Global practical tracking by output-feedback for nonlinear systems with unknown growth rate  

作　　者：YAN XueHua LIU YunGang 

机构地区：[1]School of Control Science and Engineering, Shandong University, Jinan 250061, China

出　　处：《Science China(Information Sciences)》2011年第10期2079-2090,共12页中国科学（信息科学）（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No.60974003);the Program for New Century Excellent Talents in University of China (Grant No.NCET-07-0513);the Key Science and Technique Foundation of Ministry of Education of China (Grant No.108079);the Excellent Young and Middle-Aged Scientist Award Grant of Shandong Province of China (Grant No.2007BS01010);the Natural Science Foundation for Distinguished Young Scholar of Shandong Province of China (Grant No.JQ200919);the Independent Innovation Foundation of Shandong University (Grant No.2009JQ008)

摘　　要：This paper is devoted to the global practical tracking by output-feedback for a class of uncertain nonlinear systems with only the tracking error measurable. Different from the closely related works, the systems have unmeasured states dependent growth with unknown constant rate, and the reference signal, as well as its first order derivative, has unknown bound. Mainly because of these, the tracking problem can hardly be solved by straightforwardly extending the existing results. In the paper, motivated by the related stabilization results, and flexibly using the ideas of universal control and dead zone, an adaptive output-feedback controller is designed to make the tracking error prescribed arbitrarily small after a finite time while keeping all the states of the closed-loop system bounded. A numerical example demonstrates the effectiveness of the theoretical results.This paper is devoted to the global practical tracking by output-feedback for a class of uncertain nonlinear systems with only the tracking error measurable. Different from the closely related works, the systems have unmeasured states dependent growth with unknown constant rate, and the reference signal, as well as its first order derivative, has unknown bound. Mainly because of these, the tracking problem can hardly be solved by straightforwardly extending the existing results. In the paper, motivated by the related stabilization results, and flexibly using the ideas of universal control and dead zone, an adaptive output-feedback controller is designed to make the tracking error prescribed arbitrarily small after a finite time while keeping all the states of the closed-loop system bounded. A numerical example demonstrates the effectiveness of the theoretical results.

关 键 词：uncertain nonlinear systems global practical tracking adaptive control OUTPUT-FEEDBACK dynamic high-gain 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置] TP273.2[自动化与计算机技术—控制科学与工程]