We like autonomous robots because they can do the things we can't or don't want to do. Justin Werfel, a researcher at Harvard University, calls it the "Three Ds—dirty, dangerous, and dull." And, these intelligent bots can get work done in places we aren't able to go—like other planets.
Werfel is part of a team of Harvard engineers designing an autonomous robot construction crew that can build structures without any human intervention or supervision. The latest research, published today in Science magazine, shows off the artificially intelligent bots building towers, pyramids, and staircases. It's the first step to putting robot swarms to work in hard-to-reach places like disaster zones, under the sea, or in outer space.
"We envision sending robots off to do their task and sending astronauts along only after a shelter is completed," study author Kirstin Petersen told me.
Swarming robots that can self-organize and self-assemble already hold a lot of promise for things like search and rescue, disaster relief, even manufacturing. And they’re getting better at working together. But this is the first time a team of bots have been able to build 3D structures bigger than themselves—a breakthrough in robotic construction, researchers say.
"If you want to build underwater, if you want to build a Mars base, it's going to be very difficult, dangerous and expensive to send people," Werfel said in a news release. "But if you could send a team of robots to go build the habitat as the first step—that's the really long-term vision."
As in, many decades in the future. The short-term goal is to use the robots to help in disaster areas, like building levees during floods.
The small bots work together to build a comparatively large structure. Image: Harvard University
An all-robot construction crew building a space base on Mars is impressive enough, but how the swarm works makes it even more interesting.
Unlike human workers, there's no hierarchy, no foreman, no blueprint to follow. Nor do the machines communicate with each other or even have any idea what the others are doing. Instead, the robots are programmed to observe each others' behavior and coordinate their activity based on changes in the environment.
It's not a futuristic concept; in fact, it takes a cue from nature. Specifically, termites. Termite colonies are able to build mounds massively larger than themselves by using collective intelligence, called "stigmergy." The project is named TERMES after the collaborative insects.
Image: Harvard University
“The key inspiration we took from termites is the idea that you can do something really complicated as a group, without a supervisor, and secondly that you can do it without everybody discussing explicitly what’s going on, but just by modifying the environment,” explained Radhika Nagpa, a computer scientist at Harvard.
The advantage of decentralized construction is that researchers can use cheap, expendable robots—the TERMES bots are 3D-printed and each about the size of a shoe—because without one leader in charge, the job will get done even if one of the bots breaks or, say, floats off into space.
So far, a swarm of three robots has successfully built a 10-block staircase without human control. Next, researchers are working to program the robots to build scaffolds and stairs and remove them after a task is done, so that they can climb higher and higher up, and eventually create human-scale structures.
Researchers are also considering adding extra functionality to the bricks, like electrical wiring, heating elements, or unfolding bricks to create overhangs and windows.
The system would require an industrial redesign process before being able to construct real shelters, even on Earth," said Kusek. "But hopefully this will inspire more research in the area of robotic construction, so that we can look forward to robot-built colonies on the Moon or Mars."