General design of disturbance observer for stable linear time-invariant single-input/single-output systems via an H∞ approach

摘要

In this paper, a generalized design of a disturbance observer is presented for a class of stable linear time-invariant single-input single-output (SISO) systems. First, a general configuration of a disturbance observer is proposed when control input and system output are available. Then, the design problem of minimizing the disturbance estimation error is generally formulated as an H optimization problem in order to produce two design parameters stably. From the observation that a disturbance observer of conventional approach can be one of solutions of the optimization problem, the generality of the proposed approach is addressed. Numerical example validates the generality and systematicness of the proposed method.