  This work presents a new method to design consensus controllers for perturbed
double integrator systems whose interconnection is described by a directed
graph containing a rooted spanning tree. We propose new robust controllers to
solve the consensus and synchronization problems when the systems are under the
effects of matched and unmatched disturbances. In both problems, we present
simple continuous controllers, whose integral actions allow us to handle the
disturbances. A rigorous stability analysis based on Lyapunov's direct method
for unperturbed networked systems is presented. To assess the performance of
our result, a representative simulation study is presented.
