Wm. Haddad et Jr. Corrado, Robust resilient dynamic controllers for systems with parametric uncertainty and controller gain variations, INT J CONTR, 73(15), 2000, pp. 1405-1423
One of the fundamental problems in feedback control design is the ability o
f the control system to maintain stability and performance in the face of s
ystem uncertainties. To this end, elegant multivariable robust control desi
gn frameworks such as H-infinity control, L-1 control and mu synthesis have
been developed to address the robust stability and performance control pro
blem. An implicit assumption inherent in these design frameworks is that th
e controller will be implemented exactly. In a recent paper by Keel and Bha
ttacharyya, it was shown that even though such frameworks are robust with r
espect to system uncertainty, they are extremely fragile with respect to er
rors in the controller coefficients. In this paper, we extend the robust fi
xed-structure controller synthesis approach to develop controllers which ar
e robust to system uncertainties and non-fragile or resilient to controller
gain variations.