An algorithm for finding improved D-scale transfer functions for robus
t control synthesis is presented. Generalized Popov multipliers and a
linear matrix inequality (LMI) multiplier formulation are used to find
D-scalings of polynomial order and arbitrary structure which provide
advantages over the normal curve-fit scalings in a D-K iteration. The
two primary benefits are enhanced convergence properties and the capab
ility to handle repeated scalar block uncertainty. A flexible manipula
tor control example illustrates the advantages of the new D-scaling ap
proach. (C) 1998 John Wiley & Sons, Ltd.