State Feedback Control and Kalman Filtering with MATLAB/Simulink Tutorials

6Disturbance Rejection and Reference Tracking via Control Design

6.1 Introduction

The disturbance‐observer‐based approach (see Chapter 5) is simple in both design and implementation in addition to the inclusion of anti‐windup mechanism when the control signal reaches its limitations. However, one of the main drawbacks for this type of methods is that it lacks a second degree of freedom that will separate the performance achieved in reference tracking from that in disturbance rejection.

The objective of this chapter is to introduce state feedback control for disturbance rejection and reference tracking through controller design. This is a complementary approach to that introduced in Chapter 5, and it offers a control system realization that separates the performance achieved in reference tracking from that in disturbance rejection. The chapter begins by embedding the disturbance model into the plant model to form an augmented state space model for the controller design (see Section 6.2). Based on this augmented model, state feedback controller is designed (see Section 6.3). If the state vector is not measured, then an observer is designed based for the implementation of the control law. In Section 6.4, three practical aspects of the control system are discussed. The first aspect is to introduce the two‐degree‐of‐freedom control configuration for reducing overshoot in reference tracking. The second aspect is to present an anti‐windup mechanism for the controller implementation, ...