2.5. µSYNTHESIS AND D-KITERATION 59
Figure 2.11: The generic interconnection structure for synthesis
kFu(Fl(P(s),K(s)),∆)k∞≤1. This is equivalent to K(s) satisfying
µ[Fl(P(s),K(s))] <1. In other words, the closed loop system satisfies the robust
performance specification.
Unfortunately this problem has not yet been solved, except is a few special cases. The
current approachto this problem, known as D-Kiteration, involves the iterative
application of the H∞design technique and the upper bound µcalculation. We will give
a brief conceptual overviewhere and give more algorithmic details in Section 2.5.2.
Consider applying H∞synthesis to the full P(s) interconnection structure for this
problem. Suppose that this gives a controller, K(s) such that K(s) stabilizes P(s)and
kF
l
(P(s),K(s))k∞≤1.