15th Triennial World Congress of the International Federation of Automatic Control
  Barcelona, 21–26 July 2002 
ADAPTIVE ROBUST STABILIZATION FOR A CLASS OF UNCERTAIN LINEAR TIMEûVARYING SYSTEMS WITH MULTIPLE TIME DELAYS
Hansheng Wu* and K. Kawabata**
* Department of Information Science
Hiroshima Prefectural University
Schobaraûshi, Hiroshima 727-0023, Japan
Email: hansheng@bus.hiroshima-pu.ac.jp
** Faculty of Management, Kyushu Sangyo University
Fukuoka City, Fukuoka 813-8503, Kapan
Email: kawabata@ip.kyusan-u.ac.jp

The problem of robust stabilization is considered for a class of uncertain linear time-varying systems with multiple time delays. In the paper, the upper bounds of uncertainties and external disturbances are assumed to be unknown. An adaptation law is introduced to estimate such unknown bounds, and by employing the updated values of these unknown bounds a class of memoryless state feedback controllers is proposed. Based on Lyapunov stability theory and Lyapunov-Krasovskii functional, it is shown that by making use of the proposed memoryless state feedback controller, the solutions of the resulting adaptive closed-loop time-delay system can be guaranteed to be uniformly bounded, and the states are uniformly asymptotically stable.
Keywords: Uncertain systems, time delay, robust control, adaptive control, uniform boundedness, asymptotic stability
Session slot T-Th-A17: Time Delay I/Area code 2e : Robust Control