AI News, A Thousand Kilobots Self-Assemble Into Complex Shapes

A Thousand Kilobots Self-Assemble Into Complex Shapes

Now the researchers have built one thousand of them.That's a whole kilo of Kilobots, and probably the most robots that have ever been in the same place at the same time, ever [UPDATE: Some readers wrote in to say they disagree that this is the most robots in the same place at the same time ever.

The researchers—Michael Rubenstein, Alejandro Cornejo, and Professor Radhika Nagpalof Harvard’s Self-Organizing Systems Research Group—describe their thousand-robot swarm in a paper published today in Science (they actually built 1024 robots, apparently following the computer science definition of 'kilo').

Each Kilobot [pictured below] is a small, cheap-ish ($14) device that can move around by vibrating their legs and communicate with other robots with infrared transmitters and receivers.

There are so many robots here that the importance of any individual robot is close to zero, which is a big part of the point of a swarm in the first place: robots can screw up, robots can break down, but there are so many of them that it just doesn't matter, because their collective behavior prevails.

So, to localize, they depend on an initial 'seed' group of robots to define the origin of a coordinate system, and then subsequent robots can localize based on the relative brightness of the infrared pulses coming from at least three other robots that have already been localized.

Once the robots localize themselves, the procedure for forming an arbitrary shape is relatively straightforward: robots start to move around the perimeter of the swarm until they detect that they've entered the area where the shape will be formed.

Individual robots don't necessarily have the sensors to determine when bad things like this happen, but through interacting with their neighbors and looking for patterns in the sensor data, the swarm as a whole is much more resilient.

'This motivates new investigations into advanced collective algorithms capable of detecting malfunctioning robots and recovering from large-scale external damages, as well as new robot designs that, like army ants, can physically attach to each other to form stable self-assemblages.'

A self-organizing thousand-robot swarm

Just as trillions of individual cells can assemble into an intelligent organism, or a thousand starlings can form a great flowing murmuration across the sky, the Kilobots demonstrate how complexity can arise from very simple behaviors performed en masse (see video).

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,” says lead author Michael Rubenstein, a research associate at Harvard SEAS and the Wyss Institute.

(And as Nagpal points out—with a smile—a school of fish in the movie Finding Nemo also collaborate when they form the shape of an arrow to point Nemo toward the East Australian Current.) “We are especially inspired by systems where individuals can self-assemble together to solve problems,” says Nagpal.

Four robots mark the origin of a coordinate system, all the other robots receive a 2D image that they should 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 towards an acceptable position.

“For example, the Kilobots have trouble moving in a straight line, and the accuracy of distance sensing can vary from robot to robot.” Yet, at scale, the smart algorithm overcomes these individual limitations and guarantees—both physically and mathematically—that the robots can complete a human-specified task, in this case assembling into a particular shape.

“Increasingly, we’re going to see large numbers of robots working together, whether its hundreds of robots cooperating to achieve environmental cleanup or a quick disaster response, or millions of self-driving cars on our highways,” she says.

“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.

Thousand-strong robot swarm throws shapes, slowly

Each of the identical robots is given a picture of the required shape, and then they work together to make it happen.

Inspired by biological examples, like cells forming organs or ants building bridges, the work could help develop self-assembling tools and structures.

The robots' arena is a large wooden square, about the size of a tournament snooker table, complete with edges to stop them waddling off the edge.

random selection will start first, if they are in a position to move: inching slowly around the table and flashing their own infra-red lights to broadcast information to the other Kilobots nearby.

So that they know where to start the shape they've been programmed to make, four 'seed' robots have already been placed in a suitable position by one of the scientists.

The seed robots kick off a coordinate system, which spreads through the swarm via those infrared lights, bouncing off the table from any transmitting robot to anyone 'listening' within 10cm.

'Each robot looks at its current state - so, what have I done in the past - and also looks at what its neighbours are doing, based on communication.

'Increasingly, we're going to see large numbers of robots working together,' she said, 'whether its hundreds of robots cooperating to achieve environmental cleanup or a quick disaster response, or millions of self-driving cars on our highways.

'Performing self-assembly with a thousand-robot swarm is a remarkable feat,' said Dr Sabine Hauert, a robotics lecturer at the University of Bristol, '[especially] given the advances needed to build hardware that is affordable and easy to use, and design algorithms that scale to large numbers of unreliable robots.'

'The Harvard Kilobot system is not only the largest swarm of robots in the world, but also an excellent test-bed allowing us to validate distributed algorithms in practice,' he said.

Thousand-robot swarm assembles itself intoshapes

There is something magical about seeing 1,000 robots move, when humans are not operating any of them.

Self-assembly of this kind can be found in nature – from molecules forming regular crystals and cells forming tissues, to ants building rafts to float on water and birds flocking to avoid becoming prey.

These kilobots – where a kilo stands for 1,024 – can form complex 2D shapes including a star, a wrench and the letter “k”.

It could communicate with neighbouring robots using infrared light, signal its state by changing a colour LED and sense ambient light.

With the robots ready, the Nagpal team had to develop an algorithm which could guarantee that large numbers of robots, with limited capabilities and local communication, could cooperatively self-assemble into user-specified shapes.

These seed robots emit a message that propagates to each robot in the blob and allows them to know how “far” away from the seed they are and their relative coordinates.

After years of research in this area, it looks like we are finally reaching a tipping point where both hardware and algorithms can build large-scale robotic swarms, at least in the labs.

They also enable the first steps towards creating artificial swarms for real-world applications, including disaster relief, environmental monitoring and maybe even art.

Thousand-robot swarm assembles itself into shapes

There is something magical about seeing 1,000 robots move when humans are not operating any of them.

Self-assembly of this kind can be found in nature—from molecules forming regular crystals and cells forming tissues, to ants building rafts to float on water and birds flocking to avoid becoming prey.

These kilobots—where a kilo stands for 1,024—can form complex 2D shapes including a star, a wrench, and the letter 'k.'

It could communicate with neighboring robots using infrared light, signal state by changing a color LED, and sense ambient light.

With the robots ready, the Nagpal team had to develop an algorithm which could guarantee that large numbers of robots, with limited capabilities and local communication, could cooperatively self-assemble into user-specified shapes.

These seed robots emit a message that propagates to each robot in the blob and allows them to know how 'far' away from the seed they are and their relative coordinates.

After years of research in this area, it looks like we are finally reaching a tipping point where both hardware and algorithms can build large-scale robotic swarms, at least in the labs.

These swarms have the potential to help us understand natural self-organized systems by providing fully engineered physical systems on which to do experiments.

They also enable the first steps toward creating artificial swarms for real-world applications, including disaster relief, environmental monitoring, and art.