  In this paper, an event-triggered control protocol is developed to
investigate flocking control of Lagrangian systems, where event-triggering
conditions are proposed to determine when the velocities of the agents are
transmitted to their neighbours. In particular, the proposed controller is
distributed, since it only depends on the available information of each agent
on their own reference frame. In addition, we derive sufficient conditions to
avoid Zeno behaviour. Numerical simulations are provided to show the
effectiveness of the proposed control law.
