AnH(infinity)Design of Disturbance Observer for a Class of Linear Time-invariant Single-input/Single-output Systems

Abstract

In the paper, a generalizedH(infinity)framework for design of a disturbance observer (DOB) is newly presented for a class of linear time-invariant single-input/single-output systems. Motivated by the systematic synthesis of a stabilizing controller through theH(infinity)optimization, we formulate the DOB design method into anH(infinity)design problem with weighting functions in the frequency domain. Thanks to its generality, the proposed method can be consistently applied either to the unstable systems or the non-minimum phase systems. Through the examples, the efficacy of the method is validated.