Consensus of Euler–Lagrange Agents With Internal Model Disturbance Rejection and Interconnection Delays

We propose a distributed control method to achieve consensus of heterogeneous Euler–Lagrange (EL) systems with bounded time-varying communication delays while simultaneously rejecting periodic external disturbances. Our proposed controller has a simple-to-implement structure of proportional–integral--derivative scheme that employs the internal model approach to reject the disturbance and that it is model-independent (when cancelling the gravity effects). We consider that the network of EL-systems is interconnected through an undirected weighted graph that is static and we assume that the information exchange between any connected nodes is subjected to bounded variable time-delays. In this scenario we provide a sufficient condition for the proportional and the derivative gains of the controller to ensure that the EL-systems globally and asymptotically converge to a consensus position. The efficacy of the proposed method is shown in a numerical simulation using a network of ten robotic manipulators.