Research On Dynamic Event-Triggered Cluster Formation Control For Multi-Agent Systems

In recent years,the formation control of multi-agent systems has attracted wide attention from researchers.However,due to limited network resources and frequent malicious network attacks,the system is difficult to maintain stability.Therefore,it is necessary to design an eventtriggered mechanism that can effectively deal with network attacks and save network resources.This paper focuses on the study of the cluster formation control for multi-agent systems.According to the network environment of multi-agent systems,a series of novel dynamic eventtriggered mechanisms are proposed.According to different control requirements,a variety of cluster formation control protocols are designed.The main contents are as follows:(1)The cluster formation control for the multi-agent systems based on dynamic eventtriggered mechanism is studied.Firstly,considering the multi-agent systems under Do S attacks,a dynamic event-triggered mechanism based on sampled data is proposed.A random variable is introduced to dynamically adjust its threshold parameters.When the communication network where the system resides is attacked,a smaller threshold parameter is selected,to increase the number of triggering instants and compensate for packets loss caused by attacks;When the network where the system resides is not attacked,select a larger threshold to reduce the number of triggering instants and save resources.Zeno phenomenon is effectively avoided by using sampled data.Next,a cluster formation control protocol is designed and formation information is introduced to realize the control goal of the followers following their leaders to form specific formations.Then,the stability criterion is obtained by constructing Lyapunov-Krasovskii functional.Then,the nonlinear terms in the matrix inequalities are transformed into linear terms by using the contract transformation,and the control gain and threshold parameters are designed jointly by using the linear inequality toolbox.Finally,the validity of the theory is verified by a multi-UAV system.(2)The scaled formation control for multi-agent systems based on refined dynamic eventtriggered mechanism is studied.Firstly,considering the multi-agent systems under fixed topology,an improved dynamic event-triggered mechanism based on the sampled data is proposed.The combination error of system is replaced by its absolute value,so that the system can trigger events at the moment when it cannot trigger events before,so as to obtain a better convergence effect under the same triggering times.According to the state of the network,the threshold parameter is selected flexibly,and the number of triggering instants is adjusted dynamically,which realizes the stability of the system faster.Next,the scaled formation control protocol is designed and the formation information is added to make the system clustering no longer depend on the communication topology connection.Then,the stability criterion is obtained by constructing Lyapunov-Krasovskii functional.Then,the control gain and threshold parameters are designed by using the sparrow search algorithm.In order to better adapt to the real environment,the eventtriggered mechanism and control protocol are extended to the switching topology caused by network attacks.Finally,it can be verified by a multi-UAV system that the system can realize stable cluster formation.(3)The scaled formation obstacle avoidance control of multi-agent systems based on resilient dynamic event cluster triggered mechanism is studied.Firstly,a new resilient dynamic event cluster triggered mechanism is proposed for the parameter deterministic systems.The absolute value of the combination error of system is used,and three groups of threshold parameters are designed.When the network condition of the cluster where the agent resides is good,the minimum threshold parameter is selected.When the network status of the cluster where the agent resides is poor,select the maximum threshold parameter.When calculating the combination error,different threshold parameters are selected according to the cluster where the neighbor agent resides so as to flexibly deal with the different communication network conditions of each cluster within the system.Next,the scaled formation obstacle avoidance control protocol is designed,and the formation information and the obstacle avoidance function based on potential energy are added to avoid the obstacles encountered during the execution of the task.Then,the stability criterion is obtained by constructing Lyapunov-Krasovskii functional.Then,on the basis of sparrow search algorithm,cross mutation operation of genetic algorithm is added,and the control gain and threshold parameters are designed jointly.The event-triggered mechanism and control protocol are applied to the multi-agent systems with parameter perturbation,and the feasibility is proved by theory.Finally,the feasibility of the theory is verified by a multi-UAV system.