title: Global practical tracking by output feedback for nonlinear systems with unknown growth rate and time delay.
abstract: This paper is the further investigation of work of Yan and Liu, 2011, and considers the global practical tracking problem by output feedback for a class of uncertain nonlinear systems with not only unmeasured states dependent growth but also time-varying time delay. Compared with the closely related works, the remarkableness of the paper is that the time-varying time delay and unmeasurable states are permitted in the system nonlinear growth. Motivated by the related tracking results and flexibly using the ideas and techniques of universal control and dead zone, an adaptive output-feedback tracking controller is explicitly designed with the help of a new Lyapunov-Krasovskii functional, to make the tracking error prescribed arbitrarily small after a finite time while keeping all the closed-loop signals bounded. A numerical example demonstrates the effectiveness of the results.
authors.affiliation: School of Electrical Engineering, University of Jinan, Jinan, Shandong 250022, China.
authors.forename: Xuehua
authors.initials: X
authors.lastname: Yan
authors.affiliation: School of Information Science and Engineering, Shandong Normal University, Jinan, Shandong 250014, China.
authors.forename: Xinmin
authors.identifier: 0000-0003-4690-5588
authors.initials: X
authors.lastname: Song
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D005246:Feedback; D008962:Models, Theoretical; D016571:Neural Networks, Computer; D017711:Nonlinear Dynamics; D013997:Time Factors; D035501:Uncertainty