Research On The Fractional-order Multi-agent Systems With State Constraints Via Event-triggered Strategy

With the rapid development of information technology,event-triggered control has received more and more attention.In the past decades,a series of research results have been achieved for event-triggered control,but most of them are for integer-order multi-agent systems,and relatively little research has been done for fractional-order multi-agent systems,which needs further study.Meanwhile,in some practical applications,the control inputs and states of the system may need to be restricted to a bounded region due to the limitations of physical devices.Therefore,it is of theoretical and practical significance to study the control problems of constrained systems.Based on the knowledge of algebraic graph theory,fractional-order calculus,adaptive control theory,Lyapunov stability theory and other related knowledge,we discuss the tracking control problem of fractional-order multi-agent systems with state constraints under an event-triggered control strategy in this master thesis.The main research contents of this thesis are summarized as follows:ⅰ)The fuzzy adaptive event-triggered tracking control problem of a fractional-order multiagent system with input saturation,unknown nonlinear functions,external disturbances and time-varying partial state constraints is studied based on output feedback.It is assumed that the network graph between multiple agents is directed and contains a spanning tree.Since only the system output is available data,a fractional-order state observer is designed to estimate the unmeasurable states.A fuzzy logic system is used to handle the unknown nonlinear function and an adaptive control method is used to estimate the unknown parameters.By using the barrier Lyapunov function and the backstepping design method,an event-triggered fuzzy adaptive control scheme is designed to ensure that the constrained partial states remain within the time-varying constraint boundaries,all system signals are bounded,the system output tracks to the leader signal with the tracking error converges to a bounded set containing the origin,and Zeno behavior is avoided.The effectiveness of the proposed method is verified by a numerical simulation.ⅱ)The fuzzy adaptive event-triggered finite-time tracking control problem for a fractionalorder multi-agent system is considered.The interaction topology is assumed to be directed and contain a spanning tree.The state-constrained problem is solved by constructing a suitable barrier Lyapunov function.Since only the system output is available data,a reduced-order state observer is constructed to estimate the unmeasurable states.A fuzzy logic system is used to deal with the uncertain nonlinearity in the system and the unknown parameters are estimated using adaptive control methods.An event-triggered control scheme is designed to reduce the communication burden.A distributed controller is proposed to ensure that all signals of the system are bounded,the constrained states do not violate the time-varying constraint boundaries,finite-time stability can be achieved with a bounded error and the Zeno behavior does not occur.The effectiveness of the proposed control scheme is verified by an example.