  Self-organized aggregation is a well studied behavior in swarm robotics as it
is the pre-condition for the development of more advanced group-level
responses. In this paper, we investigate the design of decentralized algorithms
for a swarm of heterogeneous robots that self-aggregate over distinct target
sites. A previous study has shown that including as part of the swarm a number
of informed robots can steer the dynamic of the aggregation process to a
desirable distribution of the swarm between the available aggregation sites. We
have replicated the results of the previous study using a simplified approach:
we removed constraints related to the communication protocol of the robots and
simplified the control mechanisms regulating the transitions between states of
the probabilistic controller. The results show that the performances obtained
with the previous, more complex, controller can be replicated with our
simplified approach which offers clear advantages in terms of portability to
the physical robots and in terms of flexibility. That is, our simplified
approach can generate self-organized aggregation responses in a larger set of
operating conditions than what can be achieved with the complex controller.
