Fuzzy Adaptive Consistency Control For Nonlinear Multi-Agent Systems

Inspired by the group behavior in nature,scholars in the field of control science began to study consensus proplem of nonlinear multi-agent systems.The time taken by multi-agents to achieve consensus is an important index to evaluate consensus control issue.Compared with asymptotic stability,the finite-time stability not only enables systems to achieve consensus control in shorter time,but also makes system have better robustness and stronger anti-interference ability.This thesis mainly investigates the problem of finite-time consensus control and fixed-time consensus control for nonlinear multi-agent systems.The specific contents are as follows:Chapter 1 mainly introduces the research status of consensus issue for multi-agent systems at home and abroad.Chapter 2 first gives some essential preliminaries,then sets up two more general finitetime stability criteria,which include a new fast finite-time stability criterion and a more general fixed-time stability criterion.Chapter 3 focuses on the finite-time consensus tracking control problem of kth-order nonlinear multi-agent systems.During the control design process,fuzzy logic system is utilized to approximate the unknown nonlinear term in each agent.First,for the kth-order nonlinear multi-agent systems,an asymptotic consensus tracking controller is designed by adaptive backstepping technology.Next,integral-Lyapunov functions are used to avoid the singularity problem of the derivative of the virtual control signals,and then a fuzzy adaptive finite-time consensus tracking controller is developed by finite-time stability theory.Simulation results show that the designed controller is effective.Chapter 4 addresses the fast finite-time consensus control issue for a class of secondorder nonlinear multi-agent systems.In the backstepping control design process,fuzzy logic systems are employed to approach these nonlinearities,and integral-Lyapunov functions are constructed to avoid the singularity problem of the derivative of the virtual controllers.Complying with the fast finite-time stability criterion,a fuzzy adaptive fast finitetime consensus tracking control strategy is proposed for the second-order nonlinear multi-agent systems.The numerical simulation shows that the suggested control strategy is feasible and effective.Chapter 5 studies the fixed-time consensus tracking control issue for a class of secondorder nonlinear multi-agent systems.Fuzzy logic systems are utilized to approximate these unknown nonlinear functions.Moreover,curve fitting method is used to construct a continuously differentiable piecewise virtual controller in order to avoid the singularity problem of the derivative of virtual control signals.After that,according to the more general fixed-time stability theory,a fuzzy adaptive fixed-time consensus tracking controller is designed by combining adaptive technology and backstepping method.Simulation results indicate that the proposed control scheme is validChapter 6 summarizes all the conclusions and puts forward some possible future research directions.