Design of discrete-time compensator for reference tracking with disturbance rejection

Abstract

The paper deals with the design of a discrete-time state space compensator to track a reference command when the plant is subject to a measurable disturbance signal. The approach called Command Generator Tracker [3] covers a broad class of reference and disturbance signals describable by linear differential equations with constant coefficients. The design technique is LQ based and its principle consists in augmenting the plant model so that the resulting compensator includes modes of both the reference and disturbance signals. In such a case, proper reference tracking and disturbance rejection are guaranteed. Standard LQ problem solution applied for the extended system yields both the feedback and the feedforward gains of the CGT compensator.