Coordination Tracking of Multiagent Systems with Active Replacement Strategy under Node Failures

Coordination tracking problem of multiagent systems is studied for the application of threat defense in a monitored area. When targets intrude this area, agents which are nearby to them are set to track the targets. Modified nonsingular terminal sliding mode controller is proposed for the agents. We design a novel continuous function in the controller to eliminate the singularity, which makes it able to estimate the finite tracking time. Based on the estimated time, generalized Voronoi diagram considering the velocity of second-order agents and targets is presented. During the tracking process, the event of node failures will trigger a designed coordination strategy. The event that the target enters a new generalized Voronoi cell triggers active replacement coordination strategy. With the proposed active replacement strategy, the tracking time is reduced even under node failures. Comparison lemma is utilized to deal with the agent switching issue caused by node failures or active replacements under new event-triggered coordination strategies.