Robot Swarm!

The geniuses at Harvard have invented “kilobots” that work together to form different shapes and patterns without human interaction. The programmers call this the first “thousand-robot swarm”.

Instead of one highly complex robot, a “kilo” of robots collaborate, providing a simple platform for the enactment of complex behaviors.

Just as trillions of individual cells can assemble into an intelligent organism the Kilobots demonstrate how complexity can arise from very simple behaviors performed on mass. To computer scientists, they also represent a significant milestone in the development of collective artificial intelligence (AI).

This self-organizing swarm was created in the lab of Radhika Nagpal, the Fred Kavli Professor of Computer Science School of Engineering and Applied Sciences (SEAS)  at Harvard University. The advance is described in the August 15 issue of Science.

“The beauty of biological systems is that they are elegantly simple — and yet, in large numbers, accomplish the seemingly impossible,” says Nagpal. “At some level, you no longer even see the individuals; you just see the collective as an entity to itself.”

“Biological collectives involve enormous numbers of cooperating entities — whether you think of cells or insects or animals — that together accomplish a single task that is a magnitude beyond the scale of any individual,” said lead author Michael Rubenstein, a research associate at Harvard SEAS and the Wyss Institute.

He cited, for example, the behavior of a colony of army ants. By linking together, they can form rafts and bridges to cross difficult terrain. Social amoebas do something similar at a microscopic scale: When food is scarce, they unite to create a fruiting body capable of escaping the local environment. In cuttlefish, color changes at the level of individual cells can help the entire organism blend into its surroundings.

The Kilobots require no micromanagement or intervention once an initial set of instructions has been delivered. Four robots mark the origin of a coordinate system. All the other robots receive a 2-D image to mimic, and then, using very primitive behaviors — following the edge of a group, tracking a distance from the origin, and maintaining a sense of relative location — they take turns moving toward an appropriate position. With co-author Alejandro Cornejo, a postdoctoral fellow at Harvard SEAS and the Wyss Institute, the researchers demonstrated a mathematical proof that the individual behaviors would lead to the right global result.

Mini Robotics
Mini Robotics

The Kilobots also correct their own mistakes. If a traffic jam forms or a robot moves off-course — errors that become much more common in a large group — nearby robots sense the problem and cooperate to fix it.

To keep the cost of the Kilobot down, each robot moves using two vibrating motors that allow it to slide across a surface on its rigid legs. An infrared transmitter and receiver allow it to communicate with a few of its neighbors and measure their proximity. But the robots are myopic and have no access to a bird’s-eye view. These design decisions come with tradeoffs, Rubenstein explained.

“These robots are much simpler than many conventional robots, and as a result, their abilities are more variable and less reliable,” he said. “For example, the Kilobots have trouble moving in a straight line, and the accuracy of distance sensing can vary from robot to robot.”

For now, the Kilobots provide an essential test bed for AI algorithms.

“We can simulate the behavior of large swarms of robots, but a simulation can only go so far,” said Nagpal. “The real-world dynamics — the physical interactions and variability — make a difference, and having the Kilobots to test the algorithm on real robots has helped us better understand how to recognize and prevent the failures that occur at these large scales.”

The Kilobot robot design and software, originally created in Nagpal’s group at Harvard, are available open-source for non-commercial use. The Kilobots have also been licensed by Harvard’s Office of Technology Development to K-Team, a manufacturer of small mobile robots.

There has already been cries from the public that this is the beginning of the end and that very soon terminators will killing us off but honestly the level of AI required to out smart humans (most of us anyway)  is way off and this should been seen as a great leap forward in robotics. Just think of the applications!

Stay Curious – C.Costigan


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