Synchronization of uncertain Euler-Lagrange systems with unknown time-varying communication delays

A decentralized controller is presented along with sufficient conditions for stability in leader-based synchronization of communication-delayed networked agents. The agents have heterogeneous dynamics modeled by uncertain, nonlinear Euler-Lagrange equations of motion affected by heterogeneous, unknown, exogenous disturbances. The developed controller requires only one-hop (delayed) communication from network neighbors and the communication delays are assumed to be heterogeneous, uncertain and time-varying. The presented approach uses a Lyapunov-based stability analysis in conjunction with Lyapunov-Krasovskii functionals to provide sufficient conditions which depend on the upper bound of the heterogeneous delays, feedback gains, and network connectivity, among other factors.