bots IN BRIEF
SERVO 07.2015 17
JEFF AND LILY
GET ALL SWARMY
Forty one tiny robot submarines is a lot of tiny robot submarines. It’s so many, in fact, that
controlling them individually doesn’t make sense. The
only way to go then is to give them levels of swarm
intelligence, so that each individual robot can take care
of itself while the swarm as a whole completes an
The CoCoRo (Collective Cognitive Robotics)
Project sponsored by the European Commission has
been working with a heterogeneous swarm of
autonomous underwater vehicles (AUVs) since 2011. However, the most important thing to
know about these robots is that 20 of them are named Jeff.
Jeffs are powerful; they’re able to swim upstream against a current of 1 m/s. The other AUVs — the Lily robots — aren’t
quite as burly, so in the swarm they stay higher in the water to provide a communications link between the Jeff robots, the
base station, and the rest of the world.
Each AUV is capable of operating on its own and small groups share data between themselves. Then, the entire swarm
makes decisions based on the collective data. The advantages here are the same as with any robot swarm: It’s versatile,
adaptable, and very robust against failures of individual members. You could lose a handful of Lilys or Jeffs — and, of course, it
would be very sad — but the mission could continue.
The specific swarm behaviors that the robots employ are modeled on swarming experts; namely, fish, birds, social insects,
and even slime molds.
A group of Lily robots can achieve a coherent shoaling or flocking configuration by emitting and receiving pulsed light
signals. Similar to slime mold or fireflies, such pulsed signals are relayed from one agent to the next, forming signal waves that
move through the whole swarm. These waves are used to keep the swarm of Lily
robots together as a group, to coordinate the swarm, and to move it in a desired
In terms of practical applications, one possible scenario could be an underwater
search, where Jeff robots spread out to locate a target, signal each other when it’s
found, and then call Lily robots over for help communicating with the surface.
Image courtesy of CoCoRo Project.