Discrete extended state observer based repetitive control system for improved disturbance rejection performance

This paper presents a discrete extended state observer (DESO) based repetitive controller (RC) to compensate periodic signals, aperiodic disturbances and uncertainties of the plant with relative degree equal or greater than zero. Since ESO has only two tuning parameters, the proposed controller provides a simple and user friendly solution to complex engineering problems in practice. Moreover, due to the model free approach of ESO-based control, it can be applied to wide variety of plants. The design procedures are proposed to ensure a stable system. Various types of disturbances have been used in simulation which show that the ESO-based RC can not only reject periodic and aperiodic disturbances but also handle the plant parameter uncertainty. The comparison studies demonstrate that the ESO-based RC has superb performance.