Decentralized Control For Lower Triangular Time-Delay Interconnected Nonlinear Systems With Prescribed Performance

With the development of science and technology,in the practical systems,the studied dynamic models of engineering systems become increasingly complicated.At the same time,the requirements on the system performance are improving.The control problem of interconnected nonlinear systems has attracted researchers' attention.Although there are many research results on the problems of decentralized control,constrained control,event-triggered control and unknown control directions for nonlinear systems,a few studies consider the coexistence of multiple problems.This dissertation will investigate the prescribed performance control for a class of interconnected nonlinear time delay systems based on Backstepping method and Lyapunov theorem.The unmeasured states problem,time varying delay,unmodeled dynamics and unknown control directions will be considered.The prescribed performance controller will be constructed.The main contents are as follows.First,the main technologies including prescribed performance control and dynamic event-triggered control are introduced.The effectiveness of prescribed performance control in guaranteeing the transient performance and stability performance are demonstrated,and so is the dynamic event-triggered control in prolonging the inter-event time of the controllers.Second,the reduced-order observer is designed for a class of interconnected nonlinear time delay systems with lower triangular.Based on the Backstepping method,the output feedback prescribed performance controller is designed.Combined with the dynamic event-triggered control method,the event-triggered controller is constructed eventually.The Lyapunov theorem is used to prove the results.Finally,based on the Backstepping method and the filter which has been designed,the output feedback prescribed performance controller is designed for a class of interconnected nonlinear time delay systems.The changing supply function method is used to deal with the unmodeled dynamics,the Lyapunov-Krasovskii functional is used to address the influence of time varying delay,and the Nussbaum function is used to deal with the unknown control direction problem.The results are proved via the method of contradiction analysis.