“Yet Another Tutorial of Disturbance Observer: Robust Stabilization and Recovery of Nominal Performance”

• published in Control Theory and Technology, Aug. 2016; Special Issue on Disturbance Rejection: A Snapshot, A Necessity, and A Beginning
  http://link.springer.com/journal/11768, or http:/dx.doi.org/10.1007/s11768-016-6006-9
• draft download at http://arxiv.org/abs/1601.02075
• written by Hyungbo Shim, Gyunghoon Park, Youngjun Joo, Juhoon Back, and Nam Hoon Jo
• Abstract: This paper presents a tutorial-style review on the recent results about the disturbance observer (DOB) in view of robust stabilization and recovery of the nominal performance. The analysis is based on the case when the bandwidth of Q-filter is large, and it is explained in a pedagogical manner that, even in the presence of plant uncertainties and disturbances, the behavior of real uncertain plant can be made almost similar to that of disturbance-free nominal system both in the transient and in the steady-state. The conventional DOB is interpreted in a new perspective, and its restrictions and extensions are discussed.

While there are several tutorial paper and monographs for disturbance observer, this “another” tutorial presents a new look to the disturbance observer as a tool for robust stabilization and disturbance rejection. This can be thought of as an introductory survey of the contributions of CDSL regarding disturbance observer technique. This tutorial is not in the theorem-proof format, but written comprehensively just to deliver the new view to the disturbance observer. It is recommended to the first comer to the disturbance observer technique.

This paper is published in the special issue of Control Theory and Technology, and we were motivated to write this survey by the guest editors. Since CDSL has been working on this topic for quite a period as seen in this post, we thought it may be the time to summarize the underlying ideas that we were based on.