  Connectivity maintenance is crucial for the real world deployment of
multi-robot systems, as it ultimately allows the robots to communicate,
coordinate and perform tasks in a collaborative way. A connectivity maintenance
controller must keep the multi-robot system connected independently from the
system's mission and in the presence of undesired real world effects such as
communication delays, model errors, and computational time delays, among
others. In this paper we present the implementation, on a real robotic setup,
of a connectivity maintenance control strategy based on Control Barrier
Functions. During experimentation, we found that the presence of communication
delays has a significant impact on the performance of the controlled system,
with respect to the ideal case. We propose a heuristic to counteract the
effects of communication delays, and we verify its efficacy both in simulation
and with physical robot experiments.
