  With the advent of inexpensive simple humanoid robots, new classes of robotic
questions can be considered experimentally. One of these is collective behavior
of groups of humanoid robots, and in particular robot synchronization and
swarming. The goal of this work is to robustly synchronize a group of humanoid
robots, and to demonstrate the approach experimentally on a choreography of 8
robots. We aim to be robust to network latencies, and to allow robots to join
or leave the group at any time (for example a fallen robot should be able to
stand up to rejoin the choreography). Contraction theory is used to allow each
robot in the group to synchronize to a common virtual oscillator, and quorum
sensing strategies are exploited to fit within the available bandwidth. The
humanoids used are Nao's, developed by Aldebaran Robotics.
