Summary: A shorter version of this paper was presented at IFAC SYSID 2000:
Symposium on System Identi"cation, which was held in Santa Barbara,
California, during June 21}23, 2000. This paper was recommended
for publication in revised form by Guest Editors F. L. Lewis and
K. S. Narendra.
* Corresponding author. Tel.: #1-217-333-3607; fax: #1-217-244-
E-mail addresses: firstname.lastname@example.org (G. Arslan),
email@example.com (T. Bas7 ar).
Automatica 37 (2001) 1175}1188
Disturbance attenuating controller design for strict-feedback systems
with structurally unknown dynamics
GuK rdal Arslan, Tamer Bas7 ar*
Coordinated Science Laboratory, University of Illinois; 1308 West Main Street; Urbana, IL 61801-2307/USA
Received 21 June 2000; revised 28 January 2001; received in "nal form 2 March 2001
Neural-net based approximators can be used to design disturbance attenuating adaptive controllers
for strict-feedback systems with structurally unknown nonlinearities.
We consider the problem of robust controller design for a class of single-input single-output nonlinear systems in strict-feedback
form with structurally unknown dynamics and also with unknown virtual control coe$cients. The unknown nonlinearities in the