Chapter 1

Introduction
Xµis a suite of Xmath functions for the modeling, analysis and synthesis of linear
robust control systems. Robust control theory has developed rapidly during the last
decade to the point where a useful set of computational tools can be used to solve a wide
range of control problems. This theory has already b een applied to a wide range of
practical problems.
This manual describes the Xµfunctions and presents a demonstration of their
application. The underlying theory is outlined here and further theoretical details can
be found in the many references provided.
It is assumed that the reader is familiar with the use of Xmath; the Xmath Basics
manual and the on-line demos are a good way of getting started with Xmath. A good
knowledge of control theory and application is also assumed. The more that is known
about robust control theory the better as the details are not all covered here.

1.1 Notation

Several font types or capitalization styles are used to distinguish between data objects.
The following table lists the various meanings.
1