  This document considers the formation control problem for a group of
non-holonomic mobile robots under time delayed communications. The agents are
assumed to be working under a directed and fixed communication topology. A
recently developed formation control technique, based on a consensus protocol
for linear systems is revisited. The stability analysis of this control
technique, in the domain of the time delays, is performed using the CTCR
paradigm under the SDS domain approach. This analysis leads to an exact
declaration of the stability boundaries in the domain of the delays. This
linear control law is adapted to the nonlinear dynamics of the non-holonomic
carts by means of feedback linearization. Simulation results show the
applicability of this method to the class of agents considered here.
