High frequency measurement noise rejection based on disturbance observer

A new feedback controller architecture based on disturbance observer (DOB) is proposed to deal with high-frequency measurement noise for high accuracy performance. Compared with the classical DOB-based control system the proposed control structure adds another controller to compensate the feedback of system output. Thus, these influences of both high-frequency measurement noise and low-frequency external disturbance on the system output could be eliminated simultaneously. Meanwhile, the new control system architecture can potentially overcome the conflict between performance and robustness in the traditional feedback framework. A numerical example is included at the end of this paper to illustrate the effectiveness.