Event-triggered Consensus Control Of Nonlinear Multi-agent Systems

Recently,the consensus problem of multi-agent systems has drawn extensive attention due to its comprehensive practical applications,for example,sensor network,aerospace measurement and electric energy.Consensus problem requires that multiple agents communicate with each other and exchange the information locally so that all agents can reach a same final state.Event-triggered control strategy,in which the updating of controller only occurs at discrete time instants when the pre-set threshold value is satisfied,is applied into the consensus protocol so as to save the communication costs for multi-agent systems.In order to comply with the various communication environment,the research on event-triggered consensus problem has expanded from the fixed topology to the general switching topology,and denial-of-service attack is worth taking into account for its more challenging on design and analysis of consensus protocol.By using event-triggered control strategy,this paper investigates the consensus problems of nonlinear multi-agent systems under fixed topology,switching topologies and denial-of-service,respectively.The main contents of our work are listed as follows:(1)Consensus problem is studied for the first-order nonlinear multi-agent systems under fixed topology,and a novel event-triggered consensus protocol is proposed.Different from the existing results with general zero-order hold,the first-order hold is adopted to construct the event-triggered control signal so as to reduce the triggering rate.Based on the strongly connected topology,and Lyapunov stability method and matrix theory,a sufficient consensus condition is derived for the agents to reach the asymptotic consensus,and Zeno behavior can be avoided.The proposed event-triggered consensus protocol possesses the less triggering rate than the event-triggered consensus protocol based on zero-order hold.(2)Consensus problem is addressed for the first-order nonlinear multi-agent systems under switching topologies,and a distributed event-triggered consensus protocol using first-order hold is developed to decrease the network communication load.Based on the switching topologies with the union of subgraphs containing a directed spanning tree,and iterative method and inequality method,several sufficient criteria are obtained for the agents to reach the bounded consensus.Furthermore,it is proved that Zeno behavior is excluded under the proposed event-triggered protocol.Meanwhile,the effectiveness of proposed protocol in saving communication resources are substantiated by means of a comparison.(3)This chapter investigates the event-triggered consensus problem of second-order nonlinear multi-agent systems subject to denial-of-service attacks,which make the communication network unable to provide normal services.Considering a general class of denial-of-service attack with limited duration,a novel distributed event-triggered consensus protocol accompanied with first-order hold is adopted to guarantee the globally bounded consensus convergence under directed network topology.Based on the linear matrix inequality approach and Lyapunov stability method,consensus converging properties are analyzed and sufficient criteria are obtained.Furthermore,Zeno-free triggering of our proposed protocol is demonstrated.