Design of disturbance observers for the compensation of low-frequency disturbance

Abstract

When the specifications of the disturbance rejection, imposed on a controlled system, are not met by a feedback controller, the control configuration can be extended with a disturbance observer. For this component a systematic design procedure is given. The design procedures provides in a few rules-of-thumb, which are based on the required additional disturbance rejection, and on the resulting overall robustness and noise rejection properties.