
Saunder January 22, 2014 10:43 K15053˙Book
Chapter 7
Nonlinear Disturbance
Observer-Based Control
for Systems with
Mismatched
Uncertainties
7.1 Introduction
A nonlinear disturbance observer-based robust control (NDOBRC) method is pre-
sented in this chapter to solve the disturbance attenuation problem of nonlinear
systems with mismatched disturbances and uncertainties. In the presence of mis-
matched disturbances/uncertainties, it is usually impossible to achieve asymptotic
stability as the disturbance and the control inputs do not appear in the same channels,
and the influence of the disturbances can not be completely canceled. The design
objective in