Adaptive Output Feedback Control For Nonlinear Multi-agent Systems

Based on the multi-agent cooperative control theory and adaptive fuzzy backstepping recursion technology,this thesis studies the adaptive consensus control and containment control problems for several classes of uncertain nonlinear multi-agent systems with unmeasurable states,and the corresponding stability proofs are given.The major contents are as follows:(1)For a class of nonlinear multi-agent systems with single leader,the fuzzy logic system is utilized to approximate the unknown nonlinear functions,and a nonlinear fuzzy state observer is designed in order to estimate the unmeasurable states.Based on the designed observer,a distributed fuzzy adaptive output feedback quantization consensus control method is proposed by combining adaptive fuzzy backstepping recursion technology and quantization control algorithm.The proposed control scheme can make all followers' outputs are well synchronized to the leader's output and improve the control precision of multi-agent systems.Based on Lyapunov stability theory,it is proved that the closed-loop system is stable(2)For a class of nonlinear multi-agent systems with output constraint and single leader,fuzzy logic system is used to approximate the unknown nonlinear functions,and a fuzzy state observer is designed to estimate the unmeasurable states.By combining the adaptive backstepping recursion control technology with a constructed Barrier Lyapunov Function,an adaptive fuzzy output constrained consensus control scheme is proposed.It is proved that the proposed control scheme can guarantee the control system is stable and that all followers' outputs are well synchronized to the leader's output.(3)For a class of nonlinear multi-agent systems with multiple leaders and input saturation,the fuzzy logic system is utilized to approximate unknown nonlinear functions and a distributed fuzzy state observer is designed.An auxiliary system is built to solve the input saturation problem of the controllers.Based on adaptive backstepping recursion control technology,an adaptive fuzzy observer-based containment control scheme is proposed by the information coming from the leaders and other neighbor follower agents.The stability of the closed-loop system is proved via Lyapunov function stability theory,the proposed scheme can make all follower agents converge to a convex hull built by leaders.(4)Numerical simulation studies are carried out for the above adaptive control methods.The simulation results further verify the effectiveness of the proposed control schemes.