Adaptive Control, Overview

Introduction

What Is Adaptive Control

Feedback control has a long history of using sensing, decision, and actuation elements to achieve an overall goal. The general structure of a control system may be illustrated in Fig. 1. It has long been known that high fidelity control relies on knowledge of the system to be controlled. For example, in most cases, knowledge of the plant gain and/or time constants (represented by θ _p in Fig. 1) is important in feedback control design. In addition, disturbance characteristics (e.g., frequency of a sinusoidal disturbance), θ _d in Fig. 1, are important in feedback compensator design.

Many control design and synthesis techniques are model based, using prior knowledge of both model structure and parameters. In other cases, a fixed controller structure is used, and the controller parameters, θ _C in Fig. 1, are tuned empirically during control system commissioning. However, if the plant parameters vary widely with time or have large uncertainties, these...