Time-domain robust stability test under plant and controller interval uncertainty

Once a controller has been designed for a certain plant with any method available, one would like to know if that controller will perform well despite structured uncertainty in the plant. Furthermore, as controller implementation is concerned, one is also interested in its fragility (Keel and Bhattacharyya, 1997). In this paper, interval parametric uncertainty is considered. As an alternative to testing robust stability by polynomial methods (Bhattacharyya et al., 1995; Ackermann, 1993), one can perform a robust simulation of the time domain response of the closed loop taking into account plant and controller uncertainties. It is shown that, based on this simulation, it is possible to test the closed loop robust stability. Copyright (C) 2000 IFAC.