Event-Triggered Control For Several Classes Of Nonlinear Time-Delay Systems

With the improvement of science and technology,the nonlinear modeling of the actual system is becoming more and more complex,and the internal performance requirements of the control system are also improved.On the one hand,time delay exists widely in the transmission process of control signals,but it is inevitable.How to reduce the influence of time delay on system stability is particularly important.On the other hand,it is inevitable that the control signal will cause system redundancy and resource waste in the transmission process,and the emergence of event-triggered control is one of the effective tools to solve the network bandwidth limitation.Therefore,how to design a controller to ensure the stability of time-delay system with limited bandwidth becomes the focus of this thesis.This thesis is based on event-triggered control strategy,combined with adaptive control,Fuzzy Logic Systems(FLSs)and Lyapunov-Krasovskii Functions(LFKs).This thesis discusses the event-triggered control of several nonlinear systems with time delay.The main contents as follows:In Chapter 2,an event-triggered adaptive control scheme is proposed to solve the problem of robust fault-tolerant control for a class of Lipschitz nonlinear systems with multi-state delays and actuator faults.An adaptive law is constructed to estimate the unknown controller parameters online when both actuator faults and delay disturbances are unknown.Then,using positive control gain functions and integrable auxiliary signals,a class of robust adaptive event-triggered controllers is designed to compensate the effects of time delay functions,external disturbances and actuator faults.In addition,the system redundancy can be greatly reduced by introducing the event-triggered control strategy.Based on LFKs theory,it is proved that the proposed control method can ensure that all closed-loop signals of the system are bounded and the system states converge to zero asymptotically.Simulation results demonstrate the effectiveness of the adaptive event-triggered control scheme.In Chapter 3,the event-triggered control problem of a class of nonlinear systems with unknown control direction,time-varying delays,full state constraints and external disturbances is studied.Firstly,an adaptive event-triggered controller is designed based on the integral Barrier Lyapunov Functions(IBLFs)to compensate the effects of full state constraints,unknown time-varying delays and external disturbances.Then,FLSs is used to approximate the unknown functions in the system.At the same time,the system redundancy is greatly reduced by introducing the event-triggered control strategy.By combining the separation technique and LFKs,it is shown that the proposed strategy can guarantee good tracking performance,and all closed-loop signals of the system are bounded.Compared with the existing results,the proposed design scheme is less conservative and more applicable.Simulation results show the effectiveness of the proposed method.Finally,the main work is summarized and the future research direction is prospected.