The parameterization of all disturbance observers for time-delay plants with any input and output disturbances

In this paper, we examine the parameterization of all disturbance observers for time-delay plants with any input and output disturbances. The disturbance observers have been used to estimate the disturbance in the plant. Several papers on design methods of disturbance observers have been published. Recently, the parameterization of all disturbance observers for plants with any input and output disturbances was clarified. However, no paper examines the parameterization of all disturbance observers for time-delay plants with any input and output disturbances. In this paper, we propose parameterizations of all disturbance observers and all linear functional disturbance observers for time-delay plants with any input and output disturbances.