matthias Kohler, both professors at the Institute of Technology in Architecture, is being conducted in collaboration with Jonas Buchli, Prof. Dr., an assistant professor in ETH Zurich's Agile & Dexterous Robotics Lab. The team opened an architectural robotic laboratory in 2005 at ETH Zurich, merging research in advanced architectural design and additive fabrication processes through the customized use of industrial robots.

For their research into on-site robotic construction, the teams from the two initiatives mounted an industrial robot created by ABB Group, a Zurich-based robotics manufacturer, onto a mobile base with two small tracks. Equipment was installed to provide the controlling system with the ability to detect objects and obstacles in the immediate surroundings. A pair of vacuum grippers enable the robotic arm to manipulate and move such building materials as bricks. The team has built increasingly complex test structures with the robot, from circular installations made of bricks, to long, undulating walls with intricate void placements and twisting structural columns that closely resemble sculptural installations.

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12 ASCENH/February, 2016