ABSTRACT
Similar to continuous-time methods, digital controllers are usually designed using frequency-domain or time-domain methods so that the overall closed-loop system meets its transient and steady-state requirements. When a digital controller is designed to control a continuous-time plant it is important to have a good understanding of the plant to be controlled as well as of the controller and its interfaces with the plant. The chapter deals with digitizing continuous-time plants and continuous-time controllers. Simulation of the closed-loop system including the plant and the controller is essential to verify the properties of a preliminary design and to test its performance under conditions that might be difficult or cumbersome to study analytically. There are two fundamental approaches to designing discrete-time control systems for continuous-time plants. Sampling is the process of deriving a discrete-time sequence from a continuous-time function.
