A new discrete-time robust stability conditions

A new robust stability condition for uncertain discrete-time systems with c onvex polytopic uncertainty is given. It enables to check stability using p arameter-dependent Lyapunov functions which an derived from LMI conditions. It is shown that this new condition provides better results than the class ical quadratic stability. Besides the use of a parameter-dependent Lyapunov function, this condition exhibits a kind of decoupling between the Lyapuno v and the system matrices which may be explored for control synthesis purpo ses. A numerical example illustrates the results. (C) 1999 Elsevier Science B.V. All rights reserved.