Coordination Control Of Multi-agent Systems With Switching Topology

It is well known that biological groups such as the school of fish,the crowd of ant,the group of bird,and the swarm of bacteria can cluster into a coordinated motion.There is no global information in these collective behaviors,and the complicated motion can be achieved only based on the information exchange between individuals.To study and simulate this motion,researchers have proposed the problems on the coordination control of multi-agent systems,where a large number of autonomous mobile agents use limited environmental information and simple rules to organize into a coordinated motion.As a distributed control,the coordination control of multi-agent systems has achieved significant results in the application of UAV formations and intelligent robot motion,and has attracted a considerable amount of attention in different fields.In order to be better applied to the real-world problems,this paper focuses on the design of control algorithms under more general conditions based on the existing results.The specific research content of the paper is as follows:1.The flocking of multi-agent systems with dynamic topology is investigated in this study.For a disconnected network,the agents may separate as isolated individuals or subnetworks.A switching control law is developed to achieve the flocking by adding the control from these individuals to their closest informed agent including the nonlinear relative velocity feedback.The multiple Lyapunov functions are then constructed and a stable analysis for the flocking is given based on the La Salle invariance principle.It is proven that the energy is bounded at all time,and asymptotically converges to the state of minimum energy;the velocities of all agents approach to the velocity of the virtual leader asymptotically;no collision happens between the mobile agents.It is shown that fewer informed agents in comparison with existing methods can guarantee the stable flocking,which is very significant in some practical applications for secure communication.2.The fixed-time flocking of multi-agent systems with nonlinear dynamics is investigated in this paper.The motion dynamics of the agents are assumed to be unknown and only satisfy the boundedness.To achieve the flocking and collision avoidance for all agents in the fixed time,a control protocol in the high-dimensional space is developed by using the graph theory and the theoretical properties of differential equations.Moreover,the upper bound of the settling time only depending on the control protocol and the topology of network is estimated.Numerical examples are used to verify the theoretical results,and show that the proposed method provides an applicable method for the control of the nonlinear dynamic systems.3.This paper investigates the fixed-time global consensus of nonlinear multi-agent systems with dynamic topology.The disconnected network topology is considered and the control algorithm is proposed via adding the control from the isolated individuals(or isolated subnetworks)to the closest informed agent.To achieve the global consensus of all agents in a fixed time,a control protocol in the high-dimensional space is developed by using the graph theory and the theoretical properties of differential equations.The stability analysis is given based on the multiple Lyapunov functions and the upper bound of the convergence time can be estimated only depending on the control protocol and the topology of network.It is proven that the non-monotonic energy function of the system can always remain bounded during the evolution,and the global convergence can be achieved in a fixed time.Finally,numerical examples are used to verify the theoretical results,and show that the proposed method provides an applicable method for the fixed-time control of the disconnected network problems.4.This paper investigates the flocking control of multi-agent systems with unknown nonlinear dynamics while the virtual leader information is heterogeneous.The uncertain nonlinearity in the virtual leader information is considered,and the weaker constraint on the velocity information measurements is assumed.A new control protocol is proposed when the unknown nonlinear dynamics only satisfies the bounded assumption.To avoid fragmentation,we construct a new potential function based on the penalty idea when the initial network is disconnected.It is proven that the velocities of all agents approach to consensus and no collision happens between the mobile agents.Finally,several simulations verify the effectiveness of the new design.For the complicated motion situations,the control methods proposed in the paper can take effect and have better application value in practical engineering.