Research On Consensus Of Multi-agent Systems Under Complex Communication Networks

In the past few decades,distributed cooperative control of multi-agent systems has received considerable concern owing to its widespread app(?)cations in a variety of areas.Generally,for multi-agent systems,it is assumed that information transmission between agents is in the ideal communication environment.However,information transmissions among agents are carried out through network topology,and thus easily encountered with various complex communication problems,such as DoS attacks,measurement noises,limited communication resources and so on.Therefore,this paper mainly studies consensus of multi-agent systems in complex communication networks,and the main contributions are given in the following:●H∞ consensus of linear multi-agent systems with semi-Markov switching network topologies and measurement noises is investigated.Communication disturbance,fading communication channels in the communication among agents can lead to the existence of noises in the information exchanges.Hence a distributed protocol is given with multiplicative noises.Meanwhile,the communication topology among the agents may not be fixed,even randomly changing due to uncertain factors such as random failures and the change of environments,therefore the switching of the network topologies are modeled by a semi-Markov process.Taking the external disturbance into account,H∞ consensus of multi-agent systems with multiplicative noises is achieved under semi-Markov switching network topologies by using semiMarkov jump theory,stochastic theory and algebraic graph theory.●Mean square consensus of linear multi-agent systems with measurement noises by using event-triggered strategy is investigated.Considering various uncertain factors in the communication environment,multiplicative noises exists in the information that each agent measures from its neighbors.Meanwhile,in order to avoid excessive information transmission,event-triggered mechanisms with time regularization are designed.Since the lower bound of the inter-execution time is positive,Zeno phenomenon can be avoided.Utilizing both static and dynamic event-triggered scheme,sufficient conditions are given to ensure exponential mean square consensus of multi-agent systems with multiplicative noises.●Secure mean square consensus of linear multi-agent systems with measurement noises by using sampled-data based event-triggered strategy under DoS attacks is investigated.Multiplicative noises are also considered in the communications among agents.Meanwhile,sampled-data based distributed event-triggered control mechanisms are developed,thus continuous information exchanges between neighbours and complex analysis in excluding Zeno phenomenon can be avoided.Taking the unreliable network environment into account,the communication on the control channels is interrupted by DoS attacks.When DoS attacks are at active periods,the communication topology is destroyed and the communication network is paralyzed.A technical lemma for stochastic multi-agent systems is obtained to solve the sampled-data based event-triggered mean square consensus problem.Sufficient conditions are given to ensure exponential mean square consensus by applying stochastic theory,switching control theory and algebraic graph theory.●Sampled-data based event-triggered control is applied to deal with bipartite tracking consensus problems of linear multi-agent systems,which are subject to DoS attacks.Owing to the properties of digital control,event-triggered control strategy based on sampled data is presented to decrease network loads.Meanwhile,taking the unreliable network environm ent into account,the communication on the control channels is interrupted by DoS attacks.In addition,antagonistic and cooperative behaviors of agents may exist simultaneously in real system networks.Therefore,sampled-data based eventtriggered bipartite tracking consensus problems of linear multi-agent systems are researched.Sufficient conditions are obtained to guarantee secure bipartite tracking consensus of the multi-agent systems by using directed signed graph theory,Lyapunov and switching control theory.