Computer scientists and engineers have created an autonomous robotic construction crew whose members cooperate to build and modify their environment.
Inspired by the work work of termites in nature, the robots need no supervisor and no communication.
The TERMES robots were created by a team of computer scientists and engineers at the Harvard School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering at Harvard University.
The machines can build complex, three-dimensional structures without the need for any central command or prescribed roles.
The results of the four-year project were presented this week at the AAAS (American Association for the Advancement of Science) 2014 Annual Meeting and published in today’s issue of the journal Science.
The TERMES robots can build towers, castles and pyramids out of foam bricks, autonomously building themselves staircases to reach higher levels and adding bricks wherever they are needed.
In the future, similar robots could lay sandbags to protect from an advancing flood or perform simple construction tasks on Mars.
“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,” says principal investigator Radhika Nagpalat Harvard.
She is also a core faculty member at the Wyss Institute, where she co-leads the Bioinspired Robotics platform.
Most human construction projects are performed by trained workers in a hierarchical organisation.
They work from a blueprint and a detailed plan of how to execute it. The foreman goes out and directs his crew.
In insect colonies, the queen doesn’t give instructions to every individual. Each termite doesn’t know what the others are doing or what the current overall state of the mound is.
Termites rely on a concept known as stigmergy: they observe each others’ changes to the environment and act accordingly.
It is currently more common for robotic systems to depend on a central controller or on all of the robots being able to talk to each other frequently.
However, with TERMES each robot executes its building process in parallel with others, but without knowing who else is working at the same time.
If one robot breaks, or has to leave, it does not affect the others.
This also means that the same instructions can be executed by five robots or 500.
Lead author Justin Werfel, a staff scientist in bioinspired robotics at the Wyss Institute, says loose connections between Harvard’s computer scientists, electrical engineers and biologists are key to this success.
“When many agents get together—whether they’re termites, bees, or robots, often some interesting, higher-level behaviour emerges that you wouldn’t predict from looking at the components by themselves,” says Werfel.
The TERMES robots perform tasks — carrying blocks, climbing the structure, attaching the blocks — with only four simple types of sensors and three actuators.
What can a TERMES robot do?
- Move forward, backward, and turn in place
- Climb up or down a step the height of one brick
- Pick up a brick, carry it, and deposit it directly in front of itself
- Detect other bricks and robots in immediate vicinity
- Keep track of its own location with respect to a “seed” brick
What instructions do the TERMES robots follow?
- Obey predetermined traffic rules
- Circle the growing structure to find the first, “seed” brick (for orientation)
- Climb onto the structure
- Obtain a brick
- Attach the brick at any vacant point that satisfies local geometric requirements
- Climb off the structure
Watch the robots here: