Synchronization of networked Euler-Lagrange systems via set-ISS: A separation approach

In this paper we propose a novel approach to deal with synchronization of networked Euler-Lagrange systems separating local controller design from topology graphs. A specified consensus network is first constructed, where many existing consensus algorithms regardless of our node dynamics can be used. Subsequently, each Euler-Lagrange system is driven by a local controller designed together with the consensus network. In virtue of set input-to-state stability and taking the consensus manifold as a desired positively invariant set, we can handle the synchronization problem immediately without converting it into a simultaneous stabilization problem. Different from the distributed observer approach, the internal model principle is not employed here and thus we need not to solve a common solution pair to a set of regulator equations. In addition, one could focus on each local controller design independently to improve the network performance. To the best of our knowledge, our proposed approach generalizing many existing results is new and easier to be implemented.