Group Tracking Control Of Nonlinear Multi-agent Systems

Multi-agent systems have attracted the attentions of scholars because of their wild applications.The consensus control problem,as the cornerstone of multi-agent systems,is also the focus of the research.At present,there have been relatively rich theoretical results on the consensus of linear multi-agent systems.However,theoretical results on group tracking and group consensus for more general second-order nonlinear multi-agent systems are relatively few.Based on algebraic graph theory,matrix theory and Lyapunov stability theory,this thesis studies the group tracking control and group consensus problems of nonlinear multi-agent systems.The main contents of this thesis are as follows:1.This thesis investigates the group tracking problem of second-order nonlinear multi-agent systems without communication delays.It is supposed that the agents are divided into two subgroups and they track the speed of a virtual leader at different scales.The control protocol is designed firstly and a series of system transformations are used to obtain a reduced-order error system and a tracking error system.Then based on the Lyapunov stability theory and input-to-state stability,a sufficient condition for the system to achieve group consensus tracking is obtained.Besides,the thesis further studies the value range of relevant parameters when the system achieves group tracking control,and obtains a sufficient condition for easy verification.2.This thesis investigates the group consensus tracking problem of second-order nonlinear multi-agent systems with asymmetric time-varying delays.A delay-dependent control protocol is designed.We employ a series of system transformation and choose a time-delay-dependent Lyapunov function to obtain a sufficient condition for the system to achieve group consensus tracking.The proof process is similar to the case without time delay,but the existence of time delay makes inequality scaling and matrix operations more complicated.Finally,through designing a simulation,the validity of the theoretical results is verified by MATLAB.3.We discuss the scaled group consensus of nonlinear multi-agent system under frequently cycber-attack,and consider two situations of leadless and leader-following.Similarly,it is supposed that the agents are divided into two subgroups.A control protocol based on the agent's neighbor state is designed.The sufficient conditions for the system to achieve scaled group consensus and leader-following group consensus are obtained by using matrix theory and Lyapunov stability theory.