Adjustment and Implementation of a Disturbance Observer without Differentiator

Abstract

This paper describes how to adjust the disturbance observer without a differentiator and to implement of it on a linear stage. This disturbance observer consists only of integrators. In the typical disturbance observer, the differentiator causes high frequency noise. However, the disturbance observer without differentiator does not have this trouble. The use of this disturbance observer allows to expand the pass band of the low pass filter, and it is predicted that the ability of estimating disturbance would be improved. Implementation of a newly created second-order lag system disturbance observer without differentiator is proposed. In order to implement the disturbance observer, it is necessary to obtain the nominal model of the plant. However, it is troublesome to use another control technology. Therefore, parameters are adjusted with implementation of disturbance observer. The effect by applying disturbance observer is verified. Different adjustment methods are also compared.