
Saunder January 22, 2014 10:43 K15053˙Book
Chapter 6
Generalized Extended
State-Observer-Based
Control for Systems with
Mismatched
Uncertainties
6.1 Introduction
During the past several decades, many elegant approaches have been proposed to
estimate disturbances, including unknown input observer (UIO) [69], disturbance
observer (DO) [27, 2, 5, 86], perturbation observer (POB) [70, 71], equivalent input
disturbance (EID)-based estimation [72, 73], and extended state observer (ESO)
[4]–[76]. The sliding-mode disturbance observer was also proposed for disturbance
estimation using states and control inputs information in References [108, 109].
Note that all