Harvard researchers have designed a swarm of small, mobile robots which are able to organize themselves into large shapes from random starting points with minimal initial human assistance.
Dubbed "Kilobots," a thousand of the simple, three-legged marchers motor up in turn after being prompted to form a set shape, slowly navigate their way to acceptable final positions in an almost organic-looking flow pattern, and can even collaborate to overcome frequent traffic jams along the way.
The only human input required is for a researcher to set four Kilobots in place as the starting point for the swarm to build a predetermined shape around. Shapes the robot "flash mob" is capable of producing include a five-pointed star and the letter "K."
The self-organizing behavior of the Kilobots was inspired in part by the cooperative activities of insects like army ants and other biological phenomenon, such as cellular growth, according to the researchers.
"The beauty of biological systems is that they are elegantly simpleand yet, in large numbers, accomplish the seemingly impossible. At some level you no longer even see the individuals; you just see the collective as an entity to itself," said research leader Radhika Nagpal, professor of computer science at the Harvard School of Engineering and Applied Sciences.
Nagpal and her colleagues published their findings in the current issue of Science.
The success at getting so many robots to self-organizeprevious efforts at similar experiments have generally topped at out at programming a hundred or fewer botscould be a "significant milestone" in the development of nanotechnology and a collective artificial intelligence, according to the researchers.
Of course, the Kilobots are not currently the fastest shape-creators in the world. Their self-organizing activities look pretty cool in the video below, but keep in mind the footage is sped up considerably via time-lapse.
The Kilobots themselves were relatively inexpensive to make, each possessing just a small circuit board, a pair of vibrating motors to power three skinny legs for locomotion, and an infrared transmitter and receiver. Keeping down the cost of the individual bots was key to the team's goal of demonstrating a very large swarm of self-organizing robots.
The bots are also very limited in their ability to interact with each other, each one only able to "communicate with a few of its neighbors and measure their proximity," the researchers said. That's by designa necessarily simple algorithm for guiding each kilobot's movement toward its end position was desired by the team to enable a larger swarm.
The capabilities of the Kilobots are "very primitive," the team said. After they receive the 2D image of the shape they're supposed to make, they can do simple things like "following the edge of a group, tracking a distance from the origin, and maintaining a sense of relative location."
Those limited capabilities proved enough to get the job done.
Using cheap materials and simple programming, the researchers were able to build a larger robot swarm than was previously manageable, though going that route did have some drawbacks, said study lead author Michael Rubenstein.
"These robots are much simpler than many conventional robots, and as a result, their abilities are more variable and less reliable. For example, the Kilobots have trouble moving in a straight line, and the accuracy of distance sensing can vary from robot to robot," Rubenstein said.
The Kilobots build on work by Nagpal and her team in devising termite-inspired units called TERMES robots which cooperate to build simple structures, but in much smaller numbers than the Kilobots, the researchers said.