  We study synchronization of nonlinear systems that satisfy an incremental
passivity property. We consider the case where the control input is subject to
a class of disturbances, including constant and sinusoidal disturbances with
unknown phases and magnitudes and known frequencies. We design a distributed
control law that recovers the synchronization of the nonlinear systems in the
presence of the disturbances. Simulation results of Goodwin oscillators
illustrate the effectiveness of the control law. Finally, we highlight the
connection of the proposed control law to the dynamic average consensus
estimator developed in [1].
