Research On Fixed-Time And Given Precision Consensus Control For Nonlinear Uncertain Multi-Agent Systems

The consensus control of multi-agent systems is widely used in many fields such as cooperative supervision,sensor network and unmanned aerial vehicle formation.The study of multi-agent systems includes linear and nonlinear characteristics at present.Compared with linear systems,nonlinear systems are further studied because they are closer to real systems.In terms of the convergence,the consensus control of nonlinear multi-agent systems mainly focuses on asymptotic consensus control,finite-time control and fixed-time control.From the perspective of the leader/leaderless,the consensus control of nonlinear multi-agent systems can be divided into leaderless consensus control and leaderless consensus control.According to the number of leaders,it can be further divided into leader-follower consensus(one leader)and containment control(multiple leaders).And the research results are abundant,but there are still some problems to be solved urgently.In this paper,the practical fixed-time consensus control is proposed to solve the deficiency of the current research on the fixed-time consensus of nonlinear multi-agent systems,and the research is carried out from two aspects of full state constraints and event trigger.In addition,in order to further satisfy the practical needs,this paper proposes the control problem of nonlinear multi-agent systems with given precision,and studies the precision control issue from the perspectives of the single leader and multiple leaders,respectively.The main content of this paper is as follows:(1)The practical fixed-time consensus of nonlinear multi-agent systems with full-state constraints and input delay is studied.Firstly,a nonlinear multi-agent model with input delay is established and the system states are constrained.Secondly,Pade estimation method is used to reconstruct the system model,which paved the way for solving the input delay.Finally,based on Backstepping technology,the concrete design scheme of the actual controller is given,and the consensus of the nonlinear multi-agent systems is analyzed.(2)The practical fixed-time containment control for stochastic nonlinear multi-agent systems is studied.A typical stochastic nonlinear multi-agent system model is firstly established for the inevitable uncertainties and random disturbances in the real system.Secondly,the design method of each virtual controller and adaptive law is proposed,and the design scheme of the actual controller after the event triggering mechanism is introduced in the channel between the system controller and the actuator is given.Finally,the problem of actual fixed time consistency of nonlinear multi-agent systems with multiple leaders based on event triggering mechanism is analyzed.(3)The consensus of nonlinear multi-agent systems with given precision is studied.Aiming at the strictly nonlinear multi-agent system model established,the control objective of distributed controller is established.A suitable Lyapunov function is established by using the introduced switching function.At the same time,the design method of distributed controller is given with Backstepping technology.Finally,the convergence of consistency error is analyzed by using Barbalat lemma and the characteristics of switching function.(4)The containment control of nonlinear multi-agent systems with non-affine structure is studied.Firstly,the non-affine multi-agent systems are transformed into a general multi-agent systems model,and the form of synchronous containment error is transformed.Secondly,the switching function is used to help create a new Lyapunov function,and the actual distributed controller design method is obtained through the evolution of virtual controller and adaptive law at each step.Finally,the convergence of agents under different given precision is analyzed.