## EVENT DETAILS AND ABSTRACT

**Interdisciplinary Seminar in Nonlinear Science**
**Title:** Robust Nonlinear Control Systems: Theory and Design

**Speaker:** Professor R. Freeman

**Speaker Info:** Northwestern U.

**Brief Description:**

**Special Note**:

**Abstract:**

A mathematical model used for the design of a controller for a physical
system does not usually describe every possible behavior of the system. A
primary task of feedback control is to achieve performance objectives
despite discrepancies between the model and the actual system. One method
of robust control design is to assume that the system is accurately
described by some unknown member of a given set of models and then to
design a controller which meets the performance objectives for every model
in the set. This set of models is usually characterized by a nominal model
in feedback with an uncertain system belonging to a prescribed uncertainty
set. The linear robust control designs developed in recent years are based
on the assumption that the nominal model is linear. This assumption can
lead to overly conservative designs because any nonlinearity in the system
must be considered as part of the uncertainty set, even if the nonlinearity
is well known. In contrast, methods of robust nonlinear control allow for
a nonlinear nominal model and can thereby reduce the effective size of the
uncertainty set. The speaker will present recent advances in the
development of techniques for the design of robust nonlinear control
systems.

**Date:** Friday, November 20, 1998

**Time:** 2:00pm

**Where:** Tech M416

**Contact Person:** Prof. Riecke

**Contact email:** h-riecke@nwu.edu

**Contact Phone:** 847-491-8316

Copyright © 1997-2024
Department of Mathematics, Northwestern University.