Team Consensus for a Network of Unmanned Vehicles in Presence of Actuator Faults

In this paper, performance analysis of a team of unmanned vehicles (agents) that are subject to actuator faults is investigated. The team goal is to accomplish a cohesive motion in a modified leader-follower architecture by using a semi-decentralized optimal control strategy. The controller, which is recently proposed by the authors, is designed based on minimization of individual cost functions by using the available information from the neighboring sets. It is shown that a loss of effectiveness (LOE) fault in an actuator does not deteriorate the stability nor the consensus seeking goal of the team. This fault would only result in a different transient behavior, e.g., a change in the agent´s convergence rate, without a change in the consensus value. On the other hand, if the fault in one or more of the agents is of the float type, either in the leader or the followers, the team could not maintain its consensus any longer, however the stability of the team can still be guaranteed. Moreover, the leader and the healthy followers adapt themselves to the follower´s change when a float fault occurs in one of the agents. Finally, the behavior of the team in presence of the lock-in-place (LIP) actuator fault is also investigated. Simulation results are provided to demonstrate the performance of the team subject to the above three actuator fault scenarios.